Adjustable dynamic and static rings for coal mill
By designing adjustable dynamic and static rings for the coal mill, the problems of high air-to-coal ratio and excessive stone and coal discharge caused by fixed dynamic and static ring gaps were solved, thereby improving the uniformity of air-to-coal mixing and the efficiency of the coal mill, and adapting to the adjustment needs after equipment wear.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-03-10
AI Technical Summary
The existing coal mill has a fixed gap between the moving and stationary rings, resulting in a high air-to-coal ratio and an excessive amount of stone and coal discharged, which cannot adapt to changes in equipment performance caused by wear.
The adjustable dynamic and static rings for the coal mill are designed with a segmented structure and a servo motor driven transmission system. By adjusting the gap between the dynamic and static rings and the angle of the guide plate, the dynamic and static rings can be flexibly adjusted. Combined with the air duct design, the air-powder mixing and grinding effect are optimized.
It improves the uniformity of air-powder mixing, reduces the air-powder ratio deviation and the amount of stone and coal discharged, enhances the operating efficiency of the coal mill and the fineness of the coal powder, and adapts to the equipment adjustment needs after wear.
Smart Images
Figure CN121623911A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of coal mill technology, specifically to an adjustable dynamic and static ring for a coal mill. Background Technology
[0002] As the source of the boiler, the coal mill determines a series of parameters affecting boiler combustion and emissions, such as the air-to-coal ratio, coal powder fineness, and coal powder uniformity. It plays a crucial role in achieving a high-efficiency balance between energy saving and environmental protection. Among these parameters, the moving and stationary rings of the coal mill play a vital role in the operation of the equipment. The stationary ring of the coal mill is fixedly installed on the casing support, while the moving ring is connected to the grinding disc and rotates together. There is a certain gap between the moving and stationary rings.
[0003] Currently, the gap between the dynamic and static rings is mostly fixed during operation, which means the device can only produce coal powder particles of a fixed size. In actual production, the following problems often occur: when the nozzle is severely worn, the primary airflow field cannot be effectively organized, ultimately leading to a high air-to-coal ratio; when the dynamic ring wears, the throat air velocity decreases, and the dynamic-static gap gradually increases, especially when the static ring is partially worn through, and the grinding roller liner is severely worn, leading to an increased grinding gap and ultimately resulting in an excessive amount of coal and stone discharged. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides an adjustable dynamic and static ring for a coal mill, which solves the problems mentioned in the background art, such as fixed dynamic and static ring gap, high air-to-coal ratio, and excessive stone and coal discharge.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: an adjustable dynamic and static ring for a coal mill, including a grinding disc, wherein the upper part of the grinding disc is provided with an annular grinding track, and a dynamic ring mechanism is bolted to one side of the bottom of the grinding disc; The radial outer wall of the moving ring mechanism is connected to a receiving mechanism. The upper part of the receiving mechanism is provided with a first stationary ring mechanism, the upper part of the first stationary ring mechanism is provided with a second stationary ring mechanism, and the moving ring mechanism is located below the second stationary ring mechanism. The moving ring mechanism, the receiving mechanism, the first stationary ring mechanism, and the second stationary ring mechanism are separated by a gap to form an L-shaped channel.
[0006] More preferably, the moving ring mechanism, the first stationary ring mechanism, and the second stationary ring mechanism are all segmented structural designs that can fit the size of the grinding disc, and the bottom of the moving ring mechanism is provided with an extended welding surface and the bottom sidewall of the grinding disc is provided with a connecting plate at the corresponding position. The extended welding surface of the moving ring mechanism is connected to the connecting plate of the grinding disc by bolts, and the extended welding surface of the moving ring mechanism is provided with bolt thrust grooves and thrust is achieved by cotter pins. Multiple sections of the moving ring mechanism are connected tangentially to prevent stress damage.
[0007] More preferably, the moving ring mechanism includes a moving ring body, and the moving ring body is generally arc-shaped and several moving ring bodies can wrap around the grinding disc. The moving ring body has several air channels distributed in a ring from the top to the bottom. The nozzles of the air channels adopt a Venturi design so that the air velocity gradually increases from the nozzle inlet to the outlet and reaches the maximum at the nozzle throat. The air channels are located inside the moving ring body and adopt a twisted and squeezed profile design. The top of the moving ring body is located on the inner side of the air channels and has several screw holes distributed in a ring.
[0008] More preferably, the receiving mechanism includes a receiving ring, and a servo motor is provided at the inner bottom of the receiving ring. One end of the output shaft of the servo motor is connected to a transmission shaft through a coupling, and the transmission shaft is fixedly connected to the central inner wall of the main bevel gear. A driven bevel gear is meshed with the outer wall of the main bevel gear, and the main bevel gear and the driven bevel gear are stably meshed through a gear carrier. The servo motor, the main bevel gear, and the driven bevel gear constitute a transmission structure, and the main bevel gear drives the driven bevel gear to rotate in the vertical direction.
[0009] More preferably, a connecting shaft is fixedly connected to the inner wall of the center of the bevel gear, and the top of the connecting shaft is rotatably connected to the inner top wall of the receiving ring body. The upper outer wall of the connecting shaft is provided with an external thread, and a push block is threadedly connected to the upper external thread of the connecting shaft. A through groove matching the size and shape of the push block is opened on the top of the receiving ring body, and a wedge-shaped protrusion is provided on the side of the top of the push block away from the connecting shaft. When the push block is located at the top of the through groove, the wedge-shaped protrusion is entirely located in the through groove and is movably sleeved with the bottom of the first stationary ring mechanism.
[0010] More preferably, the first stationary ring mechanism includes a stationary ring body, and a groove is formed from bottom to top at the bottom of the stationary ring body corresponding to the wedge-shaped protrusion of the push block. The bottom cross-section of the groove is wedge-shaped and matches the wedge-shaped protrusion of the push block, and the upper part is a T-shaped structure. The two ends of the T-shaped structure of the groove are formed with grooves at the top, and one of the grooves penetrates the stationary ring body. The inner wall of the chute is slidably connected to a contact plate, and the contact plate moves vertically along the vertical section of the chute. A connecting rod is fixedly connected to the top of the contact plate, and a horizontal plate is provided at the top of the connecting rod. The connecting rod and the horizontal plate are located inside the T-shaped structure of the chute and can move vertically along their center line.
[0011] More preferably, a through hole is provided at one top end of the horizontal plate, and a sliding rod is movably sleeved on the inner wall of the through hole of the horizontal plate. The sliding rod is located at both ends of the T-shaped structure of the chute and is vertically distributed into the chute body. A top rod is provided at the upper part of the other end of the horizontal plate. The top of the top rod overlaps with the extrusion plate, and the extrusion plate is located outside the chute body above one end of the T-shaped structure of the chute. The top rod can drive the extrusion plate to move in the vertical direction.
[0012] More preferably, the extrusion plate is located in the bottom cavity of the second stationary ring and can move up and down in the vertical direction. The top center of the extrusion plate is fixedly connected to the free end of the return spring. The other end of the return spring is fixedly connected to a fixing plate, and one end of the fixing plate is fixedly connected to the inner wall of the cavity of the second stationary ring. A telescopic rod is sleeved inside the return spring, and the two ends of the telescopic rod are respectively connected to the extrusion plate and the fixing plate. A rack is fixedly connected to the end of the extrusion plate away from the return spring. The rack moves vertically within the cavity of the second stationary ring.
[0013] More preferably, a gear is meshed with one side of the teeth of the rack, and a rotating shaft is fixedly connected to the inner wall of the center of the gear. One end of the rotating shaft is rotatably connected to the inner wall of the cavity of the second stationary ring, and the other end of the rotating shaft passes through the side wall of the second stationary ring to the outside. The rotating shaft is connected to the side wall of the second stationary ring through a bearing, and a guide plate is fixedly connected to the outer end of the rotating shaft of the second stationary ring.
[0014] More preferably, the push block is displaced vertically along the connecting shaft and moves into the slide groove to overlap with the contact plate. Under the action of the push plate, the contact plate drives the connecting rod, the cross plate and the push rod to move up and down along one end of the T-shaped structure of the slide groove. The push rod drives the extrusion plate to move up and down and drives the rotating shaft to rotate through the rack and gear.
[0015] This invention provides an adjustable dynamic and static ring for a coal mill, which has the following advantages: This adjustable coal mill uses a dynamic and static ring design. The dynamic ring duct employs a twisted and compressed profile design, and the nozzles feature a Venturi design. The air velocity gradually increases from the nozzle inlet to the outlet, reaching its maximum at the nozzle throat. This twisted and compressed profile design enhances the mixing capacity, improves the uniformity of air-coal distribution, creates a more regular internal flow field, reduces the vortex region within the air ring, lowers vortex losses within the air chamber, and makes the air velocity at each nozzle more uniform, resulting in more even air-coal mixing.
[0016] The adjustable coal mill uses segmented moving and stationary rings, which facilitate the maintenance and replacement of worn moving or stationary rings during long-term operation, reducing the workload of disassembling and assembling the moving and stationary ring mechanisms. The segmented moving and stationary ring mechanisms adopt a modular design to ensure standardization.
[0017] This adjustable coal mill uses a servo motor, main bevel gear, driven bevel gear, connecting shaft, external thread, push block, through groove, stationary ring body, slide groove, contact plate, connecting rod, cross plate, slide rod, and push rod to lift the first and second stationary rings, achieving vertical adjustment. This facilitates adjustment of the gap between the dynamic and stationary rings to ensure grinding output after wear during long-term operation.
[0018] The adjustable coal mill uses a combination of a pressing plate, a cavity, a return spring, a fixed plate, a rack, a gear, a rotating shaft, a guide plate, and a second stationary ring. The angle of the guide plate can be adjusted. When the angle of the guide plate increases, the air volume increases and the coal powder conveying speed increases. When the angle of the guide plate decreases, the air volume decreases and the coal powder stays in the grinding zone for a longer time, resulting in more thorough grinding, which is suitable for preparing fine powder.
[0019] The adjustable coal mill uses a dynamic and static ring mechanism. The static ring mechanism drives the guide plate to rotate at an angle via the rack, gear, and rotating shaft. This guides the airflow in the air duct, facilitating the grinding of coal powder. It also allows for adjustment of the gap between the dynamic and static rings, reducing primary air leakage. The primary air is utilized more efficiently, carrying and drying coal powder more effectively, thus ensuring the output of the coal mill. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the main view of the invention; Figure 2 This is a frontal view of the invention; Figure 3 This is a top view of the rotating ring mechanism in the invention; Figure 4 This is a schematic diagram of the air duct structure of the dynamic ring mechanism in this invention; Figure 5 This is a schematic diagram of the stationary ring mechanism in the invention; Figure 6 This is a partial cross-sectional schematic diagram of the receiving mechanism in the invention; Figure 7 This is a schematic diagram of the first stationary ring mechanism in the invention; Figure 8 This is a front view schematic diagram of the first stationary ring mechanism in the invention; Figure 9 This is a schematic diagram of the second stationary ring mechanism in the invention.
[0021] In the diagram: 1. Grinding disc; 2. Annular grinding track; 3. Moving ring mechanism; 301. Moving ring body; 302. Air duct; 4. Receiving mechanism; 401. Receiving ring body; 402. Servo motor; 403. Main bevel gear; 404. Driven bevel gear; 405. Coupling shaft; 406. External thread; 407. Push block; 408. Through groove; 5. First stationary ring mechanism; 501. Stationary ring body; 502. Slide groove; 503. Contact plate; 504. Connecting rod; 505. Horizontal plate; 506. Slide rod; 507. Push rod; 6. Second stationary ring mechanism; 601. Extrusion plate; 602. Cavity; 603. Return spring; 604. Fixing plate; 605. Rack; 606. Gear; 607. Rotating shaft; 608. Guide plate; 609. Second stationary ring. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0023] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0025] Please see Figures 1 to 9 The present invention provides a technical solution: an adjustable dynamic and static ring for a coal mill, including a grinding disc 1, an annular grinding track 2 on the upper part of the grinding disc 1, and a dynamic ring mechanism 3 connected to one side of the bottom of the grinding disc 1 by bolts; The radial outer wall of the moving ring mechanism 3 is connected to the receiving mechanism 4. The upper part of the receiving mechanism 4 is provided with the first stationary ring mechanism 5, the upper part of the first stationary ring mechanism 5 is provided with the second stationary ring mechanism 6, and the moving ring mechanism 3 is located below the second stationary ring mechanism 6. There is a gap between the moving ring mechanism 3, the receiving mechanism 4, the first stationary ring mechanism 5, and the second stationary ring mechanism 6, forming an L-shaped channel.
[0026] In this embodiment, as Figure 3 and Figure 4 As shown, the moving ring mechanism 3, the first stationary ring mechanism 5, and the second stationary ring mechanism 6 are all segmented structures and can fit the size of the grinding disc 1. The bottom of the moving ring mechanism 3 is provided with an extended welding surface, and the bottom side wall of the grinding disc 1 is provided with a connecting plate at the corresponding position. The extended welding surface of the rotating ring mechanism 3 is connected to the connecting plate of the grinding disc 1 by bolts, and the extended welding surface of the rotating ring mechanism 3 is provided with bolt thrust grooves and thrust is achieved by cotter pins. The multiple segments of the rotating ring mechanism 3 are connected tangentially to prevent stress damage.
[0027] In this embodiment, as Figure 3 As shown, the rotating ring mechanism 3 includes a rotating ring body 301, and the rotating ring body 301 is arc-shaped. Several rotating ring bodies 301 can wrap around the grinding disc 1. Several air ducts 302 are distributed in a ring from the top to the bottom of the rotating ring body 301. The nozzles of the air ducts 302 adopt a Venturi design so that the air velocity gradually increases from the nozzle inlet to the outlet and reaches the maximum at the nozzle throat. The air ducts 302 are located inside the rotating ring body 301 and adopt a twisted and extruded profile design. Several screw holes are distributed in a ring on the top of the rotating ring body 301 inside the air ducts 302.
[0028] In this embodiment, as Figure 6 As shown, the receiving mechanism 4 includes a receiving ring 401, and a servo motor 402 is provided at the inner bottom of the receiving ring 401. One end of the output shaft of the servo motor 402 is connected to a transmission shaft through a coupling, and the transmission shaft is fixedly connected to the central inner wall of the main bevel gear 403. The outer wall of the main bevel gear 403 is meshed with a driven bevel gear 404, and the main bevel gear 403 and the driven bevel gear 404 are stably meshed through a gear frame. The servo motor 402, the main bevel gear 403, and the driven bevel gear 404 constitute a transmission structure, and the main bevel gear 403 drives the driven bevel gear 404 to rotate in the vertical direction.
[0029] In this embodiment, as Figure 6 As shown, a connecting shaft 405 is fixedly connected to the inner wall of the center of the bevel gear 404, and the top of the connecting shaft 405 is rotatably connected to the inner top wall of the receiving ring 401. The upper outer wall of the connecting shaft 405 is provided with an external thread 406, and the upper external thread 406 of the connecting shaft 405 is threadedly connected to a push block 407. The top of the receiving ring 401 is provided with a through groove 408 that matches the size and shape of the push block 407, and the top of the push block 407 is provided with a wedge-shaped protrusion on the side away from the connecting shaft 405. When the push block 407 is located at the top of the through groove 408, the wedge-shaped protrusion is located entirely in the through groove 408 and is movably sleeved with the bottom of the first stationary ring mechanism 5.
[0030] In this embodiment, as Figure 7 and Figure 8 As shown, the first stationary ring mechanism 5 includes a stationary ring body 501, and a groove 502 is opened from bottom to top at the bottom of the stationary ring body 501 corresponding to the wedge-shaped protrusion of the push block 407. The bottom cross section of the groove 502 is wedge-shaped and matches the wedge-shaped protrusion of the push block 407, and the upper part is a T-shaped structure. The two ends of the T-shaped structure of the groove 502 are opened with grooves upward, and one of the grooves penetrates the stationary ring body 501. The inner wall of the slide 502 is slidably connected to a contact plate 503, and the contact plate 503 moves vertically along the vertical section of the slide 502. The top of the contact plate 503 is fixedly connected to a connecting rod 504, and the top of the connecting rod 504 is provided with a horizontal plate 505. The connecting rod 504 and the horizontal plate 505 are located inside the T-shaped structure of the slide 502 and can move vertically along their center line.
[0031] In this embodiment, as Figure 7 and Figure 8 As shown, a through hole is provided at one end of the top of the horizontal plate 505, and a slide rod 506 is movably sleeved on the inner wall of the through hole of the horizontal plate 505. The slide rod 506 is located at both ends of the T-shaped structure of the slide groove 502 and is vertically distributed into the groove. A top rod 507 is provided at the upper part of the other end of the horizontal plate 505. The top of the top rod 507 overlaps with the extrusion plate 601, and the extrusion plate 601 is located outside the groove above one end of the T-shaped structure of the slide groove 502. The top rod 507 can drive the extrusion plate 601 to move in the vertical direction.
[0032] In this embodiment, as Figure 9 As shown, the extrusion plate 601 is located in the bottom cavity 602 of the second stationary ring 609 and can move up and down in the vertical direction. The top center of the extrusion plate 601 is fixedly connected to the free end of the return spring 603. The other end of the return spring 603 is fixedly connected to the fixing plate 604. One end of the fixing plate 604 is fixedly connected to the inner wall of the cavity 602 of the second stationary ring 609. A telescopic rod is sleeved inside the return spring 603, and the two ends of the telescopic rod are respectively connected to the extrusion plate 601 and the fixing plate 604. A rack 605 is fixedly connected to the end of the extrusion plate 601 away from the return spring 603. The rack 605 moves vertically in the extrusion plate 601 within the cavity 602 of the second stationary ring 609.
[0033] In this embodiment, as Figure 9 As shown, a gear 606 is meshed with one side of the teeth of the rack 605, and a rotating shaft 607 is fixedly connected to the inner wall of the center of the gear 606. One end of the rotating shaft 607 is rotatably connected to the inner wall of the cavity 602 of the second stationary ring 609, and the other end of the rotating shaft 607 passes through the side wall of the second stationary ring 609 to the outside. The rotating shaft 607 is connected to the side wall of the second stationary ring 609 through a bearing, and a guide plate 608 is fixedly connected to the outer end of the rotating shaft 607 located on the second stationary ring 609.
[0034] In this embodiment, as Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9As shown, the push block 407 moves vertically along the connecting shaft 405 and moves into the slide groove 502 to overlap with the contact plate 503. Under the action of the push block 407, the contact plate 503 drives the connecting rod 504, the horizontal plate 505 and the push rod 507 to move up and down along the slide rod 506 at one end of the T-shaped structure of the slide groove 502. The push rod 507 drives the pressing plate 601 to move up and down and drives the rotating shaft 607 to rotate through the rack 605 and the gear 606.
[0035] The adjustable coal mill uses a dynamic and static ring, and its operation process is as follows: like Figures 1 to 9 As shown, firstly, the extended welding surfaces at the bottom of several segmented moving ring bodies 301 are connected to the corresponding connecting plates at the bottom sidewall of the grinding disc 1 by bolts, and the connection is secured by bolt thrust grooves and cotter pins to ensure stable connection. Several air ducts 302 are distributed in a ring around the moving ring body 301. The air ducts 302 adopt a twisted profile design, which makes the internal flow field streamline more regular, reduces the vortex area in the air ring, reduces the vortex loss in the air chamber, and makes the air velocity of each nozzle more uniform, ultimately making the air-powder mixing more uniform. The twisted and twisted profile design not only strengthens the disturbance mixing ability, but also improves the uniformity of air-powder distribution. By controlling the servo motors 402 (model: HGKR43JK) within several segmented receiving rings 401 to drive the main bevel gear 403 to rotate, a PLC controller (model: S7-200CN) can be used to control the servo motors 402 (model: HGKR43JK). The main bevel gear 403 drives the driven bevel gear 404 to rotate, which in turn drives the connecting shaft 405 to rotate within the receiving ring 401. The external thread 406 of the connecting shaft 405 drives the threaded push block 407 to move vertically upward in the through groove 408. The wedge-shaped protrusion of the push block 407 engages with the corresponding wedge-shaped groove at the bottom of the sliding groove 502 at the bottom of the stationary ring 501, and can connect the contact plate 503 within the wedge-shaped groove. The contact point pushes the material upward along the slide groove 502, causing the connecting rod 504, the horizontal plate 505, and the push rod 507 to move upward along the slide rod 506. This causes the push rod 507 to contact the extrusion plate 601 in the second stationary ring 609 and move it upward along the cavity 602. This causes the rack 605 to move upward and compress the return spring 603 and the telescopic rod. The movement of the rack 605 causes the gear 606 to rotate, thereby causing the rotating shaft 607 to rotate within the cavity 602. This allows the guide plate 608 to adjust its angle, ensuring that the coal powder can stay in the grinding zone for a longer time while maintaining coal powder transportation, resulting in more thorough grinding. The gap between the moving and stationary rings can be adjusted to reduce the phenomenon of excessively high air-to-coal ratio and excessive stone coal discharge.
[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. An adjustable static and dynamic ring for a coal mill, comprising a grinding table (1), characterized in that: The upper part of the grinding disc (1) is provided with an annular grinding track (2), and the bottom side of the grinding disc (1) is connected with a dynamic ring mechanism (3) through bolts; The radial outer wall of the dynamic ring mechanism (3) is overlapped with a receiving mechanism (4), the upper part of the receiving mechanism (4) is provided with a first static ring mechanism (5), the upper part of the first static ring mechanism (5) is provided with a second static ring mechanism (6), and the dynamic ring mechanism (3) is located below the second static ring mechanism (6); The dynamic ring mechanism (3), the receiving mechanism (4), the first static ring mechanism (5) and the second static ring mechanism (6) are left with gaps and form L-shaped channels.
2. An adjustable primary air seal for a coal mill as claimed in claim 1, wherein: The dynamic ring mechanism (3), the first static ring mechanism (5), the second static ring mechanism (6) are all designed in a segmented structure and can be matched with the size of the grinding disc (1), and the bottom of the dynamic ring mechanism (3) is provided with an extended welding surface, and the corresponding position of the sidewall of the bottom of the grinding disc (1) is provided with a connecting plate; The extended welding surface of the dynamic ring mechanism (3) is connected with the connecting plate of the grinding disc (1) through bolts, and the extended welding surface of the dynamic ring mechanism (3) is provided with a bolt thrust groove and is stopped by a split pin, and the tangential connection is adopted between the multiple dynamic ring mechanisms (3) to prevent stress damage.
3. An adjustable primary and secondary ring for a coal mill as claimed in claim 2, wherein: The dynamic ring mechanism (3) comprises a dynamic ring body (301), and the dynamic ring body (301) is arc-shaped as a whole and can wrap the grinding disc (1), a plurality of air ducts (302) are annularly distributed from the top to the bottom of the dynamic ring body (301), the nozzle of the air duct (302) adopts a Venturi design, so that the wind speed gradually increases from the inlet to the outlet of the nozzle and reaches the maximum at the throat of the nozzle, the air duct (302) inside the dynamic ring body (301) adopts a twisted extrusion profile design, and a plurality of screw holes are annularly distributed on the inner side of the top of the dynamic ring body (301).
4. An adjustable primary air seal for a coal mill as claimed in claim 3, wherein: The receiving mechanism (4) comprises a receiving ring body (401), and the inner bottom of the receiving ring body (401) is provided with a servo motor (402), one end of the output shaft of the servo motor (402) is connected with a transmission shaft through a shaft coupling, the transmission shaft and the center inner wall of the main bevel gear (403) are fixedly connected, the outer wall of the main bevel gear (403) is meshingly connected with a slave bevel gear (404), the main bevel gear (403) and the slave bevel gear (404) are stably meshed through a gear frame, the servo motor (402), the main bevel gear (403) and the slave bevel gear (404) constitute a transmission structure, and the main bevel gear (403) drives the slave bevel gear (404) to rotate in the vertical direction.
5. An adjustable primary and secondary ring for a coal mill as claimed in claim 4 wherein: The bevel gear (404) is fixedly connected with a connecting shaft (405) in the center inner wall, and the top of the connecting shaft (405) is rotatably connected with the inner top wall of the receiving ring body (401), the outer wall of the upper part of the connecting shaft (405) is provided with external threads (406), and the external threads (406) of the upper part of the connecting shaft (405) are threadedly connected with a pushing block (407), the top of the receiving ring body (401) is provided with a through slot (408) matched in size and shape with the pushing block (407), and the top of the pushing block (407) away from the connecting shaft (405) is provided with a wedge-shaped protrusion, and the wedge-shaped protrusion is located in the through slot (408) and movably sleeved with the bottom of the first static ring mechanism (5) when the pushing block (407) is located at the top of the through slot (408).
6. An adjustable primary air seal for a coal mill as claimed in claim 5 wherein: The first static ring mechanism (5) comprises a static ring body (501), and a sliding groove (502) is formed in the bottom of the static ring body (501) from bottom to top corresponding to the wedge-shaped protrusion of the pushing block (407), the bottom cross section of the sliding groove (502) is wedge-shaped and matched with the wedge-shaped protrusion of the pushing block (407), and the upper part is T-shaped structure, and the two ends of the T-shaped structure of the sliding groove (502) are provided with groove bodies upwardly, and one of the groove bodies penetrates the static ring body (501); The inner wall of the sliding groove (502) is slidably connected with a contact plate (503), and the contact plate (503) moves vertically along the vertical section of the sliding groove (502), the top of the contact plate (503) is fixedly connected with a connecting rod (504), and the top of the connecting rod (504) is provided with a horizontal plate (505), the connecting rod (504) and the horizontal plate (505) are located in the T-shaped structure of the sliding groove (502) and can move vertically along the center line thereof.
7. An adjustable primary and secondary ring for a coal mill as claimed in claim 6 wherein: The top of one end of the horizontal plate (505) is provided with a through hole, and the inner wall of the through hole of the horizontal plate (505) movably sleeved with a sliding rod (506), the sliding rod (506) is vertically distributed in the upward groove bodies at the two ends of the T-shaped structure of the sliding groove (502), and the other end of the horizontal plate (505) is provided with a top rod (507) on the upper part, the top of the top rod (507) is overlapped with an extrusion plate (601), and the extrusion plate (601) is located above the groove body outside the T-shaped structure of the sliding groove (502), and the top rod (507) can drive the extrusion plate (601) to move in the vertical direction.
8. An adjustable primary air seal for a coal mill as claimed in claim 7, wherein: The extrusion plate (601) is located in the bottom cavity (602) of the second static ring (609) and can move up and down in the vertical direction, and the top center of the extrusion plate (601) is fixedly connected with the free end of the return spring (603), one end of the return spring (603) is fixedly connected with the fixed plate (604), and the other end of the fixed plate (604) is fixedly connected with the inner wall of the cavity (602) of the second static ring (609), the telescopic rod is sleeved in the return spring (603), and the two ends of the telescopic rod are connected with the extrusion plate (601) and the fixed plate (604) respectively, and the end of the extrusion plate (601) away from the return spring (603) is fixedly connected with the rack (605), and the rack (605) moves along the cavity (602) of the second static ring (609) in the vertical direction.
9. An adjustable primary and secondary ring for a coal mill as claimed in claim 8, wherein: The teeth of the rack (605) are meshingly connected with the gear (606), the center inner wall of the gear (606) is fixedly connected with the rotating shaft (607), one end of the rotating shaft (607) is rotatably connected with the inner wall of the cavity (602) of the second static ring (609), and the other end of the rotating shaft (607) penetrates through the side wall of the second static ring (609) to the outside, the rotating shaft (607) is connected with the side wall of the second static ring (609) through a bearing, and the rotating shaft (607) is fixedly connected with the guide plate (608) at the outer end of the second static ring (609).
10. An adjustable primary air seal for a coal mill as claimed in claim 9, wherein: The push block (407) displaces along the connecting shaft (405) in the vertical direction and moves into the slide groove (502) to overlap with the contact plate (503), and the contact plate (503) drives the connecting rod (504), the cross plate (505) and the jacking rod (507) to move up and down along the slide rod (506) at one end of the T-shaped structure of the slide groove (502) under the action of the push block (407), and the jacking rod (507) drives the extrusion plate (601) to move up and drives the rotating shaft (607) to rotate through the rack (605) and the gear (606).