A double-end mechanical seal device

Abstract

This invention provides a double-end mechanical seal device, comprising a housing, a rotating shaft, a cooling system, and an adjusting system. The rotating shaft is rotatably disposed within the housing. The housing includes a first sealing cavity and a second sealing cavity. The first sealing cavity communicates with a liquid storage tank. The cooling system includes a cooler disposed outside the housing and communicates with the liquid storage tank. An isolation system communicates with the second sealing cavity and is configured to open when the pressure in the second sealing cavity is lower than a preset value and close when the pressure in the second sealing cavity reaches or exceeds the preset value. The adjusting system is used to adjust the pressure in the first and second sealing cavities. This invention's double-end mechanical seal device enables reliable backup of the second-stage seal under low-pressure or no-pressure conditions and can accurately establish working pressure when needed, thereby ensuring the redundancy and operational stability of the double-end mechanical seal device.

Description

Technical Field

[0001] This invention relates to the field of mechanical seal device technology, and in particular to a double-end mechanical seal device. Background Technology

[0002] Tandem double-end mechanical seals are commonly used for sealing high-pressure, high-risk, or easily leaking media. When the object being sealed is a single medium, the tandem double-end mechanical seal operates in either a one-in-one-backup or pressure-dividing mode. In the one-in-one-backup mode, the first-stage seal bears the full pressure of the sealed medium, while the second-stage seal is in a low-pressure standby state. In the pressure-dividing mode, the first-stage seal and the second-stage seal bear different working pressures proportionally.

[0003] Under certain special operating conditions, in order to meet process constraints, only the sealed medium is allowed to be used to cool the sealing end face.

[0004] In related technologies, the cooling medium acts directly on the end face of the second-stage seal. Since the cooling medium is pressurized and being sealed, the second-stage seal is actually operating under pressure. This causes the second-stage seal to fail to maintain the designed low-pressure or unpressurized standby state, resulting in the failure of the one-in-use-one-standby or pressure-divided working mode. The redundancy of the sealing system is reduced, leading to premature wear of the second-stage seal and a decrease in the overall sealing reliability and safety of the device. Summary of the Invention

[0005] This invention provides a dual-end mechanical seal device to solve the defect in the prior art where the second-stage seal is forced to work under pressure due to the direct action of the cooling medium, resulting in the failure of the one-in-one-backup or pressure-dividing mode. It enables the second-stage seal to be reliably on standby under low pressure or no pressure, and can accurately establish working pressure when needed, thereby ensuring the redundancy and operational stability of the dual-end mechanical seal device.

[0006] This invention provides a double-end mechanical seal device, comprising: The housing and the rotating shaft are rotatably disposed within the housing. The housing includes a first sealing cavity and a second sealing cavity arranged sequentially along the axial direction of the rotating shaft. The first sealing cavity is in communication with the liquid storage tank. The cooling system includes a cooler disposed outside the housing, the cooler being connected to the liquid storage tank, and the cooling medium in the cooler exchanging heat with the second sealing medium in the second sealed cavity; The isolation system, which communicates with the second sealing cavity, is configured to open when the pressure in the second sealing cavity is lower than a preset value, and to close when the pressure in the second sealing cavity reaches or exceeds the preset value. An adjustment system is used to adjust the pressure in the first sealing cavity and the second sealing cavity; The dual-end mechanical seal device includes a one-in-one-standby mode and a pressure-splitting mode. In the one-in-one-standby mode, the isolation system is in operation and the regulating system is off. In the pressure-splitting mode, the isolation system is off and the regulating system is in operation.

[0007] In some embodiments, the cooling system includes: Heat exchange tubes are disposed inside the cooler; The first tube connects the input end of the heat exchange tube to the second sealed cavity, and a circulation pump, a filter and a first valve are sequentially provided on the first tube; The second tube connects the output end of the heat exchange tube to the second sealing cavity, and the second tube is equipped with a second valve.

[0008] In some embodiments, the regulating system includes: A first regulating pipe is connected to the first sealing cavity and is provided with a first regulating valve; The second regulating pipe is connected to the second sealing cavity and is equipped with a second regulating valve. The main regulating pipe is connected to both the first regulating pipe and the second regulating pipe, and a main regulating valve is provided on it.

[0009] In some embodiments, the cooling system includes: The inlet pipe is connected at one end to the liquid storage tank, and at the other end is connected to the first sealing cavity and the cooler respectively through two branch pipes; The return pipe is connected at one end to the cooler and at the other end to the liquid storage tank.

[0010] In some embodiments, the partition system includes: The discharge pipe is connected to the second sealing cavity; An isolation valve is installed on the discharge pipe; The first pressure gauge is used to monitor the pressure of the second sealing medium in the second sealing cavity.

[0011] In some embodiments, the cooling system includes a component disposed on the inlet pipe: A water pump is used to provide circulating power for the cooling medium; A flow meter is used to monitor the flow rate of the cooling medium; The second pressure gauge is used to detect the pressure inside the inlet pipe.

[0012] In some embodiments, the cooling system includes: A coarse filter, a suspension separator, and a fine filter are sequentially arranged in the inlet pipe to filter impurities in the cooling medium.

[0013] In some embodiments, the two branches include: The first branch pipe connects the inlet pipe to the first sealing cavity and is equipped with a first inlet valve. The second branch pipe connects the inlet pipe to the cooler and is equipped with a second inlet valve.

[0014] In some embodiments, the cooling system includes: A thermometer is used to detect the temperature of the second sealing medium inside the second sealing cavity.

[0015] In some embodiments, the cooling system includes: A shut-off valve is located on the return pipe and is used to control the opening and closing of the return pipe.

[0016] The dual-end mechanical seal device of this invention utilizes a cooling system to isolate the cooling medium from the second sealing medium within the second sealing cavity, ensuring that the cooling process does not interfere with the pressure state of the second sealing cavity. Therefore, the second-stage seal can remain in standby mode under low or no pressure, and can also accurately establish the required working pressure when needed, thus reliably achieving a one-in-one-out or pressure-dividing operating mode. Furthermore, the dual-end mechanical seal device of this invention helps maintain the redundancy of the sealing system, extends the service life of the second-stage seal, and thereby improves the overall sealing stability of the device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the double-end mechanical seal device provided by the present invention.

[0019] Figure label: 200. Liquid storage tank; 100. Double-end mechanical seal device; 1. Housing; 11. First sealing cavity; 12. Second sealing cavity; 2. Shaft; 3. Cooling system; 31. Cooler; 311. Heat exchange tube; 312. First tube; 313. Second tube; 314. Circulation pump; 315. Filter; 316. First valve; 317. Second valve; 32. Inlet pipe; 321. Coarse filter; 322. Fine filter; 323. Water pump; 324. Flow meter; 325. Second pressure gauge; 326. Suspension separator; 327. Slag discharge pipe; 328. Slag discharge valve; 33. First branch pipe; 331. First inlet valve; 34. Second branch pipe; 341. Second inlet valve; 35. Return pipe; 351. Shut-off valve; 36. Thermometer; 4. Isolation system; 41. Discharge pipe; 42. Isolation valve; 43. First pressure gauge; 5. Regulating system; 51. First regulating pipe; 511. First regulating valve; 52. Second regulating pipe; 521. Second regulating valve; 53. Main regulating pipe; 531. Main regulating valve; 6. Sealing assembly; 61. Dynamic ring; 62. Stationary ring. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] like Figure 1 As shown, the double-end mechanical seal device 100 of this embodiment includes a housing 1, a rotating shaft 2, a cooling system 3, and an adjustment system 5. The double-end mechanical seal device 100 of this embodiment is a series-type double-end mechanical seal device.

[0022] The rotating shaft 2 is rotatably disposed inside the housing 1. The housing 1 includes a first sealing cavity 11 and a second sealing cavity 12 arranged sequentially along the axial direction of the rotating shaft 2. The first sealing cavity 11 is connected to the liquid storage tank 200.

[0023] The cooling system 3 includes a cooler 31 located outside the housing 1. The cooler 31 is connected to the liquid storage tank 200. The cooling medium in the cooler 31 exchanges heat with the second sealing medium in the second sealing cavity 12.

[0024] The isolation system 4 is connected to the second sealing cavity 12 and is configured to open when the pressure in the second sealing cavity 12 is lower than a preset value and close when the pressure in the second sealing cavity 12 reaches or exceeds the preset value.

[0025] The regulating system 5 is used to regulate the pressure of the first sealing chamber 11 and the second sealing chamber 12.

[0026] The double-end mechanical seal device 100 includes a single-use / single-standby mode and a pressure-dividing mode. In the single-use / single-standby mode, the isolation system 4 is operational and the regulating system 5 is closed. In the pressure-dividing mode, the isolation system 4 is closed and the regulating system 5 is operational.

[0027] The housing 1 includes a first sealing cavity 11 and a second sealing cavity 12, thus forming a two-stage seal. Before the double-end mechanical seal device 100 operates, the second sealing cavity 12 is filled with a second sealing medium to expel internal air. The first-stage seal is the primary seal; whether in a standby mode or a pressure-dividing mode, the pressure in the first sealing cavity 11 is greater than the pressure in the second sealing cavity 12. Therefore, a small amount of the first sealing medium may leak into the second sealing cavity 12.

[0028] The double-end mechanical seal device 100 is connected to the liquid storage tank 200 that stores the sealed medium, and the first sealing cavity 11 is in communication with the liquid storage tank 200. The first sealing medium in the first sealing cavity 11 is the same as the sealed medium in the liquid storage tank 200. The second sealing cavity 12 is not in communication with the first sealing cavity 11, and the medium in the second sealing cavity 12 is the second sealing medium.

[0029] After the sealing medium enters the cooling system 3, it becomes the cooling medium. The cooler 31 is located outside the housing 1 and is connected to the liquid storage tank 200. The cooling medium flowing inside the cooler and the second sealing medium in the second sealing cavity 12 cool the second sealing end face through heat exchange. The two do not mix directly.

[0030] In the one-in-one-outstand mode, the first sealing chamber 11 bears all the sealing pressure, while the second sealing chamber 12 is in a low-pressure standby state. At this time, the isolation system 4 operates while the regulating system 5 is closed, discharging a small amount of medium leaking from the first sealing chamber 11 to the second sealing chamber 12 to prevent the pressure in the second sealing chamber 12 from rising. The cooler 31 independently cools the second sealing chamber 12, with the cooling medium coming from the storage tank 200, but without changing the pressure state of the second sealing chamber 12. When the first-stage seal fails or the leakage increases, causing the pressure in the second sealing chamber 12 to rise to a preset value, the isolation system 4 automatically closes, the second sealing chamber 12 builds up pressure and begins operation, achieving the switchover to standby function.

[0031] In the pressure-sharing mode, the isolation system 4 remains closed, and the regulating system 5 controls the flow of the medium between the two sealing chambers so that the first sealing chamber 11 and the second sealing chamber 12 share the sealing pressure according to a set ratio. At the same time, the cooler 31 still provides independent cooling to the second sealing chamber 12.

[0032] In related technologies, the cooling medium acts directly on the end face of the second-stage seal. Since the cooling medium is pressurized and being sealed, the second-stage seal is actually operating under pressure. This causes the second-stage seal to fail to maintain the designed low-pressure or unpressurized standby state, resulting in the failure of the one-in-use-one-standby or pressure-divided working mode. The redundancy of the sealing system is reduced, leading to premature wear of the second-stage seal and a decrease in the overall sealing reliability and safety of the device.

[0033] In the dual-end mechanical seal device 100 of this embodiment, the cooling system 3 isolates the cooling medium from the second sealing medium in the second sealing cavity 12, ensuring that the cooling process does not interfere with the pressure state of the second sealing cavity 12. Therefore, the second-stage seal can remain in standby mode under low or no pressure, and can also accurately establish the required working pressure when needed, thus reliably achieving a one-in-one-out or pressure-dividing working mode. Furthermore, the dual-end mechanical seal device 100 of this embodiment helps maintain the redundancy of the sealing system, extends the service life of the second-stage seal, and thus improves the overall sealing stability of the device.

[0034] In related technologies, the internal space of the second-stage sealing cavity is limited. When a built-in cooler is used, the heat exchange area of ​​the cooler 31 cannot meet the operating conditions, and the second-stage seal cannot be effectively cooled. In the double-end mechanical seal device 100 of this invention, the cooler 31 is located outside the housing 1, thus not occupying the internal space of the second-stage sealing cavity. The heat exchange area of ​​the cooler 31 can be designed according to actual needs, thereby meeting the cooling requirements of the second-stage seal and enabling the second-stage seal to operate stably.

[0035] In some embodiments, the cooling system 3 includes a heat exchange tube 311, a first tube 312, and a second tube 313. The heat exchange tube 311 is disposed within the cooler 31. The first tube 312 connects the input end of the heat exchange tube 311 to the second sealed cavity 12, and a circulation pump 314, a filter 315, and a first valve 316 are sequentially disposed on the first tube 312. The second tube 313 connects the output end of the heat exchange tube 311 to the second sealed cavity 12, and a second valve 317 is disposed on the second tube 313.

[0036] The heat exchange tube 311 is disposed inside the cooler 31, and the heat exchange tube 311 contains a second sealing medium to exchange heat with the cooling medium in the cooler 31.

[0037] One end of the first pipe 312 is connected to the input end of the heat exchange pipe 311, and the other end is connected to the second sealing cavity 12, which is used to draw out the sealing fluid in the second sealing cavity 12 and send it to the cooler 31 for cooling. A circulation pump 314, a filter 315 and a first valve 316 are sequentially provided on the first pipe 312 along the fluid flow direction. The circulation pump 314 is used to provide circulation power, the filter 315 is used to filter out impurities in the second sealing medium, and the first valve 316 is used to regulate or cut off the fluid passage.

[0038] One end of the second pipe 313 is connected to the output end of the heat exchange pipe 311, and the other end is connected to the second sealing cavity 12, which is used to reintroduce the cooled second sealing medium into the second sealing cavity 12, thereby completing the cooling cycle. The second pipe 313 is provided with a second valve 317, which is used to regulate or cut off the fluid passage.

[0039] In some embodiments, the regulating system 5 includes a first regulating tube 51, a second regulating tube 52, and a main regulating tube 53.

[0040] The first regulating pipe 51 is connected to the first sealing cavity 11, and a first regulating valve 511 is provided on it.

[0041] The second regulating pipe 52 is connected to the second sealing cavity 12, and a second regulating valve 521 is provided on it.

[0042] The main regulating pipe 53 is connected to both the first regulating pipe 51 and the second regulating pipe 52, and a main regulating valve 531 is provided on it.

[0043] In this embodiment, the regulating system 5 forms a pressure control loop through three interconnected pipes: When the double-end mechanical seal device 100 switches from the one-in-one-standby mode to the pressure-dividing mode, first close the main regulating valve 531, then open the first regulating valve 511, and then slowly open the second regulating valve 521. At this time, the first sealing medium will flow into the second sealing cavity 12 through the first regulating valve 511 and the second regulating valve 521, causing the pressure of the second sealing medium to gradually increase. When it rises to the preset pressure, the second regulating valve 521 can be quickly closed, and then the first regulating valve 511 can be closed. At this time, the conversion from the one-in-one-standby mode to the pressure-dividing mode is completed.

[0044] When the double-end mechanical seal device 100 switches from the pressure-dividing mode to the one-use-one-standby mode, if it is necessary to reduce the working pressure of the second sealing medium or adjust the working mode to the one-use-one-standby mode, ensure that the first regulating valve 511 is closed, then open the second regulating valve 521, and then open the main regulating valve 531 to release the pressure of the sealing medium in the second-stage sealing chamber. When the pressure in the second sealing chamber 12 returns to the initial value, the main regulating valve 531 can be quickly closed, and then the second regulating valve 521 can be closed. At this time, the conversion from the pressure-dividing mode to the one-use-one-standby mode is completed.

[0045] The double-end mechanical seal device 100 of this invention utilizes a three-way adjustment structure composed of a first adjustment pipe 51, a second adjustment pipe 52 and a main adjustment pipe 53 to flexibly adjust the pressure relationship between the two sealing chambers without changing the main sealing structure, so as to establish a pressure-dividing mode.

[0046] In some embodiments, the cooling system 3 includes an inlet pipe 32 and a return pipe 35.

[0047] One end of the inlet pipe 32 is connected to the liquid storage tank 200, and the other end is connected to the first sealing cavity 11 and the cooler 31 through two branch pipes respectively.

[0048] One end of the return pipe 35 is connected to the cooler 31, and the other end is connected to the liquid storage tank 200.

[0049] In this embodiment, the cooling medium flows out of the storage tank 200 and is transported through the inlet pipe 32. At the end of the inlet pipe 32, it is divided into two paths: one path enters the first sealing cavity 11 through the first branch pipe 33 to directly cool the first sealing end face; the other path enters the cooler 31 through the second branch pipe 34, completes heat exchange in the cooler 31, and then returns to the storage tank 200 through the return pipe 35, forming a closed loop.

[0050] The double-end mechanical seal device 100 of this invention sets the cooling system 3 as a closed circulation loop, so that the cooling medium can complete heat exchange without entering the second sealing cavity 12, thereby achieving indirect cooling of the second-stage seal. This ensures that the pressure in the second sealing cavity 12 depends only on the sealing condition itself and is not affected by the flow or pressure of the cooling medium, providing a structural basis for reliable switching and stable operation of the one-in-one-out mode and the pressure-dividing mode.

[0051] In some embodiments, the isolation system 4 includes a drain pipe 41, an isolation valve 42, and a first pressure gauge 43.

[0052] The discharge pipe 41 is connected to the second sealing chamber 12. The isolation valve 42 is located on the discharge pipe 41.

[0053] The first pressure gauge 43 is used to monitor the pressure of the second sealing medium in the second sealing cavity 12.

[0054] In this embodiment, a shut-off valve 42 and a first pressure gauge 43 are installed on the discharge pipe 41, with the first pressure gauge 43 located upstream of the shut-off valve 42.

[0055] During normal operation, the isolation valve 42 remains open, discharging the medium that leaks a small amount from the first sealing chamber 11 into the second sealing chamber 12, and maintaining the second sealing chamber 12 in a low-pressure standby state. When the first-stage seal fails, causing the leakage to increase and the pressure in the second sealing chamber 12 to rise to a preset threshold, the isolation valve 42 is closed according to the reading of the first pressure gauge 43, so that the second sealing chamber 12 is sealed and the working pressure is established.

[0056] The double-end mechanical seal device 100 of this invention, through the cooperation of the discharge pipe 41, the isolation valve 42 and the first pressure gauge 43, realizes real-time perception and automatic response to the pressure status of the second sealing chamber 12. While ensuring that the second-stage seal is in a standby state for a long time, it also ensures that it can be put into sealing work in time when the main seal fails, thereby improving the functional redundancy of the sealing system.

[0057] In some embodiments, the cooling system 3 includes a water pump 323, a flow meter 324, and a second pressure gauge 325 disposed on the inlet pipe 32.

[0058] Water pump 323 is used to provide circulating power for the cooling medium.

[0059] The flow meter 324 is used to monitor the flow rate of the cooling medium.

[0060] The second pressure gauge 325 is used to detect the pressure inside the inlet pipe 32.

[0061] In this embodiment, the water pump 323 drives the cooling medium to circulate within the cooling system 3; the flow meter 324 reflects the circulation volume of the cooling medium in real time, making it easy to determine whether the cooling capacity is sufficient; the second pressure gauge 325 monitors the main pressure of the inlet pipe 32, providing a reference for the operating status of the double-end mechanical seal device 100.

[0062] The dual-end mechanical seal device 100 of this invention integrates a water pump 323, a flow meter 324, and a second pressure gauge 325 to achieve synchronous monitoring of the power, flow rate, and pressure of the cooling circuit, providing a parameter basis for the reliable operation of the cooling system 3. At the same time, the pumping capacity of the water pump 323 can be adjusted according to the actual working conditions to ensure that the two-stage sealing end faces obtain a continuous and stable cooling effect.

[0063] In some embodiments, the cooling system 3 includes a coarse filter 321, a suspension separator 326, and a fine filter 322.

[0064] The coarse filter 321, the suspension separator 326 and the fine filter 322 are sequentially arranged in the inlet pipe 32 to filter impurities in the cooling medium.

[0065] In this embodiment, after the cooling medium flows out of the storage tank 200, it first passes through the coarse filter 321 for preliminary filtration to remove larger particulate impurities. Then it enters the suspension separator 326 for further filtration to remove larger particulate impurities. Finally, it enters the fine filter 322 for fine filtration to ensure the cleanliness of the medium entering the first sealing cavity 11 and the cooler 31, and to prevent impurities from scratching the sealing surface or blocking the cooling channel.

[0066] The dual-end mechanical seal device 100 of this invention ensures the cleanliness of the cooling medium by sequentially arranging a coarse filter 321, a suspension separator 326, and a fine filter 322 on the inlet pipe 32, thereby reducing the risk of seal failure due to particulate contamination. Especially when the sealed medium is used as the cooling source, it helps to maintain the long-term stable operation of the two-stage sealing end faces.

[0067] Optionally, the cooling system 3 includes a slag discharge pipe 327, which is connected to the suspension separator 326, and a slag discharge valve 328 is provided on the slag discharge pipe 327 to control the opening and closing of the slag discharge pipe 327.

[0068] In some embodiments, the two branches include a first branch 33 and a second branch 34.

[0069] The first branch pipe 33 connects the inlet pipe 32 and the first sealing cavity 11, and is equipped with a first inlet valve 331.

[0070] The second branch pipe 34 connects the inlet pipe 32 and the cooler 31, and is equipped with a second inlet valve 341.

[0071] In this embodiment, the first branch pipe 33 and the second branch pipe 34 branching off from the end of the inlet pipe 32 lead to the first sealing cavity 11 and the cooler 31, respectively. By controlling the opening and closing states of the first inlet valve 331 and the second inlet valve 341, liquid can be selectively supplied to the first sealing cavity 11 or to the cooler 31, or they can be opened simultaneously to achieve dual-path cooling.

[0072] The dual-end mechanical seal device 100 of this invention adopts a dual-branch pipe structure with an independent control valve, which allows the direct cooling of the first-stage seal and the indirect cooling of the second-stage seal to operate independently yet collaboratively in the flow path, avoiding pressure interference caused by cooling path coupling, and providing flexible support for the cooling needs of the two-stage seals under different working modes.

[0073] In some embodiments, the cooling system 3 includes a thermometer 36.

[0074] The thermometer 36 is used to detect the temperature of the second sealing medium inside the second sealing cavity 12.

[0075] In this embodiment, the thermometer 36 is directly installed on the housing 1 of the second sealing cavity 12 to measure the temperature of the second sealing medium in real time, reflecting the heat load status of the second sealing end face; the temperature data can be used to determine whether the heat exchange efficiency of the cooler 31 is normal, or as a basis for system early warning.

[0076] The double-end mechanical seal device 100 of this invention monitors the medium temperature of the second sealing cavity 12 by setting a thermometer 36, which provides direct feedback on the indirect cooling effect and helps to detect abnormalities such as insufficient cooling or overheating in a timely manner, thus ensuring the stability of the second-stage seal in standby or working conditions.

[0077] In some embodiments, the cooling system 3 includes a shut-off valve 351.

[0078] The shut-off valve 351 is located on the return pipe 35 and is used to control the opening and closing of the return pipe 35.

[0079] In this embodiment, the shut-off valve 351 is installed on the return pipe 35 between the outlet of the cooler 31 and the liquid storage tank 200. It can be manually or automatically closed during the start-up, maintenance or abnormal operation of the cooling system 3 to cut off the return path of the cooling medium and facilitate the operation of the cooling system 3.

[0080] The dual-end mechanical seal device 100 of this invention enhances the operational flexibility and safety of the cooling system 3 by setting a shut-off valve 351 in the return pipe 35, and supports independent control and maintenance of the cooling circuit without affecting the pressure state of the second sealing chamber 12.

[0081] In some embodiments, the dual-end mechanical seal device 100 includes two sealing components 6.

[0082] Two sealing components 6 are respectively located in the first sealing cavity 11 and the second sealing cavity 12, and both are sealed to the rotating shaft 2.

[0083] In this embodiment, the sealing component 6 in the first sealing cavity 11 serves as the main seal and bears the main sealing pressure; the sealing component 6 in the second sealing cavity 12 serves as a backup or pressure-dividing seal.

[0084] Both sealing assemblies 6 are arranged around the same rotating shaft 2, forming a double-end face sealing structure connected in series along the axial direction, which together prevents the medium from leaking out. The sealing assembly 6 includes a dynamic ring 61 and a stationary ring 62.

[0085] The dual-end mechanical seal device 100 of this invention constructs a physically isolated dual-level sealing barrier by setting sealing components 6 that cooperate with the rotating shaft 2 in two independent sealing cavities.

[0086] In other embodiments, a first heat exchanger is provided in the first sealing cavity 11, the first branch pipe 33 is connected to the first heat exchanger, and the return pipe 35 is connected to the first heat exchanger, thereby ensuring that the pressure state in the first sealing cavity 11 is not affected by the pressure of the cooling medium.

[0087] In other embodiments, all valves may be designed as manual valves, electrically controlled valves, or valves that can be both manually and electrically controlled. In other embodiments, the flow meter 324, the first pressure gauge 43, the second pressure gauge 325, and the thermometer 36 may be configured as either local instruments only or local + remote instruments, depending on actual needs.

[0088] These instruments are local instruments, meaning they only display measured values ​​at the installation location of the double-end mechanical seal device 100 for direct reading by on-site operators and do not have remote transmission capabilities. Local + remote instruments mean that these instruments can not only display data on-site, but also transmit measurement signals to a remote control system to achieve remote monitoring and automated control.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double-end mechanical seal device, connected to a liquid storage tank (200) storing the sealed medium, characterized in that, include: The housing (1) and the rotating shaft (2) are rotatably disposed inside the housing (1). The housing (1) includes a first sealing cavity (11) and a second sealing cavity (12) arranged sequentially along the axial direction of the rotating shaft (2). The first sealing cavity (11) is in communication with the liquid storage tank (200). The cooling system (3) includes a cooler (31) disposed outside the housing (1), the cooler (31) being connected to the liquid storage tank (200), and the cooling medium in the cooler (31) exchanging heat with the second sealing medium in the second sealing cavity (12); The isolation system (4), which is connected to the second sealing cavity (12), is configured to open when the pressure in the second sealing cavity (12) is lower than a preset value, and to close when the pressure in the second sealing cavity (12) reaches or exceeds the preset value; The regulating system (5) is used to regulate the pressure of the first sealing cavity (11) and the second sealing cavity (12); The dual-end mechanical seal device includes a one-use-one-standby mode and a pressure-dividing mode. In the one-use-one-standby mode, the isolation system (4) is in operation and the regulating system (5) is off. In the pressure-dividing mode, the isolation system (4) is off and the regulating system (5) is in operation.

2. The double-end mechanical seal device according to claim 1, characterized in that, The cooling system (3) includes: A heat exchange tube (311) is disposed inside the cooler (31); The first tube (312) connects the input end of the heat exchange tube (311) to the second sealing cavity (12). The first tube (312) is provided with a circulation pump (314), a filter (315) and a first valve (316) in sequence. The second tube (313) connects the output end of the heat exchange tube (311) to the second sealing cavity (12), and the second tube (313) is provided with a second valve (317).

3. The double-end mechanical seal device according to claim 1, characterized in that, The regulating system (5) includes: The first regulating pipe (51) is connected to the first sealing cavity (11) and is provided with a first regulating valve (511). The second regulating pipe (52) is connected to the second sealing cavity (12), and a second regulating valve (521) is provided on it. The main regulating pipe (53) is connected to both the first regulating pipe (51) and the second regulating pipe (52), and a main regulating valve (531) is provided on it.

4. The double-end mechanical seal device according to claim 1, characterized in that, The cooling system (3) includes: The inlet pipe (32) is connected at one end to the liquid storage tank (200), and at the other end to the first sealing cavity (11) and the cooler (31) respectively through two branch pipes; The return pipe (35) is connected at one end to the cooler (31) and at the other end to the liquid storage tank (200).

5. The double-end mechanical seal device according to any one of claims 1-4, characterized in that, The partition system (4) includes: The discharge pipe (41) is connected to the second sealing cavity (12); Isolation valve (42) is provided on the discharge pipe (41); The first pressure gauge (43) is used to monitor the pressure of the second sealing medium in the second sealing cavity (12).

6. The double-end mechanical seal device according to claim 4, characterized in that, The cooling system (3) includes a component disposed on the inlet pipe (32): A water pump (323) is used to provide circulating power for the cooling medium; A flow meter (324) is used to monitor the flow rate of the cooling medium; The second pressure gauge (325) is used to detect the pressure inside the inlet pipe (32).

7. The double-end mechanical seal device according to claim 4, characterized in that, The cooling system (3) includes: A coarse filter (321), a suspension separator (326), and a fine filter (322) are sequentially arranged in the inlet pipe (32) to filter impurities in the cooling medium.

8. The double-end mechanical seal device according to claim 4, characterized in that, The two branch pipes include: The first branch pipe (33) connects the inlet pipe (32) and the first sealing cavity (11), and is provided with a first inlet valve (331). The second branch pipe (34) connects the inlet pipe (32) and the cooler (31), and is equipped with a second inlet valve (341).

9. The double-end mechanical seal device according to claim 1, characterized in that, The cooling system (3) includes: A thermometer (36) is used to detect the temperature of the second sealing medium inside the second sealing cavity (12).

10. The double-end mechanical seal device according to any one of claims 6-8, characterized in that, The cooling system (3) includes: A shut-off valve (351) is provided on the return pipe (35) for controlling the opening and closing of the return pipe (35).

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