CN112251258B

CN112251258B - TFB gasification furnace with built-in double beds

Info

Publication number: CN112251258B
Application number: CN202011220613.8A
Authority: CN
Inventors: 胡彦霞; 齐逍宇; 张凝
Original assignee: Beijing Hengran Technology Co ltd
Current assignee: Beijing Hengran Technology Co ltd
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2022-07-12
Anticipated expiration: 2040-11-05
Also published as: CN112251258A

Abstract

The invention discloses a TFB gasification furnace with built-in double beds, which comprises a gasification chamber, a feeding device, a separator and a waste heat device. The gasification chamber sequentially comprises a gradually expanding area, a constant-section gasification area, a gradually reducing area and a constant-section cooling section from bottom to top. The divergent zone comprises a turbulent gasification zone and a bubbling gasification zone arranged in parallel and separated by a partition plate. The height of the partition board is 0.5-1 m. The feeding device is arranged at one side of the turbulent gasification zone. The lower secondary tuyere is arranged at one side of the turbulent flow gasification zone; the middle secondary tuyere is arranged in the equal section gasification area, the upper secondary tuyere is arranged in the reducing area and arranged on different side wall surfaces to enable the upper secondary tuyere to spray gasification media in a mutually vertical direction. The invention has the advantages of adapting to the garbage with lower calorific value, simple and efficient deslagging structure, low carbon content of gasification residues, avoiding the adhesion of complex fuels at the lower part of the gasification chamber, and the like, and the graded gasification can adapt to the larger change of the garbage components.

Description

TFB gasification furnace with built-in double beds

Technical Field

The invention relates to a TFB gasification furnace with a built-in double bed, belonging to the field of combustible solid waste (garbage) gasification.

Background

The combustible solid waste represented by the household garbage often influences the combustion stability of the household garbage in an incinerator due to higher water content, so that the problems of insufficient combustion or deflagration and the like are caused, and the water is evaporated into the flue gas, so that the water content of the flue gas is higher, and the corrosion of a pipeline and subsequent equipment is easily caused. The water in the household garbage is fully utilized as a gasifying agent to participate in the reaction after being gasified and combusted, so that the reaction stability is improved, and the water content in the flue gas is reduced; and the gasification process has a homogenizing effect on the domestic garbage with complex components, so that the subsequent combustion process is more stable and sufficient.

Because the domestic garbage has complex components and variable forms, the Turbulent Fluidized Bed (TFB) is obviously advantageous to be used in the gasification process. At present, turbulent fluidized beds are mostly of symmetrical structures, and the deposition of materials on the wall surface is avoided as much as possible through various soot blowing modes. Turbulent fluidized beds belong to fluidization devices, have certain requirements on the size and uniformity of feed materials, and have certain difficulty in deslagging due to the fact that a certain amount of non-combustible large particles are contained. In addition, the combustible solid waste is generally high in alkali metal content and low in ash melting point, and is easy to adhere and slag on the inner wall surface of the furnace.

Disclosure of Invention

The invention aims to provide a TFB gasification furnace with a built-in double bed, which realizes subarea gasification by dividing the lower part of a gasification chamber into a turbulent flow gasification area and a bubbling gasification area, so that the TFB gasification furnace can be more suitable for the gasification of wastes; meanwhile, the staged gasification is realized through the arrangement of the upper and lower multi-stage gasification agent ports, so that the gasification degree is improved, and the calorific value of the gasified gas is also improved.

The invention is realized by the following technical scheme:

a TFB gasification furnace with a built-in double bed comprises a gasification chamber, a feeding device and a separator connected with the top of the gasification chamber.

The gasification chamber sequentially comprises a gradually expanding area, a constant-section gasification area, a gradually reducing area and a constant-section cooling section from bottom to top, wherein the gradually expanding area comprises a turbulent flow gasification area and a bubbling gasification area which are arranged in parallel; be provided with the baffle between torrent gasification district and the tympanic bulla gasification district, torrent gasification district and tympanic bulla gasification district bottom are provided with torrent air distribution device and tympanic bulla air distribution device that can independently adjust amount of wind and wind pressure respectively.

The feeding device is arranged in the divergent zone of the gasification chamber and is positioned above one side of the turbulent flow gasification zone.

The gasification chamber is also provided with a plurality of secondary tuyeres for introducing gasification agents, and the secondary tuyeres comprise a lower secondary tuyere, a middle secondary tuyere and an upper secondary tuyere; the lower secondary air port is arranged in the divergent zone and is positioned on one side of the turbulent flow gasification zone; the middle secondary tuyere is arranged in the uniform-section gasification area, the upper secondary tuyere is arranged in the tapered area, the upper secondary tuyere and the middle secondary tuyere are respectively arranged on the adjacent wall surface of the gasification chamber, and the direction of a gasification agent entering the gasification chamber through the upper secondary tuyere and the middle secondary tuyere can form opposite impact.

In the above technical scheme, the gasification furnace further comprises a waste heat utilization device, and the waste heat utilization device is connected with the gas outlet of the separator.

In the technical scheme, the height of the partition plate is 0.5-1 m.

In the technical scheme, the inner wall surfaces of the gradually expanding area, the uniform-section gasification area and the gradually reducing area of the gasification chamber are all laid with refractory materials; and refractory materials are laid on the inner wall surface of the lower part of the uniform-section cooling section.

In the technical scheme, the turbulent flow gasification zone is arranged according to the bed speed of 4-6 m/s; the bubbling gasification area is arranged according to the bed speed of 0.5-1 m/s.

The invention has the following advantages and beneficial effects: the subarea gasification can adapt to the garbage with lower calorific value, and the complex fuel is prevented from adhering to the lower part of the gasification chamber; the carbon content of the gasification residues can be greatly reduced and the calorific value of the gasified gas can be improved by virtue of the subarea gasification and grading subareas; meanwhile, the graded gasification can adapt to the larger change of the garbage components; the deslagging structure is simple and efficient.

Drawings

FIG. 1 is a schematic view of a TFB gasification furnace with built-in dual beds according to the present invention.

In the figure: 1-a gasification chamber; 101-a turbulent gasification zone; 102-a bubbling gasification zone; 103-a uniform section gasification zone; 104-a tapered region; 105-a constant section cooling section; 106-turbulent air distribution device; 107-a bubbling air distribution device; 108-lower secondary tuyere; 109-middle secondary air port; 110-secondary air inlet; 2-a feeding device; 3-a separator; 4-a waste heat utilization device.

Detailed Description

The following describes the embodiments and operation of the present invention with reference to the accompanying drawings.

The terms of orientation such as up, down, left, right, front, and rear in the present specification are established based on the positional relationship shown in the drawings. The corresponding positional relationship may also vary depending on the drawings, and therefore, should not be construed as limiting the scope of protection.

As shown in FIG. 1, the TFB gasification furnace with built-in double beds comprises a gasification chamber 1, a feeding device 2, a separator 3 and a waste heat utilization device 4.

The gasification chamber 1 comprises a divergent zone, a uniform section gasification zone 103, a convergent zone 104 and a uniform section cooling section 105 from bottom to top in sequence. The divergent zone comprises a turbulent flow gasification zone 101 and a bubbling gasification zone 102 which are arranged in parallel, the turbulent flow gasification zone 101 and the bubbling gasification zone are separated by a partition plate, and the height of the partition plate is 0.5-1 m. The bottom of the turbulent gasification zone 101 and the bottom of the bubbling gasification zone 102 are respectively provided with a turbulent air distribution device 106 and a bubbling air distribution device 107, so that a gasification agent can be introduced and independently adjusted, and the gasification agent comprises air. And deslagging systems are arranged at the bottoms of the turbulent flow gasification zone 101 and the bubbling gasification zone 102. The feeding device 2 is arranged in the divergent zone of the gasification chamber 1 and is positioned above one side of the turbulent gasification zone 101, so that the turbulent gasification zone 101 is used as a feeding zone, and the bubbling gasification zone is used as a post-gasification zone.

The turbulent gasification zone 101 is set according to the bed speed of 4-6 m/s and the material layer thickness of 0.5-1 m, and the slag discharge system and the corresponding blast cap configuration are set according to the waste condition of treatment, generally speaking, according to the waste components and size, especially the particle size distribution and proportion of the incombustible large particles. When the size of the large non-combustible particles in the waste is larger or the proportion is higher, the turbulent flow gasification area adopts a combined structure mode of an inclined air distribution plate, a directional air cap and bed slag discharge to realize the smooth discharge of the large non-combustible particles. Meanwhile, in order to reduce the power consumption, a thinner material layer can be adopted for operation, so that the elevation of the air distribution plate can be higher than that of the bubbling gasification zone (namely, the post-gasification zone) on one side of the air distribution plate. When the size of the large non-combustible particles in the waste is small or the proportion is very low, the turbulent gasification area adopts a combination arrangement mode of a horizontal air distribution plate, under-bed slag discharge and a symmetrical air cap.

The bubbling gasification zone 102 is arranged according to the bed speed of 0.5-1 m/s and the material layer thickness of 0.8-1.5 m, and a symmetrical air cap and a deslagging system under the bed are selected. The turbulent gasification zone at the feeding side adopts a higher bed speed, so that the difficulty of fluidization of large incombustible particles in the garbage can be effectively overcome, and meanwhile, the required fluidization medium flow is small due to small area, so that the influence on the whole gasification agent flow is small. The back gasification area separated by the baffle can adopt low fluidization speed due to small particles, and can operate under the working condition of a bubbling bed, thereby reducing the flow of the fluidized medium to the maximum extent. Therefore, by adopting the design of zone fluidization and different wind speeds, the gasification with lower air proportion can be realized, thereby adapting to the condition of low heat value of garbage and simultaneously improving the heat value of gasified gas.

In addition, the gasification agent is added for multiple times, so that the staged gasification is realized. The gasification chamber 1 is also provided with a plurality of secondary tuyeres for introducing gasification agents. The secondary tuyeres include a lower secondary tuyere 108, a middle secondary tuyere 109 and an upper secondary tuyere 110. The lower secondary tuyere 108 is arranged in the divergent zone and is positioned at one side of the turbulent gasification zone 101. The middle secondary tuyere 109 is arranged in the uniform section gasification area 103, the upper secondary tuyere 110 is arranged in the tapering area, and the upper secondary tuyere 110 and the middle secondary tuyere 109 are respectively arranged on the adjacent wall surfaces of the gasification chamber 1, so that the gasification agent entering the gasification chamber 1 through the upper secondary tuyere 110 and the middle secondary tuyere 109 can be vertical to each other.

As shown in fig. 1, the arrangement direction of the turbulent gasification zone 101 and the bubbling gasification zone 102 is set to the left and right, and the depth direction of the gasification furnace 1 is set to the front and back. The lower secondary tuyere 108 is provided in the turbulent gasification zone 101 in a front-rear direction arrangement because the turbulent gasification zone is a feed zone, the fuel concentration is high, and more gasifying agent is required. The middle secondary tuyere 109 and the upper secondary tuyere 110 are respectively arranged in the front-rear direction and the left-right direction, and may also be respectively arranged in the left-right direction and the front-rear direction.

The waste from the feed device 2 enters the turbulent gasification zone 101 in a double stage feed with intermediate seals where it is fluidized at a higher bed velocity while undergoing low temperature gasification. This is because the starting material has a fraction of large particles or particles of a higher density that are not easily fluidized, and a higher bed velocity is required for fluidization. The middle partition plate only divides the middle and lower fluidization regions, the upper part is communicated, and materials with smaller density or particles enter the low-speed bubbling fluidization region from the top of the partition plate to be gasified in the fluidization process. Low-temperature gasification is adopted in an area (dense-phase area) with high material concentration, so that ash with low ash melting point can be effectively prevented from adhering in the area. However, the gas generated by pyrolysis and gasification in this region has tar-like components due to low reaction temperature, and further needs to be decomposed by heating in the dilute phase region and above low ash concentration region during the rising process, so that a small amount of secondary gasification medium (gasification agent) needs to be added into the lower secondary tuyere 108 to raise the temperature for further gasification. The middle secondary tuyere 109 is arranged at the lower part of the uniform section gasification zone 103, the upper secondary tuyere 110 which is vertical to the injection direction of the middle secondary tuyere 109 is arranged in the tapering zone 104, and the secondary gasification agent is injected in a vertical mode, so that uniform mixing and full gasification can be ensured.

In order to better gasify the low-calorific-value waste, the inner wall surfaces of the divergent zone, the uniform-section gasification zone 103 and the convergent zone 104 of the gasification chamber 1 are all laid with refractory materials, so that heat storage gasification is realized. The inner wall surface of the lower part of the uniform-section cooling section 105 is coated with refractory materials, and the middle part and the upper part absorb heat in the gasified gas in a water-cooled wall structure and other modes to cool the gasified gas.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Built-in double-bed TFB gasifier, its characterized in that: the gasification furnace comprises a gasification chamber (1), a feeding device (2) and a separator (3) connected with the top of the gasification chamber (1);

the gasification chamber (1) sequentially comprises a gradually expanding area, a constant-section gasification area (103), a gradually reducing area (104) and a constant-section cooling section (105) from bottom to top, wherein the gradually expanding area comprises a turbulent flow gasification area (101) and a bubbling gasification area (102) which are arranged in parallel; a partition plate is arranged between the turbulent flow gasification zone (101) and the bubbling gasification zone (102), and the height of the partition plate is 0.5-1 m; the bottom of the turbulent flow gasification area (101) and the bottom of the bubbling gasification area (102) are respectively provided with a turbulent flow air distribution device (106) and a bubbling air distribution device (107), and the bottoms of the turbulent flow gasification area (101) and the bubbling gasification area (102) are respectively provided with a slag discharge system;

the feeding device (2) is arranged in the divergent zone of the gasification chamber (1) and is positioned above one side of the turbulent gasification zone (101);

the gasification chamber (1) is also provided with a plurality of secondary tuyeres for introducing a gasification agent, each secondary tuyere comprises a lower secondary tuyere (108), and the lower secondary tuyere (108) is arranged in the divergent zone and is positioned on one side of the turbulent gasification zone (101).

2. The built-in dual bed TFB gasifier of claim 1, wherein: the secondary tuyere further comprises a middle secondary tuyere (109) and an upper secondary tuyere (110); the middle secondary tuyere (109) is arranged in the uniform-section gasification zone (103), the upper secondary tuyere (110) is arranged in the tapered zone, the upper secondary tuyere (110) and the middle secondary tuyere (109) are respectively arranged on the adjacent wall surfaces of the gasification chamber (1), and the directions of gasification agents entering the gasification chamber (1) through the upper secondary tuyere (110) and the middle secondary tuyere (109) can be vertical to each other.

3. The built-in dual bed TFB gasifier of claim 1, wherein: the gasification furnace further comprises a waste heat utilization device (4), and the waste heat utilization device (4) is connected with a gas outlet of the separator (3).

4. The built-in dual bed TFB gasifier of claim 1, wherein: the inner wall surfaces of the gradually expanding area, the uniform section gasification area (103) and the gradually reducing area (104) of the gasification chamber (1) are all laid with refractory materials; and refractory materials are laid on the inner wall surface of the lower part of the uniform-section cooling section (105).

5. The built-in dual bed TFB gasifier of claim 1, wherein: the turbulent flow gasification zone (101) is arranged according to the bed speed of 4-6 m/s; the bubbling gasification zone (102) is arranged according to the bed speed of 0.5-1 m/s.