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(11) | EP 0 132 470 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Safety boiler with high efficiency |
| (57) A safety boiler with high efficiency comprises a plurality of water jackets disposed
around a central vaporizing chamber (1) positioned atop on a combustion chamber (2)
and a plurality of sandwiched flues (6) each respectively partitioned between each
two neighbouring water jackets so that the feed water passing the water jackets will
thoroughly pre- heated to increase the thermal efficiency and safety of the boiler. |
[0001] Conventional boilers either fire tube type or water tube type are generally found with the following defects:
1. In order to sustain the high pressure of generated steam, all the construction parts should be designed with suitable thickness durable for such high steam pressure, which can not be reduced to be thinner so that the production cost of boiler will not be reduced.
2. The heat conductivity of such thicker steel plates or tubes will be reduced so as to decrease the thermal efficiency of boiler.
3. The outmost boiler shell should be insulated to prevent heat loss therefrom to increase insulation cost and maintenance problem for the insulated material as the boiler shell still carry an appreciated heat which should be well insulated.
4. The boiler shell directly receives the high pressure of steam inside the boiler so that, once accidental explosion occuring, the outer broken scraps will directly and rapidly spread outwards to cause serious damage to the surroundings.
[0002] Σ have found these defects of conventional boilers and invented the present safety boiler with high efficiency.
[0003] According to the present invention there is provided a safety boiler wherein a plurality of water jackets are disposed around a central vaporizing chamber positioned atop on a combustion chamber and a plurality of sandwiched flues are provided each being respectively partitioned between each two neighbouring water jackets so that the feed water passing the water jackets will be thoroughly preheated to increase the thermal efficiency of the boiler.
[0004] The present invention will be further described with reference to the accompanying drawings, in which:-
Figure 1 is elevated sectional drawing of the present invention.
Figure 2 is a bottom-view partial sectional drawing of the present invention.
Figure 3 is an illustration showing the arrangement of the flue baffles of the present invention.
Figure 4 is an illustration showing another arrangement of the flue baffles of the present invention.
Figure 5 is a partial sectional drawing of a maintenance hole of the present invention.
[0005] As shown in Figure 1 and Figure 2, the present invention comprises a vaporizing chamber 1, a combustion chamber 2, a preheated water jacket 3 surrounding the combustion chamber, a top-closed pressurized water jacket 4 surrounding the vaporizing chamber, a bottom-open water jacket 5 surrounding water jacket 4, a plurality of water jackets combinations 7, 8 subsequently developed outwards each comprising an inner water jacket 7 communicated with its inner water jacket and an outer water jacket 8 communicated with its outer water jacket, a plurality of sandwiched flues 6 each respectively partitioned between each two neighbouring water jackets, an outmost water jacket 9 connected to a stack 62 and supported by a supporting frame 96 and a boosting pump 34.
[0006] Vaporizing chamber 1 is positioned centrally in the present boiler and is made as hollow spherical body 11 or other suitable shapes. Two atomizers 12 are provided in its upper portion. A maintenance hole 13 is provided on the bottom portion of chamber 1. Atomizers 12 also serve as fixing frame sturdily fix chamber 1 in the present boiler.
[0007] Combustion chamber 2 is surrounded by preheated water jacket 3. A steam delivery pipe 21 is poked into chamber 1 to lead steam outwards and the pipe 21 is then wound to form a continuous coil 22 surrounding vaporizing chamber 1 and combustion chamber 2 and finally connected with a discharge pipe 23 having a safety relief valve 24. An insulated layer 22a is provided to adhere behind the coil 22 to prevent from radiation heat loss from chamber 1. Such an insulated layer 22a may be made from glass fibre reinforced with stainless steel wire. The insulated layer 22a and coil 22 are formed with a top flue hole 22b for flue gas passage, The coil 22 and the adhered insulated layer 22a surrounding the vaporizing chamber 1 is positioned centrally between chamber 1 and water jacket 4 so that the flue gas F will pass in a counter-current way as shown in Figure 1 for efficient heat transfer. A burner 2a is provided on the bottom portion of said chamber 2. Naturally, combustion chamber 2 and pre-heated water jacket 3 may be positioned aside vaporizing chamber 1.
[0008] Preheated water jacket is made as a cylindrical jacket 3a surrounding coil 22 and combustion chamber 2. A water pipe 31 is connected with water discharging pipe 52 of water jacket 5. A by-pass drain 32 is formed on pipe 31. Pipe 31 is then connected to jacket 3a. A suction pipe 33 is provided to connect the jacket 3a with a boosting pump 34, A discharge pipe 35 is provided to connect pump 34 with pressurized water jacket 4.
[0009] Pressurized water jacket 4 comprises two connectors 41 to communicate with the two atomizers 12 of vaporizing chamber 1. The bottom periphery 42 of jacket 4 is mounted on preheated water jacket 3 by supporting means 43. Supporting means 43 is formed with flue hole 43a for passing flue gas. The jacket 4 may be reinforced by rivets connected between jacket walls to sustain high water pressure therein.
[0010] Top-closed water jacket 4 is connected to bottom-opened water jacket 5 by a flue baffle 61. Between water jacket 4 and jacket 5, there is provided another insulated layer 4a centrally positioned in the flue 6. Such insulated layer 4a is fixed on jacket 4 by bracket 4b. The layer 4a is thus formed to effect the counter-current flows of flue gas for better heat transfer. The lowest perimeter 4c of insulated layer 4a is connected with jacket 3a to leave no hole therebetween. However, the layer 4a is formed with a top flue hole 4d for flue gas passage as figure shown. An annular flue hole 51 is formed between the lowest perimeter of jacket 5 with the wall of jacket 3a. A water discharge pipe 52 is provided to connect water pipe 31 of water jacket 3. Jacket 5 is connected to a top-opened water jacket 7 by a baffle 61, Jacket 7 is further connected to an outer water jacket 8 having bottom annular hole 81. Connectors 82 are provided to connect jacket 8 with inner jacket 7. Jacket 7 is connected with jacket 8 to form a water jacket combination. The number of water jacket combination 7, 8 can be adjusted according to the practical requirement, for example, the combinations may be designed as two sets as shown in Figure 1. Inner jacket 7 of first jacket combination 7, 8 is communicated with inner jacket 5 by connectors 71. However, jacket 7 of second (outer) jacket combination 7, 8 is communicated with jacket 8 by another pair of connectors 71 as Figure 1 shown. Each jacket 7 is centrally formed with a flue hole 72 atop on jacket 7. The number of jacket combination 7, 8 is not limited in the present invention. The lowest perimeter of jacket 7 is approaching to jacket 3a.
[0011] Flue baffle 61 can be made as radial type as shown Figure 2 and Figure 3. The spiral type 61a as shown in Figure 4 or other forms may be modified. The baffles can increase the heat-exchange efficiency between the flues with the water jackets. The outmost water jacket 9 is connected to jacket 8 by a baffle 61. The flue formed therebetween is communicated with stack 62, The outmost water jacket 9 is provided with a feed water pipe 91 which is connected with a valve 92 and a check valve 93. A vent 94 is formed atop on jacket 9 to discharge air therethrough when charging the present boiler. Connectors 95 are provided to communicate jacket 9 with inner jacket 8. A supporting frame 96 is provided to support the jacket 9 and the present invention.
[0012] The outer jackets can be made from any anti-corrosive materials to prevent from any corrosion at dew point of flue gas such as below 250°C, Each water jacket may be formed with a maintenance hole M for cleaning use and may be provided with a drain D for draining or blow-down uses. Whenever opening the maintenance hole M for cleaning, preheated jacket 3 can be first dismantled for convenient maintenance.
[0013] When using the present invention, feed water w is charged into the boiler through pipe 91 into all water jackets 9, 8, 7 and 5 for preheating by the heated flue gas through all flues 6. The pre-heated water is then led into water jacket 3 and boosted by pump 34 to flow into jacket 4. The water is then pressurized and sprayed through atomizers 12 into vaporizing chamber 1 whereby the water mist is heated to become steam and discharged through pipe 21. The steam is superheated in combustion chamber 2 in coil 22 for producing superheated high-pressure steam for final consumption through pipe 23. The flue gas F will pass upwards and downwards in many passes through all flues 6 to perform heat-exchange operation with the water jackets to thoroughly heat the water therein and be drafted through stack 62 at the outmost jacket 9 at about ambient temperature.
[0014] The present invention is preferably made as spherical shape. Other suitable shapes may be modified. An automatic inter-related control system may be set up by those skill in the art for boosting pump 34 with respect to the capacity of vaporizing chamber 1 and the operating variable of burner 2a to obtain optimization for the present boiler operation.
[0015] The number of atomizers 12 and all connectors, number of jackets as well as the shapes of constructed parts are not limited in the present invention, which can be modified in practical requirements.
[0016] For multiplying the steam capacity, a plurality of boilers of the present invention may be connected in parallel to increase the steam production rate for larger consumption.
[0017] If the combustion chamber 2 is positioned aside (not under) vaporizing chamber 1, the flue holes of each water jacket combination, for example, jacket 4 and jacket 5, jacket 7 and jacket 8, should be made counter-current so that one flue hole of one water jacket is approaching flue stack 62 and another flue hole of another water jacket of the jacket combination is a approaching combustion chamber 2 or burner for reciprocatively passing the flue gas within the flues,
[0018] The present invention is superior to any conventional boiler by the following advantages:
1. The feed water in all water jackets is thoroughly preheated by the flue gas to save fuel cost and increase the boiler efficiency,
2. The materials of the parts other than the central vaporizing chamber 1 and pressurized jacket 4 can be made thinner as they do not sustain the higher pressure. Hence, the thermal efficiency can increase and the production cost can be decreased.
3. The insulated material for the outmost water jacket can be saved as the shell temperature is equal or approaching to the ambient temperature.
4. The central high-pressure chamber 1 is disposed by many jackets 4, 5, 7, 8, 9 so that, once accidentally exploded, the explosion wave or broken scraps may be buffered by the outer jackets and the possible damage can be reduced to minimum.
5. Tho spherical structure of the preferred present invention can bo stressed homogeneously and thus can be used more strongly in a longer service life.
a vaporizing chamber (1), positioned centrally within the boiler, which is provided with several atomizers (12) respectively connected to a pressurized water jacket (4) and a steam pipe (21) being poked into said chamber to lead steam into a coil (22) surrounding said vaporizing chamber (1) and combustion chamber (2) for superheating the steam; a top-closed pressurized water jacket (4) surrounding said vaporizing chamber (1), which is lowerly mounted on said preheated water jacket (3) by supporting means (43) formed with flue holes (43a) therethrough;
a combustion chamber (2) heated by a burner (2a) and positioned under said vaporizing chamber;
a preheated water jacket (3), surrounding said coil (22) and said combustion chamber (2), which is provided with water pipe (31) communicated with a water jacket (5) surrounding said pressurized water jacket (4) and provided with a boosting pump (34) to suck water from said preheated jacket (3) and boost water into said pressurized water jacket (4);
a bottom-opened water jacket (5), surrounding said pressurized water jacket (4), which is formed with an annular flue hole (51) between its lowest perimeter with said preheated water jacket (3);
a plurality of water jacket combinations each comprising an inner top-opened water jacket (7) communicated with its inner water jacket and an outer bottom-opened water jacket (8) communicated with its outer water jacket, being subsequently developed outwards;
a plurality of sandwiched flues (6) each respectively partitioned between each two neighbouring water jakcets, each sandwiched flue comprising a flue baffle (61), connecting the two neighbouring water jackets and being made as radial type or spiral type; and
an outmost water jacket (9), communicated with its inner water jacket (8) and connected outwards with a stack (62) which is communicated with said flues (6), being supported by a frame (96) connected thereunder; said vaporizing chamber and each said water jacket being respectively formed with a maintenance hole; the flue holes of each water jacket combination being made counter-current so that one flue hole of one water jacket is approaching said flue stack and another flue hole of another water jacket of the jacket combination is approaching said combustion chamber or burner for reciprocatively passing flue gas within the flues partitioned between the water jackets.