Pump shell heat insulation sealing structure of dry gas sealing cantilever shaft high-temperature pump

Abstract

The invention discloses a pump shell heat insulation sealing structure of a dry gas sealing cantilever shaft high-temperature pump, which is used for preventing heat of a high-temperature side pump shell from being transmitted to a low-temperature side pump shell, and comprises a gasket, the gasket is provided with a hollow part, a supporting part is arranged in the hollow part, and the supporting part is connected with the inner wall of a gasket body; and the supporting part enables the gasket to have deformation resistance under the clamping of the high-temperature side pump shell and the low-temperature side pump shell. The pump shell heat insulation sealing structure of the dry gas sealing cantilever shaft high-temperature pump has the beneficial effects that heat is efficiently prevented from being conducted along the pump shell, and the sealing effect is good.

Description

Technical Field

[0001] This invention relates to the field of pump sealing technology, and specifically to a pump casing heat insulation and sealing structure for a dry gas seal cantilever shaft high-temperature pump. Background Technology

[0002] In industrial fields such as petrochemicals, coal chemicals, and supercritical power generation, dry gas-sealed cantilever shaft high-temperature pumps are core equipment for conveying high-temperature media, which often reach temperatures above 280°C, and even higher under some operating conditions. These high-temperature pumps generally employ a dry gas seal structure for their shaft seals, as this structure offers advantages such as non-contact operation, extremely low leakage, and low power consumption, meeting the leak-free sealing requirements under high-temperature conditions.

[0003] However, dry gas seals are extremely sensitive to operating temperature. Their core components (such as sealing rings and auxiliary sealing rings) have a clearly defined upper temperature limit, typically not exceeding 220℃. Exceeding this limit can cause thermal deformation of the sealing ring, gas film instability, and aging and cracking of the sealing ring, directly leading to seal failure. In actual operation, the heat from the high-temperature pump casing can easily be conducted directly to the low-temperature dry gas seal assembly installation area through the pump casing connection, causing the shaft seal temperature to rise continuously, seriously threatening the stable operation and service life of the dry gas seal.

[0004] As a key component for blocking heat transfer, the pump casing thermal insulation seal structure must simultaneously achieve two core functions: first, efficiently blocking high-temperature conduction to prevent the dry gas seal temperature from exceeding the limit; and second, possessing sufficient resistance to deformation to withstand the clamping force during pump casing assembly and thermal stress under operating conditions, preventing leakage caused by increased sealing gaps. However, existing thermal insulation seal solutions struggle to meet these dual requirements and cannot adapt to the harsh operating conditions of high-temperature pumps, leading to frequent dry gas seal failures and increased equipment maintenance costs. Therefore, there is an urgent need to develop a pump casing thermal insulation seal structure that combines highly efficient thermal insulation performance with reliable sealing. Summary of the Invention

[0005] To overcome the above-mentioned shortcomings in the prior art, the present invention provides a pump casing heat insulation and sealing structure for a dry gas seal cantilever shaft high-temperature pump that efficiently blocks heat conduction along the pump casing and has a good sealing effect.

[0006] The technical solution of this invention is as follows: A heat insulation sealing structure for the pump casing of a dry gas-sealed cantilever shaft high-temperature pump, used to prevent heat transfer from the high-temperature side pump casing to the low-temperature side pump casing, comprising: A gasket having a hollow portion and a support portion disposed within the hollow portion, the support portion being connected to the inner wall of the gasket body, the support portion enabling the gasket to resist deformation under the clamping of the high-temperature side pump housing and the low-temperature side pump housing.

[0007] Preferably, the support is a frame-type support structure, which includes multiple support rods.

[0008] In any of the above embodiments, it is preferred that the frame-type support structure further includes a plurality of first annular support main frames and a plurality of second annular support main frames, wherein the first annular support main frames are arranged along the circumference of the pad and the second annular support main frames are arranged along the radial direction of the pad; The two ends of some of the support rods are respectively connected to the corresponding sections of the first annular support main frame and the second annular support main frame, and together with the corresponding sections of the first annular support main frame and the second annular support main frame, they form multiple triangular stable structures.

[0009] In any of the above schemes, it is preferred that each of the first annular support main frames and each of the second annular support main frames are flat structures.

[0010] In any of the above embodiments, it is preferred that each of the first annular support main frames and each of the second annular support main frames are embedded inside the gasket body.

[0011] In any of the above embodiments, it is preferred that the hollow portion is in a vacuum state, which is used to reduce the thermal conductivity of the gasket.

[0012] In any of the above embodiments, it is preferred that the hollow portion is filled with an inert gas, which is used to reduce the thermal conductivity of the gasket.

[0013] In any of the above embodiments, it is preferred that the gasket has outwardly extending protrusions on both sides, and each of the protrusions cooperates with the recesses at the high-temperature side pump housing and the low-temperature side pump housing to form a stop structure.

[0014] In any of the above embodiments, it is preferred that the height of each protrusion is greater than the depth of the corresponding recess, so that when each stop is engaged, each protrusion is compressed and each protrusion and the corresponding recess form an interference fit.

[0015] In any of the above embodiments, it is preferred that the support portion has a locking block fixedly connected to both sides away from the hollow portion, and the locking block is covered inside the corresponding protrusion.

[0016] The dry gas-sealed cantilever shaft high-temperature pump of the present invention has a pump casing heat insulation and sealing structure in which a gasket is sandwiched between the high-temperature side pump casing and the low-temperature side pump casing. The hollow part of the gasket extends the heat transfer path and increases the thermal resistance, directly blocking the heat conduction from the high-temperature side pump casing to the low-temperature side.

[0017] The support section bears the clamping force of the pump casing, prevents the hollow section from collapsing and deforming, maintains a tight fit between the gasket and the sealing surface of the pump casing, prevents sealing gaps due to structural deformation, and ensures sealing reliability. Attached Figure Description

[0018] Figure 1 This is a cross-sectional schematic diagram of an embodiment of the heat insulation and sealing structure of the dry gas seal cantilever shaft high-temperature pump of the present invention.

[0019] Figure 2 This is a cross-sectional schematic diagram of an embodiment of the gasket in the heat insulation and sealing structure of the pump casing of the dry gas seal cantilever shaft high-temperature pump of the present invention.

[0020] Figure 3 This is a schematic diagram of a preferred embodiment of the support portion of the pump casing heat insulation and sealing structure of the dry gas seal cantilever shaft high temperature pump of the present invention and the gasket mating.

[0021] Figure 4 This is a schematic diagram of a preferred embodiment of the first annular support main frame and support rod of the support part of the pump casing heat insulation and sealing structure of the dry gas seal cantilever shaft high temperature pump of the present invention.

[0022] Figure 5 This is a schematic diagram of another embodiment of the gasket of the pump casing heat insulation sealing structure of the dry gas seal cantilever shaft high temperature pump of the present invention.

[0023] Explanation of the labels in the diagram: 101-High temperature side pump housing; 102-Gasket; 103-Low temperature side pump housing; 104-First annular support main frame; 105-Second annular support main frame; 106-Support rod; 107-Protrusion; 108-Recess; 109-Dry gas seal. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Example 1: like Figure 1 As shown, the pump casing heat insulation and sealing structure of the dry gas seal cantilever shaft high temperature pump in this embodiment is suitable for both cantilever shaft centrifugal pumps and cantilever shaft axial flow pumps. Its core function is to block the heat from the high temperature side pump casing 101 from being transferred to the low temperature side pump casing 103, thereby preventing the dry gas seal 109 on the low temperature side from failing due to high temperature.

[0027] The high-temperature side pump casing 101 is the main body of the pump body, through which the high-temperature medium flows, serving as the primary source of heat. The low-temperature side pump casing 103 is used to assemble the dry gas seal 109. One optional form of the low-temperature side pump casing 103 is that it has an integrally formed flange at its outer periphery and a dry gas seal mounting seat at its center. The flange mating surfaces of the low-temperature side pump casing 103 and the high-temperature side pump casing 101 are fitted together and fastened together by a bolt assembly. The dry gas seal 109 is installed at the central dry gas seal mounting seat.

[0028] For applications of cantilevered centrifugal pumps, there are two core pathways for heat transfer from the high-temperature medium to the dry gas seal: The first is direct heat conduction through the metal body of the high-temperature side pump casing 101 to the low-temperature side pump casing 103, thus affecting the operating temperature of the dry gas seal. The second is that the high-temperature medium flows through the gap between the impeller and the pump casing, leaking into the dry gas seal and transferring heat to the sealing area via convection. To block this second heat transfer path, a throttling bushing or flow-blocking ring can be added at the gap between the impeller and the pump casing. By reducing the medium flow gap and increasing the medium flow resistance, the flow rate and convection heat transfer efficiency of the high-temperature medium are reduced. Alternatively, an isolator or cooler can be introduced, introducing a low-temperature insulating medium into the gap to form a physical thermal barrier, blocking heat exchange between the high-temperature medium and the sealing side.

[0029] The pump casing thermal insulation and sealing structure in this embodiment focuses on blocking the heat transfer path between pump casings. When used in conjunction with the aforementioned throttling bushing, flow-blocking ring, and other components, it achieves full-dimensional thermal insulation protection for the dry gas sealing parts.

[0030] For applications involving cantilevered axial flow pumps, the cryogenic medium enters from the dry gas seal side and flows towards the high-temperature pump casing 101 side. During this process, due to the directional flow of the cryogenic medium, only the pump casing transfers heat to the dry gas seal. Therefore, the pump casing thermal insulation sealing structure of this embodiment can block heat conduction between the pump casings.

[0031] The core component of the pump casing heat insulation and sealing structure in this embodiment is the gasket 102. The gasket 102 is generally annular and is adapted to the flange mating surface size of the high-temperature side pump casing 101 and the low-temperature side pump casing 103. The gasket 102 has a hollow part inside, which is continuously distributed along the circumference of the gasket 102.

[0032] A support is fixedly provided inside the hollow part. The support is fixedly connected to the body of the gasket 102. The function of the support is to enable the gasket 102 to resist plastic deformation under the clamping and pressing action of the high-temperature side pump housing 101 and the low-temperature side pump housing 103, so as to prevent the gasket 102 from losing its hollow structure due to excessive compression, thereby ensuring that the heat insulation performance of the gasket 102 does not decrease.

[0033] In this embodiment, as Figure 1 As shown, one possible form of the support is a frame-type support structure filled in the hollow part, which is composed of multiple support rods 106 spliced ​​together in a crisscross pattern. The ends of the support rods 106 abut against or cover the inner wall of the hollow part and the body of the gasket 102. The geometric stability of the frame structure enhances the deformation resistance of the gasket 102.

[0034] like Figure 3 , 4 As shown, another optional form of the support is to add multiple first annular support main frames 104 and multiple second annular support main frames 105 to the frame-type support structure. The first annular support main frames 104 are arranged circumferentially along the gasket 102 and are adapted to the annular structure of the gasket 102. Each first annular support main frame 104 abuts against the inner end wall of the gasket 102 or is embedded in the gasket body. Each second annular support main frame 105 is arranged radially along the gasket 102 and abuts against the inner end wall and inner peripheral wall of the gasket 102, or is embedded in the gasket body. While supporting the peripheral edge of the gasket 102, the second annular support main frames 105 are also connected to each first annular support main frame 104, thus making each first annular support main frame 104 a single unit. Both ends of some support rods 106 are fixedly connected to corresponding sections of the first annular support main frame 104 and the second annular support main frame 105, respectively, thus forming multiple triangular stable structures together with the first annular support main frame 104 and the second annular support main frame 105. Utilizing the non-deformable mechanical properties of the triangular structure, the compressive strength of the support part is further enhanced. At the same time, the mutual cooperation between each first annular support main frame 104, each second annular support main frame 105, and each support rod 106 makes the overall structure more compact.

[0035] In this embodiment, each of the first annular support main frames 104 and each of the second annular support main frames 105 adopts a flat structure. This design can reduce the space occupied by the support part in the thickness direction of the gasket 102, ensure the overall heat insulation thickness of the gasket 102, and avoid compressing the heat insulation space of the hollow part due to the excessive volume of the support part. In addition, the flat structure increases the contact area between its body and the gasket 102, thereby preventing the first annular support main frames 104 and the second annular support main frames 105 from being damaged due to concentrated force when the gasket 102 is squeezed.

[0036] In this embodiment, one way to form the gasket 102 is that the support part can be integrally formed by 3D printing. After forming, the surface burrs are removed by grinding and sandblasting to ensure the dimensional accuracy and surface flatness of the support part, so that it can fit and conform to the inner wall surface of the hollow part of the gasket 102.

[0037] To ensure both structural strength and thermal insulation performance of the support structure, high-temperature alloy powders (such as Inconel 718 powder), ceramic matrix composite powders (such as alumina-reinforced silicon carbide powder), or carbon fiber-reinforced resin matrix composite powders are preferred. Among them, ceramic matrix composites and carbon fiber-reinforced resin matrix composites have both low thermal conductivity and high structural strength, making them more suitable for thermal insulation and sealing applications.

[0038] The gasket body is preferably made of high-temperature resistant thermal insulation composite material, specifically aluminum silicate fiber reinforced silicone composite material, polyimide (PI) based thermal insulation composite material or flexible aerogel thermal insulation composite material. The above materials have high temperature resistance, flexible sealing performance and low thermal conductivity, and can maintain structural stability and thermal insulation performance for a long time under high temperature conditions.

[0039] The gasket 102 and the support unit can be integrated through a co-printing process, the specific steps of which are as follows: First, a dual-material 3D printer is used to load the powder material for the support unit and the composite material for the gasket body separately. Second, the frame structure of the support unit is 3D printed first, and then the composite material of the gasket body is printed on its outer periphery and upper and lower sides, with the support unit as the inner core, so that the support unit and the gasket body form an interface-free integrated structure. Finally, after printing, an overall curing treatment is performed to ensure the bonding strength of the connection parts and prevent the two from peeling off under the clamping action of the pump housing.

[0040] In this embodiment, to meet the manufacturing needs of large-volume gaskets 102, another forming method for gaskets 102 is that the support part is prefabricated by welding in advance. After the support part is formed, it can be coated and molded together with the gasket body using a dip-coating process. The specific steps are as follows: 1. Prefabricated support section: The support section is prefabricated by welding. The surface of the support section is cleaned and roughened to improve its bonding strength with the gasket body material.

[0041] 2. Molten gasket material: The high-temperature resistant heat-insulating composite material of the gasket body is heated to a molten state, giving it good fluidity and coating ability.

[0042] 3. Dipping and coating: Immerse the prefabricated support part into the molten gasket material, controlling the immersion depth and dwell time, so that the molten material evenly coats the outer surface of the support part and the gaps between each support rod 106.

[0043] Example 2: Based on Example 1, in order to reduce the thermal conductivity of the gasket 102, one option is to make the hollow part of the gasket 102 a vacuum state.

[0044] The main forms of heat transfer include heat conduction, heat convection, and heat radiation. Among these, the thermal motion of gas molecules is the key carrier for heat conduction and heat convection. After the hollow part is evacuated, the internal gas molecules decrease in height, and the two forms of heat transfer, heat conduction and heat convection, are greatly weakened, leaving only a small amount of heat radiation, thereby significantly improving the heat insulation effect of the gasket 102.

[0045] Example 3: Based on Example 1, in order to reduce the thermal conductivity of the gasket 102, another option is to fill the hollow part of the gasket 102 with an inert gas. This design is particularly suitable for scenarios where the gasket 102 is thin and the body material is relatively soft.

[0046] The filling with inert gas maintains a normal pressure inside the hollow section, preventing the thin, soft gasket from undergoing inward plastic deformation due to negative pressure caused by vacuuming the hollow section, thus ensuring the structural integrity of the gasket 102. Simultaneously, the low thermal activity of inert gas molecules significantly reduces heat transfer efficiency compared to air, thereby lowering the overall thermal conductivity of the gasket 102 and achieving effective insulation between the high-temperature side pump housing 101 and the low-temperature side pump housing 103.

[0047] Example 4: Based on any of the embodiments in Examples 1-3, such as Figure 1 , 5 As shown, in order to axially position the gasket 102, both end faces of the gasket 102 are integrally formed with outwardly extending protrusions 107. Each protrusion 107 is adapted to fit into the pre-set recesses 108 on the flange mating surface of the high-temperature side pump housing 101 and the flange mating surface of the low-temperature side pump housing 103, and together they form a stop structure.

[0048] The stop structure, through the interlocking of the protrusion 107 and the recess 108, allows the gasket 102 to remain centered during the clamping and fastening process of the high-temperature side pump housing 101 and the low-temperature side pump housing 103. This ensures that the heat insulation and sealing area of ​​the gasket 102 completely covers the mating surface of the pump housing, eliminating local heat insulation failure or sealing gaps caused by the offset of the gasket 102. In this way, the overall heat insulation and sealing effect is guaranteed, while preventing the gasket 102 from radially moving under the vibration conditions of the pump unit during operation.

[0049] In this embodiment, the height of each protrusion 107 is greater than the depth of the corresponding recess 108, so that when each stop is engaged, each protrusion 107 is compressed, and each protrusion 107 and the corresponding recess 108 form an interference fit.

[0050] When the high-temperature side pump housing 101 is connected to the low-temperature side pump housing 103 flange, each protrusion 107 is fitted into the corresponding recess 108. Each protrusion 107 is squeezed and undergoes elastic deformation, forming an interference fit with the recess 108.

[0051] The preload generated by the interference fit ensures that the contact surfaces of the protrusion 107 and the recess 108 are completely fitted together, eliminating the fit gap and further improving the sealing performance of the gasket 102.

[0052] In this embodiment, locking blocks are fixedly connected to both sides of the support portion away from the hollow portion, and each locking block is enclosed within the corresponding protrusion 107. Adding locking blocks to the stop structure further secures the connection between the protrusion 107 and the gasket body, preventing the protrusion 107 from loosening its fit with the pump housing recess 108 under high-temperature conditions, and improving the sealing reliability of the stop structure.

[0053] The above-described embodiments are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A heat-insulating sealing structure for the pump casing of a dry gas-sealed cantilever shaft high-temperature pump, used to prevent heat transfer from the high-temperature side pump casing (101) to the low-temperature side pump casing (103), characterized in that, include: Gasket (102) has a hollow part, and a support part is provided in the hollow part. The support part is connected to the inner wall of the gasket body. The support part enables the gasket (102) to resist deformation when clamped by the high-temperature side pump housing (101) and the low-temperature side pump housing (103).

2. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 1, characterized in that, The support is a frame-type support structure, which includes multiple support rods (106).

3. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 2, characterized in that, The frame-type support structure also includes multiple first annular support main frames (104) and multiple second annular support main frames (105). The first annular support main frames (104) are arranged circumferentially along the pad (102), and the second annular support main frames (105) are arranged radially along the pad (102). The two ends of some support rods (106) are respectively connected to the corresponding sections of the first annular support main frame (104) and the second annular support main frame (105), and together with the corresponding sections of the first annular support main frame (104) and the second annular support main frame (105), they form multiple triangular stable structures.

4. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 3, characterized in that, Each of the first annular support main frames (104) and each of the second annular support main frames (105) are flat structures.

5. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 4, characterized in that, Each first annular support main frame (104) and each second annular support main frame (105) are embedded inside the gasket body.

6. The pump casing heat insulation and sealing structure of the dry gas-tight cantilever shaft high-temperature pump as described in any one of claims 1-5, characterized in that, The hollow section is in a vacuum state, which is used to reduce the thermal conductivity of the gasket (102).

7. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in any one of claims 1-5, characterized in that, The hollow portion is filled with an inert gas, which is used to reduce the thermal conductivity of the gasket (102).

8. The pump casing heat insulation and sealing structure of the dry gas-tight cantilever shaft high-temperature pump as described in any one of claims 1-5, characterized in that, The gasket (102) has outwardly extending protrusions (107) on both sides, and each protrusion (107) cooperates with the recess (108) at the high temperature side pump housing (101) and the low temperature side pump housing (103) to form a stop structure.

9. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 8, characterized in that, The height of each protrusion (107) is greater than the depth of the corresponding recess (108), so that when each stop is engaged, each protrusion (107) is compressed, and each protrusion (107) and the corresponding recess (108) form an interference fit.

10. The pump casing heat insulation and sealing structure of the dry gas-sealed cantilever shaft high-temperature pump as described in claim 8, characterized in that, Both sides of the support portion away from the hollow portion are fixedly connected with locking blocks, and the locking blocks are covered within the corresponding protrusions (107).

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