Centrifugal extractor with rotary sealing structure
By adopting a combined sealing structure of magnetic sealing and positive pressure chamber in the centrifugal extractor, the problems of poor adaptability and low safety of the rotary sealing structure in the prior art are solved, and a higher sealing effect and use safety are achieved.
Patent Information
- Application Number
- CN202421244272.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-03
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-06-03
AI Technical Summary
The rotary seal structure of the existing centrifugal extractor has poor adaptability and low safety, resulting in high usage costs and safety risks.
Using a combined sealing structure of magnetic sealing and positive pressure chamber, sealing between the spindle and the housing, spindle and bearing seat is achieved through the magnetic sealing assembly, and additional pressure compensation and cooling functions are provided through the positive pressure chamber.
It improves the safety and stability of the sealing structure, extends the service life, improves the sealing effect and reliability, simplifies the structure and reduces power consumption.
Smart Images
Figure CN222502675U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of centrifuges, and in particular relates to a centrifugal extractor with a rotary sealing structure. Background Art
[0002] Centrifugal extractor is a new, fast and efficient liquid-liquid mixing and separation equipment. The centrifugal extractor uses a motor to drive the drum to rotate at high speed. Two immiscible liquids with different densities complete the mixing and mass transfer under the action of the shear force generated by the rotation of the drum or blades, and are quickly separated under the action of the centrifugal force generated by the high-speed rotation of the drum. It is widely used in fine chemicals, pharmaceuticals, hydrometallurgy, petrochemicals, environmental protection, plant extraction and other industries.
[0003] Among them, the sealing positions in the centrifugal extractor mainly include the dynamic seal between the rotating shaft and the stationary shell, and the static seal at the connection between the shell and the equipment. At present, mechanical seals, dry gas seals, skeleton oil seals and other forms are mostly used for the rotating seal positions of centrifugal extractors. Although the machining accuracy requirements of mechanical seals are not high, their service life is short, the power consumption is large, and liquid medium must be used to lubricate and cool the sealing surface, which seriously affects the stability and safety of the equipment. The parameter fluctuations in the production process have a great impact on the sealing performance. Dry gas seals are mostly composed of rotating rings, static rings, springs, sealing rings, spring seats and sleeves. Their structures are complex and the machining accuracy requirements are high. There is basically no sealing effect when the equipment is shut down for maintenance or in a static state, and the sealing performance is poor for volatile gases. Although the skeleton oil seal has good airtightness, it has high requirements for the rotation accuracy and surface roughness of the sealing surface and the surface hardness of the shaft; the skeleton oil seal has good gas sealing performance, but poor sealing performance for liquids, especially acid, alkali, salt and organic solvent liquids, especially when there is a small amount of solids in the sealing medium of the skeleton oil seal, the sealing performance is even worse.
[0004] It can be seen that no matter which sealing structure in the prior art is used in the centrifugal extractor, there is a problem of poor adaptability, which increases the user's investment cost and poses a safety hazard. Utility Model Content
[0005] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a centrifugal extractor with a rotary sealing structure, which consists of a magnetic seal and a positive pressure chamber, and is used to solve the technical problems of poor adaptability and low safety of the current rotary sealing structure.
[0006] To achieve the above-mentioned purpose, the technical solution of the utility model is: a centrifugal extractor with a rotary sealing structure, the centrifugal extractor includes a shell, a drum arranged in the shell, a main shaft connected to the drum and passing through the shell, and a bearing seat arranged on the main shaft, the sealing structure is arranged on the main shaft, between the shell and the bearing seat; the sealing structure includes a first magnetic sealing component arranged between the main shaft and the shell, a second magnetic sealing component arranged between the main shaft and the bearing seat, and a positive pressure chamber arranged between the first magnetic sealing component and the second magnetic sealing component, the positive pressure chamber is provided with an air inlet and an air outlet, and the positive pressure chamber is connected to the friction sealing space of the first magnetic sealing component and the second sealing component.
[0007] Preferably, the first magnetic sealing assembly includes a first moving ring seat sleeved on the main shaft and rotating synchronously with the main shaft, a first moving ring connected to the first moving ring seat, a first stationary ring sleeved on the main shaft and connected to the shell, and a first permanent magnet embedded in the end face of the first moving ring seat close to the first stationary ring. Under the action of the magnetic attraction of the permanent magnet, the first moving ring and the first stationary ring fit tightly together.
[0008] Preferably, the first magnetic sealing assembly further includes a first dynamic ring auxiliary sealing ring, a first static ring auxiliary sealing ring and a first compensation ring.
[0009] Preferably, the first permanent magnet is coated with a polytetrafluoroethylene protective layer.
[0010] Preferably, the second magnetic sealing assembly has the same structure as the first magnetic sealing assembly, including a second dynamic ring seat, a second dynamic ring, a second static ring and a second permanent magnet; the second static ring is connected to the bearing seat.
[0011] Preferably, the second magnetic sealing assembly further includes a second dynamic ring auxiliary sealing ring, a second static ring auxiliary sealing ring and a second compensation ring.
[0012] Preferably, the second permanent magnet is coated with a polytetrafluoroethylene protective layer.
[0013] The beneficial effects of adopting the technical solution of the utility model are:
[0014] The sealing structure of the utility model is arranged between the bearing seat and the shell, and comprises two magnetic sealing components, which respectively seal between the main shaft and the shell, and between the main shaft and the bearing seat, one to prevent leakage of chemical raw materials in the shell, and the other to prevent leakage of lubricant in the supporting bearing, thereby further improving safety and stability during use; compared with the mechanical sealing structure which requires a spring to provide axial compensation, the spring will experience fatigue failure after a certain period of use, resulting in failure of the mechanical seal and the need for replacement, which is time-consuming and labor-intensive and has a short service life. Based on this, the magnetic sealing component ensures that the static ring and the dynamic ring are always in close contact with each other through magnetic attraction, effectively preventing the seal from failing due to loose contact between the dynamic ring and the static ring, extending the service life and improving the sealing reliability; a positive pressure chamber is arranged between the two magnetic sealing components, and the pressure inside the positive pressure chamber is greater than the pressure inside the shell. In this way, even if there are volatile substances in the shell that can leak from the sealing component, the magnetic seal can be removed. When the positive pressure sealing component fails to seal unexpectedly, the leakage of the centrifuge is further prevented under the pressure of the positive pressure chamber, and the double seal improves the overall sealing effect and reliability of the sealing structure; the pressure inside the positive pressure chamber is greater than the pressure inside the bearing seat, so that even if the lubricant leaks from the supporting bearing in the bearing seat, the leakage of the lubricant in the supporting bearing is further prevented under the pressure of the positive pressure chamber, thereby improving the overall sealing effect and reliability of the sealing structure; since the positive pressure chamber is arranged between the two magnetic sealing components, it will provide axial top pressure to the magnetic sealing components on both sides, provide pressure compensation for the dynamic ring and the static ring of the magnetic seal, and further improve the tightness of the fit between the dynamic ring and the static ring; and the heat generated during the friction between the dynamic ring and the static ring of the magnetic sealing component will be taken away by the gas filled into the positive pressure chamber, which has a cooling effect, and there is no need to set up an additional cooling component for the magnetic sealing component, which simplifies the overall structure and reduces space occupancy. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is an overall schematic diagram of an embodiment of a centrifugal extractor with a rotary sealing structure;
[0016] Figure 2 for Figure 1 The enlarged schematic diagram is shown in Figure 1.
[0017] in, Figure 1 , 2In the figure, 1-motor, 2-coupling, 3-bearing seat, 4-support bearing, 5-frame, 6-housing, 7-spindle, 81-first moving ring seat, 82-first moving ring, 83-first static ring, 84-first moving ring auxiliary sealing ring, 85-first static ring auxiliary sealing ring, 86-first permanent magnet, 87-first compensation ring, 91-second moving ring seat, 92-second moving ring, 93-second static ring, 94-second moving ring auxiliary sealing ring, 95-second static ring auxiliary sealing ring, 96-second permanent magnet, 97-second compensation ring, 10-positive pressure chamber. DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and do not limit the scope of the present invention.
[0019] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0021] The specific embodiments are as follows:
[0022] Embodiment 1, as Figure 1 , 2 As shown, a centrifugal extractor with a rotary sealing structure includes a housing 6, a drum is arranged inside the housing 6, the drum is connected to a main shaft 7, the main shaft 7 extends from the end of the housing 6, the main shaft 7 is connected to the motor 1 through a coupling 2, a bearing seat 3 is arranged between the coupling 2 and the housing 6, and a support bearing 4 for supporting the main shaft is arranged inside the bearing seat 3. The rotary sealing structure is arranged between the bearing seat 3 and the housing 6.
[0023] In this embodiment, the centrifugal extractor is a top-suspended centrifugal extractor, which does not have a bottom bearing and a mechanical seal, and does not have the risk of bottom leakage. Therefore, only the leakage risk of the upper part of the shell needs to be considered.
[0024] The sealing structure includes a first magnetic sealing component, a second magnetic sealing component and a positive pressure chamber 10 .
[0025] The first magnetic seal assembly is disposed between the main shaft 7 and the housing 6 to prevent leakage of the centrifuge. The first magnetic seal assembly includes a first moving ring seat 81 , a first moving ring 82 , a first stationary ring 83 and a first permanent magnet 86 .
[0026] The first moving ring seat 81 is sleeved on the main shaft 7, and is fitted with the axial surface of the main shaft 7 as an interference fit to achieve synchronous rotation with the main shaft 7; the first moving ring 82 is connected to the first moving ring seat 81. The first static ring 83 is sleeved on the main shaft 7 as a clearance fit, and the first static ring 83 is sealed and connected to the housing 6, and the end of the first static ring 83 is in contact with the first moving ring 82. In this embodiment, the first static ring 83 is made of an alloy material that can be attracted by magnetic force. An annular first permanent magnet 86 is embedded in the end surface of the first moving ring seat 81 close to the first static ring 83. The first permanent magnet 86 has a magnetic attraction force on the first static ring 83. The magnetic attraction makes the first static ring 83 and the first moving ring 82 always closely fit, and when the main shaft 7 rotates, the first moving ring 82 is driven to rotate relative to the first static ring 83. The first moving ring 82 and the first static ring 83 form a friction pair to achieve a sealing effect.
[0027] The second magnetic sealing assembly is arranged between the bearing seat 3 and the main shaft 7 to prevent the leakage of the lubricant of the support bearing 4. The leakage of the lubricant may cause damage to the support bearing 4.
[0028] The second magnetic seal assembly has the same structure as the first magnetic seal assembly, including a second moving ring seat 91, a second moving ring 92, a second stationary ring 93 and a second permanent magnet 96. The second moving ring seat 91 is also connected to the main shaft 7 by interference fit; the second moving ring 92 is connected to the second moving ring seat 91, so that the second moving ring 92 fits the second stationary ring 93. The second stationary ring 93 is sleeved on the main shaft 7 with clearance fit, and the second stationary ring 93 is sealed and connected to the bearing seat 3. In this embodiment, the first stationary ring is made of an alloy material that can be attracted by magnetic force. The second permanent magnet 96 is embedded in the end of the second moving ring 92 close to the second stationary ring 93. The magnetic attraction makes the second stationary ring 93 and the second moving ring 92 always fit closely. When the main shaft 7 rotates, the second moving ring 92 is driven to rotate relative to the second stationary ring 93. The second moving ring 92 and the second stationary ring 93 constitute a friction pair to achieve a sealing effect.
[0029] The positive pressure chamber 10 is arranged between the first magnetic seal assembly and the second magnetic seal assembly, and is communicated with the friction space between the first dynamic ring seat 81 and the first static ring 83 of the first magnetic seal assembly, and is communicated with the friction space between the second dynamic ring seat 91 and the second static ring 93 of the second magnetic seal assembly. The positive pressure chamber 10 is provided with an air inlet and an air outlet for adjusting the pressure in the positive pressure chamber. Dry air, inert gas, nitrogen, etc. are introduced into the positive pressure chamber 10, so that the pressure in the positive pressure chamber 10 is greater than the pressure in the shell 6 and the bearing seat 3; on the one hand, when there is a highly volatile gas in the drum that is easy to emerge from the first magnetic sealing component or the first magnetic sealing component fails unexpectedly, the larger pressure in the positive pressure chamber 10 will press the leaked gas or liquid back into the shell 6, and when the second magnetic sealing component fails unexpectedly or the lubricant in the support bearing 4 in the bearing seat 3 accidentally leaks, the larger pressure in the positive pressure chamber 10 will press the lubricant back into the bearing seat 3 to continue to achieve sealing, further improving the sealing effect and sealing reliability, and improving safety in use; on the other hand, the friction between the friction pairs of the first magnetic sealing component and the second magnetic sealing component generates heat, and the gas introduced into the positive pressure chamber 10 just takes out the heat to achieve a cooling function, and there is no need to additionally set up a cooling component for the first magnetic sealing component and the second magnetic sealing component, which simplifies the structure and saves space.
[0030] In this embodiment, the first magnetic sealing assembly and the second magnetic sealing assembly are symmetrically arranged, that is, the first dynamic ring seat 81 and the second dynamic ring seat 91 which are interference fit with the main shaft are both arranged on the side close to the positive pressure chamber 10. This arrangement enables the positive pressure chamber 10 to form an axial compensation force on the two friction pairs for the pressure in the upper and lower directions, thereby further improving the tightness of the fit between the dynamic ring and the static ring in the two resistance sealing assemblies.
[0031] In this embodiment, the first and second permanent magnets 86 and 96 are made of neodymium iron boron or samarium cobalt magnets.
[0032] In this embodiment, the first and second moving ring seats 81 and 91 are made of stainless steel or phosphor bronze.
[0033] When a centrifugal extractor with a rotating sealing structure according to the present embodiment is in use, the first magnetic sealing component seals the connection between the shell 6 and the main shaft 7, and the first magnetic sealing component uses the attraction of the first permanent magnet 86 to ensure that the first moving ring 82 and the first static ring 83 are always tightly fitted. The second magnetic sealing component seals the connection between the main shaft and the bearing seat 3, and the second magnetic sealing component uses the attraction of the second permanent magnet 96 to ensure that the second moving ring 92 and the second static ring 93 are always tightly fitted. The springs for providing axial compensation are omitted in the above two sealing components, which simplifies the structure, saves overall space, and extends the service life. When there is a highly volatile gas in the shell 6 that can come out from the first magnetic sealing component or the first magnetic sealing component fails unexpectedly, the pressure in the positive pressure chamber 10 is greater than the pressure in the shell 6, so the high-pressure gas will push and block the gas or liquid that wants to come out for further sealing; when the second magnetic sealing component fails unexpectedly or the support bearing 4 has lubricant leakage, the pressure in the positive pressure chamber 10 is greater than the pressure in the bearing seat 3, and the high-pressure gas will push and block the lubricant for further sealing; that is, the positive pressure chamber 10 provides a substitute seal function, which improves the sealing reliability of the sealing structure. In addition, the gas introduced into the positive pressure chamber 10 will take away the heat generated by the friction pair and cool it down, so that the first magnetic sealing component and the second magnetic sealing component do not need to be provided with a cooling component, which simplifies the overall structure and reduces power consumption.
[0034] Furthermore, a first dynamic ring auxiliary sealing ring 84 is provided between the first dynamic ring 82 and the main shaft 7, a first static ring auxiliary sealing ring 85 is provided between the first static ring 83 and the housing 6, and a first compensation ring 87 is provided between the first static ring 83 and the first dynamic ring seat 81, so as to further ensure the sealing effect.
[0035] In this embodiment, the first dynamic ring auxiliary seal ring 84, the first static ring auxiliary seal ring 85 and the first compensation ring 87 can all be made of styrene-butadiene rubber, fluorine rubber, polytetrafluoroethylene and the like. Polytetrafluoroethylene is preferably used, which is commonly known as the "king of plastics". It has an extremely low friction coefficient, self-lubricating properties, and can resist corrosion from acid, alkali, salt, organic solvents and other liquids. It also has excellent heat and cold resistance and can be used for a long time at -180 to 260°C, which expands the use scenarios of the sealing structure and prolongs its service life.
[0036] Furthermore, a polytetrafluoroethylene protective layer is coated on the first permanent magnet 86. Polytetrafluoroethylene is commonly known as the "king of plastics". It has an extremely low friction coefficient, self-lubricating properties, and can resist corrosion from acid, alkali, salt, organic solvents and other liquids. It also has excellent heat and cold resistance and can be used for a long time at -180 to 260°C.
[0037] Furthermore, a second dynamic ring auxiliary sealing ring 94 is provided between the second dynamic ring 92 and the main shaft 7, a second static ring auxiliary sealing ring 95 is provided between the second static ring 93 and the bearing seat 3, and a second compensation ring 97 is provided between the second dynamic ring seat 91 and the second static ring 93, so as to further ensure the sealing effect.
[0038] In this embodiment, the second dynamic ring auxiliary seal ring 94, the second static ring auxiliary seal ring 95 and the second compensation ring 97 can all be made of styrene-butadiene rubber, fluororubber, polytetrafluoroethylene and other materials.
[0039] Furthermore, a polytetrafluoroethylene protective layer is coated on the outside of the second permanent magnet 96 .
[0040] In other embodiments, two or more first magnetic sealing components may be provided, and multiple first magnetic sealing components may be provided in series to further improve the sealing effect. Other structures are not described in detail here.
[0041] In other embodiments, two or more second magnetic sealing components may be provided, and multiple second magnetic sealing components may be provided in series to further improve the sealing effect. Other structures are not described in detail here.
[0042] In other embodiments, the positive pressure chambers are configured as two independent positive pressure chambers, one positive pressure chamber is connected to the first magnetic sealing assembly, and the other is connected to the second magnetic sealing assembly. Other structures are not described in detail herein.
[0043] In other embodiments, one or more of a labyrinth seal, a mechanical seal, a skeleton oil seal and a dry gas seal may be further provided between the main shaft and the drum and connected in series with the first magnetic seal assembly to improve the sealing effect. Other structures are not described in detail here.
[0044] In other embodiments, one or more of a labyrinth seal, a mechanical seal, a skeleton oil seal and a dry gas seal may be further provided between the main shaft and the bearing seat and connected in series with the first magnetic seal assembly to enhance the sealing effect. Other structures are not described in detail here.
[0045] In other embodiments, the centrifugal extractor adopts an upper and lower double-supported extractor, and the sealing structure is arranged at the upper and lower ends of the shell, and other structures are not repeated here.
[0046] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the technical solution of the utility model, or the concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.
Claims
1. A centrifugal extractor with a rotary sealing structure, the centrifugal extractor comprising a housing, a drum disposed in the housing, a main shaft connected to the drum and extending from the housing, and a bearing seat disposed on the main shaft, wherein: The sealing structure is arranged on the main shaft and between the shell and the bearing seat; the sealing structure includes a first magnetic sealing component arranged between the main shaft and the shell, a second magnetic sealing component arranged between the main shaft and the bearing seat, and a positive pressure chamber arranged between the first magnetic sealing component and the second magnetic sealing component, the positive pressure chamber is provided with an air inlet and an air outlet, and the positive pressure chamber is connected to the friction sealing space of the first magnetic sealing component and the second magnetic sealing component.
2. A centrifugal extractor with a rotary seal structure according to claim 1, characterized in that: The first magnetic sealing assembly includes a first moving ring seat sleeved on the main shaft and rotating synchronously with the main shaft, a first moving ring connected to the first moving ring seat, a first stationary ring sleeved on the main shaft and connected to the shell, and a first permanent magnet embedded in the end face of the first moving ring seat close to the first stationary ring. Under the action of the magnetic attraction of the permanent magnet, the first moving ring and the first stationary ring fit tightly together.
3. A centrifugal extractor with a rotary seal structure according to claim 2, characterized in that: The first magnetic sealing assembly also includes a first dynamic ring auxiliary sealing ring, a first static ring auxiliary sealing ring and a first compensation ring.
4. The centrifugal extractor with a rotary seal structure according to claim 3, characterized in that: The first permanent magnet is coated with a polytetrafluoroethylene protective layer.
5. The centrifugal extractor with a rotary seal structure according to claim 1, characterized in that: The second magnetic sealing assembly has the same structure as the first magnetic sealing assembly, and includes a second dynamic ring seat, a second dynamic ring, a second static ring and a second permanent magnet; the second static ring is connected to the bearing seat.
6. The centrifugal extractor with a rotary seal structure according to claim 5, characterized in that: The second magnetic sealing assembly also includes a second dynamic ring auxiliary sealing ring, a second static ring auxiliary sealing ring and a second compensation ring.
7. The centrifugal extractor with a rotary seal structure according to claim 6, characterized in that: The second permanent magnet is coated with a polytetrafluoroethylene protective layer.