Mechanical seal device for multi-stage centrifugal pump with non-stop adjustment of compression amount

Abstract

The utility model relates to centrifugal pump technical field, and specifically is a kind of mechanical sealing device of multistage centrifugal pump with regulating compression amount without stopping machine. Including with the fixed ring seat that static ring is located end shell body is connected and located the fixed ring seat in the outer periphery of pump shaft is provided with the regulating assembly that can move along axial direction, regulating assembly inside and static ring are connected. Through the cooperation design of fixed ring seat and the regulating assembly of axial movement, the non-stop control of mechanical seal compression amount is realized, the device can carry out preliminary compression amount setting in assembly stage, after total assembly is completed, fine calibration can be carried out again. During operation, the axial displacement of regulating assembly can real-time adjust static ring position, effectively compensate the compression amount change caused by balance disc wear or working condition fluctuation;This dynamic adjustment mechanism makes sealing end face specific pressure maintain in suitable range all the time, both avoids the premature wear of sealing surface caused by compression amount deviation of traditional device, and eliminates the production interruption caused by stoppage adjustment.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pump technology, specifically a mechanical seal device for a multi-stage centrifugal pump that allows for adjustment of compression without stopping the pump. Background Technology

[0002] In industries such as petrochemicals and power generation, multistage centrifugal pumps are critical fluid transport equipment, and the reliability of their mechanical seals directly affects the continuous operation capability of the production system. Currently, the compression adjustment of mechanical seals generally relies on the axial positioning of the rotating ring, but this design has significant limitations in dealing with rotor axial movement and changes in operating conditions.

[0003] In existing technologies, non-manifold mechanical seals fix the rotating ring at a certain position on the shaft sleeve, but each adjustment requires disassembling the stationary ring and related components, which is cumbersome. While manifold mechanical seals simplify the installation process, their factory-cured compression cannot accommodate axial displacement caused by wear of the balance disc or fluctuations in fluid pressure during operation. Long-term operation can easily lead to pressure imbalance on the sealing surface, accelerating the wear of the sealing ring.

[0004] Especially for multistage pumps with a balance disc structure, the axial movement of the rotor during operation can reach 0.1-0.3mm. Wear of the balance disc also causes changes in the axial position of the rotor, which in turn leads to changes in the compression. Traditional sealing devices lack online compensation capabilities and often require shutdown and disassembly to restore the optimal compression, which will cause significant economic losses in continuous production scenarios.

[0005] How to adjust the sealing compression in real time without interrupting operation has become a key technical challenge in improving the adaptability and lifespan of mechanical seals in multi-stage centrifugal pumps. Utility Model Content

[0006] The present invention aims to solve the above problems, thereby providing a mechanical seal device for a multi-stage centrifugal pump that can adjust the compression amount in real time without stopping the pump.

[0007] The technical solution adopted by this utility model to solve the aforementioned problem is:

[0008] A mechanical seal device for a multi-stage centrifugal pump with adjustable compression without shutting down the pump includes a rotating ring fixed on a shaft sleeve and a stationary ring located on the outer periphery of the pump shaft and abutting against the rotating ring. It also includes a fixed ring seat connected to the housing at the end of the stationary ring and located on the outer periphery of the pump shaft. An adjusting component that can move axially is provided inside the fixed ring seat, and the inner side of the adjusting component is connected to the stationary ring.

[0009] Compared with the prior art, the outstanding features of this utility model, which adopts the above technical solution, are:

[0010] Through the coordinated design of the fixed ring seat and the axially movable adjustment component, the compression of the mechanical seal can be controlled without stopping the machine. The device allows for preliminary compression setting during assembly and fine calibration after final assembly. During operation, the axial displacement of the adjustment component can adjust the position of the stationary ring in real time, effectively compensating for compression changes caused by wear of the balance disc or fluctuations in operating conditions. This dynamic adjustment mechanism keeps the specific pressure on the sealing face within a suitable range, avoiding premature wear of the sealing surface due to compression deviations in traditional devices and eliminating production interruptions caused by downtime adjustments. It is particularly suitable for the stringent reliability requirements of continuous industrial production.

[0011] As a preferred embodiment, a further technical solution of this utility model is:

[0012] Furthermore, the adjustment assembly includes an adjustment sleeve with a double-layered stepped shape along the axial direction, and the inner side of the fixed ring seat has a double-layered stepped shape along the axial direction. The inner layer of the adjustment sleeve is slidably connected to the inner surface of the fixed ring seat. The outer surface of the outer layer of the adjustment sleeve and the inner surface of the outer layer of the fixed ring seat are provided with a mating thread structure. The outer end of the adjustment sleeve is located outside the fixed ring seat and is provided with a control ring. The stepped mating structure forms a double axial guide surface. The inner sliding connection ensures the coaxiality of the adjustment, and the outer thread structure realizes the adjustment of the compression amount.

[0013] Furthermore, the control ring includes a ring body located on the outer periphery of the pump shaft, with adjustment blocks spaced apart on the outer periphery of the ring body. The spaced adjustment blocks form a multi-force point operating surface, which not only facilitates the application of force by wrench tools at multiple angles, but also evenly transmits torque to the threaded pair, avoiding thread seizing caused by local stress concentration. It is particularly suitable for adjustment operations in confined spaces.

[0014] Furthermore, the stationary ring is double-stepped along the axial direction, and a sealing ring cavity is formed at the junction of the double-stepped structure of the stationary ring and the adjusting sleeve. A first sealing ring is provided in the sealing ring cavity to effectively prevent the medium from penetrating into the threaded pair along the axial direction, while compensating for the slight wobble of the sealing surface during the adjustment process.

[0015] Furthermore, a blind hole is provided on the outer layer of the stationary ring, and a positioning hole is provided on the adjusting sleeve opposite to the blind hole. An anti-rotation pin is provided between the countersunk hole and the positioning hole to ensure synchronous displacement of the stationary ring and the adjusting sleeve.

[0016] Furthermore, a sealing groove is provided on the outer periphery of the inner layer of the adjusting sleeve, which is opposite to the fixed ring seat. A second sealing ring is provided between the sealing groove and the fixed ring seat to form a dynamic sealing interface during axial movement.

[0017] Furthermore, an anti-loosening nut is fitted on the outer layer of the adjusting sleeve and located outside the fixed ring seat. A continuous preload is generated through the locking mechanism at the end of the threaded pair to suppress the thread self-loosening phenomenon caused by equipment vibration or pressure fluctuation, and to ensure the long-term stability of the stationary ring position after adjustment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0019] Figure 2 for Figure 1 A magnified schematic diagram of the structure of part A in the diagram;

[0020] Figure 3 This is a schematic diagram of the structure of the fixing ring seat according to an embodiment of the present utility model;

[0021] Figure 4 This is a schematic diagram of the structure of the adjusting sleeve in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the anti-loosening nut according to an embodiment of the present invention;

[0023] The components in the diagram are labeled as follows: 1. Moving ring; 2. Stationary ring; 3. Fixed ring seat; 4. Adjusting sleeve; 5. Control ring; 6. First sealing ring; 7. Anti-rotation pin; 8. Second sealing ring; 9. Anti-loosening nut. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0025] A mechanical seal device for a multi-stage centrifugal pump with adjustable compression without shutting down the pump includes a rotating ring 1 fixed on a shaft sleeve and a stationary ring 2 located on the outer periphery of the pump shaft and abutting against the rotating ring 1. It also includes a fixed ring seat 3 connected to the end housing of the stationary ring 2 and located on the outer periphery of the pump shaft. The fixed ring seat 3 is connected to the end housing of the stationary ring 2 by bolts. The fixed ring seat 3 has an inclined injection hole to facilitate cooling and flushing of the cavity containing the stationary ring 2 and the rotating ring 1. An adjusting component that can move axially is provided inside the fixed ring seat 3. The inner side of the adjusting component is connected to the stationary ring 2.

[0026] Furthermore, the adjustment assembly includes an adjustment sleeve 4 with a double-layered stepped shape along the axial direction. The single-side cross-section of the adjustment sleeve 4 along the axial direction is Z-shaped. The inner side of the fixing ring seat 3 has a double-layered stepped shape along the axial direction. The inner diameter of the inner layer of the fixing ring seat 3 is larger than the inner diameter of the outer layer. The outer layer is the side near the end. The inner layer of the adjustment sleeve 4 is slidably connected to the inner surface of the fixing ring seat 3. The outer surface of the outer layer of the adjustment sleeve 4 and the inner surface of the outer layer of the fixing ring seat 3 are provided with a matching thread structure. The outer end of the adjustment sleeve 4 is located outside the fixing ring seat 3 and is provided with a control ring 5. The stepped matching structure forms a double axial guide surface. The sliding connection of the inner layer ensures the coaxiality of the adjustment, and the thread structure of the outer layer realizes the adjustment of the compression amount.

[0027] Furthermore, the control ring 5 includes a ring body located on the outer periphery of the pump shaft, with adjustment blocks spaced apart on the outer periphery of the ring body. The spaced adjustment blocks form a multi-force point operating surface, which not only facilitates the application of force by the wrench tool at multiple angles, but also evenly transmits torque to the threaded pair, avoiding thread seizing caused by local stress concentration. It is particularly suitable for adjustment operations in confined spaces.

[0028] Furthermore, the stationary ring 2 is in a double-layered stepped shape along the axial direction. The outer diameter of the inner layer of the stationary ring 2 is larger than that of the outer layer, and the outer layer is the side near the end. A sealing ring cavity is formed at the junction of the double-layered stepped structure of the stationary ring 2 and the adjusting sleeve 4. A first sealing ring 6 is provided in the sealing ring cavity to effectively prevent the medium from penetrating into the threaded pair along the axial direction, while compensating for the slight deviation of the sealing surface during the adjustment process.

[0029] Furthermore, a blind hole is provided on the outer layer of the stationary ring 2, and a positioning hole is provided on the adjusting sleeve 4 opposite to the blind hole. An anti-rotation pin 7 is provided between the countersunk hole and the positioning hole to ensure the synchronous displacement of the stationary ring 2 and the adjusting sleeve 4.

[0030] Furthermore, a sealing groove is provided on the outer periphery of the inner layer of the adjusting sleeve 4, which is opposite to the fixed ring seat 3. A second sealing ring 8 is provided between the sealing groove and the fixed ring seat 3 to form a dynamic sealing interface during axial movement.

[0031] Furthermore, an anti-loosening nut 9 is fitted on the outer layer of the adjusting sleeve 4 and located outside the fixed ring seat 3. The anti-loosening nut 9 generates a continuous preload through the locking mechanism at the end of the threaded pair, which suppresses the thread self-loosening phenomenon caused by equipment vibration or pressure fluctuation, and ensures the long-term stability of the position of the stationary ring 2 after adjustment.

[0032] When the pump is running, the wear condition of the balance disc is judged by observing or measuring the change in the clearance between the pump coupling and the motor coupling, thus preventing large changes in compression due to wear of the balance disc. The operator can directly apply torque through the adjusting block of the control ring 5 to make the adjusting sleeve 4 move axially along the thread structure of the fixed ring seat 3. At this time, the adjusting sleeve 4 drives the stationary ring 2 to move synchronously through the connecting bolt. The inner sliding surface of the double-layer stepped structure ensures the coaxiality of the adjustment, while the first sealing ring 6 and the second sealing ring 8 in the sealing ring cavity continuously block the medium from penetrating during the dynamic adjustment process. After the adjustment is in place, the anti-loosening nut 9 locks the threaded pair to resist vibration, and finally realizes the online accurate compensation of the specific pressure of the sealing end face. The whole process can be completed without stopping the machine.

[0033] The above description is only a preferred embodiment of the present utility model and does not limit the scope of the present utility model. All equivalent changes made based on the content of the present utility model specification and its drawings are included within the scope of the present utility model.

Claims

1. A mechanical seal device for a multi-stage centrifugal pump with adjustable compression without shutting down the pump, comprising a rotating ring fixed on a shaft sleeve and a stationary ring located on the outer circumference of the pump shaft and abutting against the rotating ring, characterized in that: It also includes a fixed ring seat connected to the end housing where the stationary ring is located and located on the outer periphery of the pump shaft. An adjustment component that can move axially is provided inside the fixed ring seat, and the inner side of the adjustment component is connected to the stationary ring. The adjustment assembly includes an adjustment sleeve with a double-layered stepped shape along the axial direction, and the inner side of the fixed ring seat has a double-layered stepped shape along the axial direction. The inner layer of the adjustment sleeve is slidably connected to the inner surface of the fixed ring seat. The outer surface of the outer layer of the adjustment sleeve and the inner surface of the outer layer of the fixed ring seat are provided with a matching thread structure. The outer end of the adjustment sleeve is located outside the fixed ring seat and is provided with a control ring.

2. The mechanical seal device for a multi-stage centrifugal pump with adjustable compression capacity without stopping the pump, as described in claim 1, is characterized in that: The control ring includes a ring body located on the outer periphery of the pump shaft, with adjusting blocks spaced apart on the outer periphery of the ring body.

3. The mechanical seal device for a multi-stage centrifugal pump with adjustable compression capacity without stopping the pump, as described in claim 1, is characterized in that: The stationary ring has a double-layered stepped shape along the axial direction. A sealing ring cavity is formed at the junction of the double-layered stepped structure of the stationary ring and the adjusting sleeve. A first sealing ring is provided in the sealing ring cavity.

4. The mechanical seal device for a multi-stage centrifugal pump with adjustable compression rate without stopping operation, as described in claim 3, is characterized in that: A blind hole is provided on the outer layer of the stationary ring, and a positioning hole is provided on the adjusting sleeve that is opposite to the blind hole. An anti-rotation pin is provided between the countersunk hole and the positioning hole.

5. The mechanical seal device for a multi-stage centrifugal pump with adjustable compression capacity without shutting down, as described in claim 1, is characterized in that: The outer periphery of the inner layer of the adjusting sleeve is provided with a sealing groove that is opposite to the fixed ring seat, and a second sealing ring is provided between the sealing groove and the fixed ring seat.

6. The mechanical seal device for a multi-stage centrifugal pump with adjustable compression capacity without shutting down, as described in claim 1, is characterized in that: An anti-loosening nut is fitted on the outer layer of the adjusting sleeve and on the outside of the fixed ring seat.

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