Anti-blocking structure and coal feeder

Abstract

The present invention discloses an anti-blocking structure and a coal feeder, which relate to the technical field of coal feeders and include a feed pipe installed above a machine body, wherein a discharge pipe for coal feeding is connected to the lower portion of the machine body away from the feed pipe. The anti-blocking structure and the coal feeder adjust the spacing between the partition plates through a partition mechanism and a lifting rod, and the partition plates can be raised and lowered to change the flow area of ​​the coal, causing a dynamic dispersion or squeezing operation on the coal, and can dynamically change the flow resistance of the coal, thereby affecting the flow speed and flow state of the coal, promoting the uniform distribution and smooth falling of the coal, and reducing the blockage phenomenon. At the same time, the swing mechanism can change the flow resistance and flow speed of the coal, avoid shutdown caused by blockage, and improve the working efficiency of the coal feeder. When the coal is discharged, the impact force of the hammer mechanism can help the coal overcome static friction, reduce adhesion between particles, reduce resistance caused by adhesion, promote the free fall of the coal, and reduce retention.

Description

Technical Field

[0001] The present invention relates to the technical field of coal feeders, and in particular to an anti-blocking structure and a coal feeder. Background Art

[0002] Coal feeder is an important equipment used in coal mines and power industries. It is generally composed of a frame, transmission device, belt, feeding device, etc. It is mainly used to evenly and continuously transport coal from storage areas, mines or hoisting systems to downstream equipment such as crushers, coal mills, etc. The working principle of a coal feeder is usually to move coal from one place to another through a mechanical transmission system. In coal mines and power plants, the application of coal feeders helps to improve the efficiency of coal transportation and reduce labor costs.

[0003] When the existing coal feeder is in operation, due to various reasons, the coal may adhere, accumulate, or aggregate. When the coal in these states enters the feed pipe or is discharged from the discharge pipe, the flow area and resistance at the feed pipe or discharge pipe are basically fixed, and the flow area and resistance cannot be dynamically changed, resulting in poor fluidity of the coal during transportation, causing coal retention or blockage. For this reason, we have proposed an anti-blocking structure and a coal feeder. Summary of the Invention

[0004] The object of the present invention is to provide an anti-blocking structure and a coal feeder to solve the problems raised by the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: an anti-blocking structure, comprising a feed pipe installed above a machine body, a feed pipe for coal to be dropped is connected to the lower part of the machine body away from the feed pipe, and an inner cylinder for guiding the feed is sleeved on the inner side of the feed pipe;

[0006] The inner cylinder is provided with a partition mechanism capable of adjusting the flow resistance of the coal, the lifting rod is internally connected with a swing mechanism for disturbing and dispersing the coal, the inner side of the support frame is slidably penetrated by a distributor rod capable of reciprocating transversely, and a hammer mechanism capable of periodically impacting the coal is installed below the distributor rod;

[0007] The separation mechanism cooperates with the swing mechanism to make the pitch-changing motion and rotational swing motion of the separation plate and the swing plate run synchronously, changing the flow resistance of the coal. The hammer mechanism cooperates with the dividing rod to make the hammer head and the dividing rod impact and disperse the adhered and aggregated coal.

[0008] Furthermore, the partition mechanism includes a guide groove opened on the inner wall of the inner tube for the sliding rod to slide and change the pitch. The end of the sliding rod close to the middle of the inner tube is connected to a partition plate for adjusting the flow rate of the coal material. The inner side of the partition plate is slid through by a lifting rod that moves up and down.

[0009] Furthermore, one end of the lifting rod is threadedly sleeved with a screw rod installed on the inner wall of the inner cylinder through a bearing, the top of the screw rod is fixedly sleeved with a No. 1 bevel gear, and one side of the No. 1 bevel gear is meshedly connected with a No. 2 bevel gear.

[0010] Furthermore, one side of the No. 2 bevel gear is connected to a No. 1 transmission shaft that can be driven to rotate. The No. 1 transmission shaft is movable through the inner wall of the inner cylinder, and the end of the No. 1 transmission shaft located outside the inner cylinder is connected to the No. 1 motor through a coupling.

[0011] Furthermore, the swing mechanism includes a rotating shaft movably sleeved in the inner cavity of the lifting rod, and one side of the rotating shaft is fixedly connected to three swing plates staggered with the partition plates;

[0012] The lifting rod is located on one side of the inner wall of the swing plate and is provided with an arc groove for the swing plate to swing in an arc track. The end of the rotating shaft located on the outer side of the lifting rod is fixedly connected with a gear disk.

[0013] Furthermore, a fixing frame is welded on the inner wall of the inner cylinder away from the screw rod, and a lifting groove for the lifting rod to slide up and down is opened inside the fixing frame. Tooth block groups arranged in a staggered manner are fixed on the inner walls on both sides of the lifting groove.

[0014] Furthermore, a sliding block is installed on the inner wall of the partition plate close to the lifting rod, and a sliding groove is provided on the outer surface of the lifting rod to form a sliding connection with the sliding block.

[0015] Furthermore, a support frame is fixed to the inner wall of the machine body above the discharge pipe, and the hammer mechanism includes a traction rod connected to the bottom of the distribution rod;

[0016] A turntable capable of squeezing the hammer head to perform arc-shaped hammering motion is provided on one side of the traction rod, and a round rod forming a sliding sleeve structure with the traction rod is fixed on one side surface of the turntable.

[0017] Furthermore, a rotating seat for supporting the rotation of the hammer head is provided under the turntable, and the end of the hammer head away from the rotating seat is set as a conical structure that is narrow at the top and wide at the bottom. The side of the turntable away from the round rod is fixedly connected to a No. 2 transmission shaft, and the No. 2 transmission shaft passes through the inner wall of the discharge pipe through a bearing. The end of the No. 2 transmission shaft located outside the discharge pipe is connected to the No. 2 motor through a coupling.

[0018] A coal feeder comprises a conveyor belt assembly installed in the inner cavity of the machine body and capable of transmitting coal. A guide ring is fixed on the top of an inner cylinder, which can make the coal fall into the middle of the inner cylinder.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This anti-blocking structure and coal feeder adjust the spacing between the partition plates through a partition mechanism and a lifting rod. The partition plates can be raised and lowered to change the flow area of ​​the coal, dynamically dispersing or squeezing the coal, and dynamically changing the flow resistance of the coal, thereby affecting the flow speed and flow state of the coal, promoting uniform distribution and smooth falling of the coal, and reducing blockage.

[0021] 2. This anti-blocking structure and coal feeder, when the partition mechanism rises and falls and changes pitch, the lifting rod drives the swing mechanism to operate, which can change the flow resistance and flow rate of the coal, prevent coal from agglomerating, break up agglomerated coal, avoid downtime caused by blockage, and improve the working efficiency of the coal feeder;

[0022] 3. When the coal is discharged, the impact force of the hammer mechanism of the anti-blocking structure and coal feeder can help the coal overcome static friction, reduce the adhesion between particles, reduce the resistance caused by adhesion, promote the free fall of the coal, and reduce the retention phenomenon. At the same time, the dividing rod buffers and disperses the coal falling from the end of the conveyor belt assembly to avoid excessively fast falling rate and accumulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the three-dimensional structure of the machine body of the present invention;

[0025] Figure 3 This is a schematic diagram of the internal structure of the machine body of the present invention;

[0026] Figure 4 This is a schematic diagram of the three-dimensional structure of the inner cylinder of the present invention;

[0027] Figure 5 This is a schematic diagram of the guide groove structure of the present invention;

[0028] Figure 6 This is a schematic diagram of the three-dimensional structure of the partition plate of the present invention;

[0029] Figure 7 This is a schematic diagram of the internal structure of the lifting rod of the present invention;

[0030] Figure 8 This is a schematic diagram of the three-dimensional structure of the swing mechanism of the present invention;

[0031] Figure 9 This is a schematic diagram of the internal structure of the inner cylinder of the present invention;

[0032] Figure 10 This is a schematic diagram of the internal structure of the lifting tank of the present invention;

[0033] Figure 11 This is a schematic diagram of the three-dimensional structure of the hammer mechanism of the present invention;

[0034] Figure 12 This is a schematic diagram of the three-dimensional structure of the turntable of the present invention;

[0035] Figure 13 This is a schematic diagram of the three-dimensional structure of the material distribution rod of the present invention;

[0036] Figure 14 This is an enlarged structural diagram of point A of the present invention.

[0037] In the figure: 1. Machine body; 2. Feed pipe; 3. Discharge pipe; 4. Inner cylinder; 5. Guide ring; 6. Swing mechanism; 601. Swing plate; 602. Arc groove; 603. Rotating shaft; 7. Motor No. 1; 8. Separation mechanism; 801. Guide groove; 802. Slide bar; 803. Separation plate; 9. Hammer mechanism; 901. Turntable; 902. Round rod; 903. Draw bar; 904. Rotating seat; 905. Hammer head; 10. Motor No. 2; 11. Fixed frame; 12. Lifting groove; 13. Dividing rod; 14. Support frame; 15. Conveyor belt assembly; 16. Slide block; 17. Transmission shaft No. 1; 18. Gear block group; 19. Tooth disc; 20. Lifting rod; 21. Screw; 22. Slide bar; 23. Bevel gear No. 1; 24. Bevel gear No. 2; 25. Transmission shaft No. 2. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1-Figure 5 、 Figure 9 and Figure 11 The present invention provides a technical solution: an anti-blocking structure, including a feed pipe 2 installed above a machine body 1, a feed pipe 3 for coal dropping is connected to the lower part of the machine body 1 away from the feed pipe 2, and an inner cylinder 4 for guiding the feed is sleeved on the inner side of the feed pipe 2.

[0040] In specific implementation, when the coal is transported, the coal can enter the inner cavity of the body 1 through the feed pipe 2 for transportation, and finally fall from the discharge pipe 3 to the processing equipment of the next link. Since the feed pipe 2 is fixed on the top of the body 1, the partition mechanism 8 and the swing mechanism 6 are both installed in the inner tube 4, which can be installed or disassembled as a whole. The structure is centralized and maintenance is relatively convenient.

[0041] See also Figure 3-Figure 9A partition mechanism 8 capable of adjusting the flow resistance of the coal material is installed inside the inner tube 4. The partition mechanism 8 includes a guide groove 801 provided on the inner wall of the inner tube 4 for a sliding rod 802 to slide and change its pitch. The guide groove 801 is provided with two parts, a vertical part and an inclined part. The end of the sliding rod 802 near the middle of the inner tube 4 is connected to a partition plate 803 for adjusting the flow rate of the coal material. A lifting rod 20 that moves up and down slides through the inner side of the partition plate 803. The lifting rod 20 moves up and down to drive the partition plate 803 to move up and down and change its pitch, thereby adjusting the flow area.

[0042] One end of the lifting rod 20 is threadedly sleeved with a screw rod 21 installed on the inner wall of the inner cylinder 4 through a bearing, and the top of the screw rod 21 is fixedly sleeved with a No. 1 bevel gear 23, and one side of the No. 1 bevel gear 23 is meshedly connected with a No. 2 bevel gear 24, and one side of the No. 2 bevel gear 24 is connected to a No. 1 transmission shaft 17 that can be driven to rotate. The No. 1 transmission shaft 17 is movable and passes through the inner wall of the inner cylinder 4, and the end of the No. 1 transmission shaft 17 located outside the inner cylinder 4 is connected to the No. 1 motor 7 through a coupling, and the outer side of the partition plate 803 is provided with a ring-shaped distributed tip block.

[0043] During use, when coal enters the inner tube 4, the No. 1 motor 7 drives the No. 2 bevel gear 24 to rotate through the No. 1 transmission shaft 17, and the No. 2 bevel gear 24 then drives the No. 1 bevel gear 23 to rotate, and finally the No. 1 bevel gear 23 drives the screw rod 21 to rotate. Since the screw rod 21 and the lifting rod 20 are in a threaded sleeve structure, the rotation of the screw rod 21 will drive the lifting rod 20 to move upward or downward along the outside of the screw rod 21. At the same time, the lifting rod 20 drives the partition plate 803 to move upward or downward. The sharp blocks distributed in an annular manner on the outside of the partition plate 803 can effectively break up coal lumps.

[0044] When the partition plate 803 moves upward, the partition plate 803 drives the slide bar 802 at one end to slide along the path of the guide groove 801. At the same time, since the slide bar 802 is squeezed by the inclined surface of the guide groove 801, the slide bar 802 drives the partition plate 803 to move laterally outside the lifting rod 20 and disperse. The spacing between the multiple partition plates 803 becomes larger, so that the area where the coal can flow is increased, which facilitates the coal to be quickly dispersed into the body 1, reduces the flow resistance, and increases the flow speed.

[0045] When the partition plate 803 moves downward, the slide bar 802 slides in the guide groove 801 and drives the multiple partition plates 803 to move closer to each other, reducing the circulation area of ​​the coal material, causing dynamic dispersion or squeezing operation on the coal material, and dynamically changing the flow resistance of the coal material, thereby affecting the flow speed and flow state of the coal material, promoting the uniform distribution and smooth falling of the coal material, and reducing blockage.

[0046] See also Figure 3 and Figures 6-10The interior of the lifting rod 20 is connected with a swing mechanism 6 for disturbing and dispersing the coal material. The swing mechanism 6 includes a rotating shaft 603 movably sleeved in the inner cavity of the lifting rod 20. One side of the rotating shaft 603 is fixedly connected with three swing plates 601 staggered with the partition plate 803. The swing plates 601 have a wavy structure, which can reduce the obstruction to material discharge. The lifting rod 20 is located on the inner wall of one side of the swing plate 601. An arc groove 602 is provided on the inner wall of the swing plate 601 on which the swing plate 601 can swing in an arc trajectory. The end of the rotating shaft 603 located on the outside of the lifting rod 20 is fixedly connected with a gear disk 19.

[0047] During use, while the lifting rod 20 drives the partition plate 803 to move up and down, the swing plate 601 also moves up and down with the lifting rod 20, and the rotating shaft 603 drives the gear plate 19 to slide up and down in the lifting groove 12. Due to the setting of the tooth block group 18, the gear plate 19 performs reciprocating clockwise or counterclockwise rotation. Then, the gear plate 19 drives the rotating shaft 603 to perform reciprocating rotation, so that the rotating shaft 603 drives the swing plate 601 to rotate and swing along the arc groove 602. The swing plate 601 moves up and down and rotates and swings in coordination with the variable pitch of the partition plate 803, changing the flow rate of the coal, preventing coal from agglomerating, and breaking up the agglomerated coal, avoiding blockage and shutdown, and improving the working efficiency of the coal feeder.

[0048] See also Figure 3 、 Figure 5 、 Figure 9 and Figure 10 A fixing frame 11 is welded on the inner wall of the inner cylinder 4 away from the screw rod 21. A lifting groove 12 is opened inside the fixing frame 11 for the lifting rod 20 to slide up and down. The inner walls on both sides of the lifting groove 12 are fixed with staggered tooth block groups 18, and the tooth block groups 18 are meshed with the tooth disc 19.

[0049] When in use, the lifting rod 20 slides up and down in the lifting groove 12, and the toothed disc 19 slides in the lifting groove 12 at the same time. When the toothed disc 19 is engaged with the tooth block group 18 on one side, the toothed disc 19 rotates clockwise. When the toothed disc 19 is engaged with the tooth block group 18 on the other side, the toothed disc 19 rotates counterclockwise, causing the toothed disc 19 to rotate back and forth, thereby driving the rotating shaft 603 to rotate back and forth, and finally causing the swing plate 601 to rotate back and forth and swing.

[0050] See also Figure 7-Figure 9 A slider 16 is installed on the inner wall of the partition plate 803 close to the lifting rod 20, and a sliding groove 22 is opened on the outer surface of the lifting rod 20 to form a sliding connection with the slider 16.

[0051] During use, when the partition plate 803 slides horizontally, the partition plate 803 drives the slider 16 to slide horizontally inside the slide groove 22 , and the slide groove 22 can stably guide the movement of the partition plate 803 .

[0052] See also Figure 3 and Figure 11-13 A support frame 14 is fixed in the inner wall of the machine body 1 near the top of the discharge pipe 3, and a distribution rod 13 that moves reciprocatingly laterally is slidably penetrated inside the support frame 14. A hammer mechanism 9 that can periodically impact the coal material is installed below the distribution rod 13, and the hammer mechanism 9 includes a traction rod 903 connected to the bottom of the distribution rod 13, and a turntable 901 that can squeeze the hammer head 905 to perform an arc-shaped hammering motion is provided on one side of the traction rod 903. A protruding structure is provided on one side of the turntable 901, which can squeeze the hammer head 905 so that the hammer head 905 rotates around the rotating seat 904. A round rod 902 that forms a sliding sleeve structure with the traction rod 903 is fixed to the surface of one side of the turntable 901;

[0053] A rotating seat 904 movably connected to a hammer head 905 is provided below the turntable 901. The end of the hammer head 905 away from the rotating seat 904 is set as a conical structure that is narrow at the top and wide at the bottom. The side of the turntable 901 away from the round rod 902 is fixedly connected to the No. 2 transmission shaft 25. The No. 2 transmission shaft 25 movably penetrates the inner wall of the discharge tube 3 through a bearing. The end of the No. 2 transmission shaft 25 located outside the discharge tube 3 is connected to the No. 2 motor 10 through a coupling.

[0054] During use, when the conveyor belt assembly 15 transports the coal from one end of the machine body 1 to the discharge pipe 3, the No. 2 motor 10 drives the turntable 901 to rotate through the No. 2 transmission shaft 25. The protruding portion of the turntable 901 squeezes one end of the hammer head 905, causing the hammer head 905 to rotate around the rotating seat 904. The end of the hammer head 905 away from the rotating seat 904 tilts up, and then the protruding portion of the turntable 901 breaks away from the end of the hammer head 905. Due to the action of gravity, the hammer head 905 falls away from the end of the rotating seat 904. When a large amount of coal enters the discharge pipe 3, the hammer head 905 impacts the center position of the coal. The impact force of the hammer head 905 can help the coal overcome static friction, reduce adhesion between particles, promote the free fall of the coal, and reduce retention.

[0055] When the turntable 901 rotates, it drives the round rod 902 to rotate, causing the round rod 902 to slide along the inner side of the traction rod 903. Since the traction rod 903 and the support frame 14 are in a sliding socket connection, the round rod 902 pushes or pulls the traction rod 903 to move laterally. At the same time, the traction rod 903 drives the dividing rod 13 to move laterally, buffering and dispersing the coal falling from the end of the conveyor belt assembly 15, avoiding excessively fast falling rate and accumulation.

[0056] A coal feeder includes a conveyor belt assembly 15 installed in the inner cavity of a machine body 1. A guide ring 5 is fixed to the top of an inner cylinder 4 for allowing coal to fall into the middle of the inner cylinder 4.

[0057] See also Figures 1-4 and Figure 9 When in use, the coal falls into the middle of the inner tube 4 through the inclined surface of the guide ring 5 and contacts the partition mechanism 8, and then falls on the surface of the conveyor belt assembly 15. The conveyor belt assembly 15 transports the coal to the discharge pipe 3 at one end of the body 1 for discharge operation.

[0058] To sum up, when using the anti-blocking structure and coal feeder, the coal enters the inner tube 4 from the feed pipe 2, and then the coal flow rate is changed through the operation of the separation mechanism 8 and the swing mechanism 6 to prevent the coal from agglomerating and break up the coal in a lumped state, avoiding blockage and shutdown. The dispersed coal then falls on the surface of the conveyor belt assembly 15 and is transported to the discharge pipe 3 through the conveyor belt assembly 15. The hammer mechanism 9 and the dividing rod 13 help the coal overcome static friction, reduce adhesion between particles, promote the free fall of coal, reduce retention, and improve the working efficiency of the coal feeder. The contents not described in detail in this specification belong to the existing technology well known to professional and technical personnel in this field.

Claims

1. An anti-blocking structure, characterized in that: It comprises a feed pipe (2) installed above the machine body (1); a feed pipe (3) for feeding coal is connected to the lower part of the machine body (1) away from the feed pipe (2); an inner cylinder (4) for guiding the feed is sleeved on the inner side of the feed pipe (2); A separation mechanism (8) capable of adjusting the flow resistance of the coal is installed inside the inner cylinder (4); a swing mechanism (6) for disturbing and dispersing the coal is connected to the interior of the lifting rod (20); a distribution rod (13) for transverse reciprocating movement is slidably penetrated inside the support frame (14); a hammer mechanism (9) capable of periodically impacting the coal is installed below the distribution rod (13); The separation mechanism (8) cooperates with the swing mechanism (6) to synchronize the pitch-changing motion and the rotational swing motion of the separation plate (803) and the swing plate (601) to change the flow resistance of the coal. The hammer mechanism (9) cooperates with the distribution rod (13) to cause the hammer head (905) and the distribution rod (13) to impact and disperse the adhered and aggregated coal. A conveyor belt assembly (15) capable of transmitting the coal is installed in the inner cavity of the body (1). The partition mechanism (8) includes a guide groove (801) provided on the inner wall of the inner cylinder (4) for the sliding rod (802) to slide and change pitch, one end of the sliding rod (802) close to the middle of the inner cylinder (4) is connected to a partition plate (803) for adjusting the flow rate of coal material, the inner side of the partition plate (803) is slidably penetrated by a lifting rod (20) that moves up and down, the swing mechanism (6) includes a rotating shaft (603) movably sleeved in the inner cavity of the lifting rod (20), and one side of the rotating shaft (603) is fixedly connected to three swing plates (601) staggered with the partition plate (803); The lifting rod (20) is located on an inner wall of one side of the swing plate (601), and an arc groove (602) is provided for the swing plate (601) to swing in an arc track. The end of the rotating shaft (603) located on the outside of the lifting rod (20) is fixedly connected to a gear disc (19); A support frame (14) is fixed to the inner wall of the machine body (1) above the discharge pipe (3), and the hammer mechanism (9) includes a traction rod (903) connected to the bottom of the distribution rod (13); A rotating disk (901) capable of squeezing the hammer head (905) to perform arc-shaped hammering motion is provided on one side of the traction rod (903), and a round rod (902) is fixed on one side surface of the rotating disk (901) to form a sliding sleeve structure with the traction rod (903).

2. The anti-blocking structure according to claim 1, characterized in that: One end of the lifting rod (20) is threadedly sleeved with a screw rod (21) mounted on the inner wall of the inner cylinder (4) through a bearing, and the top of the screw rod (21) is fixedly sleeved with a first bevel gear (23), and one side of the first bevel gear (23) is meshedly connected with a second bevel gear (24).

3. The anti-blocking structure according to claim 2, characterized in that: One side of the second bevel gear (24) is connected to a first transmission shaft (17) that can be driven to rotate. The first transmission shaft (17) is movable through the inner wall of the inner cylinder (4), and one end of the first transmission shaft (17) located outside the inner cylinder (4) is connected to the first motor (7) through a coupling.

4. The anti-blocking structure according to claim 2, characterized in that: A fixing frame (11) is welded to the inner wall of the inner cylinder (4) away from the screw rod (21), and a lifting groove (12) for the lifting rod (20) to slide up and down is provided inside the fixing frame (11), and tooth block groups (18) arranged in a staggered manner are fixed to the inner walls on both sides of the lifting groove (12).

5. The anti-blocking structure according to claim 4, characterized in that: A slider (16) is installed on the inner wall of the partition plate (803) close to the lifting rod (20), and a sliding groove (22) is provided on the outer surface of the lifting rod (20) to form a sliding connection with the slider (16).

6. The anti-blocking structure according to claim 5, characterized in that: A rotating seat (904) for supporting the rotation of the hammer head (905) is provided below the turntable (901), and the end of the hammer head (905) away from the rotating seat (904) is configured as a tapered structure that is narrow at the top and wide at the bottom. A second transmission shaft (25) is fixedly connected to the side of the turntable (901) away from the round rod (902), and the second transmission shaft (25) is movably passed through the inner wall of the discharge tube (3) through a bearing. The end of the second transmission shaft (25) located outside the discharge tube (3) is connected to the second motor (10) through a coupling.

7. A coal feeder, using the anti-blocking structure according to claim 6, characterized in that: The top end of the inner cylinder (4) is fixed with a guide ring (5) which allows coal to fall into the middle of the inner cylinder (4).

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