Fluidized bed

Abstract

The utility model provides a fluidized bed which comprises an air distribution plate, a fluidized bed body and a fluidized bed cover, the air pipe is arranged on the mounting hole in a penetrating manner, the air pipe is provided with an air inlet and an air outlet, the air inlet is formed in the bottom of the air distribution plate, the air outlet is formed in the top of the air distribution plate, and the air inlet is communicated with the air outlet; the cover body covers the top of the air pipe, the cover body and the air outlet are located on the same side of the air distribution plate, a circulation cavity is formed between the cover body and the air pipe, an air supply outlet is formed in the end, close to the air distribution plate, of the cover body, the circulation cavity is communicated with the air supply outlet and the air outlet, and the distance L between the air supply outlet and the air distribution plate is larger than or equal to 31 mm and smaller than or equal to 35 mm. According to the technical scheme provided by the utility model, the problem that a fluidized bed structure in the prior art is not suitable for nano hydrocarbon fuel can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of fluidized bed auxiliary equipment, and particularly relates to a fluidized bed. Background Technique

[0002] Fluidized bed combustion is an efficient combustion technology and is widely used in circulating fluidized bed boilers. The furnace of the circulating fluidized bed boiler is surrounded by membrane water walls, and the bottom of the furnace is a wind distribution plate, which divides the air caps and the air chamber to support the bed material and fuel particles. Air caps are installed on the wind distribution plate, and small holes are opened on the outer cover of the air caps. The primary air for fluidization flows from the air chamber into the furnace through the air caps to ensure uniform fluidization of the materials on the wind distribution plate.

[0003] Nano hydrocarbon fuel is a clean and efficient new type of coal-based special fuel. When the circulating fluidized bed boiler is converted to burn coal-based nano hydrocarbon fuel, due to the relatively fine basic particle size of the nano hydrocarbon fuel, new requirements are put forward for the original boiler's air distribution system, and it is necessary to control the appropriate fluidization air volume to ensure that the finer fuel particles have sufficient reaction time in the furnace. However, the existing circulating fluidized bed boilers are generally used to burn fuels such as low-quality coal and coal gangue, so the current fluidized bed structure is not suitable for nano hydrocarbon fuel, and thus the air distribution effect cannot guarantee the combustion efficiency of nano hydrocarbon fuel. Content of the Utility Model

[0004] The utility model provides a fluidized bed to solve the problem that the existing fluidized bed structure is not suitable for nano hydrocarbon fuel.

[0005] The utility model provides a fluidized bed, which includes: a wind distribution plate provided with mounting holes; an air duct passing through the mounting holes, the air duct having an air inlet and an air outlet, the air inlet being arranged at the bottom of the wind distribution plate and the air outlet being arranged at the top of the wind distribution plate, and the air inlet being communicated with the air outlet; a cover body covering the top of the air duct, the cover body and the air outlet being on the same side of the wind distribution plate, a flow cavity being formed between the cover body and the air duct, a air supply port being arranged at one end of the cover body close to the wind distribution plate, the flow cavity being communicated with the air supply port and the air outlet respectively, and the distance between the air supply port and the wind distribution plate being L, where 31mm ≤ L ≤ 35mm.

[0006] Applying the technical solution of the present utility model, an air supply port is provided at one end of the cover body close to the air distribution plate, and the distance between the air supply port and the air distribution plate is L, where 31 mm ≤ L ≤ 35 mm. If L > 35 mm, the distance between the air supply port and the air distribution plate is relatively far, which makes the path of the wind from the air supply port to the material on the fluidized bed longer, increasing the energy loss and reducing the wind force when blowing the material, thereby reducing the fluidization effect on the material; if L < 31 mm, the distance between the air supply port and the air distribution plate is relatively close, which enhances the impact force of the air outlet of the air supply port on the air distribution plate, increasing the wear of the air outlet on the air distribution plate, and thus reducing the service life of the air distribution plate; therefore, setting 31 mm ≤ L ≤ 35 mm can not only enable the air outlet of the air supply port to strongly blow the material on the fluidized bed, thereby ensuring the fluidization effect on the material, but also extend the service life of the air distribution plate. Specifically, L can be 31 mm, 32.5 mm, 33 mm, 33.8 mm or 35 mm.

[0007] Furthermore, a support portion is provided at the top of the air duct, the support portion is located inside the cover body, one end of the support portion is connected to the air duct, and the other end of the support portion abuts against the top of the cover body. Through the above setting, the support portion can provide support for the cover body, enabling the cover body to be stably placed on the top of the air duct.

[0008] Furthermore, a first protrusion is also provided at the top of the air duct, a through hole is provided at the top of the cover body, the first protrusion passes through the through hole and extends to the outside of the cover body, and the air duct is fixedly connected to the cover body through the first protrusion. Through the above setting, the air duct is connected to the cover body through the first protrusion. When the cover body is damaged, only the cover body needs to be replaced separately, improving the practicability of the device.

[0009] Furthermore, the air duct includes a pipe body and a cover body. The air inlet and the air outlet are both provided on the pipe body. The top of the pipe body has an opening, the cover body covers the opening, and the first protrusion is provided on the cover body. Through the above setting, the cover body and the pipe body are separately provided, and the connection between the air duct and the cover body is arranged on the cover body, avoiding excessive wear of the air duct by the cover body.

[0010] Furthermore, the air duct includes a first stepped pipe section and a second stepped pipe section connected in sequence. The air outlet is located on the first stepped pipe section, the air inlet is located on the second stepped pipe section, and the second stepped pipe section is fixedly connected to the air distribution plate. Through the above setting, the air in the air chamber below the air distribution plate enters the air duct from the air inlet on the second stepped pipe section and then discharges from the air outlet on the first stepped pipe section, improving the rationality of the air duct design.

[0011] Furthermore, one end of the second stepped pipe section connected to the first stepped pipe section is located above the air distribution plate. The bottom of the cover body is provided with a second protrusion, which is arranged around the inner wall of the cover body, and the second protrusion is in mutual fit with the outer wall of the second stepped pipe section. Through the above arrangement, the outer wall of the second protrusion in fit with the second stepped pipe section makes a gap exist between the first stepped pipe section and the inner wall of the cover body to form a circulation cavity.

[0012] Furthermore, a limiting portion is also arranged on the second stepped pipe section. The limiting portion is located inside the air distribution plate, and the end face of the limiting portion facing the cover body is an inclined surface, and the distance between the inclined surface and the axis of the air pipe gradually increases in the direction away from the cover body. Through the above arrangement, it can be ensured that the second stepped pipe section can be better fixed inside the air distribution plate.

[0013] Furthermore, the air supply port is inclined towards the side close to the air distribution plate along the air supply direction. Through the above arrangement, the air supply port can blow the materials on the air distribution plate more fully, thereby improving the fluidization effect of the materials.

[0014] Furthermore, the air distribution plate includes a main body, a first heat insulation layer and a second heat insulation layer. The first heat insulation layer is arranged on the upper surface of the main body, the second heat insulation layer is arranged on the lower surface of the main body, and the limiting portion is arranged inside the first heat insulation layer. Through the above arrangement, the first heat insulation layer and the second heat insulation layer can play a heat insulation role for the main body and the air pipe, avoiding damage to the main body and the air pipe due to excessive temperature.

[0015] Furthermore, a plurality of air outlet ports are provided, and the plurality of air outlet ports are evenly spaced on the side wall of the top of the air pipe. Through the above arrangement, uniform air outlet of the air pipe can be ensured, and thus uniform air outlet of the air supply port can be ensured. Description of the Drawings

[0016] The schematic diagrams in the specification that form a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0017] Figure 1 The structural schematic diagram of the fluidized bed provided by the present utility model is shown.

[0018] Among them, the above-mentioned drawings include the following reference numerals:

[0019] 10. Air distribution plate; 101. Main body; 102. First heat insulation layer; 103. Second heat insulation layer;

[0020] 20. Air pipe; 21. Air inlet; 22. Air outlet; 23. Air supply port;

[0021] 24. Support portion; 25. First protrusion; 27. Cover body; 28. First stepped pipe section; 29. Second stepped pipe section; 291. Limiting portion;

[0022] 30. Hood; 301. Second protrusion; 31. Through hole. Detailed implementation manner

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation to the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0024] As Figure 1 shown, an embodiment of the present invention provides a fluidized bed, which includes a air distribution plate 10, an air duct 20, and a hood 30. Among them, the air distribution plate 10 is provided with mounting holes. The air duct 20 is passed through the mounting holes. The air duct 20 has an air inlet 21 and an air outlet 22. The air inlet 21 is arranged at the bottom of the air distribution plate 10, and the air outlet 22 is arranged at the top of the air distribution plate 10. The air inlet 21 is communicated with the air outlet 22. The hood 30 is covered on the top of the air duct 20. The hood 30 and the air outlet 22 are located on the same side of the air distribution plate 10. A flow cavity is formed between the hood 30 and the air duct 20. A air supply port 23 is arranged at one end of the hood 30 close to the air distribution plate 10. The flow cavity is respectively communicated with the air supply port 23 and the air outlet 22. The distance between the air supply port 23 and the air distribution plate 10 is L, and 31 mm ≤ L ≤ 35 mm.

[0025] Applying the technical solution of the present invention, an air supply port 23 is arranged at one end of the hood 30 close to the air distribution plate 10, and the distance between the air supply port 23 and the air distribution plate 10 is L, and 31 mm ≤ L ≤ 35 mm. If L > 35 mm, the distance between the air supply port 23 and the air distribution plate 10 is relatively far. In this way, the path of the wind when blowing from the air supply port 23 to the materials on the fluidized bed becomes longer, more energy is lost, and the wind force decreases when blowing the materials, thereby reducing the fluidization effect on the materials. If L < 31 mm, the distance between the air supply port 23 and the air distribution plate 10 is relatively close. In this way, the impact force of the air outlet of the air supply port 23 on the air distribution plate 10 is enhanced, increasing the wear of the air outlet on the air distribution plate 10, and thereby reducing the service life of the air distribution plate 10. Therefore, setting 31 mm ≤ L ≤ 35 mm can not only make the air outlet of the air supply port 23 blow the materials on the fluidized bed powerfully, thereby ensuring the fluidization effect on the materials, but also extend the service life of the air distribution plate 10. Specifically, L can be 31 mm, 32.5 mm, 33 mm, 33.8 mm or 35 mm.

[0026] Among them, the hood 30 can change the air supply direction of the air duct 20, and can also protect the air duct 20, reducing the abrasion of the materials or slag on the fluidized bed to the air duct 20. At the same time, the air supply port 23 can change the air outlet direction of the air outlet 22 of the air duct 20, can blow the materials at the bottom of the hood 30, prevent slag accumulation at the lower part of the hood 30, and improve the uniformity of material fluidization.

[0027] Furthermore, a support portion 24 is provided at the top of the air duct 20. The support portion 24 is located inside the hood 30. One end of the support portion 24 is connected to the air duct 20, and the other end of the support portion 24 abuts against the top of the hood 30. Through the above arrangement, the hood 30 contacts the air duct 20 through the support portion 24 and is placed on the top of the air duct 20. The support portion 24 can provide support for the hood 30, enabling the hood 30 to be stably placed on the top of the air duct 20, thereby ensuring the stability and reliability of the contact between the hood 30 and the air duct 20.

[0028] Specifically, a first protrusion 25 is further provided at the top of the air duct 20, and a through hole 31 is provided at the top of the hood 30. The first protrusion 25 is inserted into the through hole 31 and extends to the outside of the hood 30. The air duct 20 is fixedly connected to the hood 30 through the first protrusion 25. Through the above arrangement, the air duct 20 is connected to the hood 30 through the first protrusion 25. When the hood 30 is damaged, there is no need to replace the air duct 20, and only the hood 30 needs to be replaced separately, improving the practicability of the device. The size of the first protrusion 25 can also be changed to adapt to different types or sizes of the hood 30, thereby improving the applicability of the device.

[0029] At the same time, the setting of the first protrusion 25 can also position the installation position of the hood 30 relative to the air duct 20, avoiding the deviation or misalignment of the installation position of the hood 30, which affects the air supply effect of the air supply port 23 and further affects the fluidization effect of the materials. And the first protrusion 25 can also limit the position of the hood 30, avoiding excessive circumferential displacement of the hood 30 and ensuring the reliability of the assembly of the hood 30 and the air duct 20.

[0030] Preferably, the through hole 31 is provided at the central position of the top of the hood 30, and the first protrusion 25 is provided at the central position of the top of the air duct 20. Such a setting can make the central axes of the top of the hood 30 and the air duct 20 coincide. This can not only ensure the uniform ventilation volume of the flow cavity outside the air duct 20, but also ensure the overall stability of the air duct 20 and the hood 30 after assembly, avoiding the situation where the hood 30 and the air duct 20 are misaligned during air supply, resulting in the inclination of the air duct 20 or the hood 30.

[0031] In this embodiment, the first protrusion 25 is connected to the through hole 31 by welding. With this arrangement, the operation is simple, facilitating the assembly and disassembly of the air duct 20 and the cover 30. In other embodiments of the present application, the first protrusion 25 and the through hole 31 can also be fixed by fasteners. Among them, the cross-sectional area of the first protrusion 25 is slightly smaller than the cross-sectional area of the through hole 31, which facilitates placing solder in the gap between the first protrusion 25 and the through hole 31 and can also prevent the outflow of solder from damaging the cover.

[0032] Furthermore, the air duct 20 includes a pipe body and a cover 27. The air inlet 21 and the air outlet 22 are both provided on the pipe body. The top of the pipe body has an opening, and the cover 27 is covered at the opening. The first protrusion 25 is provided on the cover 27. Through the above arrangement, the cover 27 and the pipe body are separately provided. When the first protrusion 25 is damaged, there is no need to replace the pipe body, and only the first protrusion 25 needs to be replaced separately. And by setting the connection between the air duct 20 and the cover 30 on the cover 27, it avoids excessive wear of the pipe body by the cover 30 and improves the service life of the pipe body.

[0033] Among them, a groove adapted to the bottom of the cover 27 is provided on the inner wall at the opening of the air duct 20. The bottom of the cover 27 is engaged with the groove and then fixed to the top of the air duct 20 by welding. Through the cooperation of the cover 27 and the support portion 24, it is ensured that the cover 30 can be stably placed on the top of the air duct 20.

[0034] Furthermore, there is also a gap between the bottom of the cover 27 and the cover 30 for placing the melted solder, preventing the melted solder from entering the interior of the pipe body and causing blockage of the pipe body over a long period, affecting the air inlet effect of the pipe body.

[0035] In the present application, the air duct 20 includes a first stepped pipe section 28 and a second stepped pipe section 29 connected in sequence. The air outlet 22 is located on the first stepped pipe section 28, and the air inlet 21 is located on the second stepped pipe section 29 at the position where the second stepped pipe section 29 is fixedly connected to the air distribution plate 10. Through the above arrangement, the air in the air chamber below the air distribution plate 10 enters the air duct 20 from the air inlet on the second stepped pipe section 29 and then is discharged from the air outlet 22 on the first stepped pipe section 28, improving the rationality of the design of the air duct 20.

[0036] Preferably, the outer diameter of the second stepped pipe section 29 is larger than the outer diameter of the first stepped pipe section 28. With this arrangement, the contact area between the second stepped pipe section 29 and the air distribution plate 10 can be increased, thereby improving the connection stability between the air duct 20 and the air distribution plate 10 and preventing the air duct 20 from tilting.

[0037] Among them, one end of the second stepped pipe section 29 connected to the first stepped pipe section 28 is located above the air distribution plate 10. A second protrusion 301 is provided at the bottom of the cover body 30. The second protrusion 301 is arranged on the inner wall of the cover body 30, and the outer wall of the second protrusion 301 is in mutual fit with the outer wall of the second stepped pipe section 29. Through the above settings, the outer wall of the second protrusion 301 in fit with the second stepped pipe section 29 forms a gap between the inner wall of the first stepped pipe section 28 and the cover body 30. The gap forms a circulation cavity, so that the air discharged from the air outlet 22 can flow in the circulation cavity and then be discharged from the air supply port 23 and blown onto the materials on the fluidized bed.

[0038] Furthermore, a limiting portion 291 is also provided on the second stepped pipe section 29. The limiting portion 291 is located inside the air distribution plate 10. The end face of the limiting portion 291 facing the cover body 30 is an inclined surface, and the distance between the inclined surface and the axis of the air pipe 20 gradually increases in the direction away from the cover body 30. Through the above settings, the portion above the fitting surface between the air distribution plate 10 and the end face of the limiting portion 291 facing the cover body 30 can provide a pressure for the limiting portion 291 to ensure that the second stepped pipe section 29 can be better fixed inside the air distribution plate 10.

[0039] At the same time, the limiting portion 291 can also fix and limit the position of the air pipe 20 inside the air distribution plate 10, improving the reliability of the fixation of the air pipe 20 inside the air distribution plate 10.

[0040] Specifically, the air supply port 23 is inclined toward the side close to the air distribution plate 10 along the air supply direction. Through the above settings, waste of wind force can be avoided. The air supply port 23 can blow the materials on the air distribution plate 10 more fully, thereby improving the fluidization effect of the materials. At the same time, it can also prevent the materials on the fluidized bed from entering the inside of the air pipe 20 and causing blockage of the air pipe 20. Among them, the air distribution plate 10 includes a main body 101, a first heat insulation layer 102 and a second heat insulation layer 103. The first heat insulation layer 102 is arranged on the upper surface of the main body 101, the second heat insulation layer 103 is arranged on the lower surface of the main body 101, and the limiting portion 291 is arranged inside the first heat insulation layer 102.

[0041] Through the above settings, the first heat insulation layer 102 and the second heat insulation layer 103 can play a heat insulation role for the main body 101 and the air pipe 20, preventing the main body 101 and the air pipe 20 from being damaged due to excessive temperature. At the same time, it plays a heat preservation role for the fluidized bed to ensure the full combustion of the materials. Among them, the limiting portion 291 is arranged between the main body 101 and the first heat insulation layer 102.

[0042] Further, there are multiple air outlets 22, and the multiple air outlets 22 are evenly spaced on the side wall of the top of the air duct 20. Through the above arrangement, the uniform air outlet of the air duct 20 can be ensured, and further the uniform air outlet of the air supply opening 23 can be ensured. In this application, the arrangement mode and shape of the air outlets 22 are not limited, as long as the uniform air outlet can be ensured. The shapes of the air outlets 22 and the air supply openings 23 are also not limited, and they can be set as a regular circle, a square, an ellipse or a special shape. In this embodiment, preferably, the air supply opening 23 is set as an ellipse, and its major axis is arranged in the vertical direction, so that the air outlet effect of the air supply opening 23 can be more three-dimensional.

[0043] In this embodiment, the air outlets 22 are arranged in multiple rows and are offset on the top of the air duct 20. The offset arrangement of the air outlets 22 can increase the arrangement density of the air outlets 22, enable the air duct 20 to uniformly discharge air around, and at the same time, cooperate with the arrangement of multiple rows of air outlets 22, so as to ensure the air volume, further improve the uniformity and wind force of the air outlet, and improve the fluidization effect on the material.

[0044] Further, according to the different effects of the fluidization wind speed in different areas of the furnace in the fluidized bed on the fluidization effect of the bed material, the number of the air supply openings 23 arranged on the hoods 30 at different positions in this application is also different. Since the fluidization resistance at the edge of the furnace is large and a large fluidization air volume is required, the hood 30 with a low resistance and 12 air supply openings 23 is adopted at the edge of the air distribution plate 10. The fluidization resistance at the center of the air distribution plate 10 is relatively small, and the hood 30 with a large resistance and 9 air supply openings 23 is adopted. The hood 30 with a transitional resistance and 10 air supply openings 23 is adopted in the remaining areas.

[0045] Through the above arrangement, when burning the nano-carbon hydrogen fuel, an effective material cycle can be ensured after the fuel enters the furnace, and by adjusting the number of the air supply openings 23 of the hoods 30 in different areas, the appropriate fluidization air volume can be controlled, ensuring that the finer fuel particles have sufficient reaction time in the furnace, ensuring uniform air distribution when burning the coal-based nano-carbon hydrogen fuel, and improving the combustion efficiency.

[0046] It should be noted that the terms used here are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0047] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model. At the same time, it should be understood that for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the description. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0048] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description. Without contrary statements, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present utility model; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0049] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationships of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0050] In addition, it should be noted that the use of words such as "first", "second" to limit components is only for the convenience of distinguishing the corresponding components. Without otherwise stating, the above words have no special meanings, and thus should not be construed as limiting the protection scope of the present utility model.

[0051] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various modifications and variations can be made to the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A fluidized bed, characterized in that, The fluidized bed includes: A distributor plate (10) provided with mounting holes thereon; An air duct (20) passing through the mounting holes. The air duct (20) has an air inlet (21) and an air outlet (22). The air inlet (21) is provided at the bottom of the distributor plate (10), the air outlet (22) is provided at the top of the distributor plate (10), and the air inlet (21) communicates with the air outlet (22); A cover body (30) covering the top of the air duct (20). The cover body (30) and the air outlet (22) are on the same side of the distributor plate (10). A flow cavity is formed between the cover body (30) and the air duct (20). An air supply port (23) is provided at one end of the cover body (30) close to the distributor plate (10). The flow cavity communicates with the air supply port (23) and the air outlet (22) respectively. The distance between the air supply port (23) and the distributor plate (10) is L, where 31 mm ≤ L ≤ 35 mm.

2. The fluidized bed according to claim 1, characterized in that, A support portion (24) is provided at the top of the air duct (20). The support portion (24) is located inside the cover body (30). One end of the support portion (24) is connected to the air duct (20), and the other end of the support portion (24) abuts against the top of the cover body (30).

3. The fluidized bed according to claim 2, wherein, A first protrusion (25) is further provided at the top of the air duct (20). A through hole (31) is provided at the top of the cover body (30). The first protrusion (25) passes through the through hole (31) and extends to the outside of the cover body (30). The air duct (20) is fixedly connected to the cover body (30) through the first protrusion (25).

4. The fluidized bed according to claim 3, wherein The air duct (20) includes a pipe body and a cover body (27). The air inlet (21) and the air outlet (22) are both provided on the pipe body. The top of the pipe body has an opening, and the cover body (27) covers the opening. The first protrusion (25) is provided on the cover body (27).

5. The fluidized bed according to claim 1, wherein The air duct (20) includes a first stepped pipe section (28) and a second stepped pipe section (29) connected in sequence. The air outlet (22) is located on the first stepped pipe section (28), and the air inlet (21) is located on the second stepped pipe section (29), at the position where the second stepped pipe section (29) is fixedly connected to the distributor plate (10).

6. The fluidized bed according to claim 5, characterized in that, One end of the second stepped pipe section (29) connected to the first stepped pipe section (28) is located above the distributor plate (10). A second protrusion (301) is provided at the bottom of the cover body (30). The second protrusion (301) surrounds the inner wall of the cover body (30), and the outer wall of the second stepped pipe section (29) is mutually attached to the second protrusion (301).

7. The fluidized bed according to claim 6, wherein A limiting part (291) is further arranged on the second stepped pipe section (29). The limiting part (291) is located inside the air distribution plate (10). The end face of the limiting part (291) facing the housing (30) is an inclined surface, and the distance between the inclined surface and the axis of the air pipe (20) gradually increases in the direction away from the housing (30).

8. The fluidized bed according to claim 1, characterized in that, The air supply port (23) is inclined in the air supply direction towards the side close to the air distribution plate (10).

9. The fluidized bed according to claim 7, characterized in that, The air distribution plate (10) comprises a body (101), a first heat insulation layer (102) and a second heat insulation layer (103). The first heat insulation layer (102) is arranged on the upper surface of the body (101), the second heat insulation layer (103) is arranged on the lower surface of the body (101), and the limiting part (291) is arranged inside the first heat insulation layer (102).

10. The fluidized bed according to claim 1, wherein, A plurality of air outlet openings (22) are arranged, and the plurality of air outlet openings (22) are evenly spaced on the side wall at the top of the air pipe (20).

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