Mechanical seal flush system for pumps

Abstract

The application relates to the technical field of sealing, in particular to a mechanical seal flushing system for a pump. The mechanical seal flushing system comprises a double sealing system and a liquid inlet pipe, the liquid inlet pipe is connected with the double sealing system, a filter is arranged on the liquid inlet pipe, the filter is used for filtering impurities in flushing medium, and the filter can prevent the impurities from mixing with easy crystallization materials to block the sealing end face and aggravate abrasion, thereby guaranteeing the continuity of sealing lubrication and cooling.

Description

Technical Field

[0001] This application relates to the field of sealing technology, and in particular to a mechanical seal flushing system for pumps. Background Technology

[0002] During the operation of pumps and machinery, mechanical seals are the core components ensuring the sealing performance of the equipment and preventing material leakage. Flushing solutions, as an important auxiliary means of mechanical seals, affect the service life of the seals and the operational stability of the equipment. With the increasing demands of industrial production on material conveying, materials with different characteristics place higher requirements on the adaptability of mechanical seals and their corresponding flushing solutions. Conventional sealing and flushing designs are no longer sufficient to fully meet the needs of special operating conditions, necessitating targeted technical optimization to solve the sealing challenges in conveying special materials.

[0003] Currently, mechanical seals for machines and pumps are generally designed and applied based on industry standards such as API610 and API682. These standards contain dozens of flushing solutions that are flexible and can be freely combined. In conventional material conveying scenarios, through scientific selection and matching of solutions, the seal can be effectively lubricated, cooled, and impurities removed, ensuring the stable operation of the mechanical seal. This is a mature technology system that is widely used and recognized in the industry.

[0004] However, existing technologies are inadequate when handling special materials that are prone to crystallization and adhesion. These materials are susceptible to crystallization or adhesion under conditions such as decreased temperature, and are difficult to wash off after crystallization; currently, there is no suitable washing solution. Utility Model Content

[0005] This application addresses, to at least some extent, one of the technical problems in the related art.

[0006] Therefore, this application aims to provide a mechanical seal flushing system for pumps.

[0007] To achieve the above objectives, this application provides a pump mechanical seal flushing system, comprising: Double-end face sealing or back-to-back combination double sealing system; The liquid inlet pipe is connected to the external part of the double-sealed system. The liquid inlet pipe is equipped with a filter, a flow meter and a first check valve in sequence. The medium transported by the liquid inlet pipe serves as the lubricating and cooling medium for the double-sealed system. A guide hole is provided at the sealing liquid outlet position of the dual sealing system, and the opening of the guide hole faces the pump head sealing cavity; A comb-tooth flow-blocking ring is disposed on the side of the pump head sealing cavity near the impeller. The comb-tooth flow-blocking ring is used to prevent easily crystallizing materials from accumulating near the seal.

[0008] In the technical solution, the double-end face sealing or back-to-back double sealing system provides a basic guarantee for sealing performance. The filter on the inlet pipe can filter impurities in the flushing medium, preventing impurities from mixing with easily crystallizing materials and clogging the sealing end face, aggravating wear, and ensuring the continuity of sealing lubrication and cooling. The flow meter can monitor the flushing medium flow rate in real time, preventing insufficient flushing due to abnormal flow rate, which could lead to crystal retention or excessive flushing, which could lead to resource waste. The first check valve can prevent easily crystallizing media in the pump from flowing back into the inlet pipe, preventing crystal blockage in the inlet pipe and ensuring unobstructed passage of the flushing system.

[0009] The guide hole facing the pump head sealing cavity can guide the sealing fluid to the sealing area, avoid local flushing blind spots caused by irregular flow of sealing fluid, ensure that the sealing end face is evenly covered with flushing medium, reduce local temperature and reduce crystal adhesion.

[0010] The comb-type flow-blocking ring prevents easily crystallizing materials from migrating to the vicinity of the seal, solving the problems of crystallization retention in the sealing area and wear on the sealing end face, extending the basic service life of the mechanical seal, and reducing downtime due to seal failure caused by crystallization.

[0011] In some embodiments of this application, the inlet pipe is further equipped with a needle valve, which is used to regulate the flow rate of the lubricating and cooling medium in the inlet pipe.

[0012] In the technical solution, the flow rate of the flushing medium can be finely adjusted by a needle valve according to the crystallization characteristics of different easily crystallizing materials. For materials with fast crystallization speed, the flow rate can be appropriately increased to enhance the flushing effect; for materials with low allowable flushing volume, the flow rate can be reduced to avoid excessive dilution, thus solving the problem that traditional fixed flow rate flushing cannot be adapted to multiple types of easily crystallizing materials.

[0013] Needle valves have higher adjustment accuracy than ordinary valves and can be used with flow meters to stabilize the flow rate within the optimal range for the operating conditions, avoiding insufficient local flushing or excessive flow due to flow fluctuations, thus improving the adaptability of the flushing system to the operating conditions.

[0014] In some embodiments of this application, the sealing cavity of the dual-seal system is provided with an adjustable spring check valve and a flow channel; the adjustable spring check valve is located on the outflow path of the sealing fluid after it flows through the sealing end face, and the flow channel is used to guide the sealing fluid after it flows through the sealing end face to the medium inside the pump; the adjustable spring check valve is used to prevent the medium inside the pump from flowing back into the sealing cavity when the sealing cavity loses pressure.

[0015] In this technical solution, the adjustable spring check valve is located on the sealing fluid outflow path. When the sealing chamber loses pressure due to a fault, it automatically closes to prevent the easily crystallizing medium in the pump from flowing back into the sealing chamber. This avoids the backflowing medium from crystallizing in the sealing chamber, blocking the sealing gap, or damaging the sealing end face. Compared to traditional structures without anti-backflow design, this significantly reduces the risk of seal failure under pressure loss conditions. The flow channel can guide the sealing fluid after passing the sealing end face to the medium in the pump in an orderly manner, avoiding disorderly accumulation of the sealing fluid in the sealing chamber, which could lead to excessively high local pressure or local lack of fluid.

[0016] In some embodiments of this application, an adjusting screw is provided on the back of the adjustable spring check valve; the adjusting screw is used to adjust the spring force so that the pressure of the lubricating and cooling medium in the sealing cavity is slightly higher than the pressure of the medium in the pump within a preset range.

[0017] In the technical solution, the spring force can be adjusted by turning the adjusting screw, thereby controlling the pressure of the flushing medium in the sealed cavity, making it slightly higher than the pressure of the medium in the pump within a preset range. This matches the pressure requirements according to the pressure characteristics of the medium for different easily crystallizing materials, avoiding problems caused by insufficient or excessive pressure.

[0018] The pressure-adjustable design allows the same sealing flushing structure to be adapted to multiple pumps with different outlet pressures, eliminating the need to customize a special sealing system for different pumps, reducing equipment procurement and replacement costs, and improving the versatility and economy of the structure.

[0019] In some embodiments of this application, an anti-backpressure ring is further provided in the sealing cavity of the dual-sealing system; the anti-backpressure ring is used to maintain the sealing performance of the medium side seal when the sealing cavity loses pressure.

[0020] In the technical solution, when the sealing cavity loses pressure, the adjustable spring check valve needs a certain response time to close. The anti-back pressure ring can maintain the sealing performance of the medium side seal for a short period of time within this response gap, preventing the easily crystallizing medium in the pump from rapidly entering the sealing gap at the moment of pressure loss. Compared with the single protection of relying solely on the check valve, the supplementary protection of the anti-back pressure ring can further reduce the seal damage caused by pressure loss, reduce the frequency of downtime maintenance caused by short-term pressure loss, and improve the operational safety of the equipment under pressure fluctuation conditions.

[0021] In some embodiments of this application, a throttling ring is provided at the outlet end of the flow channel; the sealing liquid flowing out of the flow channel is throttled through the throttling ring and then mixed with the material in the pump.

[0022] In the technical solution, the flow rate of the sealing fluid flowing out of the flow channel is steadily controlled after passing through the throttling ring, avoiding the disturbance of the medium caused by the high-speed sealing fluid directly rushing into the pump medium; the sealing fluid after throttling mixes gently with the medium, reducing the induction of crystallization.

[0023] In some embodiments of this application, the inlet pressure of the lubricating and cooling medium in the inlet pipe is not less than 2 / 3 of the pump outlet pressure.

[0024] In the technical solution, when conveying easily crystallizing materials, the pressure of the medium inside the pump is relatively high. If the flushing pressure of the inlet pipe is too low, the flushing medium is easily pushed back by the medium inside the pump and cannot effectively cover the sealing end face. This requirement ensures that the flushing medium can stably reach and cover the sealing end face by limiting the lower limit of the pressure, so as to continuously play the role of lubrication and cooling, and avoid the crystal adhesion problem caused by flushing failure from the pressure level.

[0025] In some embodiments of this application, the flow rate of the lubricating and cooling medium displayed by the flow meter is maintained at 1 / 4 or 2 / 3 of the total flow meter range; the total flow meter range is the maximum flushing volume allowed by the dual-seal system.

[0026] In the technical solution, a flow rate below 1 / 4 can easily lead to insufficient flushing volume and crystallization retention on the sealing end face; a flow rate above 2 / 3 can easily cause waste of flushing medium and may excessively dilute the material in the pump. This range can balance the flushing effect and resource conservation, solving the drawbacks of traditional flow control.

[0027] In some embodiments of this application, the dual-sealing system includes an atmospheric-side stationary ring, an atmospheric-side moving ring, a media-side stationary ring, and a media-side moving ring; the atmospheric-side stationary ring and the atmospheric-side moving ring constitute an atmospheric-side sealing pair, and the media-side stationary ring and the media-side moving ring constitute a media-side sealing pair.

[0028] In the technical solution, the mass-side sealing pair is in direct contact with the easily crystallizing material, and can be made of materials or structures that are more resistant to crystallization wear, specifically resisting the direct erosion of material crystallization; the atmospheric-side sealing pair is the second barrier, which can prevent the material from leaking to the outside world even if there is a slight leakage in the medium-side seal, thus avoiding environmental pollution or safety hazards.

[0029] The layered design makes the maintenance of the sealing system more targeted. If only the medium-side seal fails due to crystallization wear, the medium-side component can be replaced separately without replacing the entire sealing system, reducing maintenance costs and downtime, and improving maintenance convenience.

[0030] In some embodiments of this application, the dual-seal system further includes a spring; the spring is used to provide axial preload to the medium-side stationary ring or the medium-side moving ring to ensure the sealing fit of the medium-side sealing pair.

[0031] In the technical solution, during the conveying of easily crystallizing materials, the sealing pair may develop tiny gaps due to wear of crystallizing particles or temperature changes. The preload of the spring can press the stationary / dynamic ring on the medium side tightly in real time to prevent gap formation, ensure that the sealing pair is always tightly fitted, and maintain sealing performance.

[0032] As can be seen from the above technical solutions, additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view of a pump mechanical seal flushing system.

[0034] In the above figures: 1. Atmospheric side stationary ring; 2. Atmospheric side moving ring; 3. Adjustable spring check valve; 4. Flow channel; 5. Medium side stationary ring; 6. Medium side moving ring; 7. Spring; 8. Guide hole; 9. First check valve; 10. Flow meter; 11. Filter; 12. Inlet pipe; 13. Throttling ring; 14. Anti-backpressure ring; 15. Comb-type flow-blocking ring; 16. Needle valve; 17. Adjusting screw. Detailed Implementation

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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 this application.

[0036] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0040] It should be noted that during the operation of pumps and motors, the mechanical seal is the core component ensuring the sealing performance of the equipment and preventing material leakage. The flushing scheme, as an important auxiliary means of the mechanical seal, affects the seal's service life and the operational stability of the equipment. With the increasing demands on material conveying in industrial production, materials with different characteristics place higher requirements on the adaptability of mechanical seals and their corresponding flushing schemes. Conventional sealing and flushing designs are no longer sufficient to fully meet the needs of special operating conditions, necessitating targeted technical optimization to solve the sealing challenges in conveying special materials.

[0041] Currently, mechanical seals for machines and pumps are generally designed and applied based on industry standards such as API610 and API682. These standards contain dozens of flushing solutions that are flexible and can be freely combined. In conventional material conveying scenarios, through scientific selection and matching of solutions, the seal can be effectively lubricated, cooled, and impurities removed, ensuring the stable operation of the mechanical seal. This is a mature technology system that is widely used and recognized in the industry.

[0042] However, existing technologies reveal shortcomings when handling special materials that are prone to crystallization and adhesion. These materials are susceptible to crystallization or adhesion under conditions such as decreased temperature, and are difficult to wash away after crystallization.

[0043] Based on this, this application proposes a mechanical seal flushing system for pumps and a pump device using this structure. By adopting a double-seal system with double-end face sealing or back-to-back combination as the sealing unit, and with an inlet pipe sequentially equipped with a filter, flow meter and first check valve, a guide hole is opened at the sealing liquid outlet of the double-seal system facing the pump head sealing cavity to guide the flow of the sealing liquid. A comb-type flow-blocking ring is set on the side of the pump head sealing cavity near the impeller to prevent the retention of easily crystallizing materials. Simultaneously, an adjustable spring check valve, an anti-back pressure ring and a flow channel with a throttling ring are integrated in the sealing cavity. The invention achieves the effects of significantly extending the mechanical seal life under the condition of easily crystallizing material conveying, improving the integration of the flushing system, accurately controlling the flushing parameters, and providing dual protection when the sealing cavity loses pressure. It solves the technical problem in the prior art that the retention of easily crystallizing materials in the sealing area leads to rapid seal failure.

[0044] In the following, embodiments of this application will be described in detail with reference to the accompanying drawings.

[0045] As attached Figure 1 As shown, this application provides a pump mechanical seal flushing system, including a double-seal system with double-end face seals or back-to-back combinations and an inlet pipe 12. The inlet pipe 12 is connected to the outside of the double-seal system, and a filter 11, a flow meter 10, and a first check valve 9 are sequentially mounted on the inlet pipe 12. The medium transported by the inlet pipe 12 serves as the lubricating and cooling medium for the double-seal system.

[0046] Through the above scheme, the double-end face sealing or back-to-back double sealing system provides a basic guarantee for sealing performance. The filter 11 on the inlet pipe 12 can filter impurities in the flushing medium, preventing impurities from mixing with easily crystallizing materials and clogging the sealing end face, aggravating wear, and ensuring the continuity of sealing lubrication and cooling. The flow meter 10 can monitor the flushing medium flow rate in real time, preventing insufficient flushing due to abnormal flow rate, resulting in crystal retention or excessive flushing, resulting in resource waste. The first check valve 9 can prevent easily crystallizing medium in the pump from flowing back into the inlet pipe 12, preventing crystal blockage in the inlet pipe 12 and ensuring unobstructed passage of the flushing system.

[0047] In some embodiments, a guide hole 8 is provided at the sealing fluid outlet of the dual-seal system, with the opening of the guide hole 8 facing the pump head sealing cavity. The guide hole 8 facing the pump head sealing cavity can guide the sealing fluid to the sealing area, avoid local flushing blind spots caused by irregular flow of the sealing fluid, ensure that the sealing end face is uniformly covered with flushing medium, reduce local temperature, and reduce crystal adhesion.

[0048] In some embodiments, a comb-shaped flow-blocking ring 15 is provided on the side of the pump head sealing cavity near the impeller. The comb-shaped flow-blocking ring 15 is used to prevent easily crystallizing materials from accumulating near the seal. The comb-shaped flow-blocking ring 15 prevents easily crystallizing materials from migrating to the vicinity of the seal, solving the problems of crystal accumulation in the sealing area and wear on the sealing end face, extending the basic service life of the mechanical seal, and reducing downtime due to seal failure caused by crystallization.

[0049] In some embodiments, a needle valve 16 is also installed on the inlet pipe 12. The needle valve 16 is used to adjust the flow rate of the lubricating and cooling medium in the inlet pipe 12. Depending on the crystallization characteristics of different easily crystallizing materials, the flow rate of the rinsing medium can be finely adjusted by the needle valve 16. For materials with fast crystallization rates, the flow rate can be appropriately increased to enhance the rinsing effect; for materials with low allowable rinsing volume, the flow rate can be reduced to avoid excessive dilution, thus solving the problem that traditional fixed-flow rinsing cannot adapt to various easily crystallizing materials.

[0050] In addition, the adjustment accuracy of the needle valve 16 is higher than that of ordinary valves. It can work with the flow meter 10 to stabilize the flow rate in the optimal range for the appropriate working conditions, avoid insufficient local flushing or excessive flow due to flow fluctuations, and improve the adaptability of the flushing system to the working conditions.

[0051] In some embodiments, the sealing cavity of the dual-seal system is provided with an adjustable spring check valve 3 and a flow channel 4; the adjustable spring check valve 3 is located on the outflow path of the sealing fluid after it flows through the sealing end face, and the flow channel 4 is used to guide the sealing fluid after it flows through the sealing end face to the medium inside the pump; the adjustable spring check valve 3 is used to prevent the medium inside the pump from flowing back into the sealing cavity when the sealing cavity loses pressure.

[0052] With the above solution, the adjustable spring check valve 3 is located on the sealing fluid outflow path. When the sealing chamber loses pressure due to a fault, it can automatically close and block the backflow of easily crystallizing medium from the pump into the sealing chamber, preventing the backflowed medium from crystallizing in the sealing chamber, blocking the sealing gap, or damaging the sealing end face. Compared with the traditional structure without anti-backflow, this significantly reduces the risk of seal failure under pressure loss conditions. The flow channel 4 can orderly guide the sealing fluid after passing through the sealing end face to the medium in the pump, avoiding the disorderly accumulation of sealing fluid in the sealing chamber, which can lead to excessively high local pressure or local lack of fluid.

[0053] In some embodiments, an adjusting screw 17 is provided on the back of the adjustable spring check valve 3; the adjusting screw 17 is used to adjust the force of the spring 7 so that the pressure of the lubricating and cooling medium in the sealing cavity is slightly higher than the pressure of the medium in the pump within a preset range.

[0054] The above solution allows for adjusting the force of spring 7 by turning the adjusting screw 17, thereby controlling the pressure of the flushing medium in the sealed cavity to be slightly higher than the pressure of the medium in the pump within a preset range. This matches the pressure requirements to the medium pressure characteristics of different easily crystallizing materials, avoiding problems caused by insufficient or excessive pressure.

[0055] The pressure-adjustable design allows the same sealing flushing structure to be adapted to multiple pumps with different outlet pressures, eliminating the need to customize a special sealing system for different pumps, reducing equipment procurement and replacement costs, and improving the versatility and economy of the structure.

[0056] In some embodiments, the sealing cavity of the dual-sealing system is further provided with an anti-backpressure ring 14; the anti-backpressure ring 14 is used to maintain the sealing performance of the medium side seal when the sealing cavity loses pressure. When the sealing cavity loses pressure, the adjustable spring check valve 3 needs a certain response time to close, and the anti-backpressure ring 14 can maintain the sealing performance of the medium side seal for a short period of time within this response gap, preventing the easily crystallizing medium in the pump from rapidly invading the sealing gap at the moment of pressure loss; compared with the single protection of relying solely on the check valve, the supplementary protection of the anti-backpressure ring 14 can further reduce the seal damage caused by pressure loss, reduce the frequency of downtime maintenance caused by short-term pressure loss, and improve the operational safety of the equipment under pressure fluctuation conditions.

[0057] In some embodiments, a throttling ring 13 is provided at the outlet end of the flow channel 4; the sealing fluid flowing out of the flow channel 4 is throttled by the throttling ring 13 and then mixed with the material in the pump. After the sealing fluid flowing out of the flow channel 4 passes through the throttling ring 13, the flow rate is steadily controlled, avoiding medium disturbance caused by high-speed sealing fluid directly rushing into the medium in the pump; the throttled sealing fluid mixes gently with the medium, reducing the induction of crystallization.

[0058] In some embodiments, the inlet pressure of the lubricating and cooling medium in the inlet pipe 12 is not less than 2 / 3 of the pump outlet pressure. When conveying easily crystallizing materials, the medium pressure inside the pump is relatively high. If the flushing pressure of the inlet pipe 12 is too low, the flushing medium is easily pushed back by the medium inside the pump and cannot effectively cover the sealing end face. This requirement ensures that the flushing medium can stably reach and cover the sealing end face by limiting the lower pressure limit, and continuously play a lubricating and cooling role, thereby avoiding the crystal adhesion problem caused by flushing failure from the pressure level.

[0059] In some embodiments, the flow rate of the lubricating and cooling medium displayed by the flow meter 10 is maintained at 1 / 4 or 2 / 3 of the total range of the flow meter 10; the total range of the flow meter 10 is the maximum allowable flushing volume of the dual-seal system. A flow rate below 1 / 4 can easily lead to insufficient flushing volume and crystallization at the sealing end face; a flow rate above 2 / 3 can easily result in waste of flushing medium and may excessively dilute the material inside the pump. This range balances flushing effectiveness and resource conservation, solving the drawbacks of traditional flow rate control.

[0060] In some embodiments, the dual-sealing system includes an atmospheric side stationary ring 1, an atmospheric side dynamic ring 2, a medium side stationary ring 5, and a medium side dynamic ring 6; the atmospheric side stationary ring 1 and the atmospheric side dynamic ring 2 constitute an atmospheric side sealing pair, and the medium side stationary ring 5 and the medium side dynamic ring 6 constitute a medium side sealing pair.

[0061] With the above solution, the medium-side sealing pair is in direct contact with the easily crystallizing material, and can be made of materials or structures that are more resistant to crystallization wear, specifically resisting the direct erosion of material crystallization; the atmospheric-side sealing pair is the second barrier, which can prevent the material from leaking to the outside world even if there is a slight leakage in the medium-side seal, thus avoiding environmental pollution or safety hazards.

[0062] In addition, the layered design makes the maintenance of the sealing system more targeted. If only the medium-side seal fails due to crystallization wear, the medium-side component can be replaced separately without replacing the entire sealing system, reducing maintenance costs and downtime, and improving maintenance convenience.

[0063] In some embodiments, the dual sealing system further includes a spring 7; the spring 7 is used to provide axial preload to the medium-side stationary ring 5 or the medium-side moving ring 6 to ensure the sealing fit of the medium-side sealing pair.

[0064] Through the above solution, during the conveying of easily crystallizing materials, the sealing pair may develop tiny gaps due to wear from crystallizing particles or temperature changes. The preload of spring 7 can press the stationary ring 5 / dynamic ring on the medium side tightly in real time, preventing gap formation and ensuring that the sealing pair is always tightly fitted, maintaining sealing performance. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A pump mechanical seal flushing system, characterized in that, include: Double-end face sealing or back-to-back combination double sealing system; The liquid inlet pipe (12) is connected to the outside of the double sealing system. The liquid inlet pipe (12) is equipped with a filter (11), a flow meter (10) and a first check valve (9) in sequence. The medium transported by the liquid inlet pipe (12) serves as the lubrication and cooling medium of the double sealing system. A guide hole (8) is provided at the sealing liquid outlet position of the double sealing system, and the opening of the guide hole (8) faces the pump head sealing cavity. A comb-tooth flow-blocking ring (15) is disposed on the side of the pump head sealing cavity near the impeller. The comb-tooth flow-blocking ring (15) is used to prevent easily crystallizing materials from lingering near the seal.

2. The pump mechanical seal flushing system according to claim 1, characterized in that, The inlet pipe (12) is also equipped with a needle valve (16), which is used to regulate the flow rate of the lubricating and cooling medium in the inlet pipe (12).

3. The pump mechanical seal flushing system according to claim 1 or 2, characterized in that, The double-sealing system is equipped with an adjustable spring check valve (3) and a flow channel (4) in the sealing cavity. The adjustable spring check valve (3) is located on the outflow path of the sealing fluid after it flows through the sealing end face. The flow channel (4) is used to guide the sealing fluid after it flows through the sealing end face to the medium inside the pump. The adjustable spring check valve (3) is used to prevent the medium inside the pump from flowing back into the sealing cavity when the sealing cavity loses pressure.

4. The pump mechanical seal flushing system according to claim 3, characterized in that, The adjustable spring check valve (3) has an adjusting screw (17) on its back; the adjusting screw (17) is used to adjust the force of the spring (7) so that the pressure of the lubricating and cooling medium in the sealing cavity is higher than the pressure of the medium in the pump within a preset range.

5. The pump mechanical seal flushing system according to claim 1 or 2, characterized in that, The dual-sealing system is also provided with an anti-backpressure ring (14) in the sealing cavity; the anti-backpressure ring (14) is used to maintain the sealing performance of the medium side seal when the sealing cavity loses pressure.

6. The pump mechanical seal flushing system according to claim 3, characterized in that, A throttling ring (13) is provided at the outlet end of the flow channel (4); the sealing liquid flowing out of the flow channel (4) is throttled by the throttling ring (13) and then mixed with the material in the pump.

7. The pump mechanical seal flushing system according to claim 1 or 2, characterized in that, The inlet pressure of the lubricating and cooling medium in the inlet pipe (12) shall not be less than 2 / 3 of the pump outlet pressure.

8. The pump mechanical seal flushing system according to claim 1 or 2, characterized in that, The flow rate of the lubricating and cooling medium displayed by the flow meter (10) is maintained at 1 / 4 or 2 / 3 of the total range of the flow meter (10).

9. The pump mechanical seal flushing system according to claim 1, characterized in that, The dual sealing system includes an atmospheric side stationary ring (1), an atmospheric side moving ring (2), a medium side stationary ring (5), and a medium side moving ring (6); the atmospheric side stationary ring (1) and the atmospheric side moving ring (2) constitute an atmospheric side sealing pair, and the medium side stationary ring (5) and the medium side moving ring (6) constitute a medium side sealing pair.

10. The pump mechanical seal flushing system according to claim 9, characterized in that, The dual sealing system also includes a spring (7); the spring (7) is used to provide axial preload to the medium-side stationary ring (5) or the medium-side moving ring (6) to ensure the sealing fit of the medium-side sealing pair.

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