Feeding device and feeding system of coal mill

Abstract

The invention discloses a coal mill feeding device and a feeding system, the coal mill feeding device comprises a feeding hopper, the discharging end of the feeding hopper is communicated with a purging mechanism, a hoop is fixedly mounted at the joint of the feeding hopper and the purging mechanism, and the discharging end of the purging mechanism is communicated with a coal milling barrel; a feeding pipe is arranged at one end of the coal grinding barrel, a discharging pipe is arranged at the other end of the coal grinding barrel, a support is rotationally connected to the feeding pipe and the discharging pipe, a bearing is arranged on the surface of the feeding pipe in a sleeving mode, sealing filler is arranged at the feeding end of the feeding pipe, and the sealing filler seals the end face of the feeding pipe and the end face of the bearing. The technical problems that in the using process of an existing coal mill feeding device, coal slurry at the connecting position of the feeding end of a coal mill and sealing filler is inconvenient to purge through air, the coal slurry is prone to leaking from the sealing filler, operation faults of the coal mill are caused, and the maintenance cost is increased are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding equipment, in particular to a coal mill feeding device and a feeding system. Background Art

[0002] A coal mill belongs to a kind of grinding equipment and is used to crush and grind coal into pulverized coal, which is widely used in the power, metallurgy and building materials industries. It is particularly important in industrial boilers and power plants because pulverized coal burns more completely and efficiently, which helps to improve energy utilization efficiency and reduce environmental pollution. A wet overflow rod mill belongs to a kind of coal mill. The working mode of the wet overflow rod mill is that the cylinder is rotated by a motor, so that the steel rods installed in the cylinder are lifted to a certain height and then fall freely, and the crushing and fine grinding of materials are realized through the impact and friction. The materials in the cylinder are gradually ground fine and discharged from the overflow ports at both ends or one end together with the slurry.

[0003] During the use of the wet overflow rod mill, there is a sealing packing between the feeding end of the coal mill inlet and the bearing end face. The main material of the sealing packing is oil-impregnated asbestos gasket packing. The operating cycle of this sealing packing is short, and slurry leakage at the packing is serious. The accumulated and leaked coal slurry enters the gap between the large and small gears of the coal mill through the large gear ring of the coal mill. The lubricating grease between the large and small gears is contaminated and the oil film is damaged. When the oil film is seriously damaged, it will cause poor meshing of the large and small gears of the coal mill, large vibration of the main motor and reducer of the coal mill, fracture of the clutch hub bolts, and the mixed coal slurry may also catch fire. After a new packing is replaced and put into use at the inlet end face of the coal mill, the operating cycle is short, and there will be different degrees of slurry leakage at the packing. Moreover, since the coal mill is a rotating equipment, when cleaning the leaked coal slurry, the coal mill must be stopped, the operation time is long, and the start-stop times of the coal mill increase, increasing the failure rate of the equipment.

[0004] During the use of the existing coal mill feeding device, it is not convenient to use air to blow the coal slurry at the connection between the feeding end of the coal mill and the sealing packing, which easily causes the coal slurry to leak from the sealing packing, resulting in the operation failure of the coal mill and increasing the maintenance cost. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that during the use of the existing coal mill feeding device, it is not convenient to use air to blow the coal slurry at the connection between the feeding end of the coal mill and the sealing packing, which easily causes the coal slurry to leak from the sealing packing, resulting in the operation failure of the coal mill and increasing the maintenance cost.

[0006] To solve the above technical problem, the present invention provides the following technical solution: a coal mill feeding device, including a feeding hopper, the discharging end of the feeding hopper is communicated with a purging mechanism, a hoop is fixedly installed at the connection between the feeding hopper and the purging mechanism, and the discharging end of the purging mechanism is communicated with a coal grinding cylinder; One end of the coal grinding cylinder is provided with a feed pipe, and the other end of the coal grinding cylinder is provided with a discharge pipe. A support is rotatably connected to the feed pipe and the discharge pipe. A bearing is sleeved on the surface of the feed pipe. A sealing packing is provided at the feed end of the feed pipe. The sealing packing seals the end faces of the feed pipe and the bearing. The purging mechanism purges annular air into the inner wall of the sealing packing to clean the coal slurry and prevent coal slurry leakage.

[0007] As a preferred solution of the coal mill feeding device of the present invention, wherein: the bottom of the support is fixedly connected with a base, and a driving component is installed on the surface of the coal grinding cylinder. The driving component is fixedly installed on the top of the base.

[0008] As a preferred solution of the coal mill feeding device of the present invention, wherein: the discharge end of the discharge pipe is communicated with a drum screen.

[0009] As a preferred solution of the coal mill feeding device of the present invention, wherein: the purging mechanism includes a housing. The feed end of the housing is fixedly connected with the discharge end of the feed hopper. The discharge end of the housing is fixedly installed on the support and communicated with the feed end of the feed pipe.

[0010] As a preferred solution of the coal mill feeding device of the present invention, wherein: a protective cover and an annular pipe are fixedly installed on the surface of the housing. The annular pipe is located in the inner cavity of the protective cover. The top and bottom of the annular pipe are communicated with an air inlet pipe. The inner side of the annular pipe is communicated with a purging component. The purging components are distributed around the inner side of the annular pipe. The middle end of the inner wall of the housing is fixedly connected with a feed ring and a discharge ring.

[0011] As a preferred solution of the coal mill feeding device of the present invention, wherein: the right side of the feed ring is fixedly connected with the left side of the discharge ring. The air outlet end of the purging component penetrates into the inner cavity of the discharge ring.

[0012] As a preferred solution of the coal mill feeding device of the present invention, wherein: the purging component includes an air outlet pipe. The air outlet pipe is fixedly installed in the discharge ring. The air inlet end of the air outlet pipe is communicated with the annular pipe. The air outlet end of the air outlet pipe penetrates into the inner cavity of the discharge ring. A tee pipe is fixedly connected to the top of the inner cavity of the air outlet pipe. The left and right sides of the bottom of the tee pipe are communicated with air outlet heads. A first through hole is opened at the center of the top of the tee pipe. Second through holes are opened on the left and right sides of the bottom of the tee pipe. The second through holes are communicated with the tops of the air outlet heads.

[0013] As a preferred embodiment of the coal mill feeding device of the present invention, wherein: a control assembly is installed at the bottom of the inner cavity of the air outlet pipe. The control assembly includes a cylinder body, the top of the cylinder body is fixedly connected to the inner wall of the air outlet pipe, an electromagnetic coil is sleeved on the surface of the cylinder body, a sliding rod cooperating with the electromagnetic coil is movably connected to the inner wall of the cylinder body, a return spring is movably sleeved on the surface of the sliding rod, the return spring is located in the inner cavity of the cylinder body, the bottom of the sliding rod is fixedly connected to a telescopic rod, and the surface of the telescopic rod is movably connected to the inner wall of the cylinder body.

[0014] As a preferred embodiment of the coal mill feeding device of the present invention, wherein: the left and right sides of the bottom of the telescopic rod are rotatably connected to a first connecting rod, the bottom of the first connecting rod is rotatably connected to a second connecting rod, the bottom of the second connecting rod is rotatably connected to an opening and closing piece, the opposite sides of the two opening and closing pieces are rotatably connected to a fixing piece, the fixing piece is fixedly installed at the air outlet end of the bottom of the air outlet pipe, the bottom of the cylinder body is fixedly connected to a fixing frame, the bottom of the fixing frame is fixedly connected to a wind shield, and the wind shield is sleeved outside the first connecting rod and the second connecting rod and is located above the opening and closing piece.

[0015] A coal mill feeding system further includes a raw coal bunker and a coal feeder. The discharge end of the raw coal bunker is communicated with the feed end of the coal feeder, and the discharge end of the coal feeder is communicated with the feed end of the feed hopper. The raw coal bunker is used for storing raw coal and providing raw material supply for the coal feeder. A conical discharge hopper is provided at the bottom of the raw coal bunker. The bottom of the conical discharge hopper has an inclined angle structure of 60-70° to accelerate the flow of coal material by gravity. A high-chromium cast iron layer or a wear-resistant ceramic layer is provided on the inner wall of the conical discharge hopper, and a vibrator is installed on the surface of the conical discharge hopper. The working frequency of the vibrator is 15-30 Hz. The coal feeder is used for feeding raw coal into the feed hopper. The coal feeder includes a variable-frequency speed-regulation screw conveyor. The rotational speed range of the variable-frequency speed-regulation screw conveyor is 0-30 r / min. The discharge port of the variable-frequency speed-regulation screw conveyor is communicated with the feed port of the feed hopper, and a sealing structure is provided at the connection.

[0016] The beneficial effects of the present invention: 1. Through the synergistic effect of the purging mechanism and the sealing packing, the present invention significantly improves the sealing performance and anti-leakage ability of the coal mill feeding device. The purging mechanism introduces plant air through an annular pipe, and forms a high-speed air flow through the purging assembly, continuously flushing the inner wall of the sealing packing, removing the attached coal slurry, effectively preventing the sealing surface from being blocked or leaking due to the accumulation of coal slurry. At the same time, the sealing packing is made of high-temperature and wear-resistant materials, combined with the dynamically adjusted purging air volume, which not only ensures the cleanliness of the sealing surface, but also avoids the maintenance cost of frequently replacing the traditional sealing structure due to the adhesion of coal slurry. In addition, the design of the air outlet pipe of the purging assembly and the feeding ring and discharging ring further optimizes the coal material flow path, reduces the impact of coal material on the purging assembly, and extends the service life of the equipment. This design is especially suitable for industrial scenarios with strict requirements for sealing and continuous operation such as thermal power generation and cement production, significantly reducing the shutdown risk and maintenance cost caused by leakage.

[0017] 2. Through the innovative design of the control component, the present invention realizes the precise dynamic adjustment of the purging air volume, thus taking into account the cleaning efficiency and energy consumption optimization. The control component adjusts the opening and closing angle of the opening and closing piece in real time through the PLC / DCS system according to the load state or feeding speed of the coal grinding cylinder, and dynamically controls the air volume output of the air outlet head. For example, during high-load operation, the opening and closing piece rotates upward to increase the air flow speed, quickly remove the coal slurry and prevent blockage. During low-load operation, the opening and closing piece fits the fixed piece to reduce the air volume and reduce energy consumption. This intelligent adjustment mechanism not only avoids the problem of sealing packing wear caused by excessive purging in the traditional fixed air volume system, but also significantly reduces the use cost of compressed air or nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the structural schematic diagram of the present invention Figure 1 ; Figure 2 is the structural schematic diagram of the present invention Figure 2 ; Figure 3 is the partial cross-sectional view of the present invention; Figure 4 is the cross-sectional view of the purging mechanism of the present invention; Figure 5 is the structural schematic diagram of the air inlet pipe, circular pipe and purging assembly of the present invention; Figure 6 is the cross-sectional view of the purging assembly of the present invention; Figure 7 is the cross-sectional view of the tee pipe and air outlet head of the present invention; Figure 8 is the cross-sectional view of the control component of the present invention; Figure 9 is the cross-sectional view of the telescopic cylinder of the present invention.

[0019] In the figure: 1, feed hopper; 2, purging mechanism; 3, hoop; 4, coal grinding cylinder; 5, support; 6, base; 7, drive assembly; 8, discharge pipe; 9, drum screen; 10, sealing packing; 11, bearing; 12, feed pipe; 201, housing; 202, protective cover; 203, air inlet pipe; 204, annular pipe; 205, discharge ring; 206, purging assembly; 207, feed ring; 208, air outlet pipe; 209, tee; 210, threaded ring; 211, control assembly; 212, air outlet head; 213, second through hole; 214, first through hole; 215, cylinder body; 216, electromagnetic coil; 217, telescopic rod; 218, first connecting rod; 219, second connecting rod; 220, opening and closing piece; 221, fixed piece; 222, wind shield; 223, fixing bracket; 224, slide bar; 225, return spring. Detailed implementation manners

[0020] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given with reference to the accompanying drawings of the specification. Embodiment 1

[0021] Refer to Figures 1-9 , this embodiment provides a coal feeder for a coal mill, which includes a feed hopper 1. The discharge end of the feed hopper 1 is communicated with a purging mechanism 2. A hoop 3 is fixedly installed at the connection between the feed hopper 1 and the purging mechanism 2. The discharge end of the purging mechanism 2 is communicated with a coal grinding cylinder 4.

[0022] Furthermore, one end of the coal grinding cylinder 4 is provided with a feed pipe 12, and the other end of the coal grinding cylinder 4 is provided with a discharge pipe 8. A support 5 is rotatably connected to the feed pipe 12 and the discharge pipe 8. A bearing 11 is sleeved on the surface of the feed pipe 12. A sealing packing 10 is provided at the feed end of the feed pipe 12. The sealing packing 10 seals the end faces of the feed pipe 12 and the bearing 11. The purging mechanism 2 blows annular air into the inner wall of the sealing packing 10 to clean the coal slurry and prevent the coal slurry from leaking.

[0023] Furthermore, the bottom of the support 5 is fixedly connected to a base 6. A drive assembly 7 is installed on the surface of the coal grinding cylinder 4. The drive assembly 7 is fixedly installed on the top of the base 6.

[0024] Furthermore, the discharge end of the discharge pipe 8 is communicated with a drum screen 9.

[0025] Furthermore, the purging mechanism 2 includes a housing 201. The feed end of the housing 201 is fixedly connected to the discharge end of the feed hopper 1. The discharge end of the housing 201 is fixedly installed on the support 5 and is communicated with the feed end of the feed pipe 12.

[0026] Further, a protective cover 202 and an annular pipe 204 are fixedly installed on the surface of the housing 201. The annular pipe 204 is located inside the protective cover 202. The top and bottom of the annular pipe 204 are connected to an air inlet pipe 203, and the inner side of the annular pipe 204 is connected to a purging assembly 206. The purging assembly 206 is distributed around the inner side of the annular pipe 204. In the middle of the inner wall of the housing 201, a feed ring 207 and a discharge ring 205 are fixedly connected.

[0027] Further, the inner diameter of the left side of the feed ring 207 is larger than that of the right side, and the inner diameter of the right side of the discharge ring 205 is larger than that of the left side.

[0028] Further, the right side of the feed ring 207 is fixedly connected to the left side of the discharge ring 205, and the air outlet end of the purging assembly 206 penetrates into the inner cavity of the discharge ring 205.

[0029] Further, the purging assembly 206 includes an air outlet pipe 208. The air outlet pipe 208 is fixedly installed in the discharge ring 205. The air inlet end of the air outlet pipe 208 is connected to the annular pipe 204, and the air outlet end of the air outlet pipe 208 penetrates into the inner cavity of the discharge ring 205. At the top of the inner cavity of the air outlet pipe 208, a tee pipe 209 is fixedly connected. On the left and right sides of the bottom of the tee pipe 209, air outlet heads 212 are connected. At the center of the top of the tee pipe 209, a first through hole 214 is opened. On the left and right sides of the bottom of the tee pipe 209, second through holes 213 are opened, and the second through holes 213 are connected to the tops of the air outlet heads 212.

[0030] Further, a control assembly 211 is installed at the bottom of the inner cavity of the air outlet pipe 208. The control assembly 211 includes a cylinder body 215. The top of the cylinder body 215 is fixedly connected to the inner wall of the air outlet pipe 208. An electromagnetic coil 216 is sleeved on the surface of the cylinder body 215. A slide rod 224 that cooperates with the electromagnetic coil 216 is movably connected to the inner wall of the cylinder body 215. A return spring 225 is movably sleeved on the surface of the slide rod 224. The return spring 225 is located inside the cylinder body 215. The bottom of the slide rod 224 is fixedly connected to a telescopic rod 217. The surface of the telescopic rod 217 is movably connected to the inner wall of the cylinder body 215.

[0031] Further, on the left and right sides of the bottom of the telescopic rod 217, a first connecting rod 218 is rotatably connected. The bottom of the first connecting rod 218 is rotatably connected to a second connecting rod 219. The bottom of the second connecting rod 219 is rotatably connected to an opening and closing piece 220. On the opposite sides of the two opening and closing pieces 220, a fixing piece 221 is rotatably connected. The fixing piece 221 is fixedly installed at the air outlet end of the bottom of the air outlet pipe 208. At the bottom of the cylinder body 215, a fixing frame 223 is fixedly connected. At the bottom of the fixing frame 223, a wind shield 222 is fixedly connected. The wind shield 222 is sleeved outside the first connecting rod 218 and the second connecting rod 219 and is located above the opening and closing piece 220.

[0032] Furthermore, the sliding rod 224 is a permanent magnet, and a piston is provided at the top of the sliding rod 224. The piston is slidably connected to the inner wall of the cylinder body 215.

[0033] Furthermore, a threaded ring 210 is fixedly connected to the top inner wall of the air outlet pipe 208. A threaded head is provided inside the annular pipe 204. The threaded head is installed in the inner cavity of the threaded ring 210 and is threadedly connected thereto.

[0034] During the operation of the coal mill feeding device, coal and water enter from the feeding hopper 1, pass through the purging mechanism 2 and the feeding pipe 12 and enter the coal grinding cylinder 4. The driving assembly 7 drives the coal grinding cylinder 4 to rotate. The steel bars inside the coal grinding cylinder 4 are lifted to a certain height and then fall freely, and the coal is broken and finely ground through the impact and friction. The coal is gradually ground into coal slurry in the cylinder body 215, and the coal enters the inside of the drum screen 9 through the discharge pipe 8 for screening.

[0035] The annular pipe 204 in the purging mechanism 2 introduces plant air as the purging medium through the air inlet pipe 203. The air is distributed to the purging assembly 206 through the annular pipe 204. The air outlet pipe 208 of the purging assembly 206 guides the wind force to the inner wall of the sealing packing 10 to form a circular high-speed air flow for scouring, removing the attached coal slurry, preventing the sealing surface from being blocked or leaking. The control assembly 211 is energized through the electromagnetic coil 216 to drive the sliding rod 224 to move downward, compress the return spring 225 and drive the telescopic rod 217 to move. The telescopic rod 217 drives the first connecting rod 218 and the second connecting rod 219 to rotate to adjust the opening and closing angle of the opening and closing piece 220, and the air volume of the air outlet head 212 is adjusted through the opening and closing of the opening and closing piece 220 to achieve precise control of the purging air. The coal slurry cleaned by the purging mechanism 2 enters the coal grinding cylinder 4 through the feeding pipe 12.

[0036] When the coal material flows inside the housing 201, it first enters the feed ring 207, then enters the discharge ring 205 through the feed ring 207, and finally passes through the discharge ring 205 and enters the feed pipe 12. The feed ring 207 guides the incoming coal material to smoothly enter the discharge ring 205. The discharge ring 205 clamps the purging assembly 206 to prevent the coal material from colliding with the purging assembly 206 and causing damage to it. When air enters the inside of the air outlet pipe 208, it first enters the tee 209. The tee 209 divides the air into two air outlets 212 through the first through hole 214 and the second through hole 213. The two air outlets 212 divide the air into two compressed air streams and enter the left and right sides of the inner cavity of the air outlet pipe 208. These two air streams finally pass through two corresponding opening and closing pieces 220 and are discharged. When the opening and closing piece 220 rotates upward, the discharge speed of the air is increased and the cleaning strength is improved. When the opening and closing piece 220 rotates downward, the two opening and closing pieces 220 are attached to the left and right sides of the fixed piece 221, reducing the discharge speed of the air and reducing the cleaning strength. By dynamically adjusting the air volume, it is ensured that the purging air flow can thoroughly remove the coal slurry and avoid the wear of the sealing packing 10 caused by excessive air volume. The adjustment of the purging air is based on the load or feed rate of the coal grinding cylinder 4, and the purging air volume is adjusted to match the production rhythm. The operating state of the coal grinding cylinder 4 is received through the PLC / DCS system. When operating at high load, the purging air volume is increased to ensure the rapid transportation of the coal slurry and prevent blockage. When operating at low load, the air volume is reduced to reduce energy consumption while keeping the sealing packing 10 clean. Embodiment 2

[0037] Refer to Figures 1-9 , this embodiment is based on Embodiment 1 and provides a coal mill feed system, including a coal mill feeding device, and also including a raw coal bin and a coal feeder. The discharge end of the raw coal bin is communicated with the feed end of the coal feeder, and the discharge end of the coal feeder is communicated with the feed end of the feed hopper 1.

[0038] Furthermore, the raw coal bin is used to store raw coal and provide raw material supply for the coal feeder. A conical discharge hopper is provided at the bottom of the raw coal bin. The bottom of the conical discharge hopper has an inclined angle structure of 60 - 70°, which uses gravity to accelerate the flow of coal material. A high chromium cast iron layer or wear-resistant ceramic layer is provided on the inner wall of the conical discharge hopper, and a vibrator is installed on the surface of the conical discharge hopper. The working frequency of the vibrator is 15 - 30 Hz.

[0039] Furthermore, the coal feeder is used to feed the raw coal into the feed hopper 1. The coal feeder includes a variable frequency speed regulation screw conveyor. The rotational speed range of the variable frequency speed regulation screw conveyor is 0 - 30 r / min. The discharge port of the variable frequency speed regulation screw conveyor is communicated with the feed port of the feed hopper 1, and a sealing structure is provided at the connection.

[0040] The bottom of the raw coal bunker is equipped with a conical discharge hopper with an inclination angle of 60-70°. Combined with the inner wall treatment of high-chromium cast iron or wear-resistant ceramic layer, it effectively reduces the risk of coal adhesion and blockage. At the same time, it uses gravity to accelerate the flow of coal, ensuring continuous feeding. The vibrator further assists in loosening the coal to avoid the problem of feeding interruption caused by coal bridging in the traditional structure.

[0041] The coal feeder adopts a variable-frequency speed-regulating screw conveyor, which can dynamically adjust the feeding speed according to the load of the coal mill, match the production rhythm, and reduce energy consumption. For example, it reduces the rotation speed to save electricity at low load and quickly increases the feeding volume at high load.

Claims

1. A coal mill feeding device, comprising a feeding hopper (1), characterized in that: The discharge end of the feed hopper (1) is communicated with a purging mechanism (2). A hoop (3) is fixedly installed at the connection between the feed hopper (1) and the purging mechanism (2). The discharge end of the purging mechanism (2) is communicated with a coal grinding cylinder (4). One end of the coal grinding cylinder (4) is provided with a feed pipe (12), and the other end of the coal grinding cylinder (4) is provided with a discharge pipe (8). A bracket (5) is rotatably connected to the feed pipe (12) and the discharge pipe (8). A bearing (11) is sleeved on the surface of the feed pipe (12). A sealing packing (10) is provided at the feed end of the feed pipe (12). The sealing packing (10) seals the end faces of the feed pipe (12) and the bearing (11). The purging mechanism (2) purges annular air into the inner wall of the sealing packing (10) to clean the coal slurry and prevent coal slurry leakage.

2. The coal mill feeding device according to claim 1, characterized in that: The bottom of the bracket (5) is fixedly connected to a base (6). A driving assembly (7) is installed on the surface of the coal grinding cylinder (4). The driving assembly (7) is fixedly installed on the top of the base (6).

3. The coal mill feeding device according to claim 2, characterized in that: The discharge end of the discharge pipe (8) is communicated with a drum screen (9).

4. The coal mill feeding device according to claim 3, characterized in that: The purging mechanism (2) includes a housing (201). The feed end of the housing (201) is fixedly connected to the discharge end of the feed hopper (1). The discharge end of the housing (201) is fixedly installed on the bracket (5) and is communicated with the feed end of the feed pipe (12).

5. The coal mill feeding device according to claim 4, characterized in that: A protective cover (202) and an annular pipe (204) are fixedly installed on the surface of the housing (201). The annular pipe (204) is located in the inner cavity of the protective cover (202). The top and bottom of the annular pipe (204) are communicated with an air inlet pipe (203). The inner side of the annular pipe (204) is communicated with a purging assembly (206). The purging assembly (206) is distributed around the inner side of the annular pipe (204). The middle end of the inner wall of the housing (201) is fixedly connected with a feed ring (207) and a discharge ring (205).

6. The coal mill feeding device according to claim 5, characterized in that: The right side of the feed ring (207) is fixedly connected to the left side of the discharge ring (205). The air outlet end of the purging assembly (206) penetrates into the inner cavity of the discharge ring (205).

7. The coal mill feeding device according to claim 6, characterized in that: The purging assembly (206) includes an air outlet pipe (208). The air outlet pipe (208) is fixedly installed in the discharge ring (205). The air inlet end of the air outlet pipe (208) is communicated with the annular pipe (204). The air outlet end of the air outlet pipe (208) penetrates into the inner cavity of the discharge ring (205). A tee pipe (209) is fixedly connected to the top of the inner cavity of the air outlet pipe (208). The left and right sides of the bottom of the tee pipe (209) are communicated with air outlet heads (212). A first through hole (214) is opened at the center of the top of the tee pipe (209). Second through holes (213) are opened on the left and right sides of the bottom of the tee pipe (209). The second through holes (213) are communicated with the tops of the air outlet heads (212).

8. The coal mill feeding device according to claim 7, characterized in that: At the bottom of the inner cavity of the air outlet pipe (208), a control component (211) is installed. The control component (211) includes a cylinder body (215). The top of the cylinder body (215) is fixedly connected to the inner wall of the air outlet pipe (208). An electromagnetic coil (216) is sleeved on the surface of the cylinder body (215). A slide rod (224) that cooperates with the electromagnetic coil (216) is movably connected to the inner wall of the cylinder body (215). A return spring (225) is movably sleeved on the surface of the slide rod (224). The return spring (225) is located in the inner cavity of the cylinder body (215). The bottom of the slide rod (224) is fixedly connected to a telescopic rod (217). The surface of the telescopic rod (217) is movably connected to the inner wall of the cylinder body (215).

9. The coal mill feeding device according to claim 8, characterized in that: At the bottom of the left and right sides of the telescopic rod (217), a first connecting rod (218) is rotatably connected. The bottom of the first connecting rod (218) is rotatably connected to a second connecting rod (219). The bottom of the second connecting rod (219) is rotatably connected to an opening and closing piece (220). On the opposite sides of the two opening and closing pieces (220), a fixing piece (221) is rotatably connected. The fixing piece (221) is fixedly installed at the air outlet end of the bottom of the air outlet pipe (208). The bottom of the cylinder body (215) is fixedly connected to a fixing frame (223). The bottom of the fixing frame (223) is fixedly connected to a wind shield (222). The wind shield (222) is sleeved on the outer sides of the first connecting rod (218) and the second connecting rod (219) and is located above the opening and closing piece (220).

10. A coal mill feeding system, comprising the coal mill feeding device according to claim 9, characterized in that: It also includes a raw coal bunker and a coal feeder. The discharge end of the raw coal bunker is communicated with the feed end of the coal feeder. The discharge end of the coal feeder is communicated with the feed end of the feed hopper (1). The raw coal bunker is used for storing raw coal and providing raw material supply for the coal feeder. A conical discharge hopper is provided at the bottom of the raw coal bunker. The bottom of the conical discharge hopper has an inclined angle structure of 60 - 70° to accelerate the flow of coal material by gravity. A high-chromium cast iron layer or a wear-resistant ceramic layer is provided on the inner wall of the conical discharge hopper. A vibrator is installed on the surface of the conical discharge hopper. The working frequency of the vibrator is 15 - 30 Hz. The coal feeder is used for feeding raw coal into the feed hopper (1). The coal feeder includes a variable-frequency speed-regulating screw conveyor. The rotation speed range of the variable-frequency speed-regulating screw conveyor is 0 - 30 r / min. The discharge port of the variable-frequency speed-regulating screw conveyor is communicated with the feed port of the feed hopper (1), and a sealing structure is provided at the connection.

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