[0001] The present invention relates to a boiler for generating hot water or steam.
[0002] Boilers in general, and steam generators in particular, are known which comprise
a substantially cylindrical outer enclosure, which defines a heating chamber that
contains water that, in steam generators, is heated at least until it reaches its
vaporization temperature.
[0003] In particular, a furnace body is axially accommodated inside the heating chamber
and is in a position to exchange heat with the water to be heated and defines, internally,
a combustion chamber, inside which the flame bursts, produced by the combustion head
of a burner, located at one end of the combustion chamber and, usually, associated
with a door to close the boiler. Patents
EP0775869 A2 and
DE1906652A1 disclose a burner according to the preamble of claim 9. Boiler are disclosed in patent
FR2594941.
[0004] The hot combustion gases generated in the combustion chamber are channeled into heat
exchange tubes that axially pass through the heating chamber, so that the hot exhaust
gases can exchange heat with the water contained in the heating chamber, until they
lead out into an exhaust gas chamber, from which the exhaust gases exit by way of
a flue.
[0005] Typically, steam generators of this type are provided with burners that use a non-premixed
laminar flame.
[0006] "Premix" burners also exist which operate with gaseous fuels, and they have, upstream
of the combustion head, a device for mixing air and gas which is constituted by a
Venturi tube provided with an axial inlet connected to an air supply duct, a lateral
inlet connected to a gas supply duct and controlled by an adjustable gas inflow valve,
and an axial outlet, which is arranged at the opposite end of the Venturi tube with
respect to its axial inlet and connected to the combustion head by way of the interposition
of a fan, which makes it possible to continue the mixing of air and gas which is done
inside the Venturi tube and to send the air/gas mixture under pressure to the combustion
head.
[0007] Owing to such structure, traditional premix burners are known as "press" burners,
since, by way of their fan, they increase the pressure in the combustion chamber with
respect to the ambient pressure, and as a consequence steam generators made in this
way are called, in the jargon, "pressurized".
[0008] The steam generators described above have some drawbacks.
[0009] In the event of obstructions in the flue, serious problems can occur owing to a buildup
of unburned material in the furnace in the ignition phase.
[0010] Furthermore, with the steam generators described, flame backflows are possible toward
the external environment, or smoke leaks through the gaskets arranged in the door
and in the fume collection chamber.
[0011] Another drawback of pressurized steam generators is constituted by the risk of propagation
of a pressure wave, which translates to a sound wave, toward the external environment
during the ignition phases.
[0012] A further drawback of pressurized steam generators is the high space occupation at
the door owing to the presence of the premix burner and, more specifically, of its
fan and of its Venturi tube.
[0013] The aim of the present invention is to provide a boiler for generating hot water
or steam that is capable of overcoming the drawbacks of the known art indicated above,
while at the same time ensuring a high yield and extremely low pollutant emissions,
constituted by carbon monoxide and nitrogen oxides, by virtue of a better combustion
of the gas.
[0014] Within this aim, an object of the present invention is to provide a boiler for generating
hot water or steam that has a combustion system that is capable of preventing a buildup
of unburned material in the event of an increase in resistance in the flue.
[0015] Another object of the present invention is to provide a boiler for generating hot
water or steam that is not affected by problems whereby exhaust gases exit toward
the external environment.
[0016] Another object of the present invention is to provide a boiler for generating hot
water or steam that sends a considerable decrease of NOx to the flue.
[0017] Another object of the present invention is to provide a boiler for generating hot
water or steam, in which there is no damaging propagation of pressure waves, which
are the cause of noise both in the ignition phase and during normal operation.
[0018] Another object of the present invention is to provide a boiler for generating hot
water or steam that has smaller encumbrances at the door with respect to the known
art.
[0019] Another object of the present invention is to provide a boiler for generating hot
water or steam which, in addition to offering the widest guarantees of reliability
and safety in operation, is of very simple construction so as to also be competitive
from a purely economic viewpoint.
[0020] This aim and these and other objects which will become better apparent hereinafter
are achieved by a boiler for generating hot water or steam, according to the invention,
as defined in claim 1.
[0021] Further characteristics and advantages of the invention will become better apparent
from the description of some preferred, but not exclusive, embodiments of the boiler
for generating hot water or steam, according to the invention, which are illustrated,
by way of non-limiting example, in the accompanying drawings wherein:
Figure 1 is a schematic longitudinal cross-sectional view of the boiler for generating
hot water or steam according to the invention;
Figure 2 is a schematic longitudinal cross-sectional view of a device for premixing
air and gas present in the boiler for generating hot water or steam according to the
invention;
Figure 3 is a schematic view of a portion of the boiler for generating hot water or
steam according to the invention, in a possible embodiment.
[0022] With reference to the figures, the boiler for generating hot water or steam, according
to the invention, generally designated with the reference numeral 1, comprises a substantially
cylindrical containment enclosure 2, which defines a heating chamber 3, which is intended
to contain water to be heated to the desired temperatures.
[0023] It should be noted that, in the examples shown in the figures, the water contained
inside the heating chamber 3 is intended to be heated at least up to its vaporization
temperature, in order to allow the production of steam, but more generally, the boiler
according to the invention can also be used for the production of hot water.
[0024] Conveniently, in the upper part of the containment enclosure 2 there is an outlet
4, through which the steam produced exits from the heating chamber 3, as in the example
shown in Figure 1, or optionally the hot water produced.
[0025] As illustrated, the heating chamber 3 axially accommodates a furnace 5, which defines,
internally, a combustion chamber 6 in which the flame produced by a burner 7 is burned.
[0026] In particular, the burner 7 has a combustion head 8, which is accommodated in the
combustion chamber 6 and is designed to emit the flame into the combustion chamber
6, and a device 9 for premixing air and gas which is connected to the combustion head
8, in order to supply it with a mixture of air and gas.
[0027] Conveniently, the combustion head 8 is inserted in a door 10 that closes an axial
end of the combustion chamber 6.
[0028] The combustion chamber 6 is, in turn, connected to a plurality of heat exchange tubes
11 which are designed to be passed through by the hot combustion gases generated by
the flame emitted by the combustion head 8.
[0029] In particular, the heat exchange tubes 11 pass through the combustion chamber 6 longitudinally,
so as to enable the heating of the water contained in it, and lead out into a fume
collection chamber 12, which is connected to a flue, through which the combustion
gases are evacuated outside.
[0030] It should be noted that the combustion chamber 6, at the opposite end with respect
to the combustion head 8, is, conveniently, closed by a bottom wall 14 of the furnace
5 which enables the combustion gases to be returned toward the combustion head 8 and
the door 10.
[0031] In particular, at the door 10 there is, advantageously, a chamber 15 for redirecting
the exhaust gases which makes it possible to channel the combustion gases originating
from the bottom wall 14 of the furnace 5 into the heat exchange tubes 11.
[0032] According to the invention, the premixing device 9 comprises an air supply duct 17,
connected with the outside environment and connected to the combustion head 8, inside
which a mixer body 16 is axially accommodated, which is struck by the flow of air
that flows inside the supply duct 17.
[0033] In particular, such mixer body 16 has, on its front side directed against the stream
of air that arrives from the supply duct 17, a contoured portion 16a that is adapted
to create, between the internal side walls of the supply duct 17 and the lateral surface
of the mixer body 16, an intake region 18 that has a transverse air passage cross-section
that is narrower than the air passage cross-section defined by the supply duct 17
upstream of the mixer body 16, along the direction of the air stream in the mixer
body 17.
[0034] In the mixer body 16, substantially at the intake region 18, at least one gas delivery
opening 19 is defined, which is connected to a feed channel 20, which is defined,
at least partially, inside the mixer body 16 and connected to a fuel gas source.
[0035] Also according to the invention, means are provided that are adapted to create a
lower pressure in the combustion chamber 6 with respect to the external ambient pressure,
and which comprise, advantageously, at least one fan 21, controlled by a corresponding
electric motor 22, which is accommodated in the exhaust gas collection chamber 12
and has, in particular, an intake connected to the exhaust gas collection chamber
12 and a delivery connected to the flue 13.
[0036] With reference in particular to Figure 2, the contoured portion 16a of the mixer
body 16 has, conveniently, a lateral surface that progressively approaches the internal
side walls of the supply duct 17, proceeding in the direction of the air stream that
flows inside the supply duct 17.
[0037] More specifically, the contoured portion 16a of the mixer body 16 is, advantageously,
substantially ogive-shaped.
[0038] As can also be seen in Figure 2, the mixer body 16 is, advantageously, provided with
a plurality of gas delivery openings 19, which are distributed about an axis of extension
16b of the mixer body 16 that is substantially parallel to the axis of the supply
duct 17.
[0039] Conveniently, the gas delivery openings 19 defined in the mixer body 16 are open
toward the rear side of the mixer body proper.
[0040] Advantageously, the feed channel 20 also extends in the rear portion of the mixer
body 16, and is connected, conveniently, to the gas source by way of a delivery duct
23, which extends, with one of its portions, outside the supply duct 17 and is controlled,
advantageously, by a valve 24, preferably controlled pneumatically.
[0041] Preferably, the contoured portion 16a of the mixer body 16 is internally hollow and
the delivery openings 19 can be, advantageously, defined between a section of the
contoured portion 16a directed toward the rear side of the mixer body 16 and a portion
of wall of the mixer body 16 that merges from the rear into the contoured portion
16a and in which a section of the feed channel 20 is internally defined, which leads
into the cavity of the contoured portion 16a, from which the gas is deviated toward
the delivery openings 19.
[0042] Conveniently, as better shown in Figure 3, the combustion head 8 is of the type with
an internal flame.
[0043] More specifically, the combustion head 8 is cylindrical and hollow with a cylindrical
side wall 8a and an end wall 8b which are provided, on their surface directed inward,
with a plurality of flame-emitting nozzles.
[0044] Also with reference to Figure 3, advantageously, along the supply duct 17, in a position
interposed between the mixer body 16 and the combustion head 8, there can be one-way
valve means 25 the function of which is to contrast the transmission of pressure waves
from the combustion chamber 6 toward the supply duct 17, which could disturb the pressure
values in the intake region 18 and, therefore, the regular flow of gas through the
delivery openings 19 of the mixer body 16.
[0045] In particular, such valve means comprise a flap check valve that has, conveniently,
a flow control body 26 eccentrically pivoted about a pin 27, so as to considerably
increase the moment of inertia of the flow control body 26 with respect to its rotation
axis, but creating only minimal resistance upon opening.
[0046] More specifically, the flow control element 26 has, proximate to the pin 27, a counterweight
26a that enables the flow control element 26 to oppose a considerable mechanical inertia
at the moment of being switched on, while keeping the flow control element perfectly
balanced.
[0047] There is, furthermore, an abutment element 32, integral with the supply duct 17,
against which the flow control element 26 can rest in the closed condition.
[0048] It should be noted that the flow control element 26 is opened by virtue of the flow
of air and gas that is returned toward the combustion chamber 6 and the combustion
head 8 and which, in passing, is capable of generating a lift effect that makes it
possible to keep the flow control element 26 open.
[0049] Conveniently, in order to enable the flow control element 26 to be able to positively
take advantage of such lift effect, optionally the flow control element 26 can also
have a wing profile shape, for example of the NACA type.
[0050] Advantageously, in the exhaust gas collection chamber 16 there is an exhaust gas
heat exchanger 28 which is struck externally by the exhaust gases channeled toward
the flue 13 and is connected internally in input with the water mains, by way of a
pump 29, and in output to a water supply line 30 to the heating chamber 3, so as to
enable the recovery of any residual heat in the exhaust gases by way of preheating
the water that is sent to the heating chamber 3.
[0051] Conveniently, in the exhaust gas collection chamber 12 there can also be a bulkhead
29 that makes it possible to channel the exhaust gases coming from the heat exchange
tubes 11 toward the flue 13, forcing them to strike the condensing device 26.
[0052] Advantageously, as shown in Figure 1, the premixing device 9 can be accommodated
within a housing 31, integral with the door 10 and having at least one access for
air and for the gas source.
[0053] Operation of the boiler according to the invention is the following.
[0054] The heating chamber 3 is supplied with water by way of the supply line 30.
[0055] Once the fan 21 is activated, a lower pressure is created in the combustion chamber
6 which makes it possible to suck air into the supply duct 17 from the external environment.
[0056] The flow of air that flows in the supply duct 17 undergoes an increase in speed and
a consequent decrease in pressure, by the Venturi effect, at the intake region 18
created by the presence of the mixer body 16.
[0057] Such decrease in pressure causes the valve 24 to open with consequent inflow of the
gas into the delivery duct 23 and emission of the same gas from the delivery openings
19 of the mixer body 16, so that it can mix with the flow of air originating from
the supply duct 17.
[0058] The gas mixture thus obtained fuels the combustion head 8 which is then ignited so
as to generate a flame inside the combustion chamber 6.
[0059] Any pressure waves that may be generated during ignition of the combustion head 8
and which could disturb the regular flow of air and gas are obstructed by the one-way
valve means 25. In particular, the flow control element 26 opposes, at the moment
of ignition, a considerable mechanical inertia to the pressure wave that is propagated
by the furnace 5 in the opposite direction to the flow of air and gas that feeds the
combustion head 8.
[0060] With the combustion head 8 ignited, the hot combustion gases, once they have reached
the bottom wall 14 of the furnace 5, are redirected toward the door 10 where they
are channeled into the heat exchange tubes 11, so as to heat the water contained in
the heating chamber 3.
[0061] Once they have passed through the heat exchange tubes 11, the combustion gases reach
the exhaust gas collection chamber 12 where they are channeled toward the flue 13,
which they reach after having passed through the exhaust gas heat exchanger 28.
[0062] The steam or hot water produced inside the heating chamber 3 exits through the outlet
4.
[0063] The heating chamber 3 is resupplied with water by the supply line 30 which receives
preheated water from the heat exchanger 28.
[0064] In practice it has been found that the invention is capable of fully achieving the
set aim.
[0065] It must be pointed out in particular that, with the boiler for generating hot water
or steam according to the invention, it is not possible to have backflows of flame
toward the external environment, or leaks of exhaust gases through the gaskets arranged
in the door and in the exhaust gas collection chamber, since the combustion chamber
and the exhaust gas collection chamber are kept at low pressure.
[0066] Furthermore, given that the suction fan remains inside the exhaust gas collection
chamber, any resistance of the flue is interpreted by the system as a loss of performance
of the fan with consequent automatic decrease of the flame power, thus giving the
combustion system a characteristic self-regulating operation that does not modify
the combustion parameters in any way but only the power burned.
[0067] Another advantage of the boiler according to the invention consists since the premixing
device provided with a mixer body inserted in the air supply duct makes it possible
to take advantage of the principle of the Venturi effect, i.e. of the decrease in
the pressure owing to an increase in the speed of the air, like conventional burners
that premix air and gas, but making it possible at the same time to obtain a closer
air/gas mixing with consequent advantages for the reduction of NOx and an obstacle
to the propagation of the pressure wave toward the external environment during the
ignition phases, also facilitated by the presence of the one-way valve means.
[0068] Another advantage is constituted by the fact that the boiler according to the invention
has an extremely reduced space occupation in front of the door, since the premixing
device and the gas valve can be installed in the door, while the suction fan, which
is decidedly more cumbersome, is located inside the exhaust gas collection chamber
of the boiler proper.
[0069] All the characteristics of the invention, indicated above as advantageous, convenient
or similar, may also be missing or be substituted by equivalent characteristics.
[0070] The individual characteristics set out in reference to general teachings or to specific
embodiments may all be present in other embodiments or may substitute characteristics
in such embodiments.
[0071] The invention, thus conceived, is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims.
[0072] Thus, for example, with the same concept, one can provide not only steam generators
and boilers for the production of steam in general, but also boilers for hot water,
traditional or condensation, industrial boilers using superheated water or diathermic
oil and so on.
[0073] In practice the materials employed, provided they are compatible with the specific
use, and the dimensions and shapes, may be any according to requirements.
[0074] Moreover, all the details may be substituted by other, technically equivalent elements.
[0075] Where the technical features mentioned in any claim are followed by reference numerals
and/or signs, those reference numerals and/or signs have been included for the sole
purpose of increasing the intelligibility of the claims and accordingly, such reference
numerals and/or signs do not have any limiting effect on the interpretation of each
element identified by way of example by such reference numerals and/or signs.
1. A boiler for generating hot water or steam, comprising a substantially cylindrical
containment enclosure (2), which defines a heating chamber (3) intended to contain
water to be heated and accommodates axially a furnace (5), which defines internally
a combustion chamber (6) with a burner (7) associated therewith which has a combustion
head (8) accommodated in said combustion chamber (6), and a device (9) for premixing
air and gas which is connected to said combustion head (8), said combustion chamber
(6) being connected to a plurality of heat exchange tubes (11), which are intended
to be passed through by the hot combustion gases generated by the flame emitted by
said combustion head (8) and which longitudinally pass through said heating chamber
(3), said heat exchange tubes (11) leading into an exhaust gas collection chamber
(12) which is connected to a flue (13),
wherein said premixing device (9) comprises a mixer body (16) accommodated axially
in an air supply duct (17) connected to said combustion head (8), said mixer body
(16) having, on its front side, directed against the stream of air that arrives from
said supply duct, a contoured portion (16a) that is adapted to create, between the
internal side walls of said supply duct (17) and the lateral surface of said mixer
body (16), an intake region (18) that has a transverse air passage cross-section that
is narrower than the air passage cross-section defined by said supply duct (17) upstream
of said mixer body (16), along the direction of the air stream, in said mixer body
(16) there being defined, substantially at said intake region (18), at least one gas
delivery opening (19), which is connected to a feed channel (20), which is defined
at least partially inside said mixer body (16) and is connected to a gas source, means
being provided which are adapted to create a lower pressure in said combustion chamber
(6) with respect to the external ambient pressure,
characterized in that said delivery openings (19) are directed toward the rear side of said mixer body
(16).
2. The boiler according to claim 1, characterized in that said means adapted to create a lower pressure in said combustion chamber (6) comprise
at least one fan (21) accommodated in said exhaust gas collection chamber (12) and
having an intake connected to said exhaust gas collection chamber (12) and a delivery
connected to said flue (13).
3. The boiler according to one or more of the preceding claims, characterized in that said contoured portion (16a) of said mixer body (16) has a lateral surface that progressively
approaches the internal side walls of said supply duct (17), proceeding along the
direction of the air stream in said supply duct (17).
4. The boiler according to one or more of the preceding claims, characterized in that said contoured portion (16) of said mixer body (16) is substantially ogive-shaped.
5. The boiler according to one or more of the preceding claims, characterized in that said mixer body (16) has a plurality of gas delivery openings (19) which are distributed
around an axis of extension (16b) of said mixer body (16) that is substantially parallel
to the axis of said supply duct (17).
6. The boiler according to one or more of the preceding claims, characterized in that said combustion head (8) is of the type with an internal flame.
7. The boiler according to one or more of the preceding claims, characterized in that it comprises, along said supply duct (17), between said mixer body (16) and said
combustion head (8), one-way valve means (25) adapted to contrast the transmission
of pressure waves from said combustion chamber (6) toward said supply duct (17).
8. The boiler according to the preceding claim, characterized in that said valve means (25) comprise a flap check valve.
9. A burner comprising a combustion head (8) and provided with a premixing device (9)
that comprises a mixer body (16) accommodated axially in an air supply duct (17) connected
to said combustion head (8), wherein said mixer body (16) has, on its front side,
directed against the stream of air that arrives from said supply duct, a contoured
portion (16a) that is adapted to create, between the internal side walls of said supply
duct (17) and the lateral surface of said mixer body (16), an intake region (18) that
has a transverse air passage cross-section that is narrower than the air passage cross-section
defined by said supply duct (17) upstream of said mixer body (16), along the direction
of the air stream, in said mixer body (16) there being defined, substantially at said
intake region (18), at least one gas delivery opening (19), which is connected to
a feed channel (20), which is defined at least partially inside said mixer body (16)
and is connected to a gas source,
characterized in that said delivery openings (19) are directed toward the rear side of said mixer body
(16).
10. The burner according to claim 9, characterized in that said contoured portion (16a) of said mixer body (16) has a lateral surface that progressively
approaches the internal side walls of said supply duct (17), proceeding along the
direction of the air stream in said supply duct (17).
11. The burner according to claim 10 or 11, characterized in that said contoured portion (16a) of said mixer body (16) is substantially ogive-shaped.
12. The burner according to one or more of claims 9 to 11, characterized in that said mixer body (16) has a plurality of gas delivery openings (19) which are distributed
around an axis of extension (16b) of said mixer body (16) that is substantially parallel
to the axis of said supply duct (17).
13. The burner according to one or more of claims 9 to 12, characterized in that said combustion head (8) is of the type with an internal flame.
1. Ein Kessel zur Bereitung von Heißwasser oder Dampf, der ein im Wesentlichen zylindrisches
Gehäuse (2) umfasst, welches eine Heizkammer (3) bestimmt, die dazu dient, zu erhitzendes
Wasser aufzunehmen, und axial einen Ofen (5) enthält, der innen eine Verbrennungskammer
(6) mit einem damit verbundenen Brenner (7) bestimmt, der einen in der Verbrennungskammer
(6) untergebrachten Brennkopf (8) hat, und eine Vorrichtung (9) zum Vormischen von
Luft und Gas, die mit dem Brennkopf (8) verbunden ist; wobei die Verbrennungskammer
(6) mit einer Vielzahl von Wärmetauschrohren (11) verbunden ist, die dazu dienen,
von den heißen Verbrennungsgasen durchströmt zu werden, die von der von dem Brennkopf
(8) ausgestoßenen Flamme erzeugt werden, und die in Längsrichtung durch die Heizkammer
(3) verlaufen; wobei die Wärmetauschrohre (11) in einen Abgas-Sammelraum (12) führen,
der mit einem Abzug (13) verbunden ist;
wobei die Vormischvorrichtung (9) einen Mischerkörper (16) umfasst, der axial in einer
Luftzuführleitung (17) untergebracht ist, welche mit dem Brennkopf (8) verbunden ist;
wobei der Mischerkörper (16) an seiner Vorderseite, gegen den Luftstrom gerichtet,
der von der Zuführleitung kommt, einen konturierten Abschnitt (16a) hat, der ausgebildet
ist, um zwischen den inneren Seitenwänden der Zuführleitung (17) und der seitlichen
Oberfläche des Mischerkörpers (16) einen Einlassbereich (18) zu erzeugen, der einen
Luftdurchlass-Querschnitt hat, welcher schmaler ist als der Luftdurchlass-Querschnitt,
der von der Zuführleitung (17) stromaufwärts von dem Mischerkörper (16) bestimmt ist;
wobei entlang der Richtung des Luftstroms in dem Mischerkörper (16) im Wesentlichen
an dem Einlassbereich (18) mindestens eine Gasabgabeöffnung (19) bestimmt ist, die
mit einem Zufuhrkanal (20) verbunden ist, welcher zumindest teilweise innerhalb des
Mischerkörpers (16) bestimmt und mit einer Gasquelle verbunden ist; wobei Mittel bereitgestellt
sind, die ausgebildet sind, um einen Unterdruck in der Verbrennungskammer (6) mit
Bezug auf den äußeren Umgebungsdruck zu erzeugen,
dadurch gekennzeichnet, dass die Abgabeöffnungen (19) der Rückseite des Mischerkörpers (16) zugewandt sind.
2. Der Kessel gemäß Anspruch 1, dadurch gekennzeichnet, dass die Mittel, die ausgebildet sind, um einen Unterdruck in der Verbrennungskammer (6)
zu erzeugen, mindestens einen Ventilator (21) umfassen, der in dem Abgas-Sammelraum
(12) untergebracht ist und einen Einlass hat, der mit dem Abgas-Sammelraum (12) verbunden
ist, und einen Auslass, der mit dem Abzug (13) verbunden ist.
3. Der Kessel gemäß einem oder mehreren der obigen Ansprüche, dadurch gekennzeichnet, dass der konturierte Abschnitt (16a) des Mischerkörpers (16) eine seitliche Oberfläche
hat, die sich in Richtung des Luftstroms in der Zuführleitung (17) zunehmend den inneren
Seitenwänden der Zuführleitung (17) annähert.
4. Der Kessel gemäß einem oder mehreren der obigen Ansprüche, dadurch gekennzeichnet, dass der konturierte Abschnitt (16a des Mischerkörpers (16) im Wesentlichen spitzkegelförmig
ist.
5. Der Kessel gemäß einem oder mehreren der obigen Ansprüche, dadurch gekennzeichnet, dass der Mischerkörper (16) eine Vielzahl von Gasabgabeöffnungen (19) hat, die um eine
Erstreckungsachse (16b) des Mischerkörpers (16) verteilt sind, die im Wesentlichen
parallel zur Achse der Zuführleitung (17) ist.
6. Der Kessel gemäß einem oder mehreren der obigen Ansprüche, dadurch gekennzeichnet, dass der Brennkopf (8) vom Typ mit innerer Flamme ist.
7. Der Kessel gemäß einem oder mehreren der obigen Ansprüche, dadurch gekennzeichnet, dass er entlang der Zuführleitung (17), zwischen dem Mischerkörper (16) und dem Brennkopf
(8), Einwegventilmittel (25) umfasst, ausgebildet, um die Übertragung von Druckwellen
von der Verbrennungskammer (6) zu der Zuführleitung (17) zu hemmen.
8. Der Kessel gemäß dem obigen Anspruch, dadurch gekennzeichnet, dass die Ventilmittel (25) ein Klappen-Rückschlagventil umfassen.
9. Ein Brenner, der einen Brennkopf (8) umfasst und mit einer Vormischvorrichtung (9)
ausgestattet ist, die einen Mischerkörper (16) umfasst, welcher axial in einer mit
dem Brennkopf (8) verbundenen Luftzuführleitung (17) angeordnet ist; wobei der Mischerkörper
(16) an seiner Vorderseite, die gegen den von der Zuführleitung kommenden Luftstrom
gerichtet ist, einen konturierten Abschnitt (16a) hat, der ausgebildet ist, um zwischen
den inneren Seitenwänden der Zuführleitung (17) und der seitlichen Oberfläche des
Mischerkörpers (16) einen Einlassbereich (18) zu erzeugen, der einen Luftdurchlass-Querschnitt
hat, welcher schmaler ist als der Luftdurchlass-Querschnitt, der von der Zuführleitung
(17) stromaufwärts von dem Mischerkörper (16) bestimmt ist; wobei entlang der Richtung
des Luftstroms in dem Mischerkörper (16) im Wesentlichen an dem Einlassbereich (18)
mindestens eine Gasabgabeöffnung (19) bestimmt ist, die mit einem Zufuhrkanal (20)
verbunden ist, welcher zumindest teilweise innerhalb des Mischerkörpers (16) bestimmt
und mit einer Gasquelle verbunden ist;
dadurch gekennzeichnet, dass die Abgabeöffnungen (19) der Rückseite des Mischerkörpers (16) zugewandt sind.
10. Der Brenner gemäß Anspruch 9, dadurch gekennzeichnet, dass der konturierte Abschnitt (16a) des Mischerkörpers (16) eine seitliche Oberfläche
hat, die sich in Richtung des Luftstroms in der Zuführleitung (17) zunehmend den inneren
Seitenwänden der Zuführleitung (17) annähert.
11. Der Brenner gemäß Anspruch 10 oder 11, dadurch gekennzeichnet, dass der konturierte Abschnitt (16a) des Mischerkörpers (16) im Wesentlichen spitzkegelförmig
ist.
12. Der Brenner gemäß einem oder mehreren der Ansprüche 9 bis 11, dadurch gekennzeichnet, dass der Mischerkörper (16) eine Vielzahl von Gasabgabeöffnungen (19) hat, die um eine
Erstreckungsachse (16b) des Mischerkörpers (16) verteilt sind, die im Wesentlichen
parallel zur Achse der Zuführleitung (17) ist.
13. Der Brenner gemäß einem oder mehreren der Ansprüche 9 bis 12, dadurch gekennzeichnet, dass der Brennkopf (8) vom Typ mit innerer Flamme ist.
1. Chaudière de production d'eau chaude ou de vapeur, comprenant une enceinte de confinement
substantiellement cylindrique (2), qui définit une chambre de chauffe (3) destinée
à contenir de l'eau à chauffer et dans laquelle est logé axialement un four (5), qui
définit intérieurement une chambre de combustion (6) à laquelle est associé un brûleur
(7) qui comporte une tête de combustion (8) logée dans ladite chambre de combustion
(6), et un dispositif (9) pour prémélanger de l'air et du gaz qui est relié à ladite
tête de combustion (8), ladite chambre de combustion (6) étant connectée à une pluralité
de tubes d'échange de chaleur (11), qui sont destinés à faire passer les gaz de combustion
chauds produits par la flamme émise par ladite tête de combustion (8) et qui traversent
longitudinalement ladite chambre de chauffe (3), lesdits tubes d'échange de chaleur
(11) menant dans une chambre de collecte de gaz d'échappement (12) qui est reliée
à un carneau (13),
dans laquelle ledit dispositif de prémélange (9) comprend un corps de mélangeur (16)
logé axialement dans une gaine d'alimentation d'air (17) reliée à ladite tête de combustion
(8), ledit corps de mélangeur (16) comportant, sur sa face avant, dirigée contre le
flux d'air qui arrive de ladite gaine d'alimentation, une partie profilée (16a) qui
est adaptée pour créer, entre les parois latérales internes de ladite gaine d'alimentation
(17) et la surface latérale dudit corps de mélangeur (16), une région d'admission
(18) qui a une section de passage d'air transversal qui est plus étroite que la section
de passage d'air définie par ladite gaine d'alimentation (17) en amont dudit corps
de mélangeur (16), dans la direction du flux d'air, dans ledit corps de mélangeur
(16) étant définie, substantiellement au niveau de ladite région d'admission (18),
au moins une ouverture de distribution de gaz (19), qui est connectée à un canal d'alimentation
(20), qui est défini au moins partiellement à l'intérieur dudit corps de mélangeur
(16) et qui est relié à une source de gaz, un moyen étant prévu pour créer une pression
inférieure dans ladite chambre de combustion (6) par rapport à la pression ambiante
extérieure,
caractérisée en ce que lesdites ouvertures de distribution (19) sont dirigées vers la face arrière dudit
corps de mélangeur (16).
2. Chaudière selon la revendication 1, caractérisée en ce que ledit moyen adapté pour créer une pression inférieure dans ladite chambre de combustion
(6) comprend au moins un ventilateur (21) placé dans ladite chambre de collecte de
gaz d'échappement (12) et ayant une entrée reliée à ladite chambre de collecte de
gaz d'échappement (12) et une sortie reliée audit carneau (13).
3. Chaudière selon l'une ou plusieurs des revendications précédentes, caractérisée en ce que ladite partie profilée (16a) dudit corps de mélangeur (16) a une surface latérale
qui se rapproche progressivement des parois latérales internes de ladite gaine d'alimentation
(17), en allant dans la direction du flux d'air dans ladite gaine d'alimentation (17).
4. Chaudière selon l'une ou plusieurs des revendications précédentes, caractérisée en ce que ladite partie profilée (16a) dudit corps de mélangeur (16) est substantiellement
en forme d'ogive.
5. Chaudière selon l'une ou plusieurs des revendications précédentes, caractérisée en ce que ledit corps de mélangeur (16) comporte une pluralité d'ouvertures de distribution
de gaz (19) qui sont réparties autour d'un axe d'extension (16b) dudit corps de mélangeur
(16) qui est substantiellement parallèle à l'axe de ladite gaine d'alimentation (17).
6. Chaudière selon l'une ou plusieurs des revendications précédentes, caractérisée en ce que ladite tête de combustion (8) est du type à flamme interne.
7. Chaudière selon l'une ou plusieurs des revendications précédentes, caractérisée en ce qu'elle comprend, le long de ladite gaine d'alimentation (17), entre ledit corps de mélangeur
(16) et ladite tête de combustion (8), un moyen formant soupape de retenue (25) adapté
pour contraster la transmission d'ondes de pression de ladite chambre de combustion
(6) vers ladite gaine d'alimentation (17).
8. Chaudière selon la revendication précédente, caractérisée en ce que ledit moyen formant soupape (25) comprend un clapet de retenue à battant.
9. Brûleur comprenant une tête de combustion (8) et pourvu d'un dispositif de prémélange
(9) qui comprend un corps de mélangeur (16) logé axialement dans une gaine d'alimentation
d'air (17) reliée à ladite tête de combustion (8), dans lequel ledit corps de mélangeur
(16) comporte, sur sa face avant, dirigée contre le flux d'air qui arrive de ladite
gaine d'alimentation, une partie profilée (16a) qui est adaptée pour créer, entre
les parois latérales internes de ladite gaine d'alimentation (17) et la surface latérale
dudit corps de mélangeur (16), une région d'admission (18) qui a une section de passage
d'air transversal qui est plus étroite que la section de passage d'air définie par
ladite gaine d'alimentation (17) en amont dudit corps de mélangeur (16), dans la direction
du flux d'air, dans ledit corps de mélangeur (16) étant définie, substantiellement
au niveau de ladite région d'admission (18), au moins une ouverture de distribution
de gaz (19), qui est connectée à un canal d'alimentation (20), qui est défini au moins
partiellement à l'intérieur dudit corps de mélangeur (16) et qui est relié à une source
de gaz,
caractérisé en ce que lesdites ouvertures de distribution (19) sont dirigées vers la face arrière dudit
corps de mélangeur (16).
10. Brûleur selon la revendication 9, caractérisé en ce que ladite partie profilée (16a) dudit corps de mélangeur (16) a une surface latérale
qui se rapproche progressivement des parois latérales internes de ladite gaine d'alimentation
(17), en allant dans la direction du flux d'air dans ladite gaine d'alimentation (17).
11. Brûleur selon la revendication 10 ou 11, caractérisé en ce que ladite partie profilée (16a) dudit corps de mélangeur (16) est substantiellement
en forme d'ogive.
12. Brûleur selon l'une ou plusieurs des revendications 9 à 11, caractérisé en ce que ledit corps de mélangeur (16) comporte une pluralité d'ouvertures de distribution
de gaz (19) qui sont réparties autour d'un axe d'extension (16b) dudit corps de mélangeur
(16) qui est substantiellement parallèle à l'axe de ladite gaine d'alimentation (17).
13. Brûleur selon l'une ou plusieurs des revendications 9 à 12, caractérisé en ce que ladite tête de combustion (8) est du type à flamme interne.