Particle deposition prevention type mechanical seal of polypropylene granulator
By adding cylindrical glands and toothed ring grooves at the cutting shaft dynamic and static ring seal of the polypropylene pelletizer, and setting up external thread grooves to form a pressure difference, the problem of particulate matter in cooling water entering the seal is solved, and effective seal protection and long life of the bearing are achieved.
Patent Information
- Application Number
- CN202422264848.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-09-18
AI Technical Summary
In a polypropylene pelletizer, the polypropylene particles mixed in cooling water may enter the seal of the dynamic and static ring, causing the seal to fail and damage the bearing.
Add a cylindrical gland at the sealing of the dynamic and static ring of the cutting shaft, and a toothed ring groove is set at its stop ring A to prevent particles from entering. At the same time, an external thread groove is provided at the shaft sleeve to form a rotating water flow and a pressure difference, forcing the particulate matter to overflow from the discharge hole.
It effectively blocks the entry of cooling water and particulate matter, prevents seal failure and bearing damage, reduces the number of maintenance times, and improves the reliability of the equipment.
Smart Images
Figure CN222937237U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a mechanical seal structure, in particular to a mechanical seal for preventing particle deposition of a polypropylene pelletizer. Background Technique
[0002] The polypropylene granulator unit is one of the most important equipments in the propylene project. It is an integrated device that mixes polypropylene resin polymerized catalytically in the propylene project with other auxiliary materials in strict proportion according to user requirements, and then mixes, plasticizes, extrudes, underwater pelletizes, separates and dries it through the unit, and finally processes it into regular granular products. This unit consists of seven main parts: a metering and feeding system, a driving system, a mixing and extrusion system, an extrusion and granulation system, a particle processing system, other auxiliary systems, and an electrical control system.
[0003] The extrusion and granulation system mainly consists of a throttling start valve, a screen changer, a connecting and supporting device, a head device, a temperature control pipeline, an underwater pelletizing device, etc.;
[0004] The pelletizing mechanism is the key mechanism of the underwater pelletizing device. Its structural design should not only ensure the stable high-speed rotation of the cutting knife, but also ensure that the cutting knife overcomes the extrusion pressure of the material and thus clings to the template. It mainly consists of a driving motor, a coupling, a locking oil cylinder, a cutting knife shaft, a cutter head device, a knife shaft moving oil cylinder, a water chamber, a bearing box, etc. The cutting knife shaft is connected to the driving motor through a coupling and then passes through the entire bearing box and water chamber and connects the cutting knife device to itself, thus ensuring the transmission of power and the operation of the cutting knife. However, during the operation of the pelletizer unit, the water chamber is always filled with flowing cooling water, which requires ensuring that the cooling water does not enter the bearing box and cause the lubricating oil to deteriorate, thereby damaging the bearing and affecting the normal operation of the pelletizing mechanism. Content of the Utility Model
[0005] In order to overcome the deficiencies in the background technique, the utility model discloses a mechanical seal for preventing particle deposition of a polypropylene pelletizer. A cylindrical gland is added at the dynamic and static ring seal of the cutting knife rotating shaft originally used for pelletizing, and a toothed ring groove is provided at the retaining ring A of the cylindrical gland to prevent polypropylene particles mixed in the cooling water in the water chamber from entering the dynamic and static ring seal. An external thread groove is provided at the shaft sleeve covered by the cylindrical gland to play a role in forming a pressure difference by rotating the water flow, so that the polypropylene particles entering the cylindrical cavity A overflow from the discharge hole.
[0006] In order to achieve the purpose of the utility model, the utility model adopts the following technical solutions:
[0007] A particle deposition prevention type mechanical seal for a polypropylene pelletizer, comprising a cylindrical gland, a rotating shaft and a cylindrical housing. The rotating shaft is horizontally arranged, and a shaft sleeve is sleeved outside the rotating shaft. A cylindrical cavity B is arranged inside the cylindrical housing. The cylindrical housing is movably sleeved on the right part of the shaft sleeve by means of the cylindrical cavity B. A dynamic and static ring sealing structure with its left end extending outside the left end of the cylindrical housing is arranged in the cylindrical cavity B between the inner wall of the cylindrical housing and the outer wall of the shaft sleeve. A cylindrical cavity A is arranged inside the cylindrical gland. A retaining ring A is arranged at the left end of the cylindrical cavity A. A toothed ring groove is arranged on the inner edge surface of the retaining ring A. The cylindrical gland is movably sleeved on the left part of the shaft sleeve by means of the cylindrical cavity A it is provided with. The inner edge of the toothed ring groove is in clearance fit with the shaft sleeve. The right end of the cylindrical gland is fixedly connected to the left end of the cylindrical housing. A discharge hole perpendicular to the rotating shaft is arranged at the right part of the cylindrical gland. An external thread groove is arranged on the outer wall of the shaft sleeve between the dynamic and static ring sealing structure and the retaining ring A.
[0008] In the particle deposition prevention type mechanical seal for a polypropylene pelletizer, the dynamic and static ring sealing structure includes a dynamic ring and a static ring. A retaining ring B is arranged at the right end of the cylindrical cavity B. The retaining ring B is in clearance fit with the shaft sleeve. A static ring is arranged at the right end of the cylindrical cavity B outside the shaft sleeve. A half-ring groove is arranged at the outer edge of the right end of the static ring. A sealing ring B is arranged in the area between the included angle formed by the inner wall of the cylindrical cavity B and the retaining ring B and the half-ring groove. A fixing ring is sleeved on the shaft sleeve outside the left side of the cylindrical housing. A ring groove is arranged on the inner ring surface of the dynamic ring. A sealing ring A with its inner edge extending out of the ring groove is arranged in the ring groove. The dynamic ring is rotatably sleeved on the shaft sleeve in the cylindrical cavity B by means of the sealing ring A. The right end of the dynamic ring is in contact with the left end of the static ring. A corrugated spring is arranged between the fixing ring and the dynamic ring to support the dynamic ring against the static ring.
[0009] In the particle deposition prevention type mechanical seal for a polypropylene pelletizer, a screw hole is arranged on the fixing ring. The position of the screw hole corresponds to the position of the discharge hole. A fastening screw is screwed in the screw hole and passes through a through hole provided on the shaft sleeve and abuts against the rotating shaft to fix the fixing ring on the shaft sleeve.
[0010] In the particle deposition prevention type mechanical seal for a polypropylene pelletizer, the outer edge of the dynamic ring is in clearance fit with the inner edge of the cylindrical housing, and the inner edge of the static ring is in clearance fit with the shaft sleeve.
[0011] In the particle deposition prevention type mechanical seal for a polypropylene pelletizer, a perforation for its installation is arranged on the cylindrical housing.
[0012] In the particle deposition prevention type mechanical seal for a polypropylene pelletizer, a flanging is arranged at the outer edge of the right end of the cylindrical gland. After a bolt passes through a nail hole provided on the flanging, it is screwed with a screw hole provided on the left side wall of the cylindrical housing.
[0013] Due to the adoption of the above technical solutions, the utility model has the following beneficial effects:
[0014] The anti-particle deposition mechanical seal of the polypropylene pelletizer described in the present utility model adds a cylindrical gland at the dynamic and static ring seal of the cutter rotating shaft originally used for pelletizing, and sets a toothed ring groove at the retaining ring A provided on the cylindrical gland to prevent the polypropylene particles mixed in the cooling water in the water chamber from entering the dynamic and static ring seal. An external thread groove is provided at the shaft sleeve covered by the cylindrical gland to form a pressure difference at both ends of the toothed ring groove by rotating the water flow, so as to overflow the polypropylene particles entering the cylindrical cavity A from the discharge hole provided on the cylindrical gland, effectively blocking the cooling water in the water chamber and the polypropylene particles mixed in the cooling water, avoiding the drawback of the dynamic and static ring seal failing due to the adhesion of polypropylene particles, effectively protecting the bearing box, and reducing the number of times of maintenance of the bearing box due to the entry of impurities; the structure of the present utility model is simple and reasonable, easy to install, and can be realized only by making slight modifications to the dynamic and static ring seal of the cutter rotating shaft originally used for pelletizing. It has low investment and quick results, and has strong popularization value. Brief Description of the Drawings
[0015] Figure 1 It is a schematic structural diagram of the present utility model.
[0016] In the figure: 1. Shaft sleeve; 2. Retaining ring A; 3. Toothed ring groove; 4. Cylindrical gland; 5. Fastening screw; 6. Bolt; 7. Perforation; 8. Dynamic ring; 9. Seal ring A; 10. Static ring; 11. Retaining ring B; 12. Rotating shaft; 13. Flange; 14. Cylindrical cavity A; 15. External thread groove; 16. Fixed ring; 17. Discharge hole; 18. Screw hole; 19. Through hole; 20. Bellows type spring; 21. Cylindrical shell; 22. Cylindrical cavity B; 23. Ring groove; 24. Half ring groove; 25. Seal ring B. Detailed Description of the Preferred Embodiment
[0017] The present utility model can be more specifically explained through the following embodiments. The present utility model is not limited to the following embodiments. The purpose of disclosing the present utility model is to protect all changes and improvements within the scope of the present utility model;
[0018] In this application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.
[0019] Combined with the attached Figure 1The described mechanical seal for a polypropylene pelletizer to prevent particle deposition includes a cylindrical gland 4, a rotating shaft 12, and a cylindrical housing 21. The rotating shaft 12 is horizontally arranged. A sleeve 1 is sleeved outside the rotating shaft 12. A cylindrical cavity B22 is provided inside the cylindrical housing 21. The cylindrical housing 21 is movably sleeved on the right part of the sleeve 1 by means of the cylindrical cavity B22. A dynamic and static ring sealing structure with its left end extending outside the left end of the cylindrical housing 21 is provided in the cylindrical cavity B22 between the inner wall of the cylindrical housing 21 and the outer wall of the sleeve 1. The dynamic and static ring sealing structure includes a dynamic ring 8 and a static ring 10. A retaining ring B11 is provided at the right end of the cylindrical cavity B22. The retaining ring B11 is in clearance fit with the sleeve 1. The static ring 10 is provided at the right end of the cylindrical cavity B22 outside the sleeve 1. A half-ring groove 24 is provided at the outer edge of the right end of the static ring 10. A sealing ring B25 is provided in the area between the included angle formed by the inner wall of the cylindrical cavity B22 and the retaining ring B11 and the half-ring groove 24. A fixing ring 16 is sleeved on the sleeve 1 outside the left side of the cylindrical housing 21. A screw hole 18 is provided on the fixing ring 16. The position of the screw hole 18 corresponds to the position of the discharge hole 17. A fastening screw 5 is screwed into the screw hole 18 and passes through a through hole 19 provided on the sleeve 1 to abut against the rotating shaft 12 to fix the fixing ring 16 on the sleeve 1. A ring groove 23 is provided on the inner ring surface of the dynamic ring 8. A sealing ring A9 with its inner edge extending out of the ring groove 23 is provided in the ring groove 23. The dynamic ring 8 is rotatably sleeved on the sleeve 1 located in the cylindrical cavity B22 by means of the sealing ring A9. The right end of the dynamic ring 8 is in contact with the left end of the static ring 10. A bellows spring 20 is provided between the fixing ring 16 and the dynamic ring 8 to support the dynamic ring 8 against the static ring 10. The outer edge of the dynamic ring 8 is in clearance fit with the inner edge of the cylindrical housing 21. The inner edge of the static ring 10 is in clearance fit with the sleeve 1. A cylindrical cavity A14 is provided inside the cylindrical gland 4. A retaining ring A2 is provided at the left end of the cylindrical cavity A14. A toothed ring groove 3 is provided on the inner edge surface of the retaining ring A2. The cylindrical gland 4 is movably sleeved on the left part of the sleeve 1 by means of the cylindrical cavity A14 it is provided with. The inner edge of the toothed ring groove 3 is in clearance fit with the sleeve 1. A flange 13 is provided at the outer edge of the right end of the cylindrical gland 4. A bolt 6 passes through a bolt hole provided on the flange 13 and is screwed into a screw hole provided on the left side wall of the cylindrical housing 21. A discharge hole 17 perpendicular to the rotating shaft 12 is provided on the right part of the cylindrical gland 4. An external thread groove 15 is provided on the outer wall of the sleeve 1 between the dynamic and static ring sealing structure and the retaining ring A2. A perforation 7 for its installation is provided on the cylindrical housing 21.
[0020] Implement the mechanical seal with anti-particle deposition for the polypropylene pelletizer of the present utility model. Fix the cylindrical shell 21 on the bearing box with screws passing through the perforation 7. Screw the bolt 6 through the nail holes provided in the flange 13 and then thread it with the screw holes provided on the left side wall of the cylindrical shell 21. During use, the motor drives the rotating shaft 12 sleeved with the shaft sleeve 1 to rotate, thereby driving the fixed ring 16, the bellows spring 20, the moving ring 8 and the sealing ring A9 to rotate. The bellows spring 20 elastically pushes the moving ring 8 against the stationary ring 10 to seal the right bearing box. The cooling water in the left pelletizing water chamber and the polypropylene particles mixed in the cooling water are not easily introduced into the right bearing box. The bearing oil in the right bearing box is not easily leaked into the water chamber. The setting of the toothed ring groove 3 effectively blocks most of the polypropylene particles from entering the cylindrical cavity A14 from the water chamber and damaging the dynamic and static ring seals. The rotation of the shaft sleeve 1 drives the rotation of the external thread groove 15. The rotation of the external thread groove 15 can make a small amount of cooling water and polypropylene particles mixed in the cooling water that enter the cylindrical cavity A14 along the toothed ring groove 3 rotate. A pressure difference is formed on both sides of the toothed ring groove 3, so that a small amount of cooling water and polypropylene particles mixed in the cooling water that enter the cylindrical cavity A14 can effectively overflow from the discharge hole 17 provided in the cylindrical gland 4 into the pelletizing water chamber, protecting the dynamic and static ring seals, and thus protecting the bearing box.
[0021] The parts not detailed in the present utility model are prior art.
Claims
1. A particle deposition prevention mechanical seal for a polypropylene pelletizer, comprising a cylindrical gland (4), a rotating shaft (12) and a cylindrical housing (21), wherein the rotating shaft (12) is arranged transversely, a shaft sleeve (1) is sleeved on the outside of the rotating shaft (12), a cylindrical cavity B (22) is arranged in the cylindrical housing (21), the cylindrical housing (21) is movably sleeved on the right part of the shaft sleeve (1) by means of the cylindrical cavity B (22), a dynamic and static ring sealing structure is arranged in the cylindrical cavity B (22) between the inner wall of the cylindrical housing (21) and the outer wall of the shaft sleeve (1), and the left end of the dynamic and static ring sealing structure extends outward from the left end of the cylindrical housing (21), wherein: A cylindrical cavity A (14) is provided in the cylindrical gland (4), a retaining ring A (2) is provided at the left end of the cylindrical cavity A (14), and a toothed ring groove (3) is provided on the inner edge surface of the retaining ring A (2). The cylindrical gland (4) is movably sleeved on the left part of the shaft sleeve (1) by means of the cylindrical cavity A (14) provided thereon, the inner edge of the toothed ring groove (3) and the shaft sleeve (1) are clearance-matched, the right end of the cylindrical gland (4) and the left end of the cylindrical housing (21) are fixedly connected, a discharge hole (17) perpendicular to the rotating shaft (12) is provided at the right part of the cylindrical gland (4), and an external threaded groove (15) is provided on the outer wall of the shaft sleeve (1) between the dynamic and static ring sealing structure and the retaining ring A (2).
2. The particle deposition preventing mechanical seal for polypropylene pelletizer according to claim 1 is characterized in that: The dynamic and static ring sealing structure comprises a dynamic ring (8) and a static ring (10), a retaining ring B (11) is provided at the right end of a cylindrical cavity B (22), the retaining ring B (11) and the shaft sleeve (1) are clearance-matched, a static ring (10) is provided at the right end of the cylindrical cavity B (22) located outside the shaft sleeve (1), a semi-annular groove (24) is provided at the outer edge of the right end of the static ring (10), a sealing ring B (25) is provided in the area between the semi-annular groove (24) and the angle formed by the inner wall of the cylindrical cavity B (22) and the retaining ring B (11), and a sealing ring B (25) is provided at the cylindrical housing (2 1) A fixed ring (16) is sleeved on the shaft sleeve (1) on the left side. A ring groove (23) is provided on the inner ring surface of the movable ring (8). A sealing ring A (9) is provided in the ring groove (23) and the inner edge of the sealing ring A (9) extends out of the ring groove (23). The movable ring (8) is rotatably sleeved on the shaft sleeve (1) located in the cylindrical cavity B (22) by means of the sealing ring A (9). The right end of the movable ring (8) is in contact with the left end of the stationary ring (10). A bellows-type spring (20) is provided between the fixed ring (16) and the movable ring (8) to support the movable ring (8) against the stationary ring (10).
3. The particle deposition preventing mechanical seal for polypropylene pelletizer according to claim 1 is characterized in that: A screw hole (18) is provided on the fixing ring (16), and the position of the screw hole (18) corresponds to the position of the discharge hole (17). The fastening screw (5) is screwed into the screw hole (18) and passes through a through hole (19) provided on the shaft sleeve (1) to abut against the rotating shaft (12) so that the fixing ring (16) is fixed on the shaft sleeve (1).
4. The particle deposition preventing mechanical seal for polypropylene pelletizer according to claim 1 is characterized in that: The outer edge of the moving ring (8) and the inner edge of the cylindrical housing (21) are clearance-fitted, and the inner edge of the stationary ring (10) and the shaft sleeve (1) are clearance-fitted.
5. The particle deposition preventing mechanical seal for polypropylene pelletizer according to claim 1 is characterized in that: The cylindrical housing (21) is provided with a through hole (7) for installing the cylindrical housing (21).
6. The particle deposition preventing mechanical seal for polypropylene pelletizer according to claim 1 is characterized in that: A flange (13) is provided at the outer edge of the right end of the cylindrical gland (4), and the bolt (6) passes through the nail hole provided in the flange (13) and is screwed to the screw hole provided in the left side wall of the cylindrical housing (21).