Mechanical sealing structure of low-temperature medium
By introducing a separation fluid delivery and return hole design into the mechanical seal structure, the problem of low-temperature medium vaporization is solved, temperature control and pressure stability of the sealing end face are achieved, and the service life and safety of the mechanical seal are improved.
Patent Information
- Application Number
- CN202423166077.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-20
AI Technical Summary
When handling cryogenic liquid media that are prone to vaporization, existing mechanical seals suffer from heat generated by friction at the sealing end face, which causes the media to vaporize, leading to leakage, shortened service life, and increased maintenance costs.
It adopts an axially connected medium-side seal and atmospheric-side seal structure. The isolation liquid is delivered into the sealing groove through the second delivery component. The design of the return hole and pumping ring forms heat exchange and pressure balance, reduces the temperature of the sealing end face, and inhibits the vaporization of the medium.
It effectively reduces the temperature of the sealing end face, prevents the medium from vaporizing, ensures sealing performance, extends service life, and reduces maintenance costs.
Smart Images
Figure CN223594984U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of mechanical seal technology, specifically relating to a mechanical seal structure for low-temperature media. Background Technology
[0002] With the continued booming development of industries such as petroleum, chemical, aerospace, and natural gas transportation, the performance requirements for mechanical seals in various fields are becoming increasingly stringent. Especially in the case of pumping toxic and hazardous process media, achieving zero leakage and zero escape of the process media has become a crucial goal. This requires mechanical seals to not only possess excellent sealing performance, but also have a long service life, simple installation and operation procedures, and low maintenance costs.
[0003] When handling cryogenic, easily vaporized liquid media, conventional mechanical seal structures exhibit significant limitations. During operation, the friction between the dynamic and static ring sealing faces generates substantial frictional heat, causing a rapid rise in the sealing face temperature. This leads to the rapid vaporization of the cryogenic, easily vaporized liquid media, resulting in leakage to the atmosphere. These issues not only significantly shorten the service life of the mechanical seal and reduce its efficiency but also substantially increase user costs in maintenance, seal replacement, and leak handling. To effectively address these challenges, the industry urgently needs to develop more innovative and adaptable mechanical seal technologies and products to meet growing industrial demands and ensure safe, efficient, and environmentally friendly production processes.
[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention
[0005] This invention addresses the aforementioned problems in the prior art by proposing a mechanical seal structure for low-temperature media, which enables the isolation liquid to quickly enter the sealing inner diameter on the media side, effectively reducing the temperature of the sealing end face and suppressing the vaporization tendency of low-temperature liquid easily vaporized media.
[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:
[0007] A mechanical seal structure for cryogenic media, comprising:
[0008] A medium-side seal and an atmospheric seal are axially connected in series.
[0009] A first sealing groove is formed between the medium-side seal and the bushing, and a second sealing groove communicating with the first sealing groove is formed between the atmospheric-side seal and the sealing body.
[0010] A second conveying assembly for conveying the isolating liquid into the second sealing groove and for cooling the atmospheric side sealing is arranged on the sealing body;
[0011] The atmospheric side sealing has a second spring seat fixed on the shaft sleeve, and an axial extending backflow hole is arranged on the second spring seat and communicates with the first sealing groove and the second sealing groove.
[0012] In some embodiments of the present application, the second conveying assembly has a liquid inlet pipe and a liquid outlet pipe arranged on the sealing body, and a pumping ring for pumping the isolating liquid in the second sealing groove to the liquid outlet pipe is fixed on the outer side of the second spring seat, and a plurality of pumping grooves are arranged on the outer end surface of the pumping ring.
[0013] In some embodiments of the present application, the atmospheric side sealing further has a second dynamic ring, the pumping ring is sleeved on the outer side of the second dynamic ring, and a backflow gap communicating with the backflow hole is arranged between the second dynamic ring and the pumping ring.
[0014] In some embodiments of the present application, a flow gap for the flow of the isolating liquid to the first sealing groove is arranged between the outer side of the pumping ring and the sealing body.
[0015] In some embodiments of the present application, a flow limiting convex ring radially extending outward is arranged on the pumping ring near one end of the pumping groove close to the medium side sealing, and a flow limiting port communicating with the flow gap is formed between the flow limiting convex ring and the sealing body.
[0016] In some embodiments of the present application, an annular groove is arranged on the sealing body outside the pumping groove, and the annular groove is connected with the liquid outlet pipe.
[0017] In some embodiments of the present application, the first groove wall of the pumping groove near one end close to the medium side sealing is arranged flush with the first groove wall of the annular groove, one end of the pumping groove away from the medium side sealing is arranged as an open end, and the axial dimension of the pumping groove is greater than the axial dimension of the annular groove.
[0018] In some embodiments of the present application, a first heat preservation coating with low thermal conductivity is coated on the shaft sleeve, and the first heat preservation coating forms the groove wall of the first sealing groove.
[0019] In some embodiments of the present application, the medium side sealing has a first static ring, the sealing body has a first static ring seat arranged inward, and the first static ring seat is coated with a second heat preservation coating with low thermal conductivity near one end close to the air side.
[0020] In some embodiments of the present application, a third sealing groove is formed between the atmosphere side seal and the shaft sleeve, and a gas feeding pipe and a gas outlet pipe for feeding heat preservation gas to the third sealing groove are arranged on the sealing body.
[0021] In some embodiments of the present application, the sealing body has a sealing box located outside the medium side seal and a gland located outside the atmosphere side seal.
[0022] Compared with the prior art, the advantages and positive effects of the present application are that the second conveying assembly arranged on the sealing body conveys isolation liquid into the second sealing groove, and the isolation liquid can effectively absorb heat generated in the operation process of the atmosphere side seal, especially heat generated due to friction between the dynamic ring and the static ring. Through heat exchange, the temperature around the atmosphere side seal is reduced, and the gasification of the low-temperature liquid-state easy-gasification medium at the atmosphere side seal due to excessively high temperature is prevented, thereby ensuring the normal working performance of the atmosphere side seal. The backflow hole is arranged to separate the inflow and backflow of the isolation liquid reaching the first sealing groove, thereby providing a transmission channel for the isolation liquid, enabling the isolation liquid to quickly enter the inner diameter of the medium side seal, helping to timely remove the heat generated by friction, and enabling a stable and continuous low-temperature protective layer to be formed around the end face of the medium side seal, thereby effectively reducing the temperature of the sealing end face and inhibiting the gasification tendency of the low-temperature liquid-state easy-gasification medium. The backflow hole also helps to maintain the pressure balance in the entire sealing system; when the isolation liquid flows into the inner diameter of the medium side seal, the backflow hole can coordinate the pressure change in the sealing groove, avoid the situation of excessively high or low local pressure caused by the injection of the isolation liquid, and ensure the stable pressure state.
[0023] Other features and advantages of the present application will become more apparent after reading the specific embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0025] Figure 1 is a structural schematic diagram of one embodiment of the mechanical seal structure of the low-temperature medium proposed in the present application;
[0026] Figure 2 is Figure 1 a partial structural schematic diagram;
[0027] Figure 3 is Figure 2 a partial structural schematic diagram;
[0028] Figure 4 For Figure 3 Partial structural schematic diagram
[0029] Figure 5 Structural schematic diagram of pumping ring
[0030] Wherein, medium side seal 10;First static ring 11;
[0031] Atmosphere side seal 20;Second dynamic ring 22;Second spring seat 23;Backflow hole 231;Pumping ring 29;Pumping groove 291;First groove wall 2911;Flow limiting convex ring 292;
[0032] Bushing 30;First heat preservation coating 31;
[0033] Seal body 40;First static ring seat 41;Second heat preservation coating 411;Annular groove 44;First groove wall 441;Liquid inlet pipe 45;Liquid outlet pipe 46;
[0034] First sealing groove 51;Second sealing groove 52;Backflow gap 525;Flow gap 526;Flow limiting port 527;Third sealing groove 53;Air supply pipe 57;Air outlet pipe 58. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model.
[0036] In the description of the utility model, it needs to be explained that the position relationship or location relationship indicated by the terms "up", "down", "left", "right" and the like is based on the position relationship shown in the drawings, and the direction close to the rotation axis is "inner", and vice versa. The terms are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance;The features with "first", "second" can explicitly or implicitly include one or more features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.
[0037] In the utility model, unless another definite provision and limitation, the terms "mount", "link", "connect", "fix" and so on should do the broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be direct connection, also can through the indirect connection of intermediate medium, can be the communication of two elements or the interaction of two elements.For the ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0038] In the utility model, unless another definite provision and limitation, the first feature is "on" or "under" the second feature can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them.Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature.The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0039] The following disclosure provides many different embodiments or examples for implementing different structures of the utility model.For the purpose of simplifying the disclosure of the utility model, the components and settings of specific examples are described in the following.Their purpose is not to limit the utility model, of course, and they are only examples.In addition, the utility model can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed by itself.In addition, the utility model provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.
[0040] As long as possible, the various aspects and features described and shown in the specification can be applied individually, and these individual aspects can be the subject of a divisional application.
[0041] Referring to Figures 1-5 It is one embodiment of the mechanical seal structure of low-temperature medium provided by the utility model, and the mechanical seal structure of low-temperature medium comprises: medium-side seal 10 and atmosphere-side seal 20 arranged in series in the axial direction, the medium-side seal 10 and the atmosphere-side seal 20 are arranged between the shaft sleeve 30 and the sealing body 40, the sealing body 40 has a sealing box located outside the medium-side seal 10 and a gland located outside the atmosphere-side seal 20.
[0042] The first seal groove 51 is formed between the medium side seal 10 and the shaft sleeve 30, the second seal groove 52 is formed between the atmospheric side seal 20 and the seal body 40, and the second seal groove 52 is in communication with the first seal groove 51. The second delivery assembly for delivering the isolation liquid into the second seal groove 52 is arranged on the seal body 40, and the second delivery assembly is used for cooling the sealing end face of the atmospheric side seal 20. The second delivery assembly arranged on the seal body 40 delivers the isolation liquid into the second seal groove 52, and the isolation liquid can effectively absorb the heat generated by the atmospheric side seal 20 during operation, especially the heat generated by the friction between the dynamic ring and the static ring. Through heat exchange, the temperature around the atmospheric side seal 20 is reduced, and the low-temperature liquid-state easy-gasification medium is prevented from being gasified at the atmospheric side seal due to the excessively high temperature, thereby ensuring the normal working performance of the atmospheric side seal.
[0043] The atmospheric side seal 20 has a second spring seat 23 fixed on the shaft sleeve 30, the second spring seat 23 is provided with an axial extending backflow hole 231, and the backflow hole 231 is in communication with the first seal groove 51 and the second seal groove 52. The first seal groove 51 and the second seal groove 52 are in communication through the outside of the atmospheric side seal 20, the backflow hole 231 is arranged, the flow of the isolation liquid from the second seal groove 52 to the first seal groove 51 is separated into inflow and backflow, a transmission channel is provided for the isolation liquid, the isolation liquid can quickly enter the inner diameter of the medium side seal 10, the heat generated by friction can be quickly taken away in time, a stable and continuous low-temperature protection layer can be formed around the end face of the medium side seal 10, the temperature of the sealing end face is effectively reduced, and the gasification tendency of the low-temperature liquid-state easy-gasification medium is inhibited. The backflow hole 231 also helps to maintain the pressure balance in the entire sealing system; when the isolation liquid flows into the inner diameter of the medium side seal 10, the backflow hole 231 can coordinate the pressure change in the seal groove, avoid the situation that the local pressure is too high or too low due to the injection of the isolation liquid, and ensure the stable pressure state.
[0044] In some embodiments of the present application, the second conveying assembly has a liquid inlet pipe 45 and a liquid outlet pipe 46 formed on the sealing body 40, and the outer side of the second spring seat 23 is provided with a pumping ring 29 for pumping the isolation liquid in the second sealing groove 52 to the liquid outlet pipe 46, and a plurality of pumping grooves 291 are formed on the outer end surface of the pumping ring 29. The liquid inlet pipe 45 can stably convey the external isolation liquid into the second sealing groove 52, providing a source supply for the circulation of the isolation liquid; during the rotation of the shaft sleeve 30, the isolation liquid in the second sealing groove 52 is effectively pumped to the liquid outlet pipe 46 by the interaction between the plurality of pumping grooves 291 formed on the outer end surface of the shaft sleeve 30 and the isolation liquid. Through continuous circulation, the isolation liquid can fully absorb the heat of the atmospheric side seal 20 and the heat of the low-temperature liquid medium entering the second sealing groove 52 from the first sealing groove 51 through the backflow hole 231, and take the heat out of the sealing structure, thereby maintaining a lower temperature environment in the sealing area, effectively preventing the gasification of the low-temperature liquid medium, and ensuring the stable operation of the mechanical seal.
[0045] In some embodiments of the present application, the atmospheric side seal 20 further has a second dynamic ring 22, and the pumping ring 29 is sleeved on the outer side of the second dynamic ring 22, and a backflow gap 525 in communication with the backflow hole 231 is arranged between the second dynamic ring 22 and the pumping ring 29. The isolation liquid in the first sealing groove 51 flows into the backflow gap 525 through the backflow hole 231, and then reaches the second sealing groove 52, realizing smooth flow of the isolation liquid in the first sealing groove 51.
[0046] In some embodiments of the present application, a flow-through gap 526 for the flow of the isolation liquid to the first sealing groove 51 is arranged between the outer side of the pumping ring 29 and the sealing body 40. Part of the isolation liquid pumped outwards by the pumping ring 29 flows to the first sealing groove 51 along the flow-through gap 526. The flow-through gap 526 is an inflow channel for the isolation liquid in the second sealing groove 52 to reach the first sealing groove 51, and the backflow hole 231 and the backflow gap 525 are backflow channels.
[0047] In some embodiments of the present application, a flow-limiting convex ring 292 extending radially outward is arranged on the pumping ring 29 at one end of the pumping groove 291 close to the medium side seal 10, and a flow-limiting opening 527 in communication with the flow-through gap 526 is formed between the flow-limiting convex ring 292 and the sealing body 40. The liquid pressure at the pumping groove 291 is high, and the flow-limiting convex ring 292 is arranged to limit the flow through the flow-limiting opening 527. The flow-limiting opening 527 formed by the flow-limiting convex ring 292 and the sealing body 40 can accurately limit the flow of the isolation liquid from the pumping groove 291 to the flow-through gap 526. Since the liquid pressure at the pumping groove 291 is high, if there is no flow-limiting measure, the flow of the isolation liquid to the flow-through gap 526 may be too large or unstable, thereby affecting the balance of the liquid circulation and the pressure distribution in the entire sealing structure.
[0048] In some embodiments of the present application, an annular groove 44 is formed on the sealing body 40 outside the pumping groove 291, and the annular groove 44 is connected with the liquid outlet pipe 46. The annular groove 44 provides a space for collecting and discharging the isolation liquid pumped by the pumping ring 29 from the second sealing groove 52, and ensures that the isolation liquid can be efficiently discharged from the inside of the sealing structure. When the isolation liquid flows from the pumping groove 291 with relatively high pressure into the annular groove 44, the annular groove 44 plays a role of pressure transition. It can buffer the pressure fluctuation of the isolation liquid generated during the pumping process, so that the pressure of the isolation liquid gradually stabilizes before entering the liquid outlet pipe 46. Stable pressure helps the isolation liquid to flow smoothly in the liquid outlet pipe 46, reducing problems such as pipe vibration, noise and impact on pipe connection parts caused by unstable pressure.
[0049] In some embodiments of the present application, the first groove wall 2911 of the pumping groove 291 near one end of the medium-side sealing 10 is flush with the first groove wall 441 of the annular groove 44 near one end of the medium-side sealing 10, so that the flow transition of the isolation liquid is smoother when it flows from the pumping groove 291 into the annular groove 44, which helps to maintain relatively stable liquid pressure in the annular groove 44. The end of the pumping groove 291 away from the medium-side sealing 10 is open, so that the isolation liquid can enter the pumping groove 291 more smoothly under the driving of the pumping ring 29, and form an effective flow in the groove. The axial size of the pumping groove 291 is greater than the axial size of the annular groove 44; it is beneficial to maintain the liquid pressure in the annular groove 44, and it is beneficial to pump the isolation liquid out through the liquid outlet pipe 46, thereby improving the efficiency of the entire isolation liquid pumping system.
[0050] In some embodiments of the present application, a first thermal insulation coating 31 with low thermal conductivity is coated on the shaft sleeve 30, and the first thermal insulation coating 31 forms the groove wall of the first sealing groove 51. Preferably, the first thermal insulation coating 31 adopts a tetrafluoro coating, which can effectively prevent the cold transfer of the low-temperature medium, prevent the cold energy transferred to the shaft sleeve 30 from being transferred to the isolation liquid in the first sealing groove 51, prevent the heat loss of the low-temperature liquid easy-gasification medium, and prevent the low-temperature liquid easy-gasification medium from gasification and pressure rise causing medium leakage. As the groove wall of the first sealing groove 51, the first thermal insulation coating 31 can form an effective thermal barrier between the medium and the isolation liquid, preventing the cold energy of the low-temperature medium from being transferred to the isolation liquid.
[0051] In some embodiments of the present application, the medium side seal 10 has a first static ring 11, the seal body 40 has a first static ring seat 41 arranged inwardly, and the first static ring seat 41 is coated with a second heat insulation coating 411 with low thermal conductivity at the end close to the air side. The second heat insulation coating 411 is preferably a Teflon coating, which is used to prevent heat transfer between the first static ring seat 41 and the insulating liquid.
[0052] In some embodiments of the present application, a third sealing groove 53 is formed between the atmospheric side seal 10 and the shaft sleeve 30, and a gas supply pipe 57 and a gas outlet pipe 58 are arranged on the seal body 40 for supplying heat insulation gas to the third sealing groove 53. By arranging the third sealing groove 53 between the atmospheric side seal and the shaft sleeve and introducing the heat insulation gas through the gas supply pipe, the local environment where the atmospheric side seal is located can be precisely temperature-controlled; and the cold energy of the medium is prevented from being transmitted to the third sealing groove through the shaft sleeve 30, so as to avoid condensation and icing of water in the air.
[0053] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, the technical solutions recorded in the foregoing embodiments can still be modified by those skilled in the art, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed by the present application.
Claims
1. A mechanical seal structure of a cryogenic medium, characterized by, The application relates to a seal assembly for a rotating shaft, which comprises: a medium-side seal and an atmosphere-side seal arranged in series along the axial direction; a first seal groove formed between the medium-side seal and a shaft sleeve, and a second seal groove formed between the atmosphere-side seal and a seal body and communicating with the first seal groove; a second conveying assembly arranged on the seal body and used for conveying an isolation liquid into the second seal groove and cooling the atmosphere-side seal; the atmosphere-side seal is provided with a second spring seat fixed on the shaft sleeve, and an axial extending backflow hole is formed in the second spring seat and communicates with the first seal groove and the second seal groove.
2. The mechanical seal structure according to claim 1, characterized by the second conveying assembly is provided with an inlet pipe and an outlet pipe formed in the seal body, and a pumping ring is fixed on the outer side of the second spring seat and used for pumping the isolation liquid in the second seal groove to the outlet pipe, and a plurality of pumping grooves are formed in the outer end surface of the pumping ring.
3. The mechanical seal structure according to claim 2, characterized by the atmosphere-side seal is further provided with a second dynamic ring, the pumping ring is sleeved on the outer side of the second dynamic ring, and a backflow gap communicating with the backflow hole is arranged between the second dynamic ring and the pumping ring.
4. The mechanical seal structure according to claim 2, characterized by a flow gap is arranged between the outer side of the pumping ring and the seal body and used for the flow of the isolation liquid to the first seal groove.
5. The mechanical seal structure according to claim 4, characterized by a flow-limiting convex ring extending radially outward is arranged on the pumping ring and close to one end of the pumping groove near the medium-side seal, and a flow-limiting opening communicating with the flow gap is formed between the flow-limiting convex ring and the seal body.
6. The mechanical seal structure according to claim 2, characterized by an annular groove is formed in the seal body and located on the outer side of the pumping groove, and the annular groove is connected with the outlet pipe.
7. The mechanical seal structure according to claim 6, characterized by a first groove wall of the pumping groove close to one end of the medium-side seal is arranged in a flush manner with a first groove wall of the annular groove, one end of the pumping groove away from the medium-side seal is arranged in an open manner, and the axial dimension of the pumping groove is greater than that of the annular groove.
8. The mechanical seal structure according to any one of claims 1 to 7, characterized by a first heat preservation coating with low thermal conductivity is coated on the shaft sleeve, and the first heat preservation coating forms a groove wall of the first seal groove.
9. The mechanical seal structure according to any one of claims 1 to 7, characterized by the medium-side seal is provided with a first static ring, the seal body is provided with a first static ring seat arranged inward, and one end of the first static ring seat close to the air side is coated with a second heat preservation coating with low thermal conductivity.
10. The mechanical seal structure according to any one of claims 1 to 7, characterized by a third seal groove is formed between the atmosphere-side seal and the shaft sleeve, and a gas feeding pipe and a gas outlet pipe are arranged on the seal body and used for conveying a heat preservation gas into the third seal groove.