Combined fixed bed gasifier

Abstract

The utility model discloses a combined type fixed bed gasification furnace, which relates to the technical field of gasification furnaces and comprises a furnace body, the furnace body comprises an upper layer furnace and a lower layer furnace which are overlapped up and down, the upper layer furnace is an updraft type gasification furnace, and the lower layer furnace is a downdraft type gasification furnace; a hopper is arranged above the furnace body and connected with a feeding pipe, and the feeding pipe extends into the upper-layer furnace and the lower-layer furnace and supplies materials to the upper-layer furnace and the lower-layer furnace. An ash hopper is arranged below the furnace body, the ash hopper is communicated with an ash falling opening of the lower-layer furnace, a deslagging auger is arranged at the lower part of the ash hopper, and the deslagging auger is connected with a deslagging header pipe; according to the utility model, the updraft gasifier and the downdraft gasifier are combined, so that the advantages and disadvantages of the two gasifiers are complementary, and the problems that fuel gas is not easy to ignite, stable in combustion, easy to accumulate dust and the like are solved; meanwhile, due to the stacked structural design, the space above the furnace body is fully utilized, so that the gas production rate of the furnace body is higher under the condition of the same occupied area.

Description

Technical Field

[0001] The utility model relates to the technical field of gasifiers, in particular to a combined fixed-bed gasifier. Background Art

[0002] The advantage of an updraft gasifier is that the alkali metal content in the fuel gas is very low, but the tar content is high, the fuel gas temperature is low, ignition and stable combustion are difficult, and the tar easily condenses on the wall and pipeline area, causing problems such as blockage and corrosion.

[0003] The advantages of downdraft gasifiers are low tar content and, because the gas outlet temperature is high, ignition and stable combustion are not difficult. However, the disadvantage is that the alkali metal content of the gas produced by downdraft gasifiers is much higher than that of updraft gasifiers, which can easily lead to dust accumulation on the heat exchange surfaces of downstream heat-using equipment, affecting heat transfer efficiency. In addition, the gas produced by downdraft gasifiers often needs to be cooled before use. However, because the waste heat of the gas is difficult to recover (tar easily condenses on the heat exchange surfaces), heat energy is lost.

[0004] In addition, both updraft and downdraft gasifiers are fixed-bed gasifiers. Compared with fluidized-bed gasifiers that can complete the gasification process within the entire tall and slender furnace space, their gasification intensity is relatively low, resulting in lower gas production under the same floor area. Utility Model Content

[0005] The purpose of the utility model is to provide a combined fixed-bed gasifier, which combines an updraft gasifier and a downdraft gasifier, so that the advantages and disadvantages of the two are complementary, and solve the problems of difficult ignition and stable combustion of gas, easy accumulation of ash, etc.; at the same time, the stacked structural design makes full use of the space above the furnace body, so that the gas production of the furnace body is higher under the same floor area.

[0006] The utility model comprises a furnace body, which comprises an upper furnace and a lower furnace stacked up and down, wherein the upper furnace is an updraft gasification furnace and the lower furnace is a downdraft gasification furnace; a hopper is provided above the furnace body, which is connected to a feeding pipe, and the feeding pipes extend into the upper furnace and the lower furnace respectively to feed materials thereto; an ash hopper is provided below the furnace body, which is connected to an ash outlet of the lower furnace, and a slag discharge auger is provided at the lower part of the ash hopper, which is connected to a slag discharge main pipe;

[0007] A slag discharge device is provided below the upper furnace, the slag discharge device is connected to a slag discharge pipe, the lower end of the slag discharge pipe extends into the ash hopper and is connected to the ash hopper; an upper grate is provided in the upper furnace, the upper grate is provided with an upper gasification air duct, an upper water-cooling channel and an upper grate plate, the upper gasification air duct is provided with an upper gasification air outlet opening toward the upper surface of the grate upper plate; a lower grate is provided in the lower furnace, the lower grate is provided with a lower gasification air duct and a lower water-cooling channel, and the lower gasification air duct is provided with a lower gasification air outlet;

[0008] A blower is provided on the side of the furnace body, which is connected to the air inlet main pipe, and the air inlet main pipe is connected to the upper gasification air duct and the lower gasification air duct respectively; a cooling water pump is also provided on the side of the furnace body, which is connected to the water inlet main pipe, and the water inlet main pipe is connected to the upper water cooling channel and the lower water cooling channel respectively; gas outlet pipes are connected to the top of the upper furnace and the bottom of the lower furnace respectively, and the two gas outlet pipes are connected to the gas high-temperature booster fan after merging at the gas junction pipe.

[0009] Preferably, several upper grates are fixedly mounted on a bracket made of an upper air inlet branch pipe, the inlet of the upper air inlet branch pipe is connected to the air inlet main pipe through a flexible pipe, and the outlet of the upper air inlet branch pipe is connected to the upper gasification air duct; the upper air inlet branch pipe drives the upper grate to reciprocate under the push of the power device.

[0010] Preferably, an air guide plate is provided above the upper gasification air outlet, and the air guide plate is arranged parallel to the grate upper plate.

[0011] Preferably, the lower grate is annular, and a plurality of lower grates with successively increasing diameters are arranged concentrically, with an annular gap for placing fuel formed between two adjacent lower grates.

[0012] Preferably, a plurality of grooves are provided at intervals on the surface of the lower grate, and the grooves are vertically arranged on the side walls of the lower grate.

[0013] Preferably, a baffle is provided on the outer side of the lower gasification air outlet, and the baffle is arranged parallel to the side wall of the lower grate at that location. Preferably, a plurality of lower grates are connected in series from the inside to the outside to form an annular grate assembly, and the grate assembly is connected to a power device capable of driving the lower grate to rotate.

[0014] In summary, the present invention has the following beneficial effects:

[0015] 1. The furnace body consists of an upper furnace and a lower furnace stacked on top of each other. The upper furnace is an updraft gasification furnace, and the lower furnace is a downdraft gasification furnace. The upper and lower furnaces operate synchronously and produce gas at the same time. With the same floor space, the gas production is greater, making it more suitable for use in places with large-displacement gas supply. The high-temperature gas produced by the downdraft gasification furnace and the low-temperature gas produced by the updraft gasification furnace are mixed in the gas confluence pipe. The two realize heat transfer, cooling the high-temperature gas produced by the downdraft gasification furnace and heating the low-temperature gas produced by the updraft gasification furnace. The two complement each other and output gas with appropriate temperature, easy to ignite and stable combustion, realizing full utilization of heat and avoiding heat waste.

[0016] 2. The same set of blowers and cooling water pumps provide combustion air and cooling water for the upper furnace and lower furnace respectively. The upper furnace and lower furnace share a set of air supply and water supply devices, which saves costs and can ensure that both can be opened and closed at the same time. The two operate synchronously, making operation simpler;

[0017] 3. Grooves are provided on the surface of both the upper and lower grates. The grooves are arranged along the outlet direction of the gasification air and guide the gasification air. A wind guide plate is provided above the upper gasification air outlet, and a baffle is provided on the outer side of the lower gasification air outlet. The wind guide plate and the baffle force the gasification air to turn, so that the air blown out from the gasification air outlet is blown out along the grooves on the grate surface, prompting more air to flow through the area close to the grate surface, thus forcing this area to become the local highest temperature area, facilitating rapid cooling by the grate and preventing high-temperature slagging on the grate.

[0018] 4. The upper grate and the lower grate are driven by the reciprocating motor to make reciprocating motion, thereby eliminating fuel bridging and facilitating slag breaking and ash discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural diagram of a combined fixed-bed gasifier of the present utility model;

[0020] Figure 2 for Figure 1 Left view of;

[0021] Figure 3 Schematic diagram of the structure of the upper grate;

[0022] Figure 4 for Figure 1 Enlarged cross-sectional view at AA in the middle;

[0023] Figure 5 for Figure 1 Enlarged view of point B in the middle;

[0024] Figure 6 The figure shows the air flow direction and temperature distribution of the traditional grate.

[0025] Figure 7 This is a schematic diagram of the air outlet direction and temperature after the water-cooled anti-slagging air inlet structure used in this patent forces the air to turn.

[0026] In the figure: 1. furnace body; 2. upper furnace; 3. lower furnace; 4. hopper; 5. feeding pipe; 6. ash hopper; 7. slag discharge auger; 8. slag discharge main pipe; 9. slag discharge device; 10. slag discharge pipe; 11. upper grate; 1101. upper gasification air duct; 1102. upper water cooling channel; 1103. upper grate plate; 1104. upper gasification air outlet; 1105. air guide plate; 12. lower grate; 1201. lower gasification air duct; 1202. lower water cooling channel; 1203. lower gasification air outlet; 1204. baffle; 13. Blower; 14. Air inlet main pipe; 15. Cooling water pump; 16. Water inlet main pipe; 17. Gas outlet pipe; 18. Gas junction pipe; 19. Gas high-temperature booster fan; 20. Upper air inlet branch pipe; 21. Flexible pipe; 22. Groove; 23. Feeding auger; 24. Lower air inlet branch pipe; 25. Roller; 26. Guide rail; 27. Push rod; 28. Guide sleeve; 29. ​​Crank connecting rod; 30. Reciprocating motor; 31. Upper water inlet branch pipe; 32. Return pipe; 35. Cooling channel; 36. Fuel; 37. High-temperature area. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] The orientations mentioned in this specification are based on the orientations of the combined fixed-bed gasifier of the present invention during normal operation, and do not limit the orientations during storage and transportation. They only represent relative positional relationships, not absolute positional relationships.

[0029] like Figures 1 to 5 As shown together, a combined fixed-bed gasification furnace includes a furnace body 1, and the furnace body 1 includes an upper furnace 2 and a lower furnace 3 stacked up and down, the upper furnace 2 is an updraft gasification furnace, and the lower furnace 3 is a downdraft gasification furnace, and the upper furnace 2 and the lower furnace 3 are respectively provided with a drying layer, a distillation layer, an oxidation layer and a reduction layer from top to bottom; a hopper 4 is provided above the furnace body 1, and the hopper 4 is connected to a feeding pipe 5, and the feeding pipe 5 extends to the upper furnace 2 and the lower furnace 3 respectively, and supplies materials to the upper furnace 2 and the lower furnace 3 respectively through a feeding auger 23; an ash hopper 6 is provided below the furnace body 1, and the ash hopper 6 is connected to the ash outlet of the lower furnace 3, and a slag discharge auger 7 is provided at the lower part of the ash hopper 6, and the slag discharge auger 7 is connected to the slag discharge main pipe 8; a slag discharge device 9 is provided below the upper furnace 2, and the slag discharge device 9 is connected to the slag discharge pipe 10, and the lower end of the slag discharge pipe 10 extends into the ash hopper 6 and is connected to the ash hopper 6.

[0030] The biomass pellet fuel 36 enters the upper furnace 2 and the lower furnace 3 respectively through the feed pipe 5, and gradually moves downward as the fuel 36 is consumed. After passing through the drying layer and the retorting layer in turn, it falls into the oxidation layer to mix and burn with the gasifying agent, and then continues to move downward to the reduction layer. After burning out, it falls into the ash hopper 6 below the furnace body 1 through the ash outlet between the grate gaps and is discharged through the slag discharge pipe 10; the gasifying agent enters the furnace body 1 through the gasification air duct of the grate, and after mixing with the fuel 36, it produces pyrolysis, oxidation, reduction and reforming reactions at high temperature. Through the action of the gasifying agent (such as air, oxygen or water vapor), the biomass polymers are decomposed to generate small molecular hydrocarbons, carbon monoxide, hydrogen and methane and other gases, which are output from the gas outlet pipe 17 of the furnace body 1 for use by subsequent equipment.

[0031] An upper grate 11 is provided in the upper furnace 2. There are several upper grates 11, which are arranged in parallel at intervals in the upper furnace 2. The upper grate 11 is provided with an upper gasification air duct 1101, an upper water-cooling channel 1102 and a grate upper plate 1103. The upper gasification air duct 1101 is provided with an upper gasification air outlet 1104 opening toward the upper surface of the grate upper plate 1103. There are several upper gasification air outlets 1104, which are arranged at intervals along the length direction of the upper gasification air duct 1101; an air guide plate 1105 is provided above the upper gasification air outlet 1104, and the air guide plate 1105 is arranged parallel to the grate upper plate 1103; a groove 22 is provided on the surface of the grate upper plate 1103, and the groove 22 is arranged along the air outlet direction of the upper gasification air outlet 1104.

[0032] The lower grate 12 is provided in the lower furnace 3. The lower grate 12 is provided with a lower gasification air duct 1201 and a lower water cooling channel 1202. The lower grate 12 is annular. Several lower grates 12 with increasing diameters are arranged concentrically. An annular gap for placing fuel 36 is formed between two adjacent lower grates 12. Correspondingly, the lower gasification air duct 1201 and the lower water cooling channel 1202 provided in the lower grate 12 are also annular structures. The lower gasification air duct 1201 is provided with a lower gasification air outlet 1203. The lower gasification air outlet 120 3 is arranged perpendicular to the lower gasification air duct 1201. A plurality of lower gasification air outlets 1203 are provided, which are arranged at intervals around the circumference of the lower gasification air duct 1201, pass through the lower water-cooling channel 1202, and finally communicate with the annular gap between the lower grate 12. A deflector 1204 is provided on the outer side of the lower gasification air outlet 1203, and the deflector 1204 is arranged parallel to the side wall of the lower grate 12 at that location. A plurality of grooves 22 are provided on the surface of the lower grate 12 at intervals, and the grooves 22 are vertically arranged on the side wall of the lower grate 12.

[0033] like Figure 4 、 Figure 6 and Figure 7As shown, the surfaces of the upper grate 11 and the lower grate 12 are both provided with grooves 22, which are arranged along the outlet direction of the gasification air, and the grooves 22 have a guiding effect on the gasification air; an air guide plate 1105 is provided above the upper gasification air outlet 1104, and a deflector 1204 is provided on the outer side of the lower gasification air outlet 1203, and the air guide plate 1105 and the deflector 1204 have a forced deflection effect on the gasification air, so that the air blown out from the gasification air outlet is blown out along the grooves 22 on the grate surface, prompting more air to flow through the area close to the grate surface, thereby forcing this area to become the local highest temperature area 37, which is convenient for the grate to quickly cool down and prevent the generation of high-temperature slagging; avoid the gasification air from being blown out in a direction perpendicular to the grate surface like a traditional gasifier, so that the area far away from the grate surface generates high temperature, and the cooling medium in the cooling channel 35 cannot dissipate heat in time, resulting in high-temperature slagging.

[0034] like Figure 1 As shown, a blower 13 is provided on the side of the furnace body 1, and the blower 13 is connected to the air inlet main pipe 14, and the air inlet main pipe 14 is respectively connected to the upper gasification air duct 1101 and the lower gasification air duct 1201; a cooling water pump 15 is also provided on the side of the furnace body 1, and the cooling water pump 15 is connected to the water inlet main pipe 16, and the water inlet main pipe 16 is respectively connected to the upper water cooling channel 1102 and the lower water cooling channel 1202; the outlet of the lower water cooling channel 1202 is connected to the return pipe 32 for collecting cooling water; the upper part of the upper furnace 2 and the lower part of the lower furnace 3 are respectively connected to gas outlet pipes 17, and the two gas outlet pipes 17 are connected to the gas high-temperature booster fan 19 after merging at the gas merging pipe 18, and the gas high-temperature booster fan 19 transports the gas to the equipment that needs to use the gas.

[0035] After being pressurized by the blower 13, the gasified air is divided into two paths at the air inlet main pipe 14. One path enters the upper gasification air duct 1101 of each upper grate 11 through the upper air inlet branch pipe 20, and is finally blown out through the upper gasification air outlet 1104. At high temperature, the fuel 36 is decomposed, and the generated combustible gas is then output through the gas outlet pipe 17 of the furnace body 1; the other path enters the lower gasification air duct 1201 of each lower grate 12 through the lower air inlet branch pipe 24, and is finally blown out through the lower gasification air outlet 1203. At high temperature, the fuel 36 is decomposed, and the generated combustible gas is then output through the gas outlet pipe 17 of the furnace body 1.

[0036] The blower 13 and the cooling water pump 15 provide combustion-supporting air and cooling water for the upper furnace 2 and the lower furnace 3 respectively. The upper furnace 2 and the lower furnace 3 share a set of air supply and water supply devices, which saves costs and can ensure that the two are opened and closed at the same time. The upper furnace 2 and the lower furnace 3 operate synchronously, and both produce gas at the same time. Under the same floor area, the gas production is greater, and it is more suitable for use in places with large-displacement gas supply; the high-temperature fuel gas produced by the down-draft gasification furnace is mixed from bottom to top with the low-temperature fuel gas produced by the up-draft gasification furnace from top to bottom in the gas junction pipe 18, and the two realize heat transfer, cool the high-temperature fuel gas produced by the down-draft gasification furnace, and heat the low-temperature fuel gas produced by the up-draft gasification furnace. The two complement each other and output fuel gas with suitable temperature, which is easy to ignite and burn stably, so as to fully utilize the heat.

[0037] Furthermore, several upper grates 11 are fixedly mounted on a bracket made of an upper air inlet branch pipe 20, the inlet of the upper air inlet branch pipe 20 is connected to the air inlet main pipe 14 through a flexible pipe 21, and the outlet of the upper air inlet branch pipe 20 is connected to the upper gasification air duct 1101 to provide gasification agent for the upper furnace 2; a roller 25 is provided at the lower part of the upper air inlet branch pipe 20, and a guide rail 26 is provided below the roller 25, the upper air inlet branch pipe 20 is connected to a straight push rod 27, the straight push rod 27 is connected to a guide sleeve 28, the straight push rod 27 is connected to a crank connecting rod 29, and the crank connecting rod 29 is connected to a reciprocating motor 30; the upper air inlet branch pipe 20 is driven by the reciprocating motor 30 to carry the upper grate 11 to do reciprocating motion, thereby eliminating fuel 36 bridging and facilitating slag breaking and ash discharge.

[0038] Accordingly, when the upper grate 11 reciprocates, the upper water inlet branch pipe 31 connected thereto also reciprocates, and thus, the connection between the upper water inlet branch pipe 31 and the water inlet main pipe 16 should also be connected with a flexible pipe 21 .

[0039] like Figure 4 As shown, further, several lower grates 12 are connected in series from the inside to the outside to form an annular grate as a whole, a roller 25 is provided under the grate as a whole, a guide rail 26 is provided under the roller 25, and the guide rail 26 and the roller 25 support the grate as a whole; the side of the grate as a whole is connected to a straight push rod 27, and the straight push rod 27 is connected to the outer sleeve with a guide sleeve 28, the straight push rod 27 is connected to the crank connecting rod 29, and the crank connecting rod 29 is connected to the reciprocating motor 30; the grate as a whole rotates and reciprocates along the tangential direction of the lower grate 12 under the push of the reciprocating motor 30, thereby driving the lower grate 12 to rotate, and the rotation process can eliminate the bridging of the fuel 36, which is convenient for slag breaking and ash discharge.

[0040] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A combined fixed-bed gasifier, characterized by: The invention comprises a furnace body (1), wherein the furnace body (1) comprises an upper furnace (2) and a lower furnace (3) stacked up and down, wherein the upper furnace (2) is an updraft gasification furnace, and the lower furnace (3) is a downdraft gasification furnace; a hopper (4) is provided above the furnace body (1), wherein the hopper (4) is connected to a feeding pipe (5), and the feeding pipe (5) extends into the upper furnace (2) and the lower furnace (3) respectively to feed materials thereto; an ash hopper (6) is provided below the furnace body (1), wherein the ash hopper (6) is connected to an ash outlet of the lower furnace (3), and a slag discharge auger (7) is provided at the lower part of the ash hopper (6), and the slag discharge auger (7) is connected to a slag discharge main pipe (8); a slag discharge device (9) is provided below the upper furnace (2), wherein the slag discharge device (9) is connected to a slag discharge pipe (10), and the lower end of the slag discharge pipe (10) extends into the ash hopper (6) and is connected to the ash hopper (6); The upper furnace (2) is provided with an upper grate (11), the upper grate (11) is provided with an upper gasification air duct (1101), an upper water-cooling channel (1102) and a grate upper plate (1103), the upper gasification air duct (1101) is provided with an upper gasification air outlet (1104) opening toward the upper surface of the grate upper plate (1103); the lower furnace (3) is provided with a lower grate (12), the lower grate (12) is provided with a lower gasification air duct (1201) and a lower water-cooling channel (1202), the lower gasification air duct (1201) is provided with a lower gasification air outlet (1203); The side of the furnace body (1) is provided with a blower (13), the blower (13) is connected to an air inlet main pipe (14), and the air inlet main pipe (14) is respectively connected to the upper gasification air duct (1101) and the lower gasification air duct (1201); the side of the furnace body (1) is also provided with a cooling water pump (15), the cooling water pump (15) is connected to a water inlet main pipe (16), and the water inlet main pipe (16) is respectively connected to the upper water cooling channel (1102) and the lower water cooling channel (1202); the upper part of the upper furnace (2) and the lower part of the lower furnace (3) are respectively connected to gas outlet pipes (17), and the two gas outlet pipes (17) are connected to a gas high-temperature booster blower (19) after merging at a gas merging pipe (18).

2. The combined fixed-bed gasifier according to claim 1, characterized in that: A plurality of upper grates (11) are fixedly mounted on a bracket made of an upper air inlet branch pipe (20); the inlet of the upper air inlet branch pipe (20) is connected to the air inlet main pipe (14) through a flexible pipe (21); the outlet of the upper air inlet branch pipe (20) is connected to the upper gasification air duct (1101); the upper air inlet branch pipe (20) drives the upper grate (11) to perform reciprocating motion under the push of a power device.

3. The combined fixed-bed gasifier according to claim 1, characterized in that: An air guide plate (1105) is provided above the upper gasification air outlet (1104), and the air guide plate (1105) is arranged parallel to the grate upper plate (1103).

4. The combined fixed-bed gasifier according to claim 1, characterized in that: The lower grate (12) is annular, and a plurality of lower grates (12) with successively increasing diameters are arranged concentrically, with an annular gap for placing fuel (36) formed between two adjacent lower grates (12).

5. The combined fixed-bed gasifier according to claim 1, characterized in that: A plurality of grooves (22) are arranged at intervals on the surface of the lower grate (12), and the grooves (22) are vertically arranged on the side walls of the lower grate (12).

6. The combined fixed-bed gasifier according to claim 1, characterized in that: A deflector (1204) is provided on the outer side of the lower gasification air outlet (1203), and the deflector (1204) is arranged parallel to the side wall of the lower grate (12) at that location.

7. The combined fixed-bed gasifier according to claim 1, characterized in that: A plurality of lower grates (12) are sequentially connected in series from the inside to the outside to form an annular grate as a whole. The grate as a whole is connected to a power device capable of driving the lower grate (12) to rotate.

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