Mechanical seal of double-screw expander

Abstract

The utility model discloses a mechanical seal of a double-screw expander, which comprises a static ring, a moving ring, a sealing component and a limiting component. The sealing assembly comprises a static ring shell, a movable ring shell, a rotary knob, a first bevel gear, a second bevel gear, a supporting ring, a threaded column, a movable ring, a sealing spring, a sealing push plate, a limiting ring, a sealing gasket and a surface texture ring. The static ring shell is rotationally installed on the outer surface of the static ring. According to the mechanical seal, the elastic strength of the sealing spring can be conveniently adjusted by a worker according to actual requirements through the sealing assembly, so that the contact surface of the two surface texture rings is in a proper strength range, the service life of the mechanical seal is prolonged, and the sealing effect of the mechanical seal is improved. And through the arranged limiting assembly, a worker can conveniently mount or dismount the static ring and the movable ring, so that the worker can conveniently carry out daily inspection and maintenance on the mechanical seal, and the use efficiency of the mechanical seal is improved.

Description

Technical Field

[0001] This utility model relates to the field of twin-screw expander technology, and specifically to a mechanical seal for a twin-screw expander. Background Technology

[0002] A twin-screw expander is a positive displacement expander. The term "screw expander" usually refers to a twin-screw expander. It mainly consists of a pair of meshing screw rotors and a casing. The rotors are sealed with gaps, forming a working chamber with continuously variable volume. A gaseous working fluid containing heat enters the working chamber and expands adiabatically, driving the rotors to rotate and perform work. During expansion and work, the pressure and temperature of the working fluid decrease, thus achieving heat-work conversion. The inlet gas of a screw expander can be saturated steam or even steam containing liquid. Screw expanders have a wide operating range and maintain high efficiency even at low loads. They are widely used in waste heat power generation in the steel industry, industrial waste pressure power generation, geothermal power generation, and biomass power generation.

[0003] For example, patent application CN201020575524.0 includes a sealing box, a dynamic ring assembly, and a stationary ring assembly. A stationary ring assembly is provided on each side of the dynamic ring assembly. Both the dynamic and stationary ring assemblies are housed within the sealing box. A spring seat is provided at the contact point between the sealing box and the stationary ring assembly, and a spring is installed in the spring seat. This double-end mechanical seal achieves excellent sealing performance with zero leakage of the working medium while ensuring operational performance. It is low-cost and suitable for widespread application. By providing springs on both the process medium side and the bearing side, the elasticity of the springs allows the mechanical seal structure to adapt to both large pressure fluctuations and withstand greater axial torque, thus accommodating high pressure and a certain amount of axial movement. A cooling system is incorporated to prevent damage caused by dry friction common in conventional mechanical seals during the start-up and shutdown of high-speed screw expanders. The sealing box is a combination of a sealing box cover and an outer pressure cover, making installation simple and quick.

[0004] However, the aforementioned mechanical seal structure cannot adjust the elastic force of the spring during use, which in turn prevents adjustment of the friction force between the stationary and rotating ring assemblies. If the friction force between the stationary and rotating ring assemblies is high, the torque between them will be large, causing damage to the contact surfaces and reducing their service life. Conversely, if the friction force is low, the sealing performance between them will be reduced, resulting in a decrease in the sealing effect of the mechanical seal structure. Therefore, there is an urgent need to design a mechanical seal for a twin-screw expander to solve these problems. Utility Model Content

[0005] The purpose of this invention is to provide a mechanical seal for a twin-screw expander to address the aforementioned shortcomings in the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] The device includes a stationary ring, a rotating ring, a sealing assembly, and a limiting assembly. The sealing assembly is disposed on the outer surface of the stationary ring and includes a stationary ring housing, a rotating ring housing, a knob, a first bevel gear, a second bevel gear, a support ring, a threaded column, a moving ring, a sealing spring, a sealing push plate, a limiting ring, a sealing gasket, and a surface textured ring. The stationary ring housing is rotatably mounted on the outer surface of the stationary ring, and the rotating ring housing is disposed on the outer surface of the rotating ring. A first groove is formed on one side of the rotating ring housing, and a second groove is formed on one side of the stationary ring housing.

[0008] The sealing components allow operators to easily adjust the elastic force of the sealing springs according to actual needs, ensuring that the contact surfaces of the two textured rings are within a suitable force range. This increases the service life of the mechanical seal and enhances its sealing effect.

[0009] The limit components allow operators to easily install or remove the stationary and rotating rings, facilitating routine inspections and maintenance of the mechanical seal and increasing its efficiency.

[0010] The textured surface rings can form a liquid film when the rotating ring rotates, thereby increasing the sealing effect of the mechanical seal during use, reducing friction between the textured surface rings, and thus improving the service life of the mechanical seal.

[0011] A circular groove is formed on the outer surface of the stationary ring housing. The first bevel gear is rotatably installed in the circular groove. The knob is fixedly installed on the top of the first bevel gear. The support ring is fixedly installed in the second groove. The second bevel gear is rotatably installed on one side of the support ring. The threaded column is rotatably installed on one side of the support ring. The second bevel gear is connected to the support ring.

[0012] The movable ring is slidably installed in the second groove and is threadedly connected to the threaded post. The sealing push plate is slidably installed in the second groove. The sealing spring is fixedly installed between the movable ring and the sealing push plate. A limit groove is formed in the second groove. The limit ring is slidably installed in the limit groove and is fixedly connected to the sealing push plate. A sealing plate is rotatably installed in the first groove and is fixedly connected to the movable ring. The sealing gasket is fixedly installed on one side of the limit ring. Another sealing gasket is fixedly installed on one side of the sealing plate. The surface texture ring is fixedly installed on one side of the sealing gasket. A transmission belt is sleeved between the threaded posts.

[0013] The limiting component includes a retaining ring, a limiting spring, a guide plate, and a retaining plate, with the retaining ring fixedly installed on the outer surface of the moving ring housing.

[0014] The outer surface of the retaining ring has an annular groove, the guide plate is slidably installed in the annular groove, and the limiting spring is fixedly installed between the retaining ring and the guide plate.

[0015] The inner surface of the retaining ring has a square groove, the retaining plate is slidably installed in the square groove, the guide plate has a guide groove on one side, and the outer surface of the stationary ring shell has a retaining groove.

[0016] In the above technical solution, the mechanical seal of the twin-screw expander provided by this utility model has the following beneficial effects:

[0017] 1. The sealing components allow operators to easily adjust the elastic force of the sealing springs according to actual needs, ensuring that the contact surfaces of the two textured rings are within a suitable force range. This increases the service life of the mechanical seal and enhances its sealing effect.

[0018] 2. The limit components make it easy for staff to install or remove the stationary and rotating rings, which facilitates routine inspection and maintenance of the mechanical seal and increases its efficiency.

[0019] 3. The textured surface rings can form a liquid film when the rotating ring rotates, thereby increasing the sealing effect of the mechanical seal during use, reducing friction between the textured surface rings, and thus improving the service life of the mechanical seal. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0021] Figure 1 This is a schematic diagram of the mechanical seal structure provided for an embodiment of the mechanical seal of a twin-screw expander according to this utility model.

[0022] Figure 2 This is a schematic cross-sectional view of the mechanical seal structure of a twin-screw expander according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the sealing assembly structure provided for an embodiment of the mechanical seal of a twin-screw expander according to this utility model.

[0024] Figure 4 This is a schematic diagram of the limiting component structure provided for an embodiment of the mechanical seal of a twin-screw expander according to this utility model.

[0025] 1. Stationary ring; 2. Rotating ring; 3. Sealing assembly; 4. Limiting assembly; 5. Stationary ring housing; 6. Rotating ring housing; 7. Knob; 8. First bevel gear; 9. Second bevel gear; 10. Support ring; 11. Threaded post; 12. Moving ring; 13. Sealing spring; 14. Sealing push plate; 15. Limiting ring; 16. Sealing gasket; 17. Textured ring; 18. First groove; 19. Second groove; 20. Circular groove; 21. Limiting groove; 22. Sealing plate; 23. Snap ring; 24. Limiting spring; 25. Guide plate; 26. Snap plate; 27. Annular groove; 28. Guide groove; 29. ​​Snap groove; 30. Square groove; 31. Drive belt. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0027] like Figure 1-4 As shown in the figure, this utility model provides a mechanical seal for a twin-screw expander.

[0028] It includes a stationary ring 1, a rotating ring 2, a sealing assembly 3, and a limiting assembly 4. The sealing assembly 3 is disposed on the outer surface of the stationary ring 1. The sealing assembly 3 includes a stationary ring housing 5, a rotating ring housing 6, a knob 7, a first bevel gear 8, a second bevel gear 9, a support ring 10, a threaded column 11, a moving ring 12, a sealing spring 13, a sealing push plate 14, a limiting ring 15, a sealing gasket 16, and a surface texture ring 17. The stationary ring housing 5 is rotatably mounted on the outer surface of the stationary ring 1, and the rotating ring housing 6 is disposed on the outer surface of the rotating ring 2. A first groove 18 is provided on one side of the rotating ring housing 6, and a second groove 19 is provided on one side of the stationary ring housing 5.

[0029] The sealing component 3 allows operators to easily adjust the elastic force of the sealing spring 13 according to actual needs, thereby ensuring that the contact surfaces of the two textured rings 17 are within a suitable force range, thus increasing the service life of the mechanical seal and enhancing its sealing effect.

[0030] The limit component 4 allows staff to easily install or remove the stationary ring 1 and the rotating ring 2, thus facilitating routine inspection and maintenance of the mechanical seal and increasing its efficiency.

[0031] The textured surface rings 17 can form a liquid film when the moving ring 2 rotates, thereby increasing the sealing effect of the mechanical seal during use, reducing the friction between the textured surface rings 17, and thus improving the service life of the mechanical seal.

[0032] Reference Figure 3 In this embodiment, a circular groove 20 is provided on the outer surface of the stationary ring housing 5. The first bevel gear 8 is rotatably installed in the circular groove 20. The knob 7 is fixedly installed on the top of the first bevel gear 8. The support ring 10 is fixedly installed in the second groove 19. The second bevel gear 9 is rotatably installed on one side of the support ring 10. The threaded column 11 is rotatably installed on one side of the support ring 10. The second bevel gear 9 is connected to the support ring 10.

[0033] The movable ring 12 is slidably installed in the second groove 19 and is threadedly connected to the threaded post 11. The sealing push plate 14 is slidably installed in the second groove 19. The sealing spring 13 is fixedly installed between the movable ring 12 and the sealing push plate 14. A limit groove 21 is opened in the second groove 19. The limit ring 15 is slidably installed in the limit groove 21 and is fixedly connected to the sealing push plate 14. A sealing plate 22 is rotatably installed in the first groove 18 and is fixedly connected to the movable ring 2. A sealing gasket 16 is fixedly installed on one side of the limit ring 15. Another sealing gasket 16 is fixedly installed on one side of the sealing plate 22. A surface texture ring 17 is fixedly installed on one side of the sealing gasket 16. A transmission belt 31 is sleeved between the threaded posts 11.

[0034] Reference Figure 4 The limiting component 4 in this embodiment includes a retaining ring 23, a limiting spring 24, a guide plate 25, and a retaining plate 26. The retaining ring 23 is fixedly installed on the outer surface of the moving ring housing 6.

[0035] The outer surface of the retaining ring 23 has an annular groove 27, the guide plate 25 is slidably installed in the annular groove 27, and the limiting spring 24 is fixedly installed between the retaining ring 23 and the guide plate 25.

[0036] The inner surface of the retaining ring 23 has a square groove 30, the retaining plate 26 is slidably installed in the square groove 30, the guide plate 25 has a guide groove 28 on one side, and the outer surface of the stationary ring housing 5 has a retaining groove 29.

[0037] Working principle: First, hold the moving ring housing 6 and pull the guide plate 25. The guide plate 25 drives the clamping plate 26 to move through the guide groove 28, causing the clamping plate 26 to retract into the square groove 30. The guide plate 25 compresses the limiting spring 24. Next, insert the stationary ring housing 5 into the retaining ring 23, so that the square groove 30 corresponds to the retaining groove 29, and the two surface textured rings 17 correspond. Referring to the above operation, release the guide plate 25, so that the limiting spring 24 drives the guide plate 25 to reset. The guide plate 25 drives the clamping plate 26 to move, so that the clamping plate 26 inserts into the retaining groove 29, thus limiting the stationary ring housing 5. Then, as needed, turn the knob 7 to drive the threaded column 11 to rotate through the first bevel gear 8 and the second bevel gear 9. The threaded column 11 drives the other threaded columns 11 to rotate through the transmission belt 31. The threaded column 11 drives the moving ring 12 to move, adjusting the elastic force of the sealing spring 13. The sealing spring 13 presses against the sealing push plate 14, which in turn presses against the sealing gasket 16 via the limiting ring 15. The sealing gasket 16 presses against the surface textured ring 17, which in turn presses against another surface textured ring 17. After the contact force of the surface textured rings 17 is adjusted, the moving ring 2 rotates, driving the sealing plate 22 to rotate. The sealing plate 22, through the sealing gasket 16, drives the surface textured ring 17 to rotate. A liquid film is formed between the surface textured ring 17 and the other surface textured ring 17, thereby increasing the sealing effect of the mechanical seal during use, reducing the friction between the surface textured rings 17, and thus improving the service life of the mechanical seal.

[0038] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A mechanical seal for a twin-screw expander, comprising a stationary ring (1), a rotating ring (2), a sealing assembly (3), and a limiting assembly (4), characterized in that, The sealing assembly (3) is disposed on the outer surface of the stationary ring (1). The sealing assembly (3) includes a stationary ring housing (5), a rotating ring housing (6), a knob (7), a first bevel gear (8), a second bevel gear (9), a support ring (10), a threaded column (11), a moving ring (12), a sealing spring (13), a sealing push plate (14), a limiting ring (15), a sealing gasket (16), and a surface texture ring (17). The stationary ring housing (5) is rotatably mounted on the outer surface of the stationary ring (1). The rotating ring housing (6) is disposed on the outer surface of the rotating ring (2). A first groove (18) is provided on one side of the rotating ring housing (6), and a second groove (19) is provided on one side of the stationary ring housing (5).

2. The mechanical seal of a twin-screw expander according to claim 1, characterized in that, The outer surface of the stationary ring housing (5) is provided with a circular groove (20). The first bevel gear (8) is rotatably installed in the circular groove (20). The knob (7) is fixedly installed on the top of the first bevel gear (8). The support ring (10) is fixedly installed in the second groove (19). The second bevel gear (9) is rotatably installed on one side of the support ring (10). The threaded column (11) is rotatably installed on one side of the support ring (10). The second bevel gear (9) is connected to the support ring (10).

3. The mechanical seal of a twin-screw expander according to claim 1, characterized in that, The movable ring (12) is slidably installed in the second groove (19). The movable ring (12) is threadedly connected to the threaded post (11). The sealing push plate (14) is slidably installed in the second groove (19). The sealing spring (13) is fixedly installed between the movable ring (12) and the sealing push plate (14). A limiting groove (21) is opened in the second groove (19). The limiting ring (15) is slidably installed in the limiting groove (21). The limiting ring (15) is fixedly connected to the sealing push plate (14). A sealing plate (22) is rotatably installed in the first groove (18). The sealing plate (22) is fixedly connected to the movable ring (2). The sealing gasket (16) is fixedly installed on one side of the limiting ring (15). Another sealing gasket (16) is fixedly installed on one side of the sealing plate (22). The surface texture ring (17) is fixedly installed on one side of the sealing gasket (16). A transmission belt (31) is sleeved between the threaded posts (11).

4. The mechanical seal of a twin-screw expander according to claim 1, characterized in that, The limiting component (4) includes a retaining ring (23), a limiting spring (24), a guide plate (25), and a retaining plate (26). The retaining ring (23) is fixedly installed on the outer surface of the moving ring housing (6).

5. The mechanical seal of a twin-screw expander according to claim 4, characterized in that, The outer surface of the retaining ring (23) is provided with an annular groove (27), the guide plate (25) is slidably installed in the annular groove (27), and the limiting spring (24) is fixedly installed between the retaining ring (23) and the guide plate (25).

6. The mechanical seal of a twin-screw expander according to claim 4, characterized in that, The inner surface of the retaining ring (23) is provided with a square groove (30), the retaining plate (26) is slidably installed in the square groove (30), the guide plate (25) is provided with a guide groove (28) on one side, and the outer surface of the stationary ring shell (5) is provided with a retaining groove (29).

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