(19)
(11)EP 3 014 182 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
04.11.2020 Bulletin 2020/45

(21)Application number: 14742087.1

(22)Date of filing:  27.06.2014
(51)International Patent Classification (IPC): 
F23L 15/04(2006.01)
F28F 27/02(2006.01)
C03B 5/235(2006.01)
F28D 7/16(2006.01)
(86)International application number:
PCT/US2014/044488
(87)International publication number:
WO 2014/210412 (31.12.2014 Gazette  2014/53)

(54)

METHOD AND HEAT EXCHANGE SYSTEM UTILIZING VARIABLE PARTIAL BYPASS

VERFAHREN UND WÄRMEAUSTAUSCHSYSTEM MIT VERÄNDERBAREM PARTIELLEM BYPASS

PROCÉDÉ ET SYSTÈME D'ÉCHANGE THERMIQUE UTILISANT UN CONTOURNEMENT PARTIEL VARIABLE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 28.06.2013 US 201361841252 P
31.07.2013 US 201313955923

(43)Date of publication of application:
04.05.2016 Bulletin 2016/18

(73)Proprietor: L'Air Liquide Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude
75007 Paris (FR)

(72)Inventor:
  • KANG, Taekyu
    Newark, Delaware 19711 (US)

(74)Representative: De Vleeschauwer, Natalie Y.L.D. 
L'Air Liquide S.A. Direction Propriété Intellectuelle 75 Quai d'Orsay
75321 Paris Cedex 07
75321 Paris Cedex 07 (FR)


(56)References cited: : 
EP-A1- 0 356 648
US-A1- 2011 259 574
DE-A1- 4 123 243
US-B1- 6 302 191
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Background



    [0001] In processes which rely on delivery of large amounts of heat energy into a furnace by combustion of a fuel, it is particularly important to achieve as high an energy-efficiency as possible. Thus it is a common practice to recover excess heat in the flue-gas, for example by using it to heat combustion air. Another way to improve efficiency is by oxy-combustion, which, by replacing air ordinarily used in combustion with a stream that is largely oxygen, avoids heating the nitrogen component of air. While heat lost to the flue gas is reduced in oxy-combustion (because the flue-gas volume is less), the amount of heat lost is still substantial, and it would be advantageous to recover that heat.

    [0002] US 5,807,418 discloses heat recovery by "co-current indirect heat exchange" of an oxidant (at least 50% O2) by the flue-gas, followed by using the partially-cooled flue-gas to pre-heat batch and/or cullet. As used by US 5,807,418, "co-current indirect heat exchange" refers simply to a heat exchanger in which the oxidant and heat exchanger are separated by a wall, with both the oxidant and the flue gas flowing in the same direction. While a sketch is provided, details such as materials of construction of the heat exchanger are not, but for the comment that the heat exchanger is "constructed using materials and in a way that renders it compatible with and safe for handling oxygen-rich oxidants and high temperatures". Considering the practical difficulty of constructing such a heat exchanger, this instruction is not sufficient to allow practical implementation by the skilled artisan. This scheme suffers from the apparent disadvantage that unburnt fuel in the hot combustion gases may come into contact with oxygen, either from a leak or at a regenerator, thereby posing an unacceptably high risk of catastrophic uncontrolled combustion.

    [0003] US 2009/0084140 uses a scheme similar to US 5,807,418, but with batch/cullet pre-heat in parallel with oxidant pre-heat, and with additional disclosure related to the batch/cullet heat exchanger. Again, no details on the construction of the oxidant heat exchanger are disclosed other than to say that it may be a regenerative or recuperative heat exchanger. A single stream of oxidant is sent to a heat exchanger where it is heated through heat exchange with hot combustion gases. Three streams of fuel along with three streams of pre-heated oxidant from the heat exchanger are combusted by three corresponding burners. Thus, in each case, a single stream of oxidant is sent to each heat exchanger. There is no mention of controlling the temperature of internal components of the heat exchanger. This approach, too, suffers from the disadvantage that unburnt fuel in the hot combustion gases may come into contact with oxygen, either from a leak or at a regenerator, thereby posing an unacceptably high risk of catastrophic uncontrolled combustion.

    [0004] US 2009/029800 discloses a heat exchanger in which heat is exchanged between flue gases and either an oxidant or a fuel through an intermediate inert gas. Thus, a wall separates the flue gases from the inert gas and another wall separates the inert gas from the oxidant or fuel. While this reduces the chances that catastrophic uncontrolled combustion may occur, this type of heat exchanger is relatively more complicated to construct and maintain. In each case, a single stream of oxidant is sent to each heat exchanger. Additionally, there is no mention of controlling the temperature of internal components of the heat exchanger other than to say that the intermediate gas acts as a thermal buffer to dampen variations in temperature of the oxidant or fuel.

    [0005] US 2010/0258263 discloses pre-heating oxidant for a furnace where, instead of using one large heat exchanger for pre-heating many oxidant streams, it proposes the use of several, smaller-dimensioned heat exchangers for a relatively small number of burners. There is no mention of controlling the temperature of internal components of the heat exchanger.

    [0006] US 2011/0104625 discloses pre-heating oxidant for a furnace where a heat transfer fluid is first pre-heated through recuperative heat exchange with hot flue gases followed by pre-heating of the oxidant through heat exchange with the hot heat transfer fluid at an additional heat exchanger. In each case, a single stream of oxidant is sent to each heat exchanger. There is no mention of controlling the temperature of internal components of the heat exchanger.

    [0007] US 2011/0104628 similarly discloses pre-heating oxidant for a furnace where a heat transfer fluid is first pre-heated through recuperative heat exchange with hot flue gases followed by pre-heating of the oxidant through heat exchange with the hot heat transfer fluid at an additional heat exchanger. Again, in each case a single stream of oxidant is sent to each heat exchanger. It specifically discloses that the number of heat exchangers in relation to the number of burners should be increased so that the lengths of the hot oxidant lines from the heat exchanger to the burners can be minimized to avoid thermal losses. There is no mention of controlling the temperature of internal components of the heat exchanger.

    [0008] US 6,250,916 also discloses pre-heating oxidant for a furnace where a heat transfer fluid is first pre-heated through recuperative heat exchange with hot flue gases followed by pre-heating of the oxidant through heat exchange with the hot heat transfer fluid at an additional heat exchanger. Again, in each case a single stream of oxidant is sent to each heat exchanger. There is no mention of controlling the temperature of internal components of the heat exchanger.

    [0009] Many have proposed designs for performing heat exchange with a shell and tube heat exchangers where the temperature of either the tube or or shell side fluid is managed using a bypass for bypassing an amount of the fluid past the heat exchanger (i.e., US 7,234,512; US 4,593,757, US 6,003,954; US 5,615,738; US 4,991,643; US 2009/0320642; US 6,302,191; US 6,003,594, US,5,615,738). The basic concept of these designs is illustrated in FIG 1 where a feed flow of a tube-side fluid is divided between a main flow and a bypass flow. The main flow is heated or cooled by the shell-side fluid inside the heat exchanger HE while the bypass flow completely bypasses it. After bypass, each of the fluid flows are combined. The temperature of the combined flow is measured. In the case of a tube-side fluid being heated by a shell-side fluid, if the temperature is higher than a predetermined setpoint, a controller sends a signal to a control valve commanding it to increase the amount of the tube-side fluid that bypasses the heat exchanger. In this manner, the temperature of the combined flow may be managed to some degree. Shell side bypass can be achieved using external valves or mechanically manipulating baffles (i.e., US 6,003,594 and US 5,615,738) - the latter seems complex to be constructed. Other proposals (US 2009/0320642, US 4,991,643) show methods of tube side internal bypass but they require sophisticated valves.

    [0010] DE 41 23 243 A1 discloses a method and device for reducing overheating of internal components of a counter-flow shell and tube heat exchanger utilizing variable partial bypass of a reactant flow, said method comprising the steps of: dividing a first feed flow of a cool reactant with a first control valve between a first main flow of the cool reactant and a first bypass flow of the cool reactant, the first main flow flowing through a counter-flow shell and tube heat exchanger; exchanging heat at the shell and tube heat exchanger between the first main flow and a flow of a hot fluid and combining the first main flow with the first bypass flow to produce a first combined flow of heated reactant and also a flow of cooled fluid, the first combined flow exiting the heat exchanger at a first reactant outlet of the heat exchanger; measuring a temperature of the first combined flow at or downstream of the first reactant outlet; and controlling relative proportions of the first main flow and first bypass flow, resulting from division of the first feed flow, with the control valve based upon the measured temperature of the first combined flow, wherein less heat is transferred from the fluid to the first bypass flow than is transferred from the fluid to the first main flow.

    [0011] There have been some other proposals for shell side internal bypass, but in each of those cases, the purpose of the bypass is to improve the efficiency with better flow distribution, not for control of temperature.

    [0012] The proposal illustrated in FIG 1 does provide some advantages. Controlling the temperature of the combined flows is important, because a relatively constant process gas temperature can be achieved. Also, the temperature of the process gas can be controlled to a degree that the temperature of any process gas conveying pipes located downstream of the heat exchanger can be maintained below their material limit. For example, in the case of an oxidative process gas the downstream pipes must be kept below the material limit of those pipes in order to avoid premature or catastrophic failure of those pipes.

    [0013] However, the complete bypass technique illustrated in FIG 1 is also associated with some disadvantages. There can be a temperature overshoot inside the heat exchanger when the amount of bypass is too large. This is because when the flow rate of the bypass is increased, the flow rate of the tube-side fluid flowing through the heat exchanger is correspondingly decreased. A decreased flow rate of the tube-side fluid inside the heat exchanger will increase the heat exchange rate between the tube-side fluid and the hot shell-side fluid. As a result, although the setpoint temperature of the combined flows might not be exceeded downstream of the heat exchanger, the temperature inside the heat exchanger may reach unsatisfactorily high levels. When the tube-side fluid is reactive or oxidative, such as oxygen or oxygen-enriched air, unsatisfactorily high temperatures can cause corrosion and/or uncontrolled combustion inside the heat exchanger. This poses an unacceptably high risk of premature or catastrophic failure. This high risk is exacerbated when the reactive oxidative tube-side fluid follows a flow path having bends/turns that introduce localized high turbulence. Highly turbulent flow increases the rate at which the tube-side fluid reacts with or oxidizes the tube-side portion of the heat exchanger adjacent the highly turbulent flow.

    [0014] For this reason, the solution illustrated in FIG 1 must be operated well below the actual limit temperature at which the internal components of the heat exchanger may fail. For instance, if the maximum internal temperature ever reached within the heat exchanger is only 500°C (which is lower than the limit temperature of 580°C) perhaps as much as 20-30% bypass of the tube-side fluid can be achieved without fear of reaching the limit temperature 580°C. The necessity of having to operate the heat exchanger at a temperature well below the material limit temperature of the heat exchanger internal components can significantly constrain the range of safely achievable tube-side gas temperatures. In order to reach higher tube-side temperatures, the heat exchanger must be manufactured from exotic and high expensive materials.

    [0015] Thus, there is a need for a method and heat exchange system that does not exhibit an unacceptably high risk of premature and potential catastrophic failure. There is also a need for a method and heat exchange system that reduces the number of heat exchangers in relation to the number of burners receiving pre-heated oxidant or fuel from the heat exchangers. There is also a need for a method and heat exchange system that controls the temperature of internal components of a heat exchanger without incurring temperature overshoots. There is also a need for a method and heat exchange system that may safely achieve a relatively wider range of process gas temperatures at a reasonable cost. There is still also a need for a method and heat exchange system that may safely achieve a relatively wider range of process gas temperatures while still allowing the heat exchanger to be manufactured with a wide variety of materials.

    Summary



    [0016] The invention is provided for satisfying the above needs.

    [0017] There is provided a method for reducing overheating of internal components of a counter-flow shell and tube heat exchanger utilizing variable partial bypass of a reactant flow. The method includes the following steps. A first feed flow (FF1) of a cool reactant is divided with a first control valve (CV1) between a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant, the first main flow (MF1) flowing through a counter-flow shell and tube heat exchanger on a tube-side of the heat exchanger. Heat is exchanged at the shell and tube heat exchanger between the first main flow (MF1) and a flow of a hot shell-side fluid and combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant and also a flow of cooled shell-side fluid, the first combined flow (CF1) exiting the heat exchanger at a first reactant outlet (RO1) of the heat exchanger. A temperature of the first combined flow (CF1) is measured at or downstream of the first reactant outlet (RO1). Relative proportions of the first main flow (MF1) and first bypass flow (BF1), resulting from division of the first feed flow (FF1), are controlled with the control valve (CV1) based upon the measured temperature of the first combined flow (CF1), wherein less heat is transferred from the shell-side fluid to the first bypass flow (BF1) than is transferred from the shell-side fluid to the first main flow (MF1).

    [0018] There is also provided an improved counter-flow shell and tube heat exchange system for reduction of overheating of internal components thereof utilizing variable partial bypass of a reactant flow, said heat exchange system comprising: a first control valve (CV1) adapted and configured to divide a first feed flow (FF1) of cool reactant into a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant; a first main flow inlet conduit (27, 67, 106) receiving the first main flow (MF1) of cool reactant from the first control valve (CV1); a first bypass flow inlet conduit (26, 66, 107) receiving the first bypass flow (BF1) of cool reactant from the first control valve (CV1); a shell (35) having a shell-side fluid inlet and outlet (SI, SO) fluidly communicating with an interior of the shell (35) comprising a heat exchange space; means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space; means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space, wherein said means for exchanging heat between the first main flow (MF1) and the flow of the hot shell-side fluid is configured and adapted to allow more heat to be exchanged between the first main flow (MF1) and the flow of hot shell-side fluid than is exchanged between the first bypass flow (BF1) and the flow of hot shell-side fluid by the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid; means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant; at least one first downstream reactant tube (92, 112) receiving the first combined flow (CF1) and fluidly communicating with a first reactant outlet (RO1); a first outlet conduit fluidly communicating with the first reactant outlet (RO1) and receiving the first combined flow (CF1) therefrom; a first temperature sensor (T1) disposed in the outlet conduit at or downstream of the first reactant outlet (RO1); and a programmable logic controller (C) adapted and configured to control relative proportions of the first main flow (MF1) and first bypass flow (BF1) produced by division of the first feed flow (FF1) of cool reactant by the first control valve (CV1), said control being based upon a temperature of the first combined flow (CF1) sensed by the first temperature sensor (T1).

    [0019] There is also provided a glass furnace utilizing preheated reactant or reactants, comprising first and second burners (23A, 23B) disposed on a wall (22) of a furnace enclosing a combustion space adapted and configured to contain a glassmaking charge or molten glass, a source of gaseous fuel (19A, 19B), a source of oxidant (11A, 11B) selected from the group consisting of industrially pure oxygen and oxygen-enriched air, and a recuperator or regenerator (5) having an outlet (6), and the heat exchange system of claim 11. The first and second cool reactants are a same cool oxidant received from said source of oxidant (11A, 11B). The burners (23A, 23B) receive the gaseous fuel from said source of gaseous fuel (19A, 19B). The first control valve (CV1) receives the first feed flow (FF1) of cool reactant from the source of oxidant (11A). The second control valve (CV2) receives the second feed flow (FF1) of cool reactant from the source of oxidant (11B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first and second combined flows (CF1, CF2) are combusted with the gaseous fuel at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass.

    [0020] There is provided another glass furnace utilizing preheated reactant or reactants, comprising first and second burners (23A, 23B) disposed on a wall (22) of a furnace enclosing a combustion space adapted and configured to contain a glassmaking charge or molten glass, a source of gaseous fuel (19A, 19B), a source of oxidant (11A, 11B) selected from the group consisting of industrially pure oxygen and oxygen-enriched air, and a recuperator or regenerator (5) having an outlet (6), and the heat exchange system of claim 11. The first and second cool reactants are a same gaseous fuel received from said source of gaseous fuel (19A, 19B). The burners (23A, 23B) receive the oxidant from said source of oxidant (11A, 11B). The first control valve (CV1) receives the first feed flow (FF1) of cool reactant from the source of gaseous fuel (19A). The second control valve receives the second feed flow of cool reactant from the source of gaseous fuel (19B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first and second combined flows (CF1, CF2) are combusted with the oxidant at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass.

    [0021] There is provided yet another glass furnace utilizing preheated reactant or reactants, comprising first and second burners disposed on a wall of a furnace enclosing a combustion space adapted and configured to contain a glassmaking charge or molten glass, a source of gaseous fuel (19A, 19B), a source of oxidant (11A, 11B) selected from the group consisting of industrially pure oxygen and oxygen-enriched air, and a recuperator or regenerator (5) having an outlet (6), and two of the heat exchange systems of claim 11. The first and second cool reactants of a first of the two heat exchange systems are a same gaseous fuel received from said source of gaseous fuel (19A, 19B). The first and second cool reactants of a second of the two heat exchange systems are a same oxidant received from said source of oxidant (11A, 11B). The first control valve (CV1) of the first of the two heat exchange systems receives the first feed flow (FF1) of cool reactant from the source of oxidant (11A). The second control valve (CV2) of the first of the two heat exchange systems receives the second feed flow (FF2) of cool reactant from the source of oxidant (11B). The first control valve (CV1) of the second of the two heat exchange systems receives the first feed flow (FF1) of cool reactant from the source of gaseous fuel (19A). The second control valve (CV2) of the second of the two heat exchange systems receives the second feed flow (FF2) of cool reactant from the source of gaseous fuel (19B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first combined flow (CF1) from the first of the two heat exchange systems and the first combined flow (CF1) from the second of the two heat exchange systems are combusted at the first burner (23A) for producing heat to heat the charge or molten glass. The second combined flow (CF2) from the first of the two heat exchange systems and the second combined flow (CF2) from the second of the two heat exchange systems are combusted at the second burner (23B) for producing heat to heat the charge or molten glass.

    [0022] Any one or more of the heat exchange system, method, or glass furnaces may include one or more of the following aspects:
    • A second feed flow (FF2) of a cool reactant is divided with a second control valve (CV2) between a second main flow (MF2) of the cool reactant and a second bypass flow (BF2) of the cool reactant, the second main flow (MF2) flowing through a shell and tube heat exchanger on the tube-side. Heat is exchanged at the shell and tube heat exchanger between the second main flow (MF2) and a flow of a hot shell-side fluid and combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant and the flow of cooled shell-side fluid, the second combined flow (CF2) exiting the heat exchanger at a second reactant outlet (RO2) of the heat exchanger. A temperature of the second combined flow (CF2) is measured at or downstream of the second reactant outlet (RO2). Relative proportions of the second main flow (MF2) and second bypass flow (BF2), resulting from division of the second feed flow (FF2), are controlled with the second control valve (CV2) based upon the measured temperature of the second combined flow (CF2). Less heat is transferred from the shell-side fluid to the second bypass flow (BF2) than is transferred from the shell-side fluid to the second main flow (MF2). Control of the relative proportions of the first feed flow (FF1) into the first main and bypass flows (MF1, BF1) is independent of control of the relative proportions of the second feed flow (FF2) into the second main and bypass flows (MF2, BF2).
    • the reactant is an oxidant having an oxygen concentration higher than that of air.
    • the reactant is industrially pure oxygen.
    • the reactant is oxygen-enriched air.
    • the reactant is a gaseous fuel.
    • the shell-side fluid is air or an inert gas.
    • the shell-side fluid is air and the hot shell-side air is obtained by the steps comprising: pre-heating ambient air at a pre-heat exchanger through heat exchange with the cool shell-side air to produce moderately hot air; and heating the moderately hot air at a recuperator or regenerator through heat exchange with hot furnace gases to produce the hot shell-side air.
    • the shell and tube heat exchanger includes: a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30); a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34); a first main inlet plenum (29) receiving the first main flow (MF1), the first main inlet plenum (29) terminating in a downstream direction at a second tubesheet (31), the first main inlet plenum (29) surrounding the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31); and a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the first set of bypass tubes (33). Each of the main tubes (32) in the first set of main tubes fluidly communicates with the first reactant outlet (RO1). At each open downstream end (34) of one of the bypass tubes (33) of the first set of bypass tubes (33) a portion of the first main flow (MF1)combines with a respective portion of the first bypass flow (BF1) to form a portion of the first combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (32) to the first reactant outlet (RO1). Heat exchange between the first bypass flow (BF1) and the hot shell-side fluid is achieved via the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes (33).
    • the shell and tube heat exchanger includes: a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30); a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34); a first main inlet plenum (29) receiving the first main flow (MF1), the first main inlet plenum (29) terminating in a downstream direction at a second tubesheet (31), the first main inlet plenum (29) surrounding the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31); a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the first set of bypass tubes (33), each of the main tubes (32) in the first set of main tubes fluidly communicating with the first reactant outlet (RO1), at each open downstream end (34) of one of the bypass tubes (33) of the first set of bypass tubes (33) a portion of the first main flow (MF1)combines with a respective portion of the first bypass flow (BF1) to form a portion of the first combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (32) to the first reactant outlet (RO1), heat exchange between the first bypass flow (BF1) and the hot shell-side fluid being achieved via the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes (33); a second bypass inlet plenum (48) receiving the second bypass flow (BF2), the second bypass inlet plenum (48) terminating in a downstream direction at a fourth tubesheet (50), the fourth tubesheet (50) extending in a same plane with the first tubesheet (31); a second set of bypass tubes (53) fluidly communicating with the second bypass inlet plenum (48), extending downstream from the fourth tubesheet (31), and terminating at open downstream ends (54); a second main inlet plenum (49) receiving the second main flow (MF1), the second main inlet plenum (49) terminating in a downstream direction at the second tubesheet (31), the second main inlet plenum (49) surrounding the second set of bypass tubes (53) in sealing fashion in between the fourth and second tubesheets (50, 31); and a second set of main tubes (52) each one of which communicates with the second main inlet plenum (49), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the second set of bypass tubes (53). Each of the main tubes (52) in the second set of main tubes (52) fluidly communicates with a second reactant outlet (RO2). At each open downstream end (54) of one of the bypass tubes (53) of the second set of bypass tubes (53) a portion of the second main flow (MF2) combines with a respective portion of the second bypass flow (BF2) to form a portion of the second combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (52) to the second reactant outlet (RO1).
    • the shell and tube heat exchanger includes: a first inlet plenum (69) receiving the first bypass flow (BF1), the first inlet plenum (69) disposed inside the shell (35); a first outlet plenum (114, 113) fluidly communicating with the first reactant outlet (RO1); at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first outlet plenum (114, 113); and at least one first main flow tube (68) receiving the first main flow (MF1) from the first control valve (CV1), extending into an interior of the heat exchanger downstream of the first inlet plenum (89) and extending back to terminate at the first inlet plenum (89), wherein the first main flow (MF1) is combined with the first bypass flow (BF1) at the first inlet plenum (69) and the first combined flow (CF1) flows through the at least one first reactant tube (71).
    • the shell and tube heat exchanger includes: a first inlet plenum (69) receiving the first bypass flow (BF1), the first inlet plenum (69) disposed inside the shell (35); a first outlet plenum (114, 113) fluidly communicating with the first reactant outlet (RO1); at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first outlet plenum (114, 113); at least one first main flow tube (68) receiving the first main flow (MF1) from the first control valve (CV1), extending into an interior of the heat exchanger downstream of the first inlet plenum (69) and extending back to terminate at the first inlet plenum (69), wherein the first main flow (MF1) is combined with the first bypass flow (BF1) at the first inlet plenum (69) and the first combined flow (CF1) flows through the at least one first reactant tube (71); a second inlet plenum (89) receiving the second bypass flow (BF2), the second inlet plenum (89) disposed inside the shell (35); a second outlet plenum (115, 113) fluidly communicating with the second reactant outlet (RO2); at least one second reactant tube (91) fluidly communicating between the second inlet plenum (89) and the second outlet plenum (115, 113); and at least one second main flow tube (88) receiving the second main flow (MF2) from the second control valve (CV2), extending into an interior of the heat exchanger downstream of the second inlet plenum (89) and extending back to terminate at the second inlet plenum (89), wherein the second main flow (MF2) is combined with the second bypass flow (BF2) at the second inlet plenum (89) and the second combined flow (CF2) flows through the at least one second reactant tube (91).
    • the heat exchanger includes: first, second and third plenums (109, 111, 113), the third plenum (113) receiving the first combined flow (CF1) and fluidly communicating with the first reactant outlet (RO1); at least one first upstream reactant tube (110) receiving the first main flow (MF1) and extending through an interior of the shell (35) from the first plenum (109) and fluidly communicating with the second plenum (111); a first bypass tube (107) receiving the first bypass flow (BF1) and extending between the first control valve (CV1) and the second plenum (111) and extending at least partially outside the shell of the heat exchanger, wherein the first main flow (MF1) and the first bypass flow (BF1) are combined at the second plenum (111); and at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending between the second and third plenums (111, 113).
    • the shell and tube heat exchanger includes: first, second and third plenums (109, 111, 113), the third plenum (113) receiving the first combined flow (CF1) and fluidly communicating with the first reactant outlet (RO1); at least one first upstream reactant tube (110) receiving the first main flow (MF1) and extending through an interior of the shell (35) from the first plenum (109) and fluidly communicating with the second plenum (111); a first bypass tube (107) receiving the first bypass flow (BF1) and extending between the first control valve (CV1) and the second plenum (111) and extending at least partially outside the shell of the heat exchanger, wherein the first main flow (MF1) and the first bypass flow (BF1) are combined at the second plenum (111); at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending between the second and third plenums (111, 113); fourth, fifth and sixth plenums (107, 111, 113), the sixth plenum (113) receiving the second combined flow (CF2) and fluidly communicating with the second reactant outlet (RO2); at least one second upstream reactant tube (110) receiving the second main flow (MF2) and extending inside the shell (35) from the fourth plenum (109) and fluidly communicating with the fifth plenum (111); a second bypass tube (107) receiving the second bypass flow (BF2) and extending between the second control valve (CV2) and the fifth plenum (111) and extending at least partially outside the shell (35) of the heat exchanger, wherein the second main flow (MF2) and the second bypass flow (BF2) are combined at the fifth plenum (111); and at least one second downstream reactant tube (112) receiving the second combined flow (CF2) and extending between the fifth and sixth plenums (111, 113).
    • the hot shell-side fluid is obtained from a recuperator or regenerator.
    • the cooled shell-side fluid is directed to a recuperator or regenerator to heat the cooled shell-side fluid in order to produce the hot shell-side fluid.
    • the first combined flow (cF1) exiting the first and second reactant outlets (RO1, RO2) is directed to first and second burners (23A, 23B) operatively associated with a furnace, wherein: the shell-side fluid is air; the first and second reactants are the same and are selected from the group consisting of industrially pure oxygen, oxygen-enriched air, and natural gas; if the first and second reactants are industrially pure oxygen or oxygen-enriched air, the first and second reactants of the first and second combined flows (CF1, CF2) are combusted with fuel at the first and second burners (23A, 23B);if the first and second reactants are natural gas, the first and second reactants of the first and second combined flows (23A, 23B) are combusted with an oxidant at the first and second burners (23A, 23B); and the furnace is a glass melting furnace.
    • the heat exchange system further comprises: a second control valve (CV2) adapted and configured to divide a second feed flow (FF2) of cool reactant into a second main flow (MF2) of the cool reactant and a second bypass flow (BF2) of the cool reactant; a second main flow inlet conduit (47, 87, 106) receiving the second main flow (MF2) of cool reactant from the second control valve (CV2); a second bypass flow inlet conduit (46, 46, 107) receiving the second bypass flow (BF2) of cool reactant from the second control valve (CV2); means for exchanging heat between the second main flow (MF2) and a flow of the hot shell-side fluid in the heat exchange space; means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid in the heat exchange space, wherein said means for exchanging heat between the second main flow (MF2) and the flow of the hot shell-side fluid is configured and adapted to allow more heat to be exchanged between the second main flow (MF2) and the flow of hot shell-side fluid than is exchanged between the second bypass flow (BF2) and the flow of hot shell-side fluid by the means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid; means for combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant; at least one second downstream reactant tube (92, 112) receiving the second combined flow (CF2) and fluidly communicating with a second reactant outlet (RO2); a second outlet conduit fluidly communicating with the second reactant outlet (RO2) and receiving the second combined flow (CF2) therefrom; and a second temperature sensor (T2) disposed in the second outlet conduit at or downstream of the second reactant outlet (RO2). The programmable logic controller (C) is adapted and configured to control relative proportions of the second main flow (MF2) and second bypass flow (BF2) produced by division of the second feed flow (FF2) of cool reactant by the second control valve (CV2) based upon a temperature of the second combined flow (CF2) sensed by the second temperature sensor (T2).
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises:
      1. 1) a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30);
      2. 2) a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34); and
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises:
      1. 1) a first main inlet plenum (29) receiving the first main flow (MF1) and which terminates in a downstream direction at a second tubesheet (31),
      2. 2) a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), concentrically surrounds a respective one of the first set of bypass tubes (33), and extends downstream of the second tubesheet (31) past the open downstream ends (34) of the first set of bypass tubes (33).
    • the first main inlet plenum (29) surrounds the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31).
    • each of the main tubes (32) in the first set of main tubes (32) fluidly communicates with the first reactant outlet (RO1).
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises portions of the main tubes (32) of the first set of main tubes (32) where the first bypass flow (BF1) exits the open downstream ends (34) and combines with the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes 33).
    • remaining portions of the first set of main tubes (32) downstream of the open ends allows heat exchange between the first combined flow (CF1) and the hot shell-side fluid.
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises:
      1. 1) a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30);
      2. 2) a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34); and
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises:
      1. 1) a first main inlet plenum (29) receiving the first main flow (MF1) and which terminates in a downstream direction at a second tubesheet (31),
      2. 2) a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), concentrically surrounds a respective one of the first set of bypass tubes (33), and extends downstream of the second tubesheet (31) past the open downstream ends (34) of the first set of bypass tubes (33);
    • the first main inlet plenum (29) surrounds the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31);
    • each of the main tubes (32) in the first set of main tubes (32) fluidly communicates with the first reactant outlet (RO1); and
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises portions of the main tubes (32) of the first set of main tubes (32) where the first bypass flow (BF1) exits the open downstream ends (34) and combines with the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes 33);
    • remaining portions of the first set of main tubes (32) downstream of the open ends allows heat exchange between the first combined flow (CF1) and the hot shell-side fluid;
    • the means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid in the heat exchange space comprises:
      1. 1) a second bypass inlet plenum (48) receiving the second bypass flow (BF2), the second bypass inlet plenum (48) terminating in a downstream direction at a fourth tubesheet (50), the fourth tubesheet (50) extending in a same plane with the first tubesheet (31);
      2. 2) a second set of bypass tubes (53) fluidly communicating with the second bypass inlet plenum (48), extending downstream from the fourth tubesheet (50), and terminating at open downstream ends (54);
    • the means for exchanging heat between the second main flow (MF2) and a flow of a hot shell-side fluid in the heat exchange space comprises:
      1. 1) a second main inlet plenum (49) receiving the second main flow (MF2) and which terminates in a downstream direction at the second tubesheet (31),
      2. 2) a second set of main tubes (52) each one of which communicates with the second main inlet plenum (49), concentrically surrounds a respective one of the second set of bypass tubes (53), and extends downstream of the second tubesheet (31) past the open downstream ends (54) of the second set of bypass tubes (53);
    • the second main inlet plenum (49) surrounds the second set of bypass tubes (53) in sealing fashion in between the fourth and second tubesheets (50, 31);
    • each of the main tubes (52) in the second set of main tubes (52) fluidly communicates with the second reactant outlet (RO2);
    • the means for combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant comprises portions of the main tubes (52) of the second set of main tubes (52) where the second bypass flow (BF2) exits the open downstream ends (54) and combines with the second main flow (MF2) flowing in annular spaces in between the second set of main tubes (52) and the second set of bypass tubes (53); and
    • remaining portions of the second set of main tubes (52) downstream of the open ends (54) allows heat exchange between the second combined flow (CF2) and the hot shell-side fluid.
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first inlet conduit (66) receiving the first bypass flow (BF1) from the first control valve (CV1), the first inlet conduit (66) extending into the interior of the heat exchanger;
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a first inlet plenum (69) fluidly communicating with the first inlet conduit (66); and
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises at least one first main flow tube (68) fluidly communicating between the first control valve (CV1) and the first inlet plenum (69) that extends into an interior of the heat exchanger downstream of the first inlet plenum (69) and extends back to terminate at the first inlet plenum (69);
    • the heat exchanger further comprises a first outlet plenum (114) fluidly communicating with the first reactant outlet (RO1); and
    • the heat exchanger further comprises at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first reactant outlet (RO1) that allows the first combined flow (CF1) to exchange heat with the hot shell-side fluid.
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first inlet conduit (66) receiving the first bypass flow (BF1) from the first control valve (CV1), the first inlet conduit (66) extending into the interior of the heat exchanger;
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a first inlet plenum (69) fluidly communicating with the first inlet conduit (66); and
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises at least one first main flow tube (68) fluidly communicating between the first control valve (CV1) and the first inlet plenum (69) that extends into an interior of the heat exchanger downstream of the first inlet plenum (69) and extends back to terminate at the first inlet plenum (69);
    • the heat exchanger further comprises a first outlet plenum (114) fluidly communicating with the first reactant outlet (RO1); and
    • the heat exchanger further comprises at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first reactant outlet (RO1) that allows the first combined flow (CF1) to exchange heat with the hot shell-side fluid;
    • the means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid in the heat exchange space comprises a second inlet conduit (86) receiving the second bypass flow (BF2) from the second control valve (CV2), the second inlet conduit (86) extending into the interior of the heat exchanger;
    • the means for combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant comprises a second inlet plenum (89) fluidly communicating with the second inlet conduit (86); and
    • the means for exchanging heat between the second main flow (MF2) and a flow of a hot shell-side fluid in the heat exchange space comprises at least one second main flow tube (88) fluidly communicating between the second control valve (CV2) and the second inlet plenum (89) that extends into an interior of the heat exchanger downstream of the second inlet plenum (89) and extends back to terminate at the second inlet plenum (89);
    • the heat exchanger further comprises a second outlet plenum (115);
    • the heat exchanger further comprises at least one second reactant tube (91) fluidly communicating between the second inlet plenum (89) and the second outlet plenum (115) that allows the second combined flow (CF2) to exchange heat with the hot shell-side fluid.
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises a first plenum (109) receiving the first main flow (MF1) from the first control valve (CV1) and at least one first upstream reactant tube (110) extending inside the shell (35) and receiving the first main flow (MF1) from the first plenum (109);
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first bypass tube (107) receiving the first bypass flow (BF1) from the first control valve (CV1) and extending at least partially outside the shell (35) of the heat exchanger;
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a second plenum (111) that receives the first main flow (MF1) downstream of the at least one first upstream reactant tube (110) and the first bypass flow (bF1) from the first bypass tube (107); and
    • the heat exchanger further comprises at least one first downstream reactant tube (112) and a third plenum (113) that fluidly communicates with the first reactant outlet (RO1), the at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending inside the shell (35) between the second and third plenums (109, 111) to allow heat exchange between the first combined flow (CF1) and the hot shell-side fluid.
    • the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises a first plenum (109) receiving the first main flow (MF1) from the first control valve (CV1) and at least one first upstream reactant tube (110) extending inside the shell (35) and receiving the first main flow (MF1) from the first plenum (109);
    • the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first bypass tube (107) receiving the first bypass flow (BF1) from the first control valve (CV1) and extending at least partially outside the shell (35) of the heat exchanger;
    • the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a second plenum (111) that receives the first main flow (MF1) downstream of the at least one first upstream reactant tube (110) and the first bypass flow (bF1) from the first bypass tube (107); and
    • the heat exchanger further comprises at least one first downstream reactant tube (112) and a third plenum (113) that fluidly communicates with the first reactant outlet (RO1), the at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending inside the shell (35) between the second and third plenums (109, 111) to allow heat exchange between the first combined flow (CF1) and the hot shell-side fluid;
    • the means for exchanging heat between the second main flow (MF2) and a flow of a hot shell-side fluid in the heat exchange space comprises a fourth plenum (109) receiving the second main flow (MF2) from the second control valve (CV2) and at least one second upstream reactant tube (110) extending inside the shell (35) receiving the second main flow (MF2) from the fourth plenum (109);
    • the means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid in the heat exchange space comprises a second bypass tube (107) receiving the second bypass flow (BF2) from the second control valve (CV2) and extending at least partially outside the shell (35) of the heat exchanger;
    • the means for combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant comprises a fifth plenum (111) that receives the second main flow (MF2) from the at least one second upstream reactant tube (110) and the second bypass flow (BF2) from the second bypass tube (107); and
    • the heat exchanger further comprises at least one second downstream reactant tube (112) and a sixth plenum (113) that fluidly communicates with the at least one second reactant outlet (RO2), the at least one second downstream reactant tube (112) receiving the second combined flow (CF2) and extending inside the shell (35) between the fifth and sixth plenums (111, 113) to allow heat exchange between the second combined flow (CF2) and the hot shell-side fluid.
    • a recuperator or regenerator (5) havs an outlet (6) in fluid communication with the shell inlet (SI), the recuperator or regenerator (4) adapted and configured to allow the shell-side fluid to be heated and conveyed to the heat exchange space via the shell inlet (SI).
    • the recuperator or regenerator (5) includes an inlet (4) in fluid communication with the shell outlet (SO), the recuperator or regenerator (5) receiving cooled shell-side fluid from the shell outlet (SO) and heating the cooled shell-side fluid to produce the hot shell-side fluid.

    Brief Description of the Drawings



    [0023] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:

    Figure 1 is a schematic of one prior art heat recovery solution utilizing bypass of a fluid.

    Figure 2 is a schematic of the heat recovery solution of the invention.

    Figure 3 is a schematic of one embodiment of the invention illustrating only an upstream portion of the heat exchanger.

    Figure 4 is a schematic of another embodiment of the invention illustrating only an upstream portion of the heat exchanger.

    Figure 5 is a schematic of an embodiment of the invention usable with those of FIGS 3 and 4 illustrating only a downstream portion of the heat exchanger.

    Figure 6 is a schematic of another embodiment of the invention usable with those of FIGS 3 and 4 illustrating only a downstream portion of the heat exchanger.

    Figure 7 is a schematic illustrating only one fluid feed, main flow, bypass flow, and combined flow.

    Figure 8 is a schematic of one application of the invention to a furnace utilizing oxidant preheating.

    Figure 9 is a schematic of one application of the invention to a furnace utilizing fuel preheating.

    Figure 10 is a schematic of one application of the invention to a furnace utilizing both oxidant and fuel preheating.


    Detailed Description



    [0024] The inventive method and heat exchange system for reducing overheating of internal components of a counter-flow shell and tube heat exchanger utilizes variable partial bypass of a reactant flow. In general, a tube-side feed flow is divided with a control valve into two separate flows: a main flow and a bypass flow. Both flows are fed to the tube-side inside the heat exchanger and combined at a point between the upstream and downstream ends. The paths of the main flow and bypass flow are configured, sized, and structured to achieve greater heat transfer between the hot shell-side fluid and the main flow than between the hot shell-side fluid and the bypass flow. Based upon the temperature of the combined flow at or downstream of the heat exchanger outlet, the relative amounts of the main flow and the bypass flow may be adjusted with the control valve in order to control the temperature of the combined flow.

    [0025] The number of feed flows is not limited to only one or two. Rather, the number of feed flows is driven by the process requirements. Typically, it ranges from 2-12. Control of the relative proportions of one feed flow into corresponding main and bypass flows is independent of control of the relative proportions of any of the other feed flows into main and bypass flows. This means that adjustment in the relative proportions of the main and bypass flows may be made without the same adjustment in the relative proportions of the other main and bypass flows.

    [0026] The invention avoids or reduces the possibility (that is experienced by prior art solutions) that the temperature of the tube-side fluid near the outlet will exceed the material limit temperature of the internal components of the heat exchanger. By reducing the degree to which the bypass flow is heated, the overall temperature of the tube-side fluid exiting the heat exchanger may be lowered. Also, by recombining the flows inside the heat exchanger, the temperature overshoot experienced by prior art schemes may be avoided or reduced because the combined flow (after the point at which the two flows are combined inside the heat exchanger) remains the same regardless of whether all, none, or some of the flow partially bypasses the heat exchanger in the bypass flow. Thus, the rate at which heat is transferred from the shell-side hot fluid to the combined flow will not change when there is a change in the relative amounts of the main flow and bypass flow.

    [0027] As best illustrated in FIG 2, first feed flow (FF1) of a cool reactant is divided with a first control valve (CV1) between a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant. The first main flow (MF1) flows through a counter-flow shell and tube heat exchanger HEinv on a tube-side thereof. Heat at the shell and tube heat exchanger HEinv is exchanged between the first main flow (MF1) and a flow of a hot shell-side fluid via shell inlet (SI). The first main flow (MF1) is combined with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant. The first combined flow (CF1) exits the heat exchanger HEinv at a first reactant outlet (RO1) thereof, while a flow of cooled shell-side fluid exits via shell outlet (SO). A temperature of the first combined flow (CF1) is measured at or downstream of the first reactant outlet (RO1). The relative proportions of the first main flow (MF1) and first bypass flow (BF1), resulting from division of the first feed flow (FF1), with the control valve (CV1) is controlled based upon the measured temperature of the first combined flow (CF1).

    [0028] Other details of the heat exchanger are as follows. There is at least one first downstream reactant tube (92) that receives the first combined flow (CF1) and fluidly communicates with a first reactant outlet (RO1). The number of downstream reactant tubes (92) may vary depending upon the flows of the tube-side fluid and the specific heat exchanger design employed. Typically, it ranges from 2-12. A first outlet conduit fluidly communicates with the first reactant outlet (RO1) and receiving the first combined flow (CF1) therefrom. A first temperature sensor (T1) is disposed in the outlet conduit at or downstream of the first reactant outlet (RO1). A programmable logic controller (C1) is adapted and configured to control relative proportions of the first main flow (MF1) and first bypass flow (BF1) produced by division of the first feed flow (FF1) of cool reactant by the first control valve (CV1). The control is based upon a temperature of the first combined flow (CF1) sensed by the first temperature sensor (T1).

    [0029] Less heat is transferred from the shell-side fluid to the first bypass flow (BF1) than is transferred from the shell-side fluid to the first main flow (MF1). One of ordinary skill in the art will recognize the degree to which the main flow and the bypass flow are heated by the hot shell-side fluid is driven by several factors. A non-limiting list includes: the length of the main flow path and the bypass flow path, the cross-sectional surface area of the main flow path and the bypass flow path, the thickness of the tubes conveying the main and bypass flows, the presence of an intermediary fluid in between the hot shell-side fluid and the main flow or in between the hot shell-side fluid and the bypass flow, the material comprising the tubes conveying the main and bypass flows, and the route of the two flow paths. While three embodiments for achieving the relatively lower heat exchange between the hot shell-side fluid and the bypass tube-side fluid are illustrated, any design that achieves the lower heat exchange result is within the scope of the invention.

    [0030] Three heat exchanger elements of note include: means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space; means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space; and means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated. As discussed above, while a wide variety of different approaches may be taken apart from the illustrated embodiments, the means for exchanging heat between the first main flow (MF1) and the flow of the hot shell-side fluid is configured and adapted to allow more heat to be exchanged between the first main flow (MF1) and the flow of hot shell-side fluid than is exchanged between the first bypass flow (BF1) and the flow of hot shell-side fluid by the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid.

    [0031] The method and system may optionally include a second feed flow which is also treated in a similar manner. A second feed flow (FF2) of a cool reactant is divided with a second control valve (CV2) between a second main flow (MF2) of the cool reactant and a second bypass flow (BF2) of the cool reactant. The second main flow (MF2) flows through a shell and tube heat exchanger on the tube-side. Heat at the shell and tube heat exchanger is exchanged between the second main flow (MF2) and the flow of a hot shell-side fluid. The second main flow (MF2) is combined with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant. The second combined flow (CF2) exits the heat exchanger HEinv at a second reactant outlet (RO2). A temperature of the second combined flow (CF2) is measured at or downstream of the second reactant outlet (RO2). A programmable logic controller (C2) is adapted and configured to control relative proportions of the second main flow (MF2) and second bypass flow (BF2), resulting from division of the second feed flow (FF2), with the second control valve (CV2) are controlled based upon the measured temperature of the second combined flow (CF2). Alternatively, only a single programmable logic controller (C1) may be used to perform both control functions. Similar to the first main and bypass flows, less heat is transferred from the shell-side fluid to the second bypass flow (BF2) than is transferred from the shell-side fluid to the second main flow (MF2). Control of the relative proportions of the second feed flow (FF2) into the second main and bypass flows (MF2, BF2) is independent of control of the relative proportions of the second feed flow (FF2) into the second main and bypass flows (MF2, BF2). This means that adjustment in the relative proportions of the first main and bypass flows may be made without the same adjustment in the relative proportions of the second main and bypass flows.

    [0032] The heat exchanger is a counter-flow shell and tube heat exchanger. This means that there is at least some directional component of hot shell-side fluid flow that is counter to the direction of the tube-side fluid. While the hot shell-side fluid may be introduced into the interior of the shell at an angle to the direction of the tubes, the use of internal baffles is contemplated in such a case for imparting the desired counter-current behavior of the tube-side and shell-side fluids.

    [0033] While the tube-side reactant may be any fluid sought to be heated through heat exchange with the hot shell-side fluid, typically the tube-side reactant is an oxidant having an oxygen concentration higher than that of air or the reactant is a fuel. It is important to note that, while the term "reactant" is used throughout the Summary, Detailed Description and Claims, the tube-side fluid need not be reactive. Rather, it may optionally be inert as understood by one of ordinary skill in the art of fields of heat exchange or combustion. Thus, an inert "reactant" may be utilized in any of the numerous embodiments or aspects of the invention discussed herein. Typically, the oxidant is industrially pure oxygen or oxygen-enriched air. If the fuel is not being pre-heated at the heat exchanger, the fuel may be any fuel conventionally used in furnaces, including solid, liquid or gaseous fuels. If the fuel is being pre-heated at the heat exchanger, the fuel is a gaseous fuel such as methane, natural gas or propane. While the shell-side fluid may similarly be any fluid intended for heating the tube-side fluid, typically the shell-side fluid is air, carbon dioxide, or an inert gas such as nitrogen or helium, or any mixture of the foregoing. In either case, air or inert gas may first be heated at a recuperator or regenerator prior to being introduced into the heat exchanger.

    [0034] Now, three embodiments of specific heat exchanger designs will be described.

    [0035] In the first embodiment and as illustrated in FIG 3, a first bypass inlet plenum (28) receives the first bypass flow (BF1). The first bypass inlet plenum (28) terminates in a downstream direction at a first tubesheet (30). A first set of bypass tubes (33) fluidly communicates with the first bypass inlet plenum (28), extends downstream from the first tubesheet (30), and terminates at open downstream ends (34). A first main inlet plenum (29) receives the first main flow (MF1). The first main inlet plenum (29) terminates in a downstream direction at a second tubesheet (31). The first main inlet plenum (29) surrounds the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31). Each one of a first set of main tubes (32) fluidly communicates with the first main inlet plenum (29), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the first set of bypass tubes (33). Each of the main tubes (32) in the first set of main tubes fluidly communicates with the first reactant outlet (RO1). At each open downstream end (34) of one of the bypass tubes (33) of the first set of bypass tubes (33), a portion of the first main flow (MF1) combines with a respective portion of the first bypass flow (BF1) to form a portion of the first combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (32) to the first reactant outlet (RO1). Heat exchange between the first bypass flow (BF1) and the hot shell-side fluid is achieved via the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes (33).

    [0036] With continuing reference to FIG 3, a second bypass inlet plenum (48) receives the second bypass flow (BF2). The second bypass inlet plenum (48) terminates in a downstream direction at a fourth tubesheet (50). The fourth tubesheet (50) extends in a same plane with the first tubesheet (31). A second set of bypass tubes (53) fluidly communicates with the second bypass inlet plenum (48), extends downstream from the fourth tubesheet (31), and terminates at open downstream ends (54). A second main inlet plenum (49) receives the second main flow (MF1). The second main inlet plenum (49) terminates in a downstream direction at the second tubesheet (31). The second main inlet plenum (49) surrounds the second set of bypass tubes (53) in sealing fashion in between the fourth and second tubesheets (50, 31). Each one of a second set of main tubes (52) fluidly communicates with the second main inlet plenum (49), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the second set of bypass tubes (53). Each of the main tubes (52) in the second set of main tubes (52) fluidly communicates with a second reactant outlet (RO2). At each open downstream end (54) of one of the bypass tubes (53) of the second set of bypass tubes (53), a portion of the second main flow (MF2) combines with a respective portion of the second bypass flow (BF2) to form a portion of the second combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (52) to the second reactant outlet (RO1).

    [0037] Similar to the number of reactant tubes discussed above, the number of the main tubes and bypass tubes may vary depending upon the process requirements. Typically, there are 2-12 main tubes and/or bypass tubes. It will be apparent that the first and second main flows (MF1, MF2) will be subjected to greater heat transfer from the hot shell-side fluid than the first and second bypass flows (BF1, BF2) because only the main tubes separate the main flow from the hot shell-side fluid, while in the case of the bypass flow, each of the main tubes, the main flow itself, and each of the bypass tubes separate the first bypass flow from the hot shell-side fluid.

    [0038] In the second embodiment and as illustrated in FIG 4, a first inlet plenum (69) receives the first bypass flow (BF1) where the first inlet plenum (69) is disposed inside the shell (35). A first outlet plenum (114, 113) fluidly communicates with the first reactant outlet (RO1). At least one first reactant tube (71) fluidly communicates between the first inlet plenum (69) and the first outlet plenum (114, 113). At least one first main flow tube (68) receives the first main flow (MF1) from the first control valve (CV1), extends into an interior of the heat exchanger downstream of the first inlet plenum (89) and extends back to terminate at the first inlet plenum (89). The first main flow (MF1) is combined with the first bypass flow (BF1) at the first inlet plenum (69) and the first combined flow (CF1) flows through the at least one first reactant tube (71).

    [0039] With continuing reference to FIG 4, a second inlet plenum (89) receives the second bypass flow (BF2) where the second inlet plenum (89) disposed inside the shell (35). A second outlet plenum (115, 113) fluidly communicates with the second reactant outlet (RO2). At least one second reactant tube (91) fluidly communicates between the second inlet plenum (89) and the second outlet plenum (115, 113). At least one second main flow tube (88) receiving the second main flow (MF2) from the second control valve (CV2), extends into an interior of the heat exchanger downstream of the second inlet plenum (89) and extends back to terminate at the second inlet plenum (89). The second main flow (MF2) is combined with the second bypass flow (BF2) at the second inlet plenum (89) and the second combined flow (CF2) flows through the at least one second reactant tube (91).

    [0040] Similar to the number of reactant tubes discussed above, the number of the main flow tubes (68, 88) and reactant tubes (71, 91) may vary depending upon the process requirements. Typically, there are 2-12 main flow tubes (68, 88) and/or reactant tubes (71, 91). It will be apparent that the first and second main flows (MF1, MF2) will be subjected to greater heat transfer from the hot shell-side fluid than the first and second bypass flows (BF1, BF2) because only the main flows (MF1, MF2) travel a farther distance in heat-transfer contact with the hot shell-side fluid than do the bypass flows (BF1, BF2).

    [0041] In operation, the ratio of the flow rate of shell-side fluid to the flow rate of the oxidant stream or fuel stream is dependent in a trivial way upon a variety of factors, including the type of shell-side fluid, the type of oxidant, the temperature of the shell-side fluid, the temperature of the oxidant before pre-heated, the temperature of the fuel before pre-heating, the desired hot oxidant and hot fuel temperatures, process requirements, and the particular configuration of the heat exchanger. Typically, the ratio is at least 2:1.

    [0042] The temperature of the shell-side fluid and the hot combustion gases are also dependent in a trivial way upon a variety of factors, including the type of shell-side fluid, the type of combustion gases, the temperature of the shell-side fluid before heat exchange at the recuperator or regenerator, the temperature of the hot combustion gases, process requirements, and the particular configuration of the recuperator or regenerator. While higher temperatures are possible, typically the hot shell-side fluid is at a temperature up to about 730°C. Typically, the oxidant and fuel before pre-heating are at ambient temperature. After pre-heating, the oxidant is typically at a temperature of up to about 700°C, but higher temperatures are still possible. After pre-heating, the fuel is typically at a temperature of up to about 450°C. After heat exchange between the hot shell-side fluid and the oxidant and fuel streams, the cooled shell-side fluid is typically at a temperature of about 200-300°C.

    [0043] Optionally, each of the oxidant streams is pre-heated at a first heat exchanger while each of the fuel streams is pre-heated at a second heat exchanger. The flow of hot shell-side fluid may be arranged in parallel whereby two streams of the hot shell-side fluid are directed to the two heat exchangers. The flow hot shell-side fluid may instead be arranged in series whereby one of the oxidant and fuel streams is pre-heated at the first heat exchanger through heat exchange with the hot shell-side fluid, and the now-somewhat cooled hot shell-side fluid exiting the first heat exchanger is used to pre-heat the other of the oxidant and fuel streams at the second heat exchanger.

    [0044] Optionally, the shell-side fluid may be recirculated. By recirculated, we meant that after heat exchange is performed between the shell-side fluid and the oxidant and/or fuel streams, it is returned to the regenerator or recuperator to complete a circuit. In this case, shell-side fluids other than air become more cost-effective. The shell-side fluid may be chosen so as to optimize heat transfer between conduits, for example, by choosing a fluid of high thermal conductivity such as helium. Alternatively, overall heat transfer may be optimized by choosing a fluid of high heat capacity such as carbon dioxide. Optionally, the shell-side fluid is any other inert gas or mixtures of any of helium, carbon dioxide, and the other inert gas.

    [0045] Alternatively, the shell-side fluid is air and the hot shell-side air is obtained by pre-heating ambient air at a pre-heat exchanger through heat exchange with the cool shell-side air to produce moderately hot air. The moderately hot air is then heated at a recuperator or regenerator through heat exchange with hot combustion/furnace gases to produce the hot shell-side air.

    [0046] The overall design of the heat exchanger is optimized based upon the total power of the combined burners receiving pre-heated oxidant (and/or fuel). This means that the diameter of the oxidant (or fuel) tubes, the number of oxidant (or fuel) tubes, the oxidant (or fuel) tube pitch (i.e., the tube to tube spacing), and the oxidant (or fuel) length to diameter ratio are optimized based upon the total combined power of the burners receiving the pre-heated oxidant (or fuel). Once these variables are optimized, the heat exchanger is provided with a single shell. Then, the oxidant (or fuel) tubes are divided into sets based upon the number of oxidant (or fuel) streams to be pre-heated by the heat exchanger where each set receives a separate oxidant (or fuel) stream. This design optimization can be distinguished from a combination of heat exchangers each one of which has been individually optimized based upon the burners it supplies with pre-heated oxidant or fuel where the combination includes a number of shells equal to the number of heat exchangers combined. A combination of heat exchangers is less efficient than the optimized heat exchanger of the invention. The shell and tube heat exchanger may have a cross-sectional configuration conventionally used in the heat exchanger art, including but not limited to: circular, oval, rectangular, and square.

    [0047] Regardless whether the first or second embodiments is selected, as best illustrated in FIG 5, the combined flows (CF1, CF2) of oxidant (or fuel) from main tubes 32 or reactant tubes 71, as the case may be, discharge into associated collection spaces 114, 116 that are enclosed and sealed with an associated bonnet 115, 117 (the bonnets associated with other flows of oxidant or fuel are not illustrated in FIG 6). Each of the bonnets 115, 117 (including those for the other flows) is directly connected to the shell 36. The combination of a downstream tubesheet 93 and oxidant (or fuel) tubes 92 (constituting the downstream portions of the main tubes 32 or reactant tubes 71, as the case may be) separates the hot shell-side fluid flowing through space 120 from the combined flows (CF1, CF2). Space 122 in between the tubesheet 93 and the downstream end of the shell 35 is essentially dead space. One of ordinary skill in the art will recognize that the particular configuration/structure/device for collecting a particular oxidant (or fuel) stream may be chosen from a wide variety of techniques well known in the field of heat exchangers. In this case, each oxidant (or fuel) stream is of course kept separated from the other oxidant (or fuel) streams.

    [0048] The flow rate of each individual, separately controlled, oxidant (or fuel) stream is typically varied over time in response to process requirements. If the flow rate of one or less than all of the oxidant (or fuel) streams is lowered, the slower oxidant (or fuel) stream flow rate causes that slower-rate stream to be heated to a relatively higher temperature than other faster-rate streams. This is because the longer residence time of the oxidant (or fuel) inside the heat exchanger allows greater heat transfer between the hot heat transfer fluid to the slower-rate stream. Conversely, a higher oxidant (or fuel) stream flow rate causes that faster-rate stream to be heated to a relatively lower temperature than other slower-rate streams because of the shorter residence time of the faster rate stream.

    [0049] Despite performance of the invention, the thermal expansion or thermal contraction of each oxidant (or fuel) tube conveying a higher (or lower) flow rate stream may be different that those of the other oxidant (or fuel) streams because the higher (or lower) flow rate stream may be heated to a lower (or higher) temperature than the other streams. In order to avoid the possibility that the differing thermal expansions and/or contractions may place undue stresses on the oxidant (or fuel) tubes and the shell, each set of oxidant (or fuel) tubes may be provided with a separate thermal expansion joint. In this manner, the separate joints may allow the differing expansions and contractions of the different sets of tubes without subjecting the heat exchanger to undue stresses. As best illustrated in FIG 6, each flow of oxidant or fuel discharges into an associated collection space 114, 116 that is enclosed and sealed with an associated bonnet 115, 117 (the bonnets associated with other flows of oxidant or fuel are not illustrated in FIG 6). Each of the bonnets 115, 117 (including those for the other flows) is connected to the shell 36 via an associated expansion joint 94, 96 in order to accommodate the differing thermal expansion/contraction.

    [0050] The heat exchanger of FIG 6 is not provided with the downstream tubesheet 93 as is that of FIG 5. Rather, the heat exchanger includes a "tube sheet-like" divider 118 that provides an imperfect seal in between, on one hand, the interior portion 120 of the shell through which the hot shell-side fluid flows, and on the other hand, the space 122 in between the divider 118 and the downstream end of the shell 35. The divider 118 includes orifices having a cross-section approximating those of the oxidant (or fuel) tubes 92 only with wider dimensions so that the oxidant (or fuel) tubes 92 may slide through expansion or contraction through the orifices. Instead of using a tubesheet 93 (as illustrated in FIG 5) to separate the hot shell-side fluid from the oxidant (or fuel) in the collection spaces 114, 116 at the discharge end of the heat exchanger, the combination of the oxidant (or fuel) tubes 92, the expansion joint 94, 96, and the divider 118 keeps the oxidant and hot shell-side fluid separate.

    [0051] In the third embodiment and as illustrated in FIG 7, the heat exchanger includes first, second and third plenums (109, 111, 113). The third plenum (113) receives the first combined flow (CF1) and fluidly communicates with the first reactant outlet (RO1). At least one first upstream reactant tube (110) receives the first main flow (MF1) and extends through an interior of the shell (35) from the first plenum (109) and fluidly communicates with the second plenum (111). A first bypass tube (107) receives the first bypass flow (BF1) and extends between the first control valve (CV1) and the second plenum (111) and at least partially extends outside the shell of the heat exchanger. The first main flow (MF1) and the first bypass flow (BF1) are combined at the second plenum (111). At least one first downstream reactant tube (112) receives the first combined flow (CF1) and extends between the second and third plenums (111, 113).

    [0052] The shell and tube heat exchanger may also include duplicate elements for a second feed flow (FF2). For reasons of clarity, FIG 7 does not illustrate the duplicate elements. But it will be understood that the first main flow (MF1) and first bypass flow (MF2) may be replicated with a similar second main flow (MF2) and second bypass flow (BF2) placed parallel to the first main flow (MF1) and first bypass flow (BF1). As discussed above, the number of different feed flows is not limited. Thus, it may be seen that the design of the embodiment of FIG 8 may be scaled up or down in a modular fashion to suit the process requirements.

    [0053] Similar to the number of reactant tubes discussed above, the number of the upstream and downstream reactant tubes (110, 112) is not limited and may vary depending upon process requirements and the specific heat exchanger design selected. Typically, it ranges from 2-12.

    [0054] Regardless of whether the first, second or third embodiment is selected, the hot shell-side fluid is typically obtained from a recuperator or regenerator (4). Optionally, the cooled shell-side fluid may be recycled back to the recuperator or regenerator to heat the cooled shell-side fluid in order to produce the hot shell-side fluid.

    [0055] While the heat exchange method and system may be applied to a wide variety of process requiring heat exchange between a relatively cooler tube-side fluid and a relatively warmer shell-side fluid, the method and system is advantageously used with preheating of either oxidant or fuel for burners, more particularly, for burners associated with a melting furnace, such as a blast furnace, metal melting furnace, or glass furnace.

    [0056] One generalized and illustrative application of the invention to a furnace is shown in FIG 8. Hot combustion gases 1 preheat a heat transfer fluid (i.e., the shell-side fluid) 3 at a recuperator or regenerator 5. The resultant hot shell-side fluid 7 flows to a heat exchanger 9 for preheating oxidant where it exchanges heat with flows of cold oxidant 11A, 11B, 11C, 11D. The resultant flows of hot oxidant 13A, 13B, 13c, 13D are directed to burners 23A, 23B, 23C, 23D. The flows of fuel 19A, 19B, 19C, 19D are directed to the burners 23A, 23B, 23C, 23D where the fuel combusts with the hot oxidant to produce the hot combustion gases 1. The hot shell-side fluid is cooled at heat exchanger 9 and is optionally recirculated to the recuperator or regenerator 5 as the shell-side fluid 3 to complete a loop.

    [0057] Another generalized and illustrative application of the invention to a furnace is shown in FIG 9. Hot combustion gases 1 preheat the shell-side fluid 3 at a recuperator or regenerator 5. The resultant hot shell-side fluid 7 flows to a heat exchanger 17 for preheating fuel where it exchanges heat with flows of cold fuel 19A, 19B, 19C, 19D. The resultant flows of hot fuel 21A, 21B, 21C, 21D are directed to the burners 23A, 23B, 23C, 23D where the hot fuel combusts with the flows of oxidant 11A, 11B, 11C, 11D. The hot shell-side fluid is cooled at heat exchanger 17 and is optionally recirculated to the recuperator or regenerator 5 as the shell-side fluid 3 to complete a loop.

    [0058] Another generalized and illustrative application of the invention to a furnace is shown in FIG 10. Hot combustion gases 1 preheat the shell-side fluid 3 at a recuperator or regenerator 5. The resultant hot shell-side fluid 7 flows to a heat exchanger 9 for preheating oxidant where it exchanges heat with flows of cold oxidant 11A, 11B, 11C, 11D. The resultant flows of hot oxidant 13A, 13B, 13C, 13D are directed to burners 23A, 23B, 23C, 23D. The hot shell-side fluid is cooled at heat exchanger 9 and is directed to a heat exchanger 17 for preheating fuel where it exchanges heat with flows of cold fuel 19A, 19B, 19C, 19D. The resultant flows of hot fuel 21A, 21B, 21C, 21D are directed to the burners 23A, 23B, 23C, 23D where the hot fuel combusts with the hot oxidant to produce the hot combustion gases 1. Optionally, the shell-side fluid 3 (before heating at the recuperator or regenerator 5) may be the cooled shell-side fluid after heat exchanger at the heat exchanger 17.

    [0059] While FIGS 8-10 illustrate one heat exchanger for every four streams of oxidant 11A, 11B, 11C, 11D and one heat exchanger for every four streams of fuel 19A, 19B, 19C, 19D, the invention is not limited in such a manner. Rather, each heat exchanger may handle as few as two or three oxidant streams 11A, 11B, 11C, 11D or fuel streams 19A, 19B, 19C, 19D or it may handle more than four. Also, while FIGS 4-6 illustrate only four burners, there may be as few as two or three or as many as several dozen. In the case of a glass melting furnace, typically all of the burners (utilizing pre-heated oxidant and/or fuel) on one side of a furnace receive pre-heated oxidant and pre-heated fuel from a pair of heat exchangers (one of oxidant and one for fuel) while all of the burners on the opposite side receive pre-heated oxidant and pre-heated fuel from a different pair of heat exchangers (again, one for oxidant and one for fuel). Also, while FIG 10 illustrates pre-heating of the oxidant before the shell-side fluid 3 is used to pre-heat the fuel, this order may be reversed.

    [0060] When the control scheme illustrated in FIG 2 is applied to the furnace of FIG 8, the first control valve (CV1) receives the first feed flow (FF1) of cool reactant from the source of oxidant (11A). The second control valve (CV2) receives the second feed flow (FF1) of cool reactant from the source of oxidant (11B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first and second combined flows (CF1, CF2) are combusted with the gaseous fuel at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass. It will be understood that the other flows of oxidant (11C, 11D) may be similarly preheated at the heat exchanger.

    [0061] When the control scheme illustrated in FIG 2 is applied to the furnace of FIG 9, the first control valve (CV1) receives the first feed flow (FF1) of cool reactant from the source of gaseous fuel (19A). The second control valve receives the second feed flow of cool reactant from the source of gaseous fuel (19B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first and second combined flows (CF1, CF2) are combusted with the oxidant at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass. It will be understood that the other flows of fuel (19C, 19D) may be similarly preheated at the heat exchanger.

    [0062] When the control scheme illustrated in FIG 2 is applied to the furnace of FIG 10, the first control valve (CV1) of the first of the two heat exchange systems receives the first feed flow (FF1) of cool reactant from the source of oxidant (11A). The second control valve (CV2) of the first of the two heat exchange systems receives the second feed flow (FF2) of cool reactant from the source of oxidant (11B). The first control valve (CV1) of the second of the two heat exchange systems receives the first feed flow (FF1) of cool reactant from the source of gaseous fuel (19A). The second control valve (CV2) of the second of the two heat exchange systems receives the second feed flow (FF2) of cool reactant from the source of gaseous fuel (19B). The hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5). The first combined flow (CF1) from the first of the two heat exchange systems and the first combined flow (CF1) from the second of the two heat exchange systems are combusted at the first burner (23A) for producing heat to heat the charge or molten glass. The second combined flow (CF2) from the first of the two heat exchange systems and the second combined flow (CF2) from the second of the two heat exchange systems are combusted at the second burner (23B) for producing heat to heat the charge or molten glass. It will be understood that the other flows of fuel (19C, 19D) and oxidant (11C, 11D) may be similarly preheated at the heat exchangers.

    [0063] The burner may be any burner suitable for the combustion of a fuel with an oxidant, in particular those suitable for use in a melting furnace such as a metal or glass furnace, for example, those disclosed by US 6,910,879, US 2007-0172781, and US 2007-0281254.

    [0064] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

    [0065] The singular forms "a", "an" and "the" include plural referents, unless the context clearly dictates otherwise.

    [0066] "Comprising" in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of "comprising." "Comprising" is defined herein as necessarily encompassing the more limited transitional terms "consisting essentially of" and "consisting of"; "comprising" may therefore be replaced by "consisting essentially of" or "consisting of" and remain within the expressly defined scope of "comprising".

    [0067] "Providing" in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

    [0068] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

    [0069] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.


    Claims

    1. A method for reducing overheating of internal components of a counter-flow shell and tube heat exchanger utilizing variable partial bypass of a reactant flow, said method comprising the steps of:

    dividing a first feed flow (FF1) of a cool reactant with a first control valve (CV1) between a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant, the first main flow (MF1) flowing through a counter-flow shell and tube heat exchanger on a tube-side of the heat exchanger;

    exchanging heat at the shell and tube heat exchanger between the first main flow (MF1) and a flow of a hot shell-side fluid and combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant and also a flow of cooled shell-side fluid, the first combined flow (CF1) exiting the heat exchanger at a first reactant outlet (RO1) of the heat exchanger;

    measuring a temperature of the first combined flow (CF1) at or downstream of the first reactant outlet (RO1);

    controlling relative proportions of the first main flow (MF1) and first bypass flow (BF1), resulting from division of the first feed flow (FF1), with the control valve (CV1) based upon the measured temperature of the first combined flow (CF1), wherein less heat is transferred from the shell-side fluid to the first bypass flow (BF1) than is transferred from the shell-side fluid to the first main flow (MF1);

    dividing a second feed flow (FF2) of a cool reactant with a second control valve (CV2) between a second main flow (MF2) of the cool reactant and a second bypass flow (BF2) of the cool reactant, the second main flow (MF2) flowing through a shell and tube heat exchanger on the tube-side;

    exchanging heat at the shell and tube heat exchanger between the second main flow (MF2) and a flow of a hot shell-side fluid and combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant and the flow of cooled shell-side fluid, the second combined flow (CF2) exiting the heat exchanger at a second reactant outlet (RO2) of the heat exchanger;

    measuring a temperature of the second combined flow (CF2) at or downstream of the second reactant outlet (RO2); and

    controlling relative proportions of the second main flow (MF2) and second bypass flow (BF2), resulting from division of the second feed flow (FF2), with the second control valve (CV2) based upon the measured temperature of the second combined flow (CF2), wherein:

    less heat is transferred from the shell-side fluid to the second bypass flow (BF2) than is transferred from the shell-side fluid to the second main flow (MF2); and

    control of the relative proportions of the first feed flow (FF1) into the first main and bypass flows (MF1, BF1) is independent of control of the relative proportions of the second feed flow (FF2) into the second main and bypass flows (MF2, BF2).


     
    2. The method of claim 1, further comprising the step of directing the first and second combined flows (CF1, CF2) exiting the first and second reactant outlets (RO1, RO2) to first and second burners (23A, 23B) operatively associated with a furnace, wherein:

    the shell-side fluid is air;

    the first and second reactants of the first and second combined flows (CF1, CF2) are the same and are selected from the group consisting of industrially pure oxygen, oxygen-enriched air, and natural gas;

    if the first and second reactants are industrially pure oxygen or oxygen-enriched air, the first and second reactants of the first and second combined flows (CF1, CF2) are combusted with fuel at the first and second burners (23A, 23B);

    if the first and second reactants are natural gas, the first and second reactants of the first and second combined flows (CF1, CF2) are combusted with an oxidant at the first and second burners (23A, 23B); and

    the furnace is a glass melting furnace.


     
    3. The method of claim 1, wherein the reactant is a gaseous fuel or an oxidant having an oxygen concentration higher than that of air, the oxidant being preferably industrially pure oxygen or oxygen-enriched air.
     
    4. The method of claim 1 or 3, wherein the shell-side fluid is air or an inert gas.
     
    5. The method of any one of the preceding claims, wherein the shell and tube heat exchanger includes:

    a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30);

    a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34);

    a first main inlet plenum (29) receiving the first main flow (MF1), the first main inlet plenum (29) terminating in a downstream direction at a second tubesheet (31), the first main inlet plenum (29) surrounding the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31); and

    a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), extends downstream of the second tubesheet (31), and concentrically surrounds a respective one of the first set of bypass tubes (33), each of the main tubes (32) in the first set of main tubes fluidly communicating with the first reactant outlet (RO1), at each open downstream end (34) of one of the bypass tubes (33) of the first set of bypass tubes (33) a portion of the first main flow (MF1) combines with a respective portion of the first bypass flow (BF1) to form a portion of the first combined flow (CF1) which flows along a remaining downstream portion of the respective main tube (32) to the first reactant outlet (RO1), heat exchange between the first bypass flow (BF1) and the hot shell-side fluid being achieved via the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes (33).


     
    6. The method of any one of claims 1 to 4, wherein the shell and tube heat exchanger includes:

    a first inlet plenum (69) receiving the first bypass flow (BF1), the first inlet plenum (69) disposed inside the shell (35);

    a first outlet plenum (114, 113) fluidly communicating with the first reactant outlet (RO1);

    at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first outlet plenum (114, 113); and

    at least one first main flow tube (68) receiving the first main flow (MF1) from the first control valve (CV1), extending into an interior of the heat exchanger downstream of the first inlet plenum (89) and extending back to terminate at the first inlet plenum (89), wherein the first main flow (MF1) is combined with the first bypass flow (BF1) at the first inlet plenum (69) and the first combined flow (CF1) flows through the at least one first reactant tube (71).


     
    7. The method of any one of claims 1 to 4, wherein the heat exchanger includes:

    first, second and third plenums (109, 111, 113), the third plenum (113) receiving the first combined flow (CF1) and fluidly communicating with the first reactant outlet (RO1);

    at least one first upstream reactant tube (110) receiving the first main flow (MF1) and extending through an interior of the shell (35) from the first plenum (109) and fluidly communicating with the second plenum (111);

    a first bypass tube (107) receiving the first bypass flow (BF1) and extending between the first control valve (CV1) and the second plenum (111) and extending at least partially outside the shell of the heat exchanger, wherein the first main flow (MF1) and the first bypass flow (BF1) are combined at the second plenum (111); and

    at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending between the second and third plenums (111, 113).


     
    8. The method of any one of the preceding claims, wherein the hot shell-side fluid is obtained from a recuperator or regenerator.
     
    9. The method of claim 8, wherein the cooled shell-side fluid is directed to a recuperator or regenerator to heat the cooled shell-side fluid in order to produce the hot shell-side fluid.
     
    10. The method of any one of the preceding claims, wherein the shell-side fluid is air and the hot shell-side air is obtained by the steps comprising:

    pre-heating ambient air at a pre-heat exchanger through heat exchange with the cool shell-side air to produce moderately hot air; and

    heating the moderately hot air at a recuperator or regenerator through heat exchange with hot furnace gases to produce the hot shell-side air.


     
    11. A counter-flow shell and tube heat exchange system for reduction of overheating of internal components thereof utilizing variable partial bypass of a reactant flow, said heat exchange system comprising:

    a first control valve (CV1) adapted and configured to divide a first feed flow (FF1) of cool reactant into a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant;

    a first main flow inlet conduit (27, 67, 106) receiving the first main flow (MF1) of cool reactant from the first control valve (CV1);

    a first bypass flow inlet conduit (26, 66, 107) receiving the first bypass flow (BF1) of cool reactant from the first control valve (CV1);

    a shell (35) having a shell-side fluid inlet and outlet (SI, SO) fluidly communicating with an interior of the shell (35) comprising a heat exchange space;

    means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space;

    means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space, wherein said means for exchanging heat between the first main flow (MF1) and the flow of the hot shell-side fluid is configured and adapted to allow more heat to be exchanged between the first main flow (MF1) and the flow of hot shell-side fluid than is exchanged between the first bypass flow (BF1) and the flow of hot shell-side fluid by the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid;

    means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant;

    at least one first downstream reactant tube (92, 112) receiving the first combined flow (CF1) and fluidly communicating with a first reactant outlet (RO1);

    a first outlet conduit fluidly communicating with the first reactant outlet (RO1) and receiving the first combined flow (CF1) therefrom;

    a first temperature sensor (T1) disposed in the outlet conduit at or downstream of the first reactant outlet (RO1);

    a programmable logic controller (C) adapted and configured to control relative proportions of the first main flow (MF1) and first bypass flow (BF1) produced by division of the first feed flow (FF1) of cool reactant by the first control valve (CV1), said control being based upon a temperature of the first combined flow (CF1) sensed by the first temperature sensor (Ti),a second control valve (CV2) adapted and configured to divide a second feed flow (FF2) of cool reactant into a second main flow (MF2) of the cool reactant and a second bypass flow (BF2) of the cool reactant;

    a second main flow inlet conduit (47, 87, 106) receiving the second main flow (MF2) of cool reactant from the second control valve (CV2);

    a second bypass flow inlet conduit (46, 46, 107) receiving the second bypass flow (BF2) of cool reactant from the second control valve (CV2);

    means for exchanging heat between the second main flow (MF2) and a flow of the hot shell-side fluid in the heat exchange space;

    means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid in the heat exchange space, wherein said means for exchanging heat between the second main flow (MF2) and the flow of the hot shell-side fluid is configured and adapted to allow more heat to be exchanged between the second main flow (MF2) and the flow of hot shell-side fluid than is exchanged between the second bypass flow (BF2) and the flow of hot shell-side fluid by the means for exchanging heat between the second bypass flow (BF2) and the flow of hot shell-side fluid;

    means for combining the second main flow (MF2) with the second bypass flow (BF2) to produce a second combined flow (CF2) of heated reactant;

    at least one second downstream reactant tube (92, 112) receiving the second combined flow (CF2) and fluidly communicating with a second reactant outlet (RO2);

    a second outlet conduit fluidly communicating with the second reactant outlet (RO2) and receiving the second combined flow (CF2) therefrom;

    a second temperature sensor (T2) disposed in the second outlet conduit at or downstream of the second reactant outlet (RO2), wherein the programmable logic controller (C) is adapted and configured to control relative proportions of the second main flow (MF2) and second bypass flow (BF2) produced by division of the second feed flow (FF2) of cool reactant by the second control valve (CV2) based upon a temperature of the second combined flow (CF2) sensed by the second temperature sensor (T2).


     
    12. The heat exchange system of claim 11, wherein:

    a) the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises:

    1) a first bypass inlet plenum (28) receiving the first bypass flow (BF1), the first bypass inlet plenum (28) terminating in a downstream direction at a first tubesheet (30);

    2) a first set of bypass tubes (33) fluidly communicating with the first bypass inlet plenum (28), extending downstream from the first tubesheet (30), and terminating at open downstream ends (34); and

    b) the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises:

    1) a first main inlet plenum (29) receiving the first main flow (MF1) and which terminates in a downstream direction at a second tubesheet (31),

    2) a first set of main tubes (32) each one of which communicates with the first main inlet plenum (29), concentrically surrounds a respective one of the first set of bypass tubes (33), and extends downstream of the second tubesheet (31) past the open downstream ends (34) of the first set of bypass tubes (33);

    c) the first main inlet plenum (29) surrounds the first set of bypass tubes (33) in sealing fashion in between the first and second tubesheets (30, 31);

    d) each of the main tubes (32) in the first set of main tubes (32) fluidly communicates with the first reactant outlet (RO1); and

    e) the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises portions of the main tubes (32) of the first set of main tubes (32) where the first bypass flow (BF1) exits the open downstream ends (34) and combines with the first main flow (MF1) flowing in annular spaces in between the first set of main tubes (32) and the first set of bypass tubes (33); and

    f) remaining portions of the first set of main tubes (32) downstream of the open ends allows heat exchange between the first combined flow (CF1) and the hot shell-side fluid.


     
    13. The heat exchange system of claim 11, wherein:

    a) the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first inlet conduit (66) receiving the first bypass flow (BF1) from the first control valve (CV1), the first inlet conduit (66) extending into the interior of the heat exchanger;

    b) the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a first inlet plenum (69) fluidly communicating with the first inlet conduit (66); and

    c) the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises at least one first main flow tube (68) fluidly communicating between the first control valve (CV1) and the first inlet plenum (69) that extends into an interior of the heat exchanger downstream of the first inlet plenum (69) and extends back to terminate at the first inlet plenum (69);

    d) the heat exchanger further comprises a first outlet plenum (114) fluidly communicating with the first reactant outlet (RO1); and

    e) the heat exchanger further comprises at least one first reactant tube (71) fluidly communicating between the first inlet plenum (69) and the first reactant outlet (RO1) that allows the first combined flow (CF1) to exchange heat with the hot shell-side fluid.


     
    14. The heat exchange system of claim 11, wherein:

    a) the means for exchanging heat between the first main flow (MF1) and a flow of a hot shell-side fluid in the heat exchange space comprises a first plenum (109) receiving the first main flow (MF1) from the first control valve (CV1) and at least one first upstream reactant tube (110) extending inside the shell (35) and receiving the first main flow (MF1) from the first plenum (109);

    b) the means for exchanging heat between the first bypass flow (BF1) and the flow of hot shell-side fluid in the heat exchange space comprises a first bypass tube (107) receiving the first bypass flow (BF1) from the first control valve (CV1) and extending at least partially outside the shell (35) of the heat exchanger;

    c) the means for combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant comprises a second plenum (111) that receives the first main flow (MF1) downstream of the at least one first upstream reactant tube (110) and the first bypass flow (BF1) from the first bypass tube (107); and

    d) the heat exchanger further comprises at least one first downstream reactant tube (112) and a third plenum (113) that fluidly communicates with the first reactant outlet (RO1), the at least one first downstream reactant tube (112) receiving the first combined flow (CF1) and extending inside the shell (35) between the second and third plenums (109, 111) to allow heat exchange between the first combined flow (CF1) and the hot shell-side fluid.


     
    15. The heat exchange system of any one of claims 11 to 14, further comprising a recuperator or regenerator (5) having an outlet (6) in fluid communication with the shell inlet (SI), the recuperator or regenerator (4) being adapted and configured to allow the shell-side fluid to be heated and conveyed to the heat exchange space via the shell inlet (SI).
     
    16. The heat exchange system of claim 15, wherein the recuperator or regenerator (5) includes an inlet (4) in fluid communication with the shell outlet (SO), the recuperator or regenerator (5) receiving cooled shell-side fluid from the shell outlet (SO) and heating the cooled shell-side fluid to produce the hot shell-side fluid.
     
    17. A glass furnace utilizing preheated reactant or reactants, comprising first and second burners (23A, 23B) disposed on a wall (22) of a furnace enclosing a combustion space adapted and configured to contain a glassmaking charge or molten glass, a source of gaseous fuel (19A, 19B), a source of oxidant (11A, 11B) selected from the group consisting of industrially pure oxygen and oxygen-enriched air, a recuperator or regenerator (5) having an outlet (6), and the heat exchange system of claim 11, wherein:

    the first control valve (CV1) receives the first feed flow (FF1) of cool reactant from the source of oxidant (11A);

    the second control valve (CV2) receives the second feed flow (FF2) of cool reactant from the source of oxidant (11B); and

    the hot shell-side fluid is air received from the outlet (6) of the recuperator or regenerator (5);

    whereby:
    If the first and second cool reactants of the first and second feed flows (FF1, FF2) are a same cool oxidant received from said source of oxidant (11A, 11B):

    the burners (23A, 23B) receive the gaseous fuel from said source of gaseous fuel (19A, 19B); and

    the first and second combined flows (CF1, CF2) are combusted with the gaseous fuel at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass.

    a) if the first and second cool reactants of the first and second feed flows (FF1, FF2) are a same gaseous fuel received from said source of gaseous fuel (19A, 19e);

    the burners (23A, 23B) receive the oxidant from said source of oxidant (11A, 11B); and

    the first and second combined flows (CF1, CF2) are combusted with the oxidant at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass.

    b) if the first and second cool reactants of the first and second feed flows (FF1, FF2) are a same gaseous fuel received from said source of gaseous fuel (19A, 19e);

    - the burners (23A, 23B) receive the oxidant from said source of oxidant (11A, 11B); and

    - the first and second combined flows (CF1, CF2) are combusted with the oxidant at the first and second burners (23A, 23B), respectively for producing heat to heat the charge or molten glass.


     


    Ansprüche

    1. Verfahren zum Verringern einer Überhitzung von internen Komponenten eines Gegenstrom-Rohrbündelwärmeaustauschers, wobei ein variabler partieller Bypass eines Reaktantenstroms genutzt wird, wobei das Verfahren die folgenden Schritte umfasst:

    Aufteilen eines ersten Zufuhrstroms (FF1) eines kühlen Reaktanten mit einem ersten Steuerventil (CV1) zwischen einem ersten Hauptstrom (MF1) des kühlen Reaktanten und einem ersten Bypass-Strom (BF1) des kühlen Reaktanten, wobei der erste Hauptstrom (MF1) durch einen Gegenstrom-Rohrbündelwärmeaustauscher an einer Rohrseite des Wärmeaustauschers strömt;

    Austauschen von Wärme an dem Rohrbündelwärmeaustauscher zwischen dem ersten Hauptstrom (MF1) und einem Strom eines heißen mantelseitigen Fluids und Kombinieren des ersten Hauptstroms (MF1) mit dem ersten Bypass-Strom (BF1), um einen ersten kombinierten Strom (CF1) eines erwärmten Reaktanten und auch einen Strom eines gekühlten mantelseitigen Fluids zu erzeugen, wobei der erste kombinierte Strom (CF1) den Wärmeaustauscher an einem ersten Reaktantenauslass (RO1) des Wärmeaustauschers verlässt;

    Messen einer Temperatur des ersten kombinierten Stroms (CF1) an dem oder stromabwärts des ersten Reaktantenauslass(es) (RO1);

    Steuern relativer Anteile des ersten Hauptstroms (MF1) und des ersten Bypass-Stroms (BF1), die sich aus der Aufteilung des ersten Zufuhrstroms (FF1) ergeben, mit dem Steuerventil (CV1) auf der Grundlage der gemessenen Temperatur des ersten kombinierten Stroms (CF1), wobei weniger Wärme von dem mantelseitigen Fluid an den ersten Bypass-Strom (BF1) übertragen wird als von dem mantelseitigen Fluid an den ersten Hauptstrom (MF1) übertragen wird;

    Aufteilen eines zweiten Zufuhrstroms (FF2) eines kühlen Reaktanten mit einem zweiten Steuerventil (CV2) zwischen einem zweiten Hauptstrom (MF2) des kühlen Reaktanten und einem zweiten Bypass-Strom (BF2) des kühlen Reaktanten, wobei der zweite Hauptstrom (MF2) durch einen Gegenstrom-Rohrbündelwärmeaustauscher an einer Rohrseite strömt;

    Austauschen von Wärme an dem Rohrbündelwärmeaustauscher zwischen dem zweiten Hauptstrom (MF2) und einem Strom eines heißen mantelseitigen Fluids und Kombinieren des zweiten Hauptstroms (MF2) mit dem zweiten Bypass-Strom (BF2), um einen zweiten kombinierten Strom (CF2) eines erwärmten Reaktanten und den Strom des gekühlten mantelseitigen Fluids zu erzeugen, wobei der zweite kombinierte Strom (CF2) den Wärmeaustauscher an einem zweiten Reaktantenauslass (RO2) des Wärmeaustauschers verlässt;

    Messen einer Temperatur des zweiten kombinierten Stroms (CF2) an dem oder stromabwärts des zweiten Reaktantenauslass(es) (RO2); und

    Steuern relativer Anteile des zweiten Hauptstroms (MF2) und des zweiten Bypass-Stroms (BF2), die sich aus der Aufteilung des zweiten Zufuhrstroms (FF2) ergeben, mit dem zweiten Steuerventil (CV2) auf der Grundlage der gemessenen Temperatur des zweiten kombinierten Stroms (CF2), wobei:

    weniger Wärme von dem mantelseitigen Fluid an den zweiten Bypass-Strom (BF2) übertragen wird als von dem mantelseitigen Fluid an den zweiten Hauptstrom (MF2) übertragen wird; und

    die Steuerung der relativen Anteile des ersten Zufuhrstroms (FF1) in den ersten Haupt- und Bypass-Strom (MF1, BF1) unabhängig von der Steuerung der relativen Anteile des zweiten Zufuhrstroms (FF2) in den zweiten Haupt- und Bypass-Strom (MF2, BF2) ist.


     
    2. Verfahren nach Anspruch 1 weiter umfassend den Schritt eines Leitens der ersten und zweiten kombinierten Ströme (CF1, CF2), der aus dem ersten und dem zweiten Reaktantenauslass (RO1, RO2) austritt, an einen ersten und einen zweiten Brenner (23A, 23B), die betriebsfähig mit einem Ofen verbunden sind, wobei:

    das mantelseitige Fluid Luft ist;

    der erste und der zweite Reaktant des ersten und des zweiten kombinierten Stroms (CF1, CF2) der gleiche sind und ausgewählt sind aus der Gruppe bestehend aus industriell reinem Sauerstoff, mit Sauerstoff angereicherter Luft und Erdgas;

    wenn der erste und der zweite Reaktant industriell reiner Sauerstoff oder mit Sauerstoff angereicherte Luft sind, der erste und der zweite Reaktant des ersten und des zweiten kombinierten Stroms (CF1, CF2) mit Brennstoff an dem ersten und dem zweiten Brenner (23A, 23B) verbrannt werden;

    wenn der erste und der zweite Reaktant Erdgas sind, der erste und der zweite Reaktant des ersten und des zweiten kombinierten Stroms (CF1, CF2) mit einem Oxidationsmittel an dem ersten und dem zweiten Brenner (23A, 23B) verbrannt werden; und

    der Ofen ein Glasschmelzofen ist.


     
    3. Verfahren nach Anspruch 1, wobei der Reaktant ein gasförmiger Brennstoff oder ein Oxidationsmittel mit einer höheren Sauerstoffkonzentration als jene von Luft ist, wobei das Oxidationsmittel vorzugsweise industriell reiner Sauerstoff oder mit Sauerstoff angereicherte Luft ist.
     
    4. Verfahren nach Anspruch 1 oder 3, wobei das mantelseitige Fluid Luft oder ein inertes Gas ist.
     
    5. Verfahren nach einem der vorstehenden Ansprüche, wobei der Rohrbündelwärmeaustauscher einschließt:

    ein erstes Bypass-Einlassplenum (28), das den ersten Bypass-Strom (BF1) empfängt, wobei das erste Bypass-Einlassplenum (28) in einer stromabwärtigen Richtung an einem ersten Rohrboden (30) endet;

    einen ersten Satz von Bypass-Rohren (33) in Fluidkommunikation mit dem ersten Bypass-Einlassplenum (28), die sich von dem ersten Rohrboden (30) stromabwärts erstrecken und an offenen stromabwärtigen Enden (34) enden;

    ein erstes Haupteinlassplenum (29), das den ersten Hauptstrom (MF1) empfängt, wobei das erste Haupteinlassplenum (29) in einer stromabwärtigen Richtung an einem zweiten Rohrboden (31) endet, wobei das erste Haupteinlassplenum (29) den ersten Satz von Bypass-Rohren (33) auf dichtende Art zwischen dem ersten und dem zweiten Rohrboden (30, 31) umgibt; und

    einen ersten Satz von Hauptrohren (32), von denen jedes mit dem ersten Haupteinlassplenum (29) kommuniziert, sich stromabwärts von dem zweiten Rohrboden (31) erstreckt und ein jeweiliges des ersten Satzes von Bypass-Rohren (33) konzentrisch umgibt, wobei jedes der Hauptrohre (32) in dem ersten Satz von Hauptrohren in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1) ist, wobei an jedem offenen stromabwärtigen Ende (34) von einem der Bypass-Rohre (33) des ersten Satzes von Bypass-Rohren (33) sich ein Teil des ersten Hauptstroms (MF1) mit einem jeweiligen Teil des ersten Bypass-Stroms (BF1) kombiniert, um einen Teil des ersten kombinierten Stroms (CF1) zu bilden, der entlang eines übrigen stromabwärtigen Abschnitts des jeweiligen Hauptrohrs (32) zu dem ersten Reaktantenauslass (RO1) strömt, wobei Wärmeaustausch zwischen dem ersten Bypass-Strom (BF1) und dem heißen mantelseitigen Fluid dadurch erzielt wird, dass der erste Hauptstrom (MF1) in Ringräumen zwischen dem ersten Satz von Hauptrohren (32) und dem ersten Satz von Bypass-Rohren (33) strömt.


     
    6. Verfahren nach einem der Ansprüche 1 bis 4, wobei der Rohrbündelwärmeaustauscher einschließt:

    ein erstes Einlassplenum (69), das den ersten Bypass-Strom (BF1) empfängt, wobei das erste Einlassplenum (69) innerhalb des Mantels (35) angeordnet ist;

    ein erstes Auslassplenum (114, 113) in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1);

    mindestens ein erstes Reaktantenrohr (71) in Fluidkommunikation zwischen dem ersten Einlassplenum (69) und dem ersten Auslassplenum (114, 113); und

    mindestens ein erstes Hauptstromrohr (68), das den ersten Hauptstrom (MF1) von dem ersten Steuerventil (CV1) empfängt, sich in ein Inneres des Wärmeaustauschers stromabwärts des ersten Einlassplenums (89) erstreckt und sich zurück erstreckt, um an dem ersten Einlassplenum (89) zu enden, wobei der erste Hauptstrom (MF1) mit dem ersten Bypass-Strom (BF1) an dem ersten Einlassplenum (69) kombiniert wird und der erste kombinierte Strom (CF1) durch das mindestens eine erste Reaktantenrohr (71) strömt.


     
    7. Verfahren nach einem der Ansprüche 1 bis 4, wobei der Wärmeaustauscher einschließt:

    ein erstes, ein zweites und ein drittes Plenum (109, 111, 113), wobei das dritte Plenum (113) den ersten kombinierten Strom (CF1) empfängt und in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1) ist;

    mindestens ein erstes stromaufwärtiges Reaktantenrohr (110), das den ersten Hauptstrom (MF1) empfängt und sich durch ein Inneres des Mantels (35) von dem ersten Plenum (109) aus erstreckt und in Fluidkommunikation mit dem zweiten Plenum (111) ist;

    ein erstes Bypass-Rohr (107), das den ersten Bypass-Strom (BF1) empfängt und sich zwischen dem ersten Steuerventil (CV1) und dem zweiten Plenum (111) erstreckt und sich zumindest teilweise außerhalb des Mantels des Wärmeaustauschers erstreckt, wobei der erste Hauptstrom (MF1) und der erste Bypass-Strom (BF1) an dem zweiten Plenum (111) kombiniert werden; und

    mindestens ein erstes stromabwärtiges Reaktantenrohr (112), das den ersten kombinierten Strom (CF1) empfängt und sich zwischen dem zweiten und dem dritten Plenum (111, 113) erstreckt.


     
    8. Verfahren nach einem der vorstehenden Ansprüche, wobei das heiße mantelseitige Fluid von einem Rekuperator oder Regenerator erhalten wird.
     
    9. Verfahren nach Anspruch 8, wobei das gekühlte mantelseitige Fluid zu einem Rekuperator oder Regenerator geleitet wird, um das gekühlte mantelseitige Fluid zu erwärmen, um das heiße mantelseitige Fluid zu erzeugen.
     
    10. Verfahren nach einem der vorstehenden Ansprüche, wobei das mantelseitige Fluid Luft ist und die heiße mantelseitige Luft durch die Schritte erhalten wird, die Folgendes umfassen:

    Vorwärmen von Umgebungsluft an einem Vorwärmeaustauscher durch Wärmeaustausch mit der kühlen mantelseitigen Luft, um mäßig heiße Luft zu erzeugen; und

    Erwärmen der mäßig heißen Luft an einem Rekuperator oder Regenerator durch Wärmeaustausch mit heißen Ofengasen, um die heiße mantelseitige Luft zu erzeugen.


     
    11. Gegenstrom-Rohrbündelwärmeaustauschsystem zur Verringerung einer Überhitzung von internen Komponenten davon, wobei ein variabler partieller Bypass eines Reaktantenstroms genutzt wird, wobei das Wärmeaustauschsystem umfasst:

    ein erstes Steuerventil (CV1), ausgelegt und konfiguriert zum Aufteilen eines ersten Zufuhrstroms (FF1) eines kühlen Reaktanten in einen ersten Hauptstrom (MF1) des kühlen Reaktanten und einen ersten Bypass-Strom (BF1) des kühlen Reaktanten;

    eine erste Hauptstrom-Einlassleitung (27, 67, 106), die den ersten Hauptstrom (MF1) des kühlen Reaktanten von dem ersten Steuerventil (CV1) empfängt;

    eine erste Bypass-Strom-Einlassleitung (26, 66, 107), die den ersten Bypass-Strom (BF1) des kühlen Reaktanten von dem ersten Steuerventil (CV1) empfängt;

    einen Mantel (35) aufweisend einen mantelseitigen Fluideinlass und - auslass (SI, SO) in Fluidkommunikation mit einem Inneren des Mantels (35), das einen Wärmeaustauschraum umfasst;

    Mittel zum Austauschen von Wärme zwischen dem ersten Hauptstrom (MF1) und einem Strom eines heißen mantelseitigen Fluids in dem Wärmeaustauschraum;

    Mittel zum Austauschen von Wärme zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum, wobei das Mittel zum Austauschen von Wärme zwischen dem ersten Hauptstrom (MF1) und dem Strom des heißen mantelseitigen Fluids dafür konfiguriert und ausgelegt ist, es zu gestatten, dass mehr Wärme zwischen dem ersten Hauptstrom (MF1) und dem Strom des heißen mantelseitigen Fluids ausgetauscht wird als zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids durch das Mittel zum Austauschen von Wärme zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids ausgetauscht wird;

    Mittel zum Kombinieren des ersten Hauptstroms (MF1) mit dem ersten Bypass-Strom (BF1), um einen ersten kombinierten Strom (CF1) eines erwärmten Reaktanten zu erzeugen;

    mindestens ein erstes stromabwärtiges Reaktantenrohr (92, 112), das den ersten kombinierten Strom (CF1) empfängt und in Fluidkommunikation mit einem ersten Reaktantenauslass (RO1) ist;

    eine erste Auslassleitung in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1), die den ersten kombinierten Strom (CF1) davon empfängt;

    einen ersten Temperatursensor (T1), angeordnet in der Auslassleitung an dem oder stromabwärts des ersten Reaktantenauslass(es) (RO1);

    eine speicherprogrammierbare Steuerung (C), ausgelegt und konfiguriert zum Steuern relativer Anteile des ersten Hauptstroms (MF1) und des ersten Bypass-Stroms (BF1), die durch die Aufteilung des ersten Zufuhrstroms (FF1) eines kühlen Reaktanten durch das erste Steuerventil (CV1) erzeugt werden, wobei die Steuerung auf einer Temperatur des ersten kombinierten Stroms (CF1) basiert, die durch den ersten Temperatursensor (T1) erfasst wird, ein zweites Steuerventil (CV2), ausgelegt und konfiguriert zum Aufteilen eines zweiten Zufuhrstroms (FF2) eines kühlen Reaktanten in einen zweiten Hauptstrom (MF2) des kühlen Reaktanten und einen zweiten Bypass-Strom (BF2) des kühlen Reaktanten;

    eine zweite Hauptstrom-Einlassleitung (47, 87, 106), die den zweiten Hauptstrom (MF2) des kühlen Reaktanten von dem zweiten Steuerventil (CV2) empfängt;

    eine zweite Bypass-Strom-Einlassleitung (46, 46, 107), die den zweiten Bypass-Strom (BF2) des kühlen Reaktanten von dem zweiten Steuerventil (CV2) empfängt;

    Mittel zum Austauschen von Wärme zwischen dem zweiten Hauptstrom (MF2) und einem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum;

    Mittel zum Austauschen von Wärme zwischen dem zweiten Bypass-Strom (BF2) und dem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum, wobei das Mittel zum Austauschen von Wärme zwischen dem zweiten Hauptstrom (MF2) und dem Strom des heißen mantelseitigen Fluids dafür konfiguriert und ausgelegt ist, es zu gestatten, dass mehr Wärme zwischen dem zweiten Hauptstrom (MF2) und dem Strom des heißen mantelseitigen Fluids ausgetauscht wird als zwischen dem zweiten Bypass-Strom (BF2) und dem Strom des heißen mantelseitigen Fluids durch das Mittel zum Austauschen von Wärme zwischen dem zweiten Bypass-Strom (BF2) und dem Strom des heißen mantelseitigen Fluids ausgetauscht wird;

    Mittel zum Kombinieren des zweiten Hauptstroms (MF2) mit dem zweiten Bypass-Strom (BF2), um einen zweiten kombinierten Strom (CF2) eines erwärmten Reaktanten zu erzeugen;

    mindestens ein zweites stromabwärtiges Reaktantenrohr (92, 112), das den zweiten kombinierten Strom (CF2) empfängt und in Fluidkommunikation mit einem zweiten Reaktantenauslass (RO2) ist;

    eine zweite Auslassleitung in Fluidkommunikation mit dem zweiten Reaktantenauslass (RO2), die den zweiten kombinierten Strom (CF2) davon empfängt;

    einen zweiten Temperatursensor (T2), angeordnet in der zweiten Auslassleitung an dem oder stromabwärts des zweiten Reaktantenauslass(es) (RO2), wobei die speicherprogrammierbare Steuerung (C) dafür ausgelegt und konfiguriert ist, relative Anteile des zweiten Hauptstroms (MF2) und des zweiten Bypass-Stroms (BF2) zu steuern, die durch die Aufteilung des zweiten Zufuhrstroms (FF2) eines kühlen Reaktanten durch das Steuerventil (CV2) erzeugt werden, auf der Grundlage einer Temperatur des zweiten kombinierten Stroms (CF2), die durch den zweiten Temperatursensor (T2) erfasst wird.


     
    12. Wärmeaustauschsystem nach Anspruch 11, wobei:

    a) das Mittel zum Austauschen von Wärme zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum umfasst:

    1) ein erstes Bypass-Einlassplenum (28), das den ersten Bypass-Strom (BF1) empfängt, wobei das erste Bypass-Einlassplenum (28) in einer stromabwärtigen Richtung an einem ersten Rohrboden (30) endet;

    2) einen ersten Satz von Bypass-Rohren (33) in Fluidkommunikation mit dem ersten Bypass-Einlassplenum (28), die sich von dem ersten Rohrboden (30) stromabwärts erstrecken und an offenen stromabwärtigen Enden (34) enden; und

    b) das Mittel zum Austauschen von Wärme zwischen dem ersten Hauptstrom (MF1) und einem Strom eines heißen mantelseitigen Fluids in dem Wärmeaustauschraum umfasst:

    1) ein erstes Haupteinlassplenum (29), das den ersten Hauptstrom (MF1) empfängt und in einer stromabwärtigen Richtung an einem zweiten Rohrboden (31) endet;

    2) einen ersten Satz von Hauptrohren (32), von denen jedes mit dem ersten Haupteinlassplenum (29) kommuniziert, ein jeweiliges des ersten Satzes von Bypass-Rohren (33) konzentrisch umgibt und sich stromabwärts von dem zweiten Rohrboden (31) über die offenen stromabwärtigen Enden (34) des ersten Satzes von Bypass-Rohren (33) hinaus erstreckt;

    c) das erste Haupteinlassplenum (29) den ersten Satz von Bypass-Rohren (33) auf dichtende Art zwischen dem ersten und dem zweiten Rohrboden (30, 31) umgibt;

    d) jedes der Hauptrohre (32) in dem ersten Satz von Hauptrohren (32) in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1) ist; und

    e) das Mittel zum Kombinieren des ersten Hauptstroms (MF1) mit dem ersten Bypass-Strom (BF1) zum Erzeugen eines ersten kombinierten Stroms (CF1) eines erwärmten Reaktanten Abschnitte der Hauptrohre (32) des ersten Satzes von Hauptrohren (32) umfasst, wobei der erste Bypass-Strom (BF1) aus den offenen stromabwärtigen Enden (34) austritt und sich mit dem ersten Hauptstrom (MF1) kombiniert, der in Ringräumen zwischen dem ersten Satz von Hauptrohren (32) und dem ersten Satz von Bypass-Rohren (33) strömt; und

    f) übrige Abschnitte des ersten Satzes von Hauptrohren (32) stromabwärts der offenen Enden einen Wärmeaustausch zwischen dem ersten kombinierten Strom (CF1) und dem heißen mantelseitigen Fluid gestatten.


     
    13. Wärmeaustauschsystem nach Anspruch 11, wobei:

    a) das Mittel zum Austauschen von Wärme zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum eine erste Einlassleitung (66) umfasst, die den ersten Bypass-Strom (BF1) von dem ersten Steuerventil (CV1) empfängt, wobei sich die erste Einlassleitung (66) in das Innere des Wärmeaustauschers erstreckt;

    b) das Mittel zum Kombinieren des ersten Hauptstroms (MF1) mit dem ersten Bypass-Strom (BF1) zum Erzeugen eines ersten kombinierten Stroms (CF1) eines erwärmten Reaktanten ein erstes Einlassplenum (69) in Fluidkommunikation mit der ersten Einlassleitung (66) umfasst; und

    c) das Mittel zum Austauschen von Wärme zwischen dem ersten Hauptstrom (MF1) und einem Strom eines heißen mantelseitigen Fluids in dem Wärmeaustauschraum mindestens ein erstes Hauptstromrohr (68) in Fluidkommunikation zwischen dem ersten Steuerventil (CV1) und dem ersten Einlassplenum (69) umfasst, das sich in ein Inneres des Wärmeaustauschers stromabwärts des ersten Einlassplenums (69) erstreckt und sich zurück erstreckt, um an dem ersten Einlassplenum (69) zu enden;

    d) der Wärmeaustauscher weiter ein erstes Auslassplenum (114) in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1) umfasst; und

    e) der Wärmeaustauscher weiter mindestens ein erstes Reaktantenrohr (71) in Fluidkommunikation zwischen dem ersten Einlassplenum (69) und dem ersten Reaktantenauslass (RO1) umfasst, das es dem ersten kombinierten Strom (CF1) gestattet, Wärme mit dem heißen mantelseitigen Fluid auszutauschen.


     
    14. Wärmeaustauschsystem nach Anspruch 11, wobei:

    a) das Mittel zum Austauschen von Wärme zwischen dem ersten Hauptstrom (MF1) und einem Strom eines heißen mantelseitigen Fluids in dem Wärmeaustauschraum ein erstes Plenum (109) umfasst, das den ersten Hauptstrom (MF1) von dem ersten Steuerventil (CV1) empfängt, und mindestens ein erstes stromaufwärtiges Reaktantenrohr (110), das sich innerhalb des Mantels (35) erstreckt und den ersten Hauptstrom (MF1) von dem ersten Plenum (109) empfängt;

    b) das Mittel zum Austauschen von Wärme zwischen dem ersten Bypass-Strom (BF1) und dem Strom des heißen mantelseitigen Fluids in dem Wärmeaustauschraum ein erstes Bypass-Rohr (107) umfasst, das den ersten Bypass-Strom (BF1) von dem ersten Steuerventil (CV1) empfängt und sich zumindest teilweise außerhalb des Mantels (35) des Wärmeaustauschers erstreckt;

    c) das Mittel zum Kombinieren des ersten Hauptstroms (MF1) mit dem ersten Bypass-Strom (BF1) zum Erzeugen eines ersten kombinierten Stroms (CF1) eines erwärmten Reaktanten ein zweites Plenum (111) umfasst, das den ersten Hauptstrom (MF1) stromabwärts des mindestens einen ersten stromaufwärtigen Reaktantenrohrs (110) und den ersten Bypass-Strom (BF1) von dem ersten Bypass-Rohr (107) empfängt; und

    d) der Wärmeaustauscher weiter mindestens ein erstes stromabwärtiges Reaktantenrohr (112) und ein drittes Plenum (113) in Fluidkommunikation mit dem ersten Reaktantenauslass (RO1) umfasst, wobei das mindestens eine erste stromabwärtige Reaktantenrohr (112) den ersten kombinierten Strom (CF1) empfängt und sich innerhalb des Mantels (35) zwischen dem zweiten und dem dritten Plenum (109, 111) erstreckt, um einen Wärmeaustausch zwischen dem ersten kombinierten Strom (CF1) und dem heißen mantelseitigen Fluid zu gestatten.


     
    15. Wärmeaustauschsystem nach einem der Ansprüche 11 bis 14, weiter umfassend einen Rekuperator oder Regenerator (5) aufweisend einen Auslass (6) in Fluidkommunikation mit dem Manteleinlass (SI), wobei der Rekuperator oder Regenerator (4) dafür ausgelegt und konfiguriert ist, es dem mantelseitigen Fluid zu gestatten, erwärmt und über den Manteleinlass (SI) zu dem Wärmeaustauschraum befördert zu werden.
     
    16. Wärmeaustauschsystem nach Anspruch 15, wobei der Rekuperator oder Regenerator (5) einen Einlass (4) in Fluidkommunikation mit dem Mantelauslass (SO) einschließt, wobei der Rekuperator oder Regenerator (5) gekühltes mantelseitiges Fluid von dem Mantelauslass (SO) empfängt und das gekühlte mantelseitige Fluid erwärmt, um das heiße mantelseitige Fluid zu erzeugen.
     
    17. Glasofen, der einen oder mehrere vorgewärmte Reaktanten nutzt, umfassend einen ersten und einen zweiten Brenner (23A, 23B), angeordnet an einer Wand (22) eines Ofens, die einen Verbrennungsraum umschließt, ausgelegt und konfiguriert zum Enthalten einer Glasherstellungsladung oder geschmolzenen Glases, einer Quelle von gasförmigem Brennstoff (19A, 19B), einer Quelle eines Oxidationsmittels (11A, 11B), ausgewählt aus der Gruppe bestehend aus industriell reinem Sauerstoff und mit Sauerstoff angereicherter Luft, eines Rekuperators oder Regenerators (5) aufweisend einen Auslass (6) und des Wärmeaustauschsystems nach Anspruch 11, wobei:

    das erste Steuerventil (CV1) den ersten Zufuhrstrom (FF1) eines kühlen Reaktanten von der Quelle des Oxidationsmittels (11A) empfängt;

    das zweite Steuerventil (CV2) den zweiten Zufuhrstrom (FF2) eines kühlen Reaktanten von der Quelle des Oxidationsmittels (11B) empfängt; und

    das heiße mantelseitige Fluid Luft ist, die von dem Auslass (6) des Rekuperators oder Regenerators (5) empfangen wird;

    wobei:
    wenn der erste und der zweite kühle Reaktant des ersten und des zweiten Zufuhrstroms (FF1, FF2) ein gleiches kühles Oxidationsmittel sind, das von der Quelle des Oxidationsmittels (11A, 11B) empfangen wird:

    die Brenner (23A, 23B) den gasförmigen Brennstoff von der Quelle des gasförmigen Brennstoffs (19A, 19B) empfangen; und

    der erste und der zweite kombinierte Strom (CF1, CF2) mit dem gasförmigen Brennstoff am ersten bzw. zweiten Brenner (23A, 23B) verbrannt werden, um Wärme zum Erwärmen der Ladung oder des geschmolzenen Glases zu erzeugen;

    a) wenn der erste und der zweite kühle Reaktant des ersten und des zweiten Zufuhrstroms (FF1, FF2) ein gleicher gasförmiger Brennstoff sind, der von der Quelle des gasförmigen Brennstoffs (19A, 19B) empfangen wird:

    die Brenner (23A, 23B) das Oxidationsmittel von der Quelle des Oxidationsmittels (11A, 11B) empfangen; und

    der erste und der zweite kombinierte Strom (CF1, CF2) mit dem Oxidationsmittel am ersten bzw. zweiten Brenner (23A, 23B) verbrannt werden, um Wärme zum Erwärmen der Ladung oder des geschmolzenen Glases zu erzeugen;

    b) wenn der erste und der zweite kühle Reaktant des ersten und des zweiten Zufuhrstroms (FF1, FF2) ein gleicher gasförmiger Brennstoff sind, der von der Quelle des gasförmigen Brennstoffs (19A, 19B) empfangen wird:

    - die Brenner (23A, 23B) das Oxidationsmittel von der Quelle des Oxidationsmittels (11A, 11B) empfangen; und

    - der erste und der zweite kombinierte Strom (CF1, CF2) mit dem Oxidationsmittel am ersten bzw. zweiten Brenner (23A, 23B) verbrannt werden, um Wärme zum Erwärmen der Ladung oder des geschmolzenen Glases zu erzeugen.


     


    Revendications

    1. Procédé de réduction de surchauffe de composants internes d'un échangeur de chaleur à tubes et calandre à contre-courant utilisant une dérivation partielle variable d'un débit de réactif, ledit procédé comprenant les étapes consistant à :

    diviser un premier débit d'alimentation (FF1) d'un réactif froid avec un premier clapet de commande (CV1) entre un premier débit principal (MF1) du réactif froid et un premier débit de dérivation (BF1) du réactif froid, le premier débit principal (MF1) circulant à travers un échangeur de chaleur à tubes et calandre à contre-courant sur un côté tube de l'échangeur de chaleur ;

    échanger de la chaleur au niveau de l'échangeur de chaleur à tubes et calandre entre le premier débit principal (MF1) et un débit d'un fluide chaud côté calandre et combiner le premier débit principal (MF1) avec le premier débit de dérivation (BF1) pour produire un premier débit combiné (CF1) de réactif chauffé et également un débit de fluide refroidi côté calandre, le premier débit combiné (CF1) sortant de l'échangeur de chaleur au niveau d'une première sortie de réactif (RO1) de l'échangeur de chaleur ;

    mesurer une température du premier débit combiné (CF1) au niveau de ou en aval de la première sortie de réactif (RO1) ;

    commander des proportions relatives du premier débit principal (MF1) et du premier débit de dérivation (BF1), résultant de la division du premier débit d'alimentation (FF1), avec le clapet de commande (CV1) sur la base de la température mesurée du premier débit combiné (CF1), dans lequel une moindre quantité de chaleur est transférée depuis le fluide côté calandre vers le premier débit de dérivation (BF1) que celle transférée depuis le fluide côté calandre vers le premier débit principal (MF1) ;

    diviser un second débit d'alimentation (FF2) d'un réactif froid avec un second clapet de commande (CV2) entre un second débit principal (MF2) du réactif froid et un second débit de dérivation (BF2) du réactif froid, le second débit principal (MF2) circulant à travers un échangeur de chaleur à tubes et calandre sur le côté tube ;

    échanger de la chaleur au niveau de l'échangeur de chaleur à tubes et calandre entre le second débit principal (MF2) et un débit d'un fluide chaud côté calandre et combiner le second débit principal (MF2) avec le second débit de dérivation (BF2) pour produire un second débit combiné (CF2) de réactif chauffé et le débit de fluide refroidi côté calandre, le second débit combiné (CF2) sortant de l'échangeur de chaleur au niveau d'une seconde sortie de réactif (RO2) de l'échangeur de chaleur ;

    mesurer une température du second débit combiné (CF2) au niveau de ou en aval de la seconde sortie de réactif (RO2) ; et

    commander des proportions relatives du second débit principal (MF2) et du second débit de dérivation (BF2), résultant de la division du second débit d'alimentation (FF2), avec le second clapet de commande (CV2) sur la base de la température mesurée du second débit combiné (CF2), dans lequel :

    une moindre quantité de chaleur est transférée depuis le fluide côté calandre vers le second débit de dérivation (BF2) que celle transférée depuis le fluide côté calandre vers le second débit principal (MF2) ; et

    la commande des proportions relatives du premier débit d'alimentation (FF1) dans les premiers débits principal et de dérivation (MF1, BF1) est indépendante de la commande des proportions relatives du second débit d'alimentation (FF2) dans les seconds débits principal et de dérivation (MF2, BF2).


     
    2. Procédé selon la revendication 1, comprenant en outre l'étape consistant à diriger les premier et seconds débits combinés (CF1, CF2) sortant des première et seconde sorties de réactif (RO1, RO2) vers des premier et second brûleurs (23A, 23B) associés de manière fonctionnelle à un four, dans lequel :

    le fluide côté calandre est de l'air ;

    les premier et second réactifs des premier et second débits combinés (CF1, CF2) sont identiques et sont sélectionnés à partir du groupe consistant en de l'oxygène industriellement pur, de l'air enrichi en oxygène, et du gaz naturel ;

    si les premier et second réactifs sont de l'oxygène industriellement pur ou de l'air enrichi en oxygène, les premier et second réactifs des premier et second débits combinés (CF1, CF2) sont brûlés avec du combustible au niveau des premier et second brûleurs (23A, 23B) ;

    si les premier et second réactifs sont du gaz naturel, les premier et second réactifs des premier et second débits combinés (CF1, CF2) sont brûlés avec un oxydant au niveau des premier et second brûleurs (23A, 23B) ; et

    le four est un four de fusion de verre.


     
    3. Procédé selon la revendication 1, dans lequel le réactif est un combustible gazeux ou un oxydant présentant une concentration en oxygène supérieure à celle de l'air, l'oxydant étant de préférence de l'oxygène industriellement pur ou de l'air enrichi en oxygène.
     
    4. Procédé selon la revendication 1 ou 3, dans lequel le fluide côté calandre est de l'air ou un gaz inerte.
     
    5. Procédé selon l'une quelconque des revendications précédentes, dans lequel l'échangeur de chaleur à tubes et calandre inclut :

    un premier plénum d'entrée de dérivation (28) recevant le premier débit de dérivation (BF1), le premier plénum d'entrée de dérivation (28) se terminant dans une direction en aval au niveau d'une première plaque tubulaire (30) ;

    un premier ensemble de tubes de dérivation (33) communiquant fluidiquement avec le premier plénum d'entrée de dérivation (28), s'étendant en aval depuis la première plaque tubulaire (30), et se terminant au niveau d'extrémités en aval ouvertes (34) ;

    un premier plénum d'entrée principal (29) recevant le premier débit principal (MF1), le premier plénum d'entrée principal (29) se terminant dans une direction en aval au niveau d'une seconde plaque tubulaire (31), le premier plénum d'entrée principal (29) entourant le premier ensemble de tubes de dérivation (33) de manière étanche entre les première et seconde plaques tubulaires (30, 31) ; et

    un premier ensemble de tubes principaux (32) dont chacun communique avec le premier plénum d'entrée principal (29), s'étend en aval de la seconde plaque tubulaire (31), et entoure concentriquement un respectif du premier ensemble de tubes de dérivation (33), chacun des tubes principaux (32) dans le premier ensemble de tubes principaux communiquant fluidiquement avec la première sortie de réactif (RO1), au niveau de chaque extrémité en aval ouverte (34) d'un des tubes de dérivation (33) du premier ensemble de tubes de dérivation (33), une portion du premier débit principal (MF1) se combine avec une portion respective du premier débit de dérivation (BF1) pour former une portion du premier débit combiné (CF1) qui circule le long d'une portion en aval restante du tube principal respectif (32) jusqu'à la première sortie de réactif (RO1), un échange de chaleur entre le premier débit de dérivation (BF1) et le fluide chaud côté calandre étant effectué par l'intermédiaire du premier débit principal (MF1) circulant dans des espaces annulaires entre le premier ensemble de tubes principaux (32) et le premier ensemble de tubes de dérivation (33).


     
    6. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel l'échangeur de chaleur à tubes et calandre inclut :

    un premier plénum d'entrée (69) recevant le premier débit de dérivation (BF1), le premier plénum d'entrée (69) étant disposé à l'intérieure de la calandre (35) ;

    un premier plénum de sortie (114, 113) communiquant fluidiquement avec la première sortie de réactif (RO1) ;

    au moins un premier tube de réactif (71) communiquant fluidiquement entre le premier plénum d'entrée (69) et le premier plénum de sortie (114, 113) ; et

    au moins un premier tube de débit principal (68) recevant le premier débit principal (MF1) depuis le premier clapet de commande (CV1), s'étendant dans un intérieur de l'échangeur de chaleur en aval du premier plénum d'entrée (89) et s'étendant en retour pour se terminer au niveau du premier plénum d'entrée (89), dans lequel le premier débit principal (MF1) est combiné avec le premier débit de dérivation (BF1) au niveau du premier plénum d'entrée (69) et le premier débit combiné (CF1) circule à travers l'au moins un premier tube de réactif (71).


     
    7. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel l'échangeur de chaleur inclut :

    des premier, deuxième et troisième plénums (109, 111, 113), le troisième plénum (113) recevant le premier débit combiné (CF1) et communiquant fluidiquement avec la première sortie de réactif (RO1) ;

    au moins un premier tube de réactif en amont (110) recevant le premier débit principal (MF1) et s'étendant à travers un intérieur de la calandre (35) depuis le premier plénum (109) et communiquant fluidiquement avec le deuxième plénum (111) ;

    un premier tube de dérivation (107) recevant le premier débit de dérivation (BF1) et s'étendant entre le premier clapet de commande (CV1) et le deuxième plénum (111) et s'étendant au moins partiellement à l'extérieur de la calandre de l'échangeur de chaleur, dans lequel le premier débit principal (MF1) et le premier débit de dérivation (BF1) sont combinés au niveau du deuxième plénum (111) ; et

    au moins un premier tube de réactif en aval (112) recevant le premier débit combiné (CF1) et s'étendant entre les deuxième et troisième plénums (111, 113).


     
    8. Procédé selon l'une quelconque des revendications précédentes, dans lequel le fluide chaud côté calandre est obtenu depuis un récupérateur ou un régénérateur.
     
    9. Procédé selon la revendication 8, dans lequel le fluide refroidi côté calandre est dirigé vers un récupérateur ou un régénérateur pour chauffer le fluide refroidi côté calandre afin de produire le fluide chaud côté calandre.
     
    10. Procédé selon l'une quelconque des revendications précédentes, dans lequel le fluide côté calandre est de l'air et l'air chaud côté calandre est obtenu par les étapes comprenant :

    le préchauffage de l'air ambiant au niveau d'un pré-échangeur de chaleur par un échange de chaleur avec l'air froid côté calandre pour produire de l'air modérément chaud ; et

    le chauffage de l'air modérément chaud au niveau d'un récupérateur ou d'un régénérateur par un échange de chaleur avec des gaz de four chauds pour produire l'air chaud côté calandre.


     
    11. Système d'échange de chaleur à tubes et calandre à contre-courant pour la réduction d'une surchauffe de composants internes de celui-ci utilisant une dérivation partielle variable d'un débit de réactif, ledit système d'échange de chaleur comprenant :

    un premier clapet de commande (CV1) adapté et configuré pour diviser un premier débit d'alimentation (FF1) de réactif froid en un premier débit principal (MF1) du réactif froid et un premier débit de dérivation (BF1) du réactif froid ;

    un premier conduit d'entrée de débit principal (27, 67, 106) recevant le premier débit principal (MF1) de réactif froid depuis le premier clapet de commande (CV1) ;

    un premier conduit d'entrée de débit de dérivation (26, 66, 107) recevant le premier débit de dérivation (BF1) de réactif froid depuis le premier clapet de commande (CV1) ;

    une calandre (35) présentant une entrée et une sortie de fluide côté calandre (SI, SO) communiquant fluidiquement avec un intérieur de la calandre (35) comprenant un espace d'échange de chaleur ;

    un moyen pour échanger de la chaleur entre le premier débit principal (MF1) et un débit d'un fluide chaud côté calandre dans l'espace d'échange de chaleur ;

    un moyen pour échanger de la chaleur entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre dans l'espace d'échange de chaleur, dans lequel ledit moyen pour échanger de la chaleur entre le premier débit principal (MF1) et le débit du fluide chaud côté calandre est configuré et adapté pour permettre à une plus grande quantité de chaleur d'être échangée entre le premier débit principal (MF1) et le débit de fluide chaud côté calandre que celle échangée entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre par le moyen pour échanger de la chaleur entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre ;

    un moyen pour combiner le premier débit principal (MF1) avec le premier débit de dérivation (BF1) pour produire un premier débit combiné (CF1) de réactif chauffé ;

    au moins un premier tube de réactif en aval (92, 112) recevant le premier débit combiné (CF1) et communiquant fluidiquement avec une première sortie de réactif (RO1) ;

    un premier conduit de sortie communiquant fluidiquement avec la première sortie de réactif (RO1) et recevant le premier débit combiné (CF1) depuis celle-ci ;

    un premier capteur de température (T1) disposé dans le conduit de sortie au niveau de ou en aval de la première sortie de réactif (RO1) ;

    un dispositif de commande de logique programmable (C) adapté et configuré pour commander des proportions relatives du premier débit principal (MF1) et du premier débit de dérivation (BF1) produits par la division du premier débit d'alimentation (FF1) de réactif froid par le premier clapet de commande (CV1), ladite commande étant basée sur une température du premier débit combiné (CF1) détectée par le premier capteur de température (T1), un second clapet de commande (CV2) adapté et configuré pour diviser un second débit d'alimentation (FF2) de réactif froid en un second débit principal (MF2) du réactif froid et un second débit de dérivation (BF2) du réactif froid ;

    un second conduit d'entrée de débit principal (47,87,106) recevant le second débit principal (MF2) de réactif froid depuis le second clapet de commande (CV2) ;

    un second conduit d'entrée de débit de dérivation (46, 46, 107) recevant le second débit de dérivation (BF2) de réactif froid depuis le second clapet de commande (CV2) ;

    un moyen pour échanger de la chaleur entre le second débit principal (MF2) et un débit du fluide chaud côté calandre dans l'espace d'échange de chaleur ;

    un moyen pour échanger de la chaleur entre le second débit de dérivation (BF2) et le débit de fluide chaud côté calandre dans l'espace d'échange de chaleur, dans lequel ledit moyen pour échanger de la chaleur entre le second débit principal (MF2) et le débit du fluide chaud côté calandre est configuré et adapté pour permettre à une plus grande quantité de chaleur d'être échangée entre le second débit principal (MF2) et le débit de fluide chaud côté calandre que celle échangée entre le second débit de dérivation (BF2) et le débit de fluide chaud côté calandre par le moyen pour échanger de la chaleur entre le second débit de dérivation (BF2) et le débit de fluide chaud côté calandre ;

    un moyen pour combiner le second débit principal (MF2) avec le second débit de dérivation (BF2) pour produire un second débit combiné (CF2) de réactif chauffé ;

    au moins un second tube de réactif en aval (92, 112) recevant le second débit combiné (CF2) et communiquant fluidiquement avec une seconde sortie de réactif (RO2) ;

    un second conduit de sortie communiquant fluidiquement avec la seconde sortie de réactif (RO2) et recevant le second débit combiné (CF2) depuis celle-ci ;

    un second capteur de température (T2) disposé dans le second conduit de sortie au niveau de ou en aval de la seconde sortie de réactif (RO2), dans lequel le dispositif de commande de logique programmable (C) est adapté et configuré pour commander des proportions relatives du second débit principal (MF2) et du second débit de dérivation (BF2) produits par la division du second débit d'alimentation (FF2) de réactif froid par le second clapet de commande (CV2) sur la base d'une température du second débit combiné (CF2) détectée par le second capteur de température (T2).


     
    12. Système d'échange de chaleur selon la revendication 11, dans lequel :

    a) le moyen pour échanger de la chaleur entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre dans l'espace d'échange de chaleur comprend :

    1) un premier plénum d'entrée de dérivation (28) recevant le premier débit de dérivation (BF1), le premier plénum d'entrée de dérivation (28) se terminant dans une direction en aval au niveau d'une première plaque tubulaire (30) ;

    2) un premier ensemble de tubes de dérivation (33) communiquant fluidiquement avec le premier plénum d'entrée de dérivation (28), s'étendant en aval depuis la première plaque tubulaire (30), et se terminant au niveau d'extrémités en aval ouvertes (34) ; et

    b) le moyen pour échanger de la chaleur entre le premier débit principal (MF1) et un débit d'un fluide chaud côté calandre dans l'espace d'échange de chaleur comprend :

    1) un premier plénum d'entrée principal (29) recevant le premier débit principal (MF1) et qui se termine dans une direction en aval au niveau d'une seconde plaque tubulaire (31),

    2) un premier ensemble de tubes principaux (32) dont chacun communique avec le premier plénum d'entrée principal (29), entoure concentriquement un respectif du premier ensemble de tubes de dérivation (33), et s'étend en aval de la seconde plaque tubulaire (31) au-delà des extrémités en aval ouvertes (34) du premier ensemble de tubes de dérivation (33) ;

    c) le premier plénum d'entrée principal (29) entoure le premier ensemble de tubes de dérivation (33) de manière étanche entre les première et seconde plaques tubulaires (30, 31) ;

    d) chacun des tubes principaux (32) dans le premier ensemble de tubes principaux (32) communique fluidiquement avec la première sortie de réactif (RO1) ; et

    e) le moyen pour combiner le premier débit principal (MF1) avec le premier débit de dérivation (BF1) pour produire un premier débit combiné (CF1) de réactif chauffé comprend des portions des tubes principaux (32) du premier ensemble de tubes principaux (32) où le premier débit de dérivation (BF1) sort des extrémités en aval ouvertes (34) et se combine avec le premier débit principal (MF1) circulant dans des espaces annulaires entre le premier ensemble de tubes principaux (32) et le premier ensemble de tubes de dérivation (33) ; et

    f) des portions restantes du premier ensemble de tubes principaux (32) en aval des extrémités ouvertes permettent un échange de chaleur entre le premier débit combiné (CF1) et le fluide chaud côté calandre.


     
    13. Système d'échange de chaleur selon la revendication 11, dans lequel :

    a) le moyen pour échanger de la chaleur entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre dans l'espace d'échange de chaleur comprend un premier conduit d'entrée (66) recevant le premier débit de dérivation (BF1) depuis I premier clapet de commande (CV1), le premier conduit d'entrée (66) s'étendant dans l'intérieur de l'échangeur de chaleur ;

    b) le moyen pour combiner le premier débit principal (MF1) avec le premier débit de dérivation (BF1) pour produire un premier débit combiné (CF1) de réactif chauffé comprend un premier plénum d'entrée (69) communiquant fluidiquement avec le premier conduit d'entrée (66) ; et

    c) le moyen pour échanger de la chaleur entre le premier débit principal (MF1) et un débit d'un fluide chaud côté calandre dans l'espace d'échange de chaleur comprend au moins un premier tube de débit principal (68) communiquant fluidiquement entre le premier clapet de commande (CV1) et le premier plénum d'entrée (69) qui s'étend dans un intérieur de l'échangeur de chaleur en aval du premier plénum d'entrée (69) et s'étend en retour pour se terminer au niveau du premier plénum d'entrée (69) ;

    d) l'échangeur de chaleur comprend en outre un premier plénum de sortie (114) communiquant fluidiquement avec la première sortie de réactif (RO1) ; et

    e) l'échangeur de chaleur comprend en outre au moins un premier tube de réactif (71) communiquant fluidiquement entre le premier plénum d'entrée (69) et la première sortie de réactif (RO1) qui permet au premier débit combiné (CF1) d'échanger de la chaleur avec le fluide chaud côté calandre.


     
    14. Système d'échange de chaleur selon la revendication 11, dans lequel :

    a) le moyen pour échanger de la chaleur entre le premier débit principal (MF1) et un débit d'un fluide chaud côté calandre dans l'espace d'échange de chaleur comprend un premier plénum (109) recevant le premier débit principal (MF1) depuis le premier clapet de commande (CV1) et au moins un premier tube de réactif en amont (110) s'étendant à l'intérieur de la calandre (35) et recevant le premier débit principal (MF1) depuis le premier plénum (109) ;

    b) le moyen pour échanger de la chaleur entre le premier débit de dérivation (BF1) et le débit de fluide chaud côté calandre dans l'espace d'échange de chaleur comprend un premier tube de dérivation (107) recevant le premier débit de dérivation (BF1) depuis le premier clapet de commande (CV1) et s'étendant au moins partiellement à l'extérieur de la calandre (35) de l'échangeur de chaleur ;

    c) le moyen pour combiner le premier débit principal (MF1) avec le premier débit de dérivation (BF1) pour produire un premier débit combiné (CF1) de réactif chauffé comprend un deuxième plénum (111) qui reçoit le premier débit principal (MF1) en aval de l'au moins un premier tube de réactif en amont (110) et le premier débit de dérivation (BF1) depuis le premier tube de dérivation (107) ; et

    d) l'échangeur de chaleur comprend en outre au moins un premier tube de réactif en aval (112) et un troisième plénum (113) qui communique fluidiquement avec la première sortie de réactif (RO1), l'au moins un premier tube de réactif en aval (112) recevant le premier débit combiné (CF1) et s'étendant à l'intérieur de la calandre (35) entre les deuxième et troisième plénums (109, 111) pour permettre un échange de chaleur entre le premier débit combiné (CF1) et le fluide chaud côté calandre.


     
    15. Système d'échange de chaleur selon l'une quelconque des revendications 11 à 14, comprenant en outre un récupérateur ou un régénérateur (5) présentant une sortie (6) en communication fluidique avec l'entrée de calandre (SI), le récupérateur ou le régénérateur (4) étant adapté et configuré pour permettre au fluide côté calandre d'être chauffé et transporté vers l'espace d'échange de chaleur par l'intermédiaire de l'entrée de calandre (SI).
     
    16. Système d'échange de chaleur selon la revendication 15, dans lequel le récupérateur ou le régénérateur (5) inclut une entrée (4) en communication fluidique avec la sortie de calandre (SO), le récupérateur ou le régénérateur (5) recevant du fluide refroidi côté calandre depuis la sortie de calandre (SO) et chauffant le fluide refroidi côté calandre pour produire le fluide chaud côté calandre.
     
    17. Four à verre utilisant un réactif ou des réactifs préchauffé(s), comprenant des premier et second brûleurs (23A, 23B) disposés sur une paroi (22) d'un four entourant un espace de combustion adapté et configuré pour contenir une charge de fabrication de verre ou du verre fondu, une source de combustible gazeux (19A, 19B), une source d'oxydant (11A, 11B) sélectionné à partir du groupe constitué par de l'oxygène industriellement pur et de l'air enrichi en oxygène, un récupérateur ou un régénérateur (5) présentant une sortie (6), et le système d'échange de chaleur selon la revendication 11, dans lequel :

    le premier clapet de commande (CV1) reçoit le premier débit d'alimentation (FF1) de réactif froid depuis la source d'oxydant (11A) ;

    le second clapet de commande (CV2) reçoit le second débit d'alimentation (FF2) de réactif froid depuis la source d'oxydant (11B) ; et

    le fluide chaud côté calandre est de l'air reçu depuis la sortie (6) du récupérateur ou du régénérateur (5) ;

    selon lequel :
    si les premier et second réactifs froids des premier et second débits d'alimentation (FF1, FF2) sont un même oxydant froid reçu depuis ladite source d'oxydant (11A, 11B) :

    les brûleurs (23A, 23B) reçoivent le combustible gazeux depuis ladite source de combustible gazeux (19A, 19B) ; et

    les premier et second débits combinés (CF1, CF2) sont brûlés avec le combustible gazeux au niveau des premier et second brûleurs (23A, 23B), respectivement pour produire de la chaleur pour chauffer la charge ou le verre fondu ;

    a) si les premier et second réactifs froids des premier et second débits d'alimentation (FF1, FF2) sont un même combustible gazeux reçu depuis ladite source de combustible gazeux (19A, 19B) ;

    les brûleurs (23A, 23B) reçoivent l'oxydant depuis ladite source d'oxydant (11A, 11B) ; et

    les premier et second débits combinés (CF1, CF2) sont brûlés avec l'oxydant au niveau des premier et second brûleurs (23A, 23B), respectivement pour produire de la chaleur pour chauffer la charge ou le verre fondu ;

    b) si les premier et second réactifs froids des premier et second débits d'alimentation (FF1, FF2) sont un même combustible gazeux reçu depuis ladite source de combustible gazeux (19A, 19B) :

    - les brûleurs (23A, 23B) reçoivent l'oxydant depuis ladite source d'oxydant (11A, 11B) ; et

    - les premier et second débits combinés (CF1, CF2) sont brûlés avec l'oxydant au niveau des premier et second brûleurs (23A, 23B), respectivement pour produire de la chaleur pour chauffer la charge ou le verre fondu.


     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description