A horizontally split multistage centrifugal pump casing

Abstract

The utility model discloses a horizontal middle -open multistage centrifugal pump shell, including lower pump shell and detachable installation in the top of lower pump shell's upper pump shell, bottom pump shell with upper pump shell includes the shell body and sets up in the inner lining of shell body, wherein the inner lining is hard and is made of corrosion -resistant material, the inner lining is as the insert in the mould and is integrally formed with the shell body, the inner lining is separated and is formed with a plurality of intercommunication cavities through a plurality of baffle, when upper pump shell with lower pump shell cover, the cavity of upper pump shell with lower pump shell is surrounded and forms the water pressure chamber for placing the impeller. The utility model provides technical scheme, through the corrosion -resistant inner lining and the cast -iron shell composite structure of innovation, can the material performance advantage maximization, has overcome the single cast -iron pump shell easy corrosion, short -lived shortcoming, can greatly prolong the overall service life of pump shell while the additional increase is less cost.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pump technology, and in particular to a horizontal split-case multistage centrifugal pump casing. Background Technology

[0002] A multistage centrifugal pump is a type of centrifugal pump that increases liquid pressure (head) through multiple impellers connected in series (each impeller is called a stage). Each impeller provides a portion of the pressure increment for the liquid it pumps, and the final output pressure is the sum of the pressures produced by all the impellers. A horizontally split-case multistage centrifugal pump is a type of multistage centrifugal pump designed to be divided into upper and lower halves (upper and lower pump casings) along a horizontal plane passing through the pump shaft centerline for easier subsequent maintenance.

[0003] Currently, traditional pump casings are mostly cast from a single piece of cast iron. However, because the output pressure of a multi-stage centrifugal pump gradually increases from front to back, using only a single cast iron casing can lead to wear and tear on the internal chambers after prolonged use, affecting the media delivery efficiency. Existing technologies typically address these issues in two ways: one is to use high-wear-resistant materials such as alloy steel for the entire casing, but this significantly increases manufacturing costs; the other is to weld or nest independent liners inside the cast iron pump casing, but this carries the risk of insufficient bonding strength between the liner and the base material, making it prone to detachment and failure, and the positioning accuracy of the liner in complex cavity structures is difficult to guarantee. Furthermore, the pressure chambers of multi-stage pumps need to be separated by baffles to form a series flow channel, which can easily generate eddy current losses during operation.

[0004] Therefore, this application provides a horizontal split-case multistage centrifugal pump casing. Utility Model Content

[0005] This invention provides a horizontal split-case multistage centrifugal pump casing that can solve the problems of easy wear and eddy current loss in the pump casing.

[0006] This utility model provides a horizontal split-case multistage centrifugal pump casing, including a lower pump casing and an upper pump casing detachably installed on top of the lower pump casing. The lower pump casing and the upper pump casing include an outer shell and an inner liner disposed inside the outer shell. The inner liner is made of a hard and corrosion-resistant material. The inner liner is integrally formed with the outer shell as an insert in a mold. The inner liner has multiple interconnected cavities separated by several partitions. When the upper pump casing and the lower pump casing are closed, the cavities between the upper pump casing and the lower pump casing form a pressure chamber for placing the impeller. The inner wall of the pressure chamber is provided with spiral reinforcing ribs in the same direction as the medium flow.

[0007] In one embodiment of this utility model, the inner liner of a horizontal split-case multistage centrifugal pump casing is made of alloy steel, and the outer casing is made of cast iron.

[0008] In a horizontal split-opening multistage centrifugal pump casing according to one embodiment of the present invention, the inner wall of the outer casing is provided with a plurality of engagement grooves at intervals, and the end of the inner liner facing the engagement groove is provided with a engagement portion adapted to the engagement groove.

[0009] In a horizontal split-opening multistage centrifugal pump casing according to one embodiment of the present invention, the connecting groove has a T-shaped or dovetail-shaped structure.

[0010] In a horizontal split-opening multistage centrifugal pump casing according to one embodiment of the present invention, a flange edge is formed by extending outward from the top edge of the outer casing, and a plurality of mounting through holes are spaced apart circumferentially on the flange edge.

[0011] In a horizontal split-case multistage centrifugal pump casing according to an embodiment of the present invention, the top of the flange edge on the lower pump casing protrudes upward in the circumferential direction to form a lower sealing protrusion, and one side of the sealing protrusion is recessed downward on the flange edge to form a lower sealing groove. The flange edge on the upper pump casing is provided with an upper sealing groove and an upper sealing protrusion that are respectively adapted to the sealing protrusion and the lower sealing groove to achieve a labyrinth seal.

[0012] In a horizontal split-case multistage centrifugal pump casing according to an embodiment of the present invention, the thickness of the sealing groove is less than the thickness of the sealing protrusion, and a sealing strip is also correspondingly provided in the sealing groove.

[0013] In one embodiment of this utility model, a horizontal split-stage centrifugal pump casing is provided with an inlet and an outlet that communicate with the cavity.

[0014] The technical solution provided in this application embodiment may include the following beneficial effects: Through the innovative corrosion-resistant inner lining and cast iron outer shell composite structure, alloy steel is used as the main contact surface of the medium flow channel to effectively resist the chemical corrosion and wear erosion of the transported liquid, while the outer shell is made of cast iron, which mainly undertakes the structural support role. The casting properties and economy of cast iron are fully utilized, which can maximize the material performance advantages and overcome the disadvantages of easy corrosion and short life of single cast iron pump shell. While adding a small amount of extra cost, the overall service life of the pump shell can be greatly extended.

[0015] Secondly, the pressure chamber is designed with spiral reinforcing ribs that are in the same direction as the medium flow. On the one hand, the spiral reinforcing ribs themselves can be used as reinforcing ribs of the lining to increase their strength. On the other hand, their spiral direction guides the rotational movement of the fluid, which conforms to the natural flow trajectory of the fluid at the centrifugal pump impeller outlet. This can effectively reduce eddies and flow resistance, reduce hydraulic losses, and thus improve the pump's operating efficiency.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

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

[0018] Figure 1 This is a three-dimensional structural diagram of the combination of the lower pump casing and impeller in a horizontal split-case multistage centrifugal pump casing according to an embodiment of this application;

[0019] Figure 2 yes Figure 1 A simplified diagram of the enlarged structure at point A in the middle;

[0020] Figure 3 This is a simplified cross-sectional plan view of the lower pump casing and impeller assembly in an embodiment of this application.

[0021] Figure 4 This application provides a schematic diagram of a partial cross-sectional plan view of the joint position between the inner liner and the outer shell of a horizontal split-case multistage centrifugal pump casing (the joint groove is T-shaped) according to an embodiment of the application.

[0022] Figure 5 This is a simplified cross-sectional planar structural diagram of the junction between the inner liner and the outer shell of a horizontal split-case multistage centrifugal pump casing (the junction groove is dovetail-shaped). Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0024] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] like Figures 1 to 5 As shown, this application provides a horizontal split-case multistage centrifugal pump casing, including a lower pump casing and an upper pump casing (not shown) detachably mounted on top of the lower pump casing. The lower and upper pump casings include an outer shell 100 and an inner liner 200 disposed inside the outer shell 100. The inner liner 200 is made of a hard and corrosion-resistant material and is integrally formed with the outer shell 100 in a mold as an insert. The inner liner 200 is divided by several partitions 210 to form multiple interconnected cavities 300. When the upper and lower pump casings are closed, the cavities 300 between the upper and lower pump casings form a pressure chamber for placing the impeller. The inner wall of the pressure chamber is provided with spiral reinforcing ribs 230 in the same direction as the medium flow.

[0027] By adopting the above technical solution, through the innovative composite structure of corrosion-resistant inner lining and outer shell, the inner lining 200, which is made of hard and corrosion-resistant material, serves as the main contact surface of the medium flow channel, effectively resisting the chemical corrosion and wear erosion of the transported liquid. The outer shell 100 is made of cast iron and mainly undertakes the structural support function. It makes full use of the castability and economy of cast iron, maximizes the material performance advantages, overcomes the disadvantages of easy corrosion and short life of single cast iron pump shells, and significantly extends the overall service life of the pump shell while adding a small amount of extra cost.

[0028] Secondly, a spiral reinforcing rib 230 with the same direction of medium flow is designed inside the pressure chamber. On the one hand, the spiral reinforcing rib 230 itself can be used as a reinforcing rib of the inner lining 200 to increase its strength. On the other hand, its spiral direction guides the rotational movement of the fluid, which conforms to the natural flow trajectory of the fluid at the centrifugal pump impeller outlet. This can effectively reduce eddies and flow resistance, reduce hydraulic losses, and thus improve the pump's operating efficiency.

[0029] In one alternative embodiment, the inner liner 200 is made of alloy steel and the outer shell 100 is made of cast iron. Alloy steel has excellent wear resistance and corrosion resistance, which can meet the requirements for use in multi-stage pressurized environments.

[0030] It should be noted that the inner lining 200 can also be switched according to different usage scenarios. For example, in the case of conveying solid particles (such as slurry, mineral slurry, ash slurry, mud slurry, etc.), high chromium cast iron can also be used. There is no limitation here.

[0031] The bending part 441 is made of a material with elastic properties, which is not limited here.

[0032] In one alternative implementation, please refer to Figure 4 and Figure 5 As shown, the inner wall of the outer shell 100 is provided with multiple interlocking grooves 140 at intervals. The end of the inner liner 200 facing the interlocking grooves 140 is provided with a connecting part 200 adapted to the interlocking grooves 140. The interlocking grooves 140 are T-shaped or dovetail-shaped. The interlocking grooves 140 and the connecting part 220 can form a strong mechanical interlock after the mold is formed, which significantly increases the bonding area and shear strength between the two materials. This can effectively resist the pressure pulsation, thermal stress and stress caused by the difference in thermal expansion coefficients of different materials during operation, prevent the inner liner 200 from peeling off from the outer shell 100, and ensure the long-term stability of the composite structure.

[0033] In other embodiments, interlocking structures such as trapezoids may also be used, and this is not limited to them.

[0034] In one alternative implementation, please refer to Figure 1 and Figure 2 As shown, a flange edge 130 extends outward from the top edge of the outer casing 100. Multiple mounting through holes 131 are spaced apart circumferentially on the flange edge 130. During the assembly of the lower pump casing and the upper pump casing, the corresponding mounting through holes 131 are aligned together, and then bolts are inserted and locked using lock nuts (not shown in the figure). The multiple mounting through holes 131 arranged circumferentially can ensure the consistency of force at each position after assembly.

[0035] In one optional embodiment, the lower pump housing is provided with an inlet 110 and an outlet 120 that communicate with the cavity 300.

[0036] In one alternative implementation, please refer to Figure 2 As shown, the flange edge 130 on the lower pump casing has a lower sealing convex edge 131 that protrudes upward circumferentially from the top. One side of the sealing convex edge 131 is recessed downward on the flange edge 130 to form a lower sealing groove 133. The flange edge 130 on the upper pump casing is provided with an upper sealing groove and an upper sealing convex edge that are adapted to the sealing convex edge 131 and the lower sealing groove 133, respectively, to achieve a labyrinth seal. The thickness of the sealing groove 133 is less than the thickness of the sealing convex edge 131. A sealing strip is also correspondingly provided in the sealing groove 133. The design of the lower sealing convex edge 131 and the upper sealing groove and the lower sealing groove 133 and the upper sealing convex edge forms a complex labyrinth seal channel at the joint of the upper and lower pump casing flanges. Through the linkage with the sealing strip, an excellent sealing effect can be achieved, effectively preventing high-pressure liquid from leaking from the interstage flange surface. It is especially suitable for high-pressure conditions of multi-stage centrifugal pumps, with reliable sealing and long service life.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0038] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0039] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0040] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A horizontal split-case multistage centrifugal pump casing, characterized in that, The device includes a lower pump housing and an upper pump housing that is detachably mounted on top of the lower pump housing. The lower pump housing and the upper pump housing each include an outer shell and an inner liner disposed inside the outer shell. The inner liner is made of a hard and corrosion-resistant material and is integrally formed with the outer shell as an insert in a mold. The inner liner has multiple interconnected cavities separated by several partitions. When the upper pump housing and the lower pump housing are closed, the cavities between the upper pump housing and the lower pump housing form a water pressure chamber for placing the impeller. The inner wall of the water pressure chamber is provided with spiral reinforcing ribs in the same direction as the medium flow.

2. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 1, characterized in that, The inner liner is made of alloy steel, and the outer shell is made of cast iron.

3. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 2, characterized in that, The inner wall of the outer shell is provided with a plurality of engagement slots at intervals, and the end of the inner liner facing the engagement slot is provided with a engagement part that is adapted to the engagement slot.

4. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 3, characterized in that, The connecting slot has a T-shaped or dovetail-shaped structure.

5. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 1, characterized in that, The outer casing has a flange edge extending outward from the top edge, and multiple mounting through holes are spaced apart circumferentially on the flange edge.

6. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 5, characterized in that, The flange edge on the lower pump housing has a lower sealing protrusion protruding upward along the circumferential direction at the top, and a lower sealing groove is formed by a downward indentation on one side of the sealing protrusion on the flange edge. The flange edge on the upper pump housing is provided with an upper sealing groove and an upper sealing protrusion that are respectively adapted to the sealing protrusion and the lower sealing groove to achieve a labyrinth seal.

7. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 6, characterized in that, The thickness of the sealing groove is less than the thickness of the sealing protrusion, and a sealing strip is also provided in the sealing groove.

8. The pump casing of the horizontal split-case multistage centrifugal pump according to claim 1, characterized in that, The lower pump casing is provided with an inlet and an outlet that communicate with the cavity.

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