Discharging device for coal feeding of boiler coal bunker

Abstract

The utility model provides a discharging device for boiler coal bunker coal feeding, which comprises a coal dropping pipe and an air supply pipe, the coal dropping pipe comprises an upper feeding section, a middle inclined section and a lower discharging section, and the air supply pipe comprises an upper air supply section communicated with the feeding section and a lower air supply section communicated with the discharging section; an air blowing mechanism used for conveying hot air into the coal dropping pipe is arranged at the position, corresponding to the joint of the feeding section and the inclined section, of the coal dropping pipe; the positions, corresponding to the inclined section, of the coal falling pipe are provided with a plurality of kicking and unblocking mechanisms and a plurality of air cannon unblocking mechanisms, and the multiple kicking and unblocking mechanisms and the multiple air cannon unblocking mechanisms are alternately arranged in the length direction of the inclined section one by one. The discharging device for coal feeding of the coal bunker of the boiler has the advantages of being not prone to blockage, good in applicability, high in reliability and easy to use, stable conveying of raw coal can be achieved, and the stability of operation of the boiler can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal chute clogging removal equipment, in particular to a discharging device for feeding coal from a boiler coal bunker. Background Art

[0002] The coal feeding of a CFB boiler enters each vertical section of the coal chute from the raw coal bunker through 4 closed coal feeding belts, and then enters the furnace through a 45° inclined coal chute. When the water content of the raw coal is small, there is no coal sticking or clogging in the coal chute, and it can smoothly enter the furnace for combustion. However, with the increase in the blending ratio of inferior coal, the water content of the inferior coal increases, resulting in frequent coal clogging in the coal chute during operation. The coal clogging phenomenon in the CFB boiler coal chute is particularly serious. The key parts of coal clogging are the inclined elbow and the reduced diameter part of the coal chute. The raw coal accumulates at the inclined elbow and the reduced diameter part of the coal chute, and continuously reduces the channel area, eventually completely blocking the coal chute. The coal cannot enter the furnace, causing the boiler bed temperature to drop, and the load has to be reduced. Frequent coal clogging seriously affects the safe operation of the boiler and environmental protection emissions.

[0003] The existing Chinese utility model patent with the application number 202122832811.6 discloses a CFB boiler coal chute clogging removal device, which includes a coal chute and a clogging removal device. The clogging removal device is arranged on the coal chute. The clogging removal device includes a pipeline body, a driving motor, a driving gear, a scraper and a gear ring. The driving motor drives the driving gear to rotate. Under the meshing action between the driving gear and the gear ring, the scraper is driven to rotate in a circle, and the scraper scrapes the coal adhered to the inner surface of the coal chute to eliminate the blockage. However, when the above device is used for long-distance discharging and conveying of inferior coal with more water content and impurities, due to the length limitation of the scraper, the coverage area is limited, resulting in poor cleaning effect of the scraper on the adhered inferior coal in the coal chute, and it cannot reduce the water content of the inferior coal, and the downward pushing and dredging effect on the inferior coal is also limited, and it cannot ensure the continuous conveying ability of the discharging device for inferior coal. Summary of the Utility Model

[0004] In view of this, the purpose of the present utility model is to provide a discharging device for feeding coal from a boiler coal bunker to solve the problem that the existing discharging device for feeding coal from a boiler coal bunker has poor cleaning effect on blocked inferior coal and affects the continuous conveying ability of the discharging device when conveying inferior coal.

[0005] To achieve the above object, the technical solution of the present utility model is realized as follows:

[0006] A coal discharging device for a boiler coal bunker, comprising a coal dropping pipe and an air supply pipe. The coal dropping pipe includes a feeding section at the upper part, an inclined section in the middle, and a discharging section at the lower part. The air supply pipe includes an upper air supply section communicated with the feeding section and a lower air supply section communicated with the discharging section. A blowing mechanism for conveying hot air into the coal dropping pipe is arranged at the position of the coal dropping pipe corresponding to the connection between the feeding section and the inclined section. A plurality of kicking and unblocking mechanisms and air cannon unblocking mechanisms are arranged at the position of the coal dropping pipe corresponding to the inclined section, and the plurality of kicking and unblocking mechanisms and the plurality of air cannon unblocking mechanisms are alternately arranged along the length direction of the inclined section.

[0007] Further, the kicking and unblocking mechanism includes a kicking and unblocking device arranged on the coal dropping pipe.

[0008] Further, the air cannon unblocking mechanism includes a plurality of air cannon unblocking devices arranged at intervals on the coal dropping pipe.

[0009] Further, the air cannon unblocking mechanism further includes a compressed air main pipe connected to the air cannon unblocking device, and the compressed air main pipe is arranged parallel to the inclined section.

[0010] Further, the blowing mechanism includes a self-spreading coal air main pipe communicated with the coal dropping pipe, and the self-spreading coal air main pipe is arranged parallel to the inclined section.

[0011] Further, one end of the self-spreading coal air main pipe extending into the coal dropping pipe is provided with a wind dividing cover. One end of the wind dividing cover facing the inclined section is provided with a flat part, and the other end is provided with an inclined part. The flat part is perpendicular to the inclined section, and a plurality of wind dividing holes are arranged on the flat part. The inclined part is arranged parallel to the inclined section.

[0012] Further, a plurality of air guiding plates are arranged in the wind dividing cover. The length direction of each air guiding plate is the same as the length direction of the self-spreading coal air main pipe, and an air guiding gap for communicating the wind dividing holes and the self-spreading coal air main pipe exists between adjacent two air guiding plates.

[0013] Further, both the wind dividing cover and the air guiding plates are made of heat-conducting metal materials.

[0014] Further, the end of the air guiding plate facing the self-spreading coal air main pipe is provided with a tapered end.

[0015] Further, the self-spreading coal air main pipe is a rectangular pipe.

[0016] Compared with the prior art, the coal discharging device for a boiler coal bunker of the present utility model has the following advantages:

[0017] The coal unloading device for a boiler coal bunker described in the present utility model has the advantages of not being easily blocked, good applicability, high reliability, and easy use. It can achieve stable conveyance of raw coal, which is beneficial to improving the stability of boiler operation. By connecting the upper air supply section of the air supply pipe to the feeding section of the coal dropping pipe and connecting the lower air supply section of the air supply pipe to the discharging section of the coal dropping pipe, the raw coal in the coal dropping pipe can not only move under the downward push of the air flow in the upper air supply pipe, but also be pushed out of the coal dropping pipe under the activation of the lower air supply pipe, enabling the continuous conveyance of raw coal through the coal dropping pipe. In addition, by arranging a plurality of air cannon clog clearing devices at the positions between adjacent kicking and loosening clog clearing devices, multi-stage crushing and clog clearing can also be carried out through the plurality of air cannon clog clearing devices. Compared with only using an air cannon for clog clearing, the effect of this clog clearing is better, which is beneficial to the long-distance transmission of raw coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings forming a part of the present utility model 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:

[0019] Figure 1 FIG. is a schematic structural diagram of a coal unloading device for a boiler coal bunker according to an embodiment of the present utility model;

[0020] Figure 2 FIG. is a schematic structural diagram of the air blowing mechanism in a coal unloading device for a boiler coal bunker according to an embodiment of the present utility model;

[0021] Figure 3 FIG. is a schematic structural diagram of the air distribution hood in a coal unloading device for a boiler coal bunker according to an embodiment of the present utility model.

[0022] DESCRIPTION OF THE REFERENCE NUMERALS:

[0023] 1. Feeding section; 2. Inclined section; 3. Discharging section; 4. Upper air supply section; 5. Lower air supply section; 6. Air blowing mechanism; 7. Kicking and loosening clog clearing device; 8. Air cannon clog clearing device; 9. Compressed air main pipe; 10. Air distribution hood; 11. Air distribution hole; 12. Inclined surface part; 13. Flat surface part; 14. Air guiding plate; 15. Conical end part; 16. Air guiding gap; 17. Self-spreading coal air main pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0025] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0026] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific circumstances.

[0027] The present utility model will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0028] A coal discharging device for a boiler coal bunker for coal feeding, as Figures 1 to 3 shown, includes a coal dropping pipe and an air supply pipe. The coal dropping pipe includes a feeding section 1 at the upper part, an inclined section 2 in the middle, and a discharging section 3 at the lower part. The air supply pipe includes an upper air supply section 4 communicating with the feeding section 1 and a lower air supply section 5 communicating with the discharging section 3. At the position corresponding to the connection between the feeding section 1 and the inclined section 2 on the coal dropping pipe, there is a blowing mechanism 6 for conveying hot air into the coal dropping pipe. At the position corresponding to the inclined section 2 on the coal dropping pipe, there are a plurality of kicking and loosening and blockage clearing mechanisms and air cannon blockage clearing mechanisms. The plurality of kicking and loosening and blockage clearing mechanisms and the plurality of air cannon blockage clearing mechanisms are arranged alternately one by one along the length direction of the inclined section 2, that is, there is an air cannon blockage clearing mechanism behind each kicking and loosening and blockage clearing mechanism.

[0029] Exemplarily, the air supply pipe and the coal dropping pipe can be connected by a flange. Among them, the upper air supply section 4 and the lower air supply section 5 of the air supply pipe are both horizontally arranged, so that the air flow entering the coal dropping pipe through the air supply pipe can better push the raw coal in the coal dropping pipe. By connecting the upper air supply section 4 of the air supply pipe to the feeding section 1 of the coal dropping pipe and connecting the lower air supply section 5 of the air supply pipe to the discharging section 3 of the coal dropping pipe, the raw coal in the coal dropping pipe can not only move downward under the downward push of the air flow in the upper air supply pipe, but also move out of the coal dropping pipe under the horizontal push of the air flow in the lower air supply pipe, so that the raw coal can be continuously transported through the coal dropping pipe.

[0030] Preferably, the kicking and loosening and blockage clearing mechanism includes a kicking and loosening and blockage clearing device 7 arranged on the coal dropping pipe. Exemplarily, the kicking and loosening and blockage clearing device 7 can adopt existing kicking devices, bin wall vibrators, air hammers, etc. Those skilled in the art can also install other types of kicking and loosening and blockage clearing devices 7 on the coal dropping pipe according to actual needs to achieve the kicking and loosening and blockage clearing of the blocked raw coal in the coal dropping pipe, which will not be elaborated here.

[0031] Preferably, the air cannon blockage clearing mechanism includes a plurality of air cannon blockage clearing devices 8 arranged at intervals on the coal dropping pipe. Exemplarily, the air cannon blockage clearing device 8 can adopt existing air cannons. The air cannon blockage clearing devices 8 can be arranged at intervals of two, three or more along the length direction of the coal dropping pipe, and each air cannon blockage clearing device 8 is communicated with the coal dropping pipe. By arranging a plurality of air cannon blockage clearing devices 8 at the position between two kicking and loosening and blockage clearing devices 7, and using the cooperation of the air cannon blockage clearing devices 8 and the kicking and loosening and blockage clearing devices 7, it can play a good role in loosening the blocked raw coal in the coal dropping pipe. Coupled with the air flow pushing effect of the air blowing mechanism 6 and the air supply pipe, it can ensure that this unloading device can continuously and stably transport raw coal.

[0032] In addition, the air cannon blockage clearing mechanism further includes a compressed air main pipe 9 connected to the air cannon blockage clearing device 8, and the compressed air main pipe 9 is arranged in parallel with the inclined section 2. By arranging the compressed air main pipe 9 parallel to the inclined section 2 to supply air to each air cannon, the stability and consistency of the air supply to each air cannon can be ensured, thereby improving the loosening effect of each air cannon on the blocked raw coal in the coal dropping pipe.

[0033] In the actual application process, the air supply pipe and the air blowing mechanism 6 can be used to continuously supply hot air into the coal dropping pipe. By continuously supplying hot air into the coal dropping pipe, it can not only push the raw coal in the coal dropping pipe to move downward continuously, avoid the accumulation of raw coal on the inner wall and the bending part of the coal dropping pipe, but also continuously dry the raw coal in the coal dropping pipe, thereby reducing the moisture content of the raw coal, effectively preventing the raw coal from sticking in the coal dropping pipe, and avoiding the blockage of the coal dropping pipe.

[0034] Meanwhile, by alternately arranging the kicking and loosening blockage clearing mechanism and the air cannon blockage clearing mechanism, the operator can also make the kicking and loosening blockage clearing mechanism and the air cannon blockage clearing mechanism work alternately. For example, the raw coal in the coal dropping pipe can be loosened by the kicking and loosening blockage clearing mechanism first, so that pores are generated at the adhered raw coal. Then, as the adhered raw coal continues to move downward along the coal dropping pipe, the operator can also use the air cannon blockage clearing mechanism to further loosen the adhered raw coal. At this time, the high-pressure gas can more easily enter the interior of the adhered raw coal, so that the adhered raw coal is further loosened and broken, making the raw coal here not easily adhere and block the coal dropping pipe again during the subsequent movement. In addition, by arranging a plurality of air cannon blockage clearing devices 8 at the positions between two adjacent kicking and loosening blockage clearing devices 7, multi-stage crushing and blockage clearing can also be carried out through the plurality of air cannon blockage clearing devices 8. Compared with only using the air cannon for blockage clearing, the effect of using the kicking and loosening blockage clearing device 7 and the air cannon blockage clearing device 8 in cooperation to achieve blockage clearing is better, which is beneficial to the long-distance transmission of raw coal.

[0035] Preferably, the air blowing mechanism 6 includes a self-spreading coal air main pipe 17 communicated with the coal dropping pipe, and the self-spreading coal air main pipe 17 is arranged parallel to the inclined section 2. Exemplarily, one end of the self-spreading coal air main pipe 17 can be fixedly installed on the coal dropping pipe, and the other end can be connected to an external hot air supply device to continuously blow hot air into the coal dropping pipe.

[0036] In the actual application process, the self-spreading coal air main pipe 17 can be arranged close to the inner side wall of the lower part of the coal dropping pipe, so that the air flow blown into the coal dropping pipe by the self-spreading coal air main pipe 17 can flow along the inner side wall of the lower part of the coal dropping pipe, and the pushing effect on the raw coal just falling into the inclined section 2 is better. By arranging the air blowing mechanism 6 corresponding to the connection of the feeding section 1 and the inclined section 2, and using the continuous air supply of the air blowing mechanism 6, it can effectively prevent the raw coal from accumulating at the connection of the feeding section 1 and the inclined section 2, and at the same time quickly push and dry the raw coal falling from the feeding section 1 to the inclined section 2, accelerating the speed of the raw coal flowing downward along the inclined section 2 and reducing the probability of the raw coal adhering and blocking in the coal dropping pipe.

[0037] Preferably, a wind distributing cover 10 is provided at one end of the self-spreading coal air main pipe 17 extending into the coal dropping pipe. A flat surface part 13 is provided at one end of the wind distributing cover 10 facing the inclined section 2, and an inclined surface part 12 is provided at the other end. The flat surface part 13 is perpendicular to the inclined section 2, and a plurality of wind distributing holes 11 are provided on the flat surface part 13. The inclined surface part 12 is arranged parallel to the inclined section 2. Exemplarily, the wind distributing cover 10 can be fixed on the self-spreading coal air main pipe 17 or installed on the coal dropping pipe. Those skilled in the art can select a suitable scheme to install the wind distributing cover 10 according to actual needs, and will not be elaborated here.

[0038] In the actual application process, by setting a wind distribution hood 10 at one end of the self-blowing coal air main pipe 17 extending into the coal dropping pipe, and arranging a number of wind distribution holes 11 on the wind distribution hood 10, the air flow entering the coal dropping pipe through the self-blowing coal air main pipe 17 can be dispersed into multiple air flows under the action of the wind distribution holes 11, which is beneficial to expanding the pushing area of the hot air flow on the raw coal and the drying effect. In addition, by setting an inclined surface part 12 on the wind distribution hood 10, the inclined surface part 12 can play a good guiding role in the raw coal falling through the feeding section 1 and avoid the accumulation of raw coal at the wind distribution holes 11. A boss structure that blocks the wind distribution holes 11 can also be formed between the flat surface part 13 and the inner side wall of the coal dropping pipe, which can provide further shielding protection for the wind distribution holes 11, is beneficial to further reducing the probability of blockage of the wind distribution holes 11, and ensures that each wind distribution hole 11 can continuously and stably blow out hot air flow.

[0039] Preferably, a number of air guiding plates 14 are arranged inside the wind distribution hood 10. The length direction of each air guiding plate 14 is the same as the length direction of the self-blowing coal air main pipe 17, and there is an air guiding gap 16 for communicating the wind distribution holes 11 and the self-blowing coal air main pipe 17 between two adjacent air guiding plates 14. Exemplarily, five wind distribution holes 11 can be arranged at intervals, and an air guiding plate 14 is arranged at the position between two adjacent wind distribution holes 11, and each air guiding plate 14 is fixed on the wind distribution hood 10. By arranging the air guiding plates 14, the air flow entering the wind distribution hood 10 through the self-blowing coal air main pipe 17 can be evenly dispersed and guided to each wind distribution hole 11, which is beneficial to avoiding the disorder of the air flow in the wind distribution hood 10 and affecting the air flow velocity, and ensuring that the air flow can continuously and stably blow out through the wind distribution holes 11, and play a role in pushing and drying the raw coal in the coal dropping pipe.

[0040] Preferably, both the wind distribution hood 10 and the air guiding plates 14 are made of heat-conducting metal materials. Exemplarily, the wind distribution hood 10 and the air guiding plates 14 can be made of steel or aluminum alloy materials. By making the wind distribution hood 10 and the air guiding plates 14 of heat-conducting metal materials, the hot air flow entering the wind distribution hood 10 can also play a good heating role on the wind distribution hood 10 and the air guiding plates 14. Among them, the air guiding plates 14 can increase the contact area between the wind distribution hood 10 and the hot air flow, thereby improving the heating effect of the hot air flow on the wind distribution hood 10. The heated wind distribution hood 10 can play a role in quickly drying the raw coal falling on the inclined surface part 12, avoiding the adhesion of the raw coal at the inclined surface part 12, and thus reducing the possibility of adhesion and blockage of the raw coal at the feeding section 1.

[0041] Preferably, a tapered end part 15 is arranged at one end of the air guiding plate 14 facing the self-blowing coal air main pipe 17. By arranging the tapered end part 15 on the air guiding plate 14, the blocking effect of the end part of the air guiding plate 14 on the hot air flow can be reduced, ensuring that while the air guiding plate 14 can disperse and guide the hot air flow, the reduction of the hot air flow velocity can also be avoided, thereby ensuring the pushing effect of the hot air flow on the raw coal in the coal dropping pipe.

[0042] In the actual application process, a flared opening can also be formed between the conical ends 15 on the two air guide plates 14, so that during the process of the hot air flow flowing along the air guide gap 16, as the width of the diversion gap becomes smaller, the flow rate of the hot air flow gradually increases, enabling the hot air flow blown out through the air distribution holes 11 to better push the raw coal to be conveyed downward along the inclined section 2.

[0043] Preferably, the self-spreading coal air main pipe 17 is a rectangular pipe. Compared with the self-spreading coal air main pipes 17 of other shapes, the rectangular pipe has a larger air outlet area, which can not only ensure the effect of pushing and drying the raw coal, but also facilitate the diversion and guidance of the hot air flow by the air distribution hood 10, improving the effect of the hot air flow on the raw coal.

[0044] The unloading device for coal feeding in a boiler coal bunker described in the present invention has the advantages of not being easily blocked, good applicability, high reliability, and easy use, can realize the stable transportation of raw coal, and is beneficial to improving the stability of boiler operation. By connecting the upper air supply section of the air supply pipe with the feeding section of the coal dropping pipe, and connecting the lower air supply section of the air supply pipe with the discharging section of the coal dropping pipe, the raw coal in the coal dropping pipe can not only move under the downward push of the air flow in the upper air supply pipe, but also be pushed out of the coal dropping pipe under the push of the lower air supply pipe starting, enabling the raw coal to be continuously transported through the coal dropping pipe. In addition, by arranging a plurality of air cannon blockage clearing devices at the positions between adjacent two kicking and loosening blockage clearing devices, multi-stage crushing and blockage clearing can also be carried out through the plurality of air cannon blockage clearing devices. Compared with only using an air cannon for blockage clearing, the effect of this blockage clearing is better, which is beneficial to the long-distance transmission of raw coal.

[0045] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A discharging device for feeding coal into a boiler coal bunker, characterized in that: It includes a coal dropping pipe and an air supply pipe. The coal dropping pipe includes a feeding section (1) at the upper part, an inclined section (2) in the middle, and a discharging section (3) at the lower part. The air supply pipe includes an upper air supply section (4) communicated with the feeding section (1) and a lower air supply section (5) communicated with the discharging section (3). At the position corresponding to the connection between the feeding section (1) and the inclined section (2) on the coal dropping pipe, there is a blowing mechanism (6) for conveying hot air into the coal dropping pipe. At the position corresponding to the inclined section (2) on the coal dropping pipe, there are multiple kicking and unblocking mechanisms and air cannon unblocking mechanisms. The multiple kicking and unblocking mechanisms and the multiple air cannon unblocking mechanisms are arranged alternately one by one along the length direction of the inclined section (2).

2. The discharging device for coal feeding in a boiler coal bunker according to claim 1, characterized in that: The kicking and unblocking mechanism includes a kicking and unblocking device (7) arranged on the coal dropping pipe.

3. A coal discharging device for a boiler coal bunker according to claim 1, characterized in that: The air cannon unblocking mechanism includes multiple air cannon unblocking devices (8) arranged at intervals on the coal dropping pipe.

4. The discharging device for coal feeding in a boiler coal bunker according to claim 3, characterized in that: The air cannon unblocking mechanism further includes a compressed air main pipe (9) connected to the air cannon unblocking device (8). The compressed air main pipe (9) is arranged parallel to the inclined section (2).

5. The coal discharging device for a boiler coal bunker according to claim 1, characterized in that: The blowing mechanism (6) includes a self-spreading coal air main pipe (17) communicated with the coal dropping pipe. The self-spreading coal air main pipe (17) is arranged parallel to the inclined section (2).

6. The discharging device for coal feeding in a boiler coal bunker according to claim 5, characterized in that: One end of the self-spreading coal air main pipe (17) extending into the coal dropping pipe is provided with a wind distribution hood (10). One end of the wind distribution hood (10) facing the inclined section (2) is provided with a flat part (13), and the other end is provided with an inclined part (12). The flat part (13) is perpendicular to the inclined section (2). There are several air distribution holes (11) on the flat part (13). The inclined part (12) is arranged parallel to the inclined section (2).

7. The coal discharging device for a boiler coal bunker according to claim 6, characterized in that: Several air guiding plates (14) are arranged in the wind distribution hood (10). The length direction of each air guiding plate (14) is the same as the length direction of the self-spreading coal air main pipe (17). There is an air guiding gap (16) for communicating the air distribution hole (11) and the self-spreading coal air main pipe (17) between two adjacent air guiding plates (14).

8. A coal discharging device for a boiler coal bunker according to claim 7, characterized in that: Both the wind distribution hood (10) and the air guiding plates (14) are made of heat-conducting metal materials.

9. The discharging device for coal feeding in a boiler coal bunker according to claim 7, characterized in that: One end of the air guiding plate (14) facing the self-spreading coal air main pipe (17) is provided with a tapered end (15).

10. A coal discharging device for a boiler coal bunker according to any one of claims 5-9, characterized in that: The self-spreading coal air main pipe (17) is a rectangular pipe.

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