Cooling device of horizontal mixed kiln

Abstract

The cooling device comprises a support, a rotating tank horizontally arranged on the support and a water cooling box body wrapping the rotating tank, a water inlet pipe is arranged at the upper end of the water cooling box body, a water accumulating jar and a water outlet pipe are arranged at the lower end of the water cooling box body, the water inlet pipe and the water outlet pipe are externally connected with a cooling-water machine, and a transverse water pipe located in the water cooling box body is arranged at the lower end of the water inlet pipe. The transverse water pipe is provided with a plurality of spraying heads facing the rotating tank, the rotating tank can rotate on the support, a mixing structure is arranged in the rotating tank, a feeding assembly is arranged at one end of the rotating tank, and a discharging assembly is arranged at the other end of the rotating tank. The cooling device of the horizontal mixed kiln replaces a slow cooling section and a cooling section production line of a traditional kiln, the occupied area is greatly reduced, energy consumption and loss are lower, the spraying head sprays water to cool the rotating tank, the cooling time is shorter, the mixing structure mixes internal materials while the rotating tank rotates, the cooling speed is further increased, and the production efficiency is improved. And the rotary tank replaces the labor cost of a sagger of a kiln in the traditional technology, so that the production cost is lower.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery powder processing equipment, and in particular to a cooling device for a horizontal mixing kiln. Background Art

[0002] Lithium battery powder needs to be removed from the powder to obtain lithium battery powder with higher purity, so as to increase the storage capacity of the lithium battery. At present, most lithium battery powder is heated in a kiln to evaporate impurities and discharge exhaust gas, and then discharged by cooling. For example, the Chinese invention patent with application number 202110681868.2 discloses a gas-heated roller kiln for producing lithium battery materials, which includes a kiln body (1), a protective gas replacement chamber (2), a mechanical transmission device and an automatic control device, and is characterized in that: the kiln body (1) is divided into a heating section, a heat preservation section, a slow cooling section, and a cooling section, and a gas heating system is arranged in the heating section and the heat preservation section of the kiln body (1), and a self-preheating induced radiation tube combustion is adopted. The burner is used as a combustion device. The burner adopts an upper and lower staggered, multi-point symmetrical and uniform distribution, and is divided into multiple zones for pulse timing control. A smoke exhaust pipe (8) and a waste exhaust pipe (9) are set on the kiln top, and a stirring fan (22) is set on each kiln top. The roller (3) is sealed with a sealing box, and the parts leaking out of the sealing box on both sides are sealed with flanges; a water cooling device (10) and an air cooling pipe (25) are set in the slow cooling section and the cooling section of the kiln body (1). The protective gas replacement chamber (2) is set at both ends of the inlet and outlet of the kiln, and is sent into the furnace and the transmission sealing cover through the protective gas pipe (7) and the bottom protective gas branch pipe (26) and the upper protective gas branch pipe (27) set below the kiln body (1). This gas-heated roller kiln for producing lithium battery materials cools the heated sagger (lithium battery powder is sealed in the sagger) through the slow cooling section and the cooling section. It has the following disadvantages: 1. The slow cooling section and the cooling section have a long production line, which occupies a large area, takes up a long cooling time, and consumes a lot of energy; 2. The lithium battery powder raw material is cooled in the sealed sagger, which is slow and inefficient; 3. The service life of the sagger is limited, and the sagger generally needs to be replaced after about three months, which increases production costs. Summary of the Invention

[0003] In view of the shortcomings of the background technology, the technical problem to be solved by the present invention is to provide a cooling device for a horizontal mixing kiln with smaller footprint, lower energy consumption, higher efficiency and lower production cost.

[0004] To this end, the present invention is achieved by adopting the following technical solutions:

[0005] A cooling device for a horizontal mixing kiln is characterized by comprising a support, a rotating tank horizontally arranged on the support, and a water cooling box body wrapping the rotating tank; a water inlet pipe is provided at the upper end of the water cooling box body, a water accumulation bowl and a water outlet pipe are provided at the lower end thereof; the water inlet pipe and the water outlet pipe are externally connected to a chiller; a horizontal water pipe located in the water cooling box body is provided at the lower end of the water inlet pipe; the horizontal water pipe is provided with a plurality of spray heads facing the rotating tank; the rotating tank can rotate on the support; a mixing structure is provided in the rotating tank; a feeding assembly is provided at one end of the rotating tank; and a discharging assembly is provided at the other end of the rotating tank.

[0006] Furthermore, a cold air inlet pipe is connected to the left side of the upper end of the water cooling box, and a hot air outlet pipe is connected to the right side.

[0007] Furthermore, the rotating tank has a feed oblique cone on one side and a discharge oblique cone on the other side. The feed oblique cone is connected to the feed component, and the discharge oblique cone is connected to the discharge component. The feed component includes a fixedly connected feed ring and a feed flange. The discharge component includes a fixedly connected discharge ring and a discharge flange. The feed flange and the discharge flange are fixedly connected to the support. The feed ring is provided with a feed pipe, and the discharge ring is provided with a discharge hopper.

[0008] Furthermore, the feed inclined cone is provided with a plurality of inclined cone sprockets, the support is provided with a driving motor, the rotating shaft of the driving motor is provided with a motor sprocket aligned with the inclined cone sprocket, the motor sprocket and the inclined cone sprocket are linked and driven by a chain, the feed inclined cone and the discharge inclined cone are both provided with circular rings, and the support is provided with a plurality of supporting wheels that can rest on the circular rings.

[0009] Furthermore, the mixing structure includes a first spiral blade and a second spiral blade with opposite spiral directions, the outer ring of the first spiral blade is welded and fixed to the inner wall of the rotating tank, the outer diameter of the second spiral blade is smaller than the inner diameter of the first spiral blade, and the outer ring of the second spiral blade and the inner ring of the first spiral blade are connected by a plurality of connecting rods, the discharging inclined cone has a discharging port, the inner wall of the discharging inclined cone is provided with a plurality of guide plates, the guide plates extend from the right end of the discharging inclined cone to the discharging port position, the guide plates are arc-shaped as a whole, and the angle between the guide plates and the inner wall of the discharging inclined cone is an acute angle, the guide plates and the discharging inclined cone form a feeding trough, the inner wall of the discharging flange is provided with a transition ring, the middle of the transition ring bulges toward the inner ring to form an angle, one side of the transition ring smoothly transitions to the inner wall of the discharging inclined cone, and the other side smoothly transitions to the inner wall of the discharging hopper, the discharging hopper is placed on an isolation frame, and a cylinder is provided at the outer end of the isolation frame, the driving rod of the cylinder is inserted into the discharging hopper, and the other end of the driving rod is provided with a discharging tongue that can rest on the transition ring.

[0010] Furthermore, the feed pipe is connected to an air inlet pipe, the upper part of the discharge hopper is connected to an exhaust pipe, the feed ring is provided with a temperature sensor inserted into the feed inclined cone, the feed pipe is inserted with a pressure differential sensor, the exhaust pipe is inserted with an oxygen sensor, and the left and right ends of the water cooling box are provided with water retaining rings, and a high-temperature resistant sealing gasket is provided between the water retaining ring and the water cooling box, which is against the feed inclined cone and the discharge inclined cone.

[0011] Furthermore, thin-walled bearings and multiple graphite packing sealing assemblies are provided between the feed ring and the feed inclined cone, and between the discharge ring and the discharge inclined cone. The feed ring and the discharge ring are provided with oil channels communicating with the corresponding graphite packing sealing assemblies, and the oil channel entrances have oil injection nozzles.

[0012] Furthermore, the inner rings of the feed ring and the discharge ring are provided with multiple circles of first grooves, the feed inclined cone and the discharge inclined cone are provided with multiple circles of second grooves that are staggered and connected to the first grooves, the feed ring and the discharge ring are provided with air ducts that are connected to the first grooves of the outermost circle, and the air duct entrances have air injection nozzles.

[0013] After adopting the above technical solution, the cooling device is mainly composed of a rotating tank and a water cooling box, which replaces the slow cooling section and cooling section production line of the traditional kiln. The floor space is greatly reduced, and the energy consumption and loss are also lower. Moreover, while the rotating tank rotates, the spray head sprays water to cool the rotating tank, which shortens the cooling time. While the rotating tank rotates, the mixing structure mixes the internal materials, further improving the cooling speed and improving the cooling efficiency. In addition, the rotating tank replaces the cost of the sagger of the traditional technical kiln, thereby lowering the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention has the following accompanying drawings:

[0015] Figure 1 Schematic diagram of the internal structure of the present invention;

[0016] Figure 2 It is a right side structural schematic diagram of the present invention;

[0017] Figure 3 Schematic diagram of the internal structure of the first groove, the second groove, the airway and other structures in the present invention;

[0018] Figure 4 This is a schematic diagram of the internal structure of the graphite packing sealing assembly, oil channel and other structures in the present invention.

[0019] Figure 1: Cooling device; 2: Support; 3: Rotating tank; 4: Exhaust pipe; 5: Inlet pipe; 9: Water cooling box; 10: Water inlet pipe; 11: Water sump; 12: Water outlet pipe; 13: Horizontal water pipe; 14: Sprinkler; 16: Cold air inlet pipe; 17: Hot air outlet pipe; 18: Feeding cone; 19: Discharging cone; 20: Feeding ring; 21: Feeding flange; 22: Discharging ring; 23: Discharging flange; 24: Feeding pipe; 25: Discharging hopper; 26: Cone sprocket; 27: Drive motor; 28: Motor sprocket; 30: Ring; 31: Support wheel; 32. Thin-walled bearing; 33. Graphite packing sealing assembly; 37. First spiral blade; 38. Second spiral blade; 39. Connecting rod; 40. Guide plate; 41. Temperature sensor; 42. Oxygen sensor; 43. Pressure differential sensor; 44. Water retaining ring; 45. High-temperature resistant sealing gasket; 47. Oil channel; 48. Oiling nozzle; 51. Discharge port; 52. Feed trough; 53. Transition ring; 54. Isolation frame; 55. Cylinder; 56. Drive rod; 57. Discharge tongue; 58. First groove; 59. Second groove; 60. Air channel; 61. Air injection nozzle. DETAILED DESCRIPTION

[0020] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0021] With reference to the above-mentioned drawings, a cooling device 1 for a horizontal mixing kiln provided by the present invention comprises a support 2, a rotating tank 3 horizontally arranged on the support 2, and a water cooling box 9 wrapped around the rotating tank 3. The upper end of the water cooling box 9 is provided with a water inlet pipe 10, the lower end is provided with a water sump 11, and a water outlet pipe 12. The water inlet pipe 10 and the water outlet pipe 12 are externally connected to a chiller. The lower end of the water inlet pipe 10 is provided with a horizontal water pipe 13 located in the water cooling box 9. The horizontal water pipe 13 is provided with a number of spray heads 14 facing the rotating tank 3. The rotating tank 3 can rotate on the support 2. A mixing structure is provided in the rotating tank 3, and a feeding assembly is provided at one end of the rotating tank 3 and a discharging assembly is provided at the other end of the rotating tank 3. The left side of the upper end of the water cooling box 9 is connected to a cold air inlet pipe 1 6. A hot air outlet pipe 17 is connected to the right side. A feed oblique cone 18 is provided on one side of the rotating tank 3 and a discharge oblique cone 19 is provided on the other side. The feed oblique cone 18 is connected to the feed assembly, and the discharge oblique cone 19 is connected to the discharge assembly. The feed assembly includes a fixedly connected feed ring 20 and a feed flange 21. The discharge assembly includes a fixedly connected discharge ring 22 and a discharge flange 23. The feed flange 21 and the discharge flange 23 are fixedly connected to the support 2. The feed ring 20 is provided with a feed pipe 24, and the discharge ring 22 is provided with a discharge hopper 25. A plurality of oblique cone sprockets 26 are provided on the feed oblique cone 18. A drive motor 27 is provided on the support 2, and a motor sprocket aligned with the oblique cone sprocket 26 is provided on the rotating shaft of the drive motor 27. 28, the motor sprocket 28 and the inclined cone sprocket 26 are driven by a chain link, the feed inclined cone 18 and the discharge inclined cone 19 are both provided with a ring 30, and the support 2 is provided with a plurality of supporting wheels 31 that can be supported on the ring 30, and the mixing structure includes a first spiral blade 37 and a second spiral blade 38 with opposite spiral directions, the outer ring of the first spiral blade 37 is welded and fixed to the inner wall of the rotating tank 3, the outer diameter of the second spiral blade 38 is smaller than the inner diameter of the first spiral blade 37, and the outer ring of the second spiral blade 38 and the inner ring of the first spiral blade 37 are connected by a plurality of connecting rods 39, the discharge inclined cone 19 has a discharge port 51, and the inner wall of the discharge inclined cone 19 is provided with a plurality of guide pieces 40, which extend from the right end of the discharge inclined cone 19 to the discharge port. At the feed port 51, the guide piece 40 is arc-shaped as a whole, and the included angle between the guide piece 40 and the inner wall of the discharge oblique cone 19 is an acute angle. The guide piece 40 and the discharge oblique cone 19 form a feed trough 52. The inner wall of the discharge flange 23 is provided with a transition ring 53. The middle of the transition ring 53 bulges toward the inner circle to form a folded angle. One side of the transition ring 53 smoothly transitions to the inner wall of the discharge oblique cone 19 and the other side smoothly transitions to the inner wall of the discharge hopper 25. The discharge hopper 25 has an isolation frame 54, and the outer end of the isolation frame 54 is provided with a cylinder 55. The drive rod 56 of the cylinder 55 is inserted into the discharge hopper 25, and the other end of the drive rod 56 is provided with a discharge tongue 57 that can rest on the transition ring 53. The guide piece 40 with this structure is convenient for conveying lithium battery powder to the discharge hopper 25.When the rotating tank 3 rotates forward, the first spiral blade 37 conveys the lithium battery powder raw material to the direction of the feed inclined cone 18, and the second spiral blade 38 conveys the lithium battery powder raw material to the direction of the discharge inclined cone 19, so that the lithium battery powder raw material in the rotating tank 3 is mixed more evenly. When the rotating tank 3 rotates backward, the first spiral blade 37 conveys the lithium battery powder raw material to the direction of the discharge inclined cone 19, and then is conveyed to the discharge hopper 25 by the guide piece 40. The feed pipe 24 is connected to the air inlet pipe 5, and the discharge hopper 25 is provided with an air inlet pipe 5. The exhaust pipe 4 is connected to the feed ring 20, and a temperature sensor 41 is provided on the feed ring 20 to be inserted into the feed oblique cone 18. A pressure differential sensor 43 is inserted on the feed pipe 24, and an oxygen sensor 42 is inserted on the exhaust pipe 4. Water retaining rings 44 are provided on both ends of the water cooling box 9. A high-temperature resistant sealing gasket 45 is provided between the water retaining ring 44 and the water cooling box 9 to be against the feed oblique cone 18 and the discharge oblique cone 19. The temperature sensor 41 is used to detect the temperature in the rotary tank 3, and the oxygen sensor 42 is used to detect the temperature in the rotary tank 3. In order to detect the oxygen content in the rotating tank 3, the pressure in the rotating tank 3 is controlled according to the signal of the pressure difference sensor 43. A thin-walled bearing 32 and a plurality of graphite packing sealing assemblies 33 are provided between the feed ring 20 and the feed inclined cone 18, and between the discharge ring 22 and the discharge inclined cone 19. The graphite packing sealing assembly 33 is mainly made of graphite wire reinforced with various reinforcing fibers, metal wires (steel wire, copper wire, nickel wire, carbon fiber, pre-oxidized wire, glass yarn) as raw materials, and is suitable for dynamic sealing under high temperature and high pressure conditions. The feed ring 20 and discharge ring 22 are equipped with oil passages 47 that communicate with the corresponding graphite packing seal assembly 33. The entrance of the oil passage 47 has an oil injection nozzle 48. The inner rings of the feed ring 20 and discharge ring 22 are each equipped with multiple circles of first grooves 58. The feed cone 18 and discharge cone 19 are each equipped with multiple circles of second grooves 59 that are staggered and communicate with the first grooves 58. The feed ring 20 and discharge ring 22 are equipped with air passages 60 that communicate with the outermost first grooves 58. The entrance of the air passage 60 has an air injection nozzle 61.

[0022] The working principle of the present invention is as follows:

[0023] The driving motor 27 is started to drive the feed inclined cone 18, the rotating tank 3 and the discharging inclined cone 19 to rotate forward, and the water inlet pipe 10 transports cold water to the horizontal water pipe 13 and sprays it to the outer surface of the feed inclined cone 18, the rotating tank 3 and the discharging inclined cone 19 through the sprinkler head 14 to cool the high-temperature lithium battery powder in the rotating tank 3. At the same time, the cold air inlet pipe 16 inputs cold air into the cooling box, and the hot air outlet pipe 17 discharges the hot air in the cooling box to the outside until the lithium battery powder is completely cooled. The driving motor 27 of the cooling device 1 is reversed to drive the feed inclined cone 18, the rotating tank 3 and the discharging inclined cone 19 to rotate in the opposite direction, and drives the cylinder 55 to open the discharging tongue 57 of the cooling device 1. The cooled lithium battery powder is lifted by the guide plate 40 to the discharging ring 22 and discharged through the discharging hopper 25.

[0024] In this embodiment, the cooling device 1 is mainly composed of a rotating tank 3 and a water cooling box 9, which replaces the slow cooling section and cooling section production line of the traditional kiln, greatly reduces the floor space, and reduces energy consumption and loss. Moreover, while the rotating tank 3 rotates, the spray head 14 sprays water to cool the rotating tank 3, which shortens the cooling time. While the rotating tank 3 rotates, the mixing structure mixes the internal materials, further improving the cooling speed and making the cooling efficiency higher. The rotating tank 3 replaces the cost of the sagger of the traditional technical kiln, which reduces the production cost. The setting of the air inlet pipe 16 and the hot air outlet pipe 17 can further accelerate the cooling of the high-temperature lithium battery powder in the rotating tank 3; the setting of the water retaining ring 44 and the high-temperature resistant sealing gasket 45 makes the sealing of the water cooling box 9 better; the lubricating oil is regularly injected into the oil channel 47 through the oil injection nozzle 48, thereby keeping the graphite packing assembly lubricated and improving the service life; the discharging inclined cone 19 does not perform the discharging operation when it rotates forward, and the material will enter the feeding trough 52 and move to the discharge port 51 position for discharging operation when the discharging inclined cone 19 is reversed. The arc shape enables the feed trough 52 to be loaded with more materials, thereby increasing the discharge speed. Moreover, the materials will slide to the bottom of the feed trough 52 (arc shape) due to their own weight. As the discharge oblique cone 19 continues to reverse, the bottom of the relative feed trough 52 (arc shape) is constantly changing, so that the materials have a tendency to slide toward the discharge port 51, further accelerating the discharge speed. The transition ring 53 on the inner wall of the discharge flange 23 bulges inward to form a folded angle. One side of the transition ring 53 smoothly transitions to the inner wall of the discharge oblique cone 19 and the other side transitions to the inner wall of the discharge hopper 25. The smooth transition effectively prevents the material from being deposited on the inner wall of the discharge flange 23, thus avoiding affecting the sealing and making the discharge more thorough. The driving cylinder 55 can drive the discharge tongue 57 to move left and right. When the materials are mixed, the discharge tongue 57 moves to the right so that the discharge tongue 57 rests on the transition ring 53 to complete the sealing of the discharge port 51. When discharging, the discharge tongue 57 moves to the left to separate from the transition ring 53. The structure is stable and reliable. The setting of the isolation frame 54 keeps the cylinder 55 away from the rotating tank 3, preventing the cylinder 55 from operating in a high temperature environment for a long time, thereby increasing its service life.

[0025] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A cooling device for a horizontal mixing kiln, characterized in that: It includes a support, a rotating tank horizontally arranged on the support and a water cooling box body wrapped around the rotating tank. The upper end of the water cooling box body is provided with a water inlet pipe, the lower end is provided with a water sump and a water outlet pipe, the water inlet pipe and the water outlet pipe are externally connected to a chiller, the lower end of the water inlet pipe is provided with a transverse water pipe located in the water cooling box body, the transverse water pipe is provided with a plurality of spray heads facing the rotating tank, the rotating tank can rotate on the support, a mixing structure is provided in the rotating tank, a feeding assembly is provided at one end of the rotating tank, and a discharging assembly is provided at the other end of the rotating tank.

2. The cooling device of a horizontal mixing kiln according to claim 1, characterized in that: The left side of the upper end of the water cooling box is connected to a cold air inlet pipe, and the right side is connected to a hot air outlet pipe.

3. A cooling device for a horizontal mixing kiln according to claim 1 or 2, characterized in that: The rotating tank has a feed oblique cone on one side and a discharge oblique cone on the other side. The feed oblique cone is connected to the feed component, and the discharge oblique cone is connected to the discharge component. The feed component includes a fixedly connected feed ring and a feed flange, and the discharge component includes a fixedly connected discharge ring and a discharge flange. The feed flange and the discharge flange are fixedly connected to the support. The feed ring is provided with a feed pipe, and the discharge ring is provided with a discharge hopper.

4. The cooling device for a horizontal mixing kiln according to claim 3, characterized in that: The feed inclined cone is provided with a plurality of inclined cone sprockets, the support is provided with a driving motor, the rotating shaft of the driving motor is provided with a motor sprocket aligned with the inclined cone sprocket, the motor sprocket and the inclined cone sprocket are linked and driven by a chain, the feed inclined cone and the discharge inclined cone are both provided with circular rings, and the support is provided with a plurality of supporting wheels that can rest on the circular rings.

5. The cooling device for a horizontal mixing kiln according to claim 3, characterized in that: The mixing structure comprises a first spiral blade and a second spiral blade with opposite spiral directions, the outer ring of the first spiral blade is welded and fixed to the inner wall of the rotating tank, the outer diameter of the second spiral blade is smaller than the inner diameter of the first spiral blade, and the outer ring of the second spiral blade and the inner ring of the first spiral blade are connected by a plurality of connecting rods, the discharging inclined cone has a discharging port, the inner wall of the discharging inclined cone is provided with a plurality of guide plates, the guide plates extend from the right end of the discharging inclined cone to the position of the discharging port, the guide plates are arc-shaped as a whole, and the angle between the guide plates and the inner wall of the discharging inclined cone is an acute angle, the guide plates and the discharging inclined cone form a feeding trough, the inner wall of the discharging flange is provided with a transition ring, the middle of the transition ring bulges toward the inner ring to form a folded angle, one side of the transition ring smoothly transitions to the inner wall of the discharging inclined cone, and the other side smoothly transitions to the inner wall of the discharging hopper, the discharging hopper is provided with an isolation frame, the outer end of the isolation frame is provided with a cylinder, the driving rod of the cylinder is inserted into the discharging hopper, and the other end of the driving rod is provided with a discharging tongue that can be rested on the transition ring.

6. The cooling device for a horizontal mixing kiln according to claim 4, characterized in that: The feed pipe is connected to an air inlet pipe, the upper part of the discharge hopper is connected to an exhaust pipe, the feed ring is provided with a temperature sensor inserted into the feed inclined cone, the feed pipe is inserted with a pressure difference sensor, the exhaust pipe is inserted with an oxygen sensor, the left and right ends of the water cooling box are provided with water retaining rings, and high-temperature resistant sealing gaskets are provided between the water retaining ring and the water cooling box to rest against the feed inclined cone and the discharge inclined cone.

7. The cooling device for a horizontal mixing kiln according to claim 4, characterized in that: Thin-walled bearings and multiple graphite packing sealing components are arranged between the feed ring and the feed oblique cone, and between the discharge ring and the discharge oblique cone. The feed ring and the discharge ring are provided with oil passages communicating with the corresponding graphite packing sealing components, and the oil passage entrances are provided with oil injection nozzles.

8. The cooling device for a horizontal mixing kiln according to claim 4, characterized in that: The inner rings of the feed ring and the discharge ring are both provided with multiple circles of first grooves, the feed inclined cone and the discharge inclined cone are both provided with multiple circles of second grooves that are staggered and connected to the first grooves, the feed ring and the discharge ring are provided with air ducts that are connected to the first grooves of the outermost circle, and the air duct entrances have air injection nozzles.

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