A multi-stage centrifugal pump with reduced cavitation

Abstract

A multi-stage centrifugal pump with reduced cavitation, relates to a centrifugal pump, the multi-stage centrifugal pump suction pipe, cooling water cavity and suction section are connected by welding;Front pump cover (4) and winding pad (5) are installed on suction section component (11) through front pump cover fastener (29), which constitutes stator suction component;First stage impeller (28) and first stage impeller baffle (27) are installed on pump shaft (1) and penetrate into stator suction component assembly;Through the bar (8) through the suction section component (11) installation flat pad (10) and nut (9);First stage sealing pad (6) and sealing ring (12) are installed on the first stage middle section (7), and are installed with the stator suction component;The multi-stage centrifugal pump effectively avoids the occurrence of cavitation, ensures the safe and stable transportation of process medium close to the gasification point. It is suitable for the transportation of various media, especially for the transportation of process medium close to the gasification point.

Description

Technical Field

[0001] This utility model relates to a centrifugal pump, and more particularly to a multi-stage centrifugal pump with reduced cavitation. Background Technology

[0002] Multistage centrifugal pumps are generally top-in and top-out structures, consisting of suction section components, intermediate section, guide vanes, rotor components, discharge section components, balancing mechanism, sealing gland, sealing device, and bearing housing components, used to transport high-lift process media.

[0003] When the pump design is completed, its cavitation performance is already determined. When conveying process media close to the vaporization point, cavitation can only be reduced by increasing the installation height of the device, increasing the diameter of the inlet pipe, and reducing the pump's operating speed.

[0004] Increasing the installation height of the device is limited by site constraints and increases manufacturing costs. Increasing the diameter of the inlet pipe is limited by the selected pump type. Reducing the pump's operating speed cannot achieve the required head. Therefore, it is necessary to invent a multistage centrifugal pump with reduced cavitation. Summary of the Invention

[0005] The purpose of this invention is to provide a multistage centrifugal pump with reduced cavitation. This invention changes the suction method from top suction to horizontal suction, increasing the pressure at the suction liquid surface. The first-stage impeller of the multistage centrifugal pump adopts a double-suction structure, effectively preventing cavitation. This ensures the safe and stable delivery of process media near their vaporization point.

[0006] The objective of this utility model is achieved through the following technical solution: A multistage centrifugal pump with reduced cavitation is disclosed. The pump's suction pipe, cooling water chamber, and suction section are welded together. A front pump cover and spiral wound gasket are mounted on the suction section components via front pump cover fasteners, forming a stator suction component. The first-stage impeller and first-stage impeller retainer are mounted on the shaft and inserted into the stator suction component for assembly. A through-bar passes through the suction section components to install a flat washer and nut. The first-stage sealing gasket and sealing ring are mounted on the first-stage intermediate section and installed together with the stator suction component. Interstage retaining rings, impellers, guide vanes, intermediate sections, anti-rotation pins, and discharge section components are respectively mounted on the shaft and stator suction component. A through-bar passes through the discharge section components to install a flat washer and tightens the nut. A sealing box fastener secures the sealing box to the discharge section component. A mechanical seal is mounted on the shaft. The drive-end bearing housing component and the non-drive-end bearing housing component are mounted on the shaft, and the mechanical seal fastener secures the mechanical seal.

[0007] In the aforementioned multi-stage centrifugal pump designed to reduce cavitation, a gap is provided between the drive-end bearing housing component and the non-drive-end bearing housing component and the pump shaft.

[0008] The multi-stage centrifugal pump for reducing cavitation has bearing body fasteners that fix the drive end bearing body component and the non-drive end bearing body component at both ends.

[0009] The advantages and effects of this utility model are: 1. This utility model proposes a method to reduce cavitation in a multistage centrifugal pump by changing the suction method from top suction to horizontal suction, thereby increasing the pressure on the suction liquid surface and effectively preventing cavitation. A cooling water chamber is added to the short suction pipe of the suction section component. The cooling water removes the temperature of the process medium, keeping the process medium near its vaporization point away from it, effectively preventing cavitation.

[0010] 2. The multistage centrifugal pump of this utility model can effectively avoid cavitation and ensure the safe and stable delivery of process media close to the vaporization point without increasing the installation height of the device, increasing the diameter of the inlet pipe, or reducing the pump operating speed. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the inhalation section of this utility model; Figure 2 This utility model presents an installation diagram of a multistage centrifugal pump.

[0012] Components shown in the diagram: 1. Pump shaft; 2. Drive end bearing housing assembly; 3. Mechanical seal; 4. Front pump cover; 5. Spiral wound gasket; 6. First stage sealing gasket; 7. First stage intermediate section; 8. Through rod; 9. Nut; 10. Flat washer; 11. Suction section assembly; 12. Sealing ring; 13. Balance pipe assembly; 14. Impeller; 15. Guide vane; 16. Interstage section; 17. Interstage retaining ring; 18. Anti-rotation pin; 19. Discharge section assembly; 20. Balance bushing (pressure sleeve) assembly; 21. Balance drum assembly; 22. Sealing box; 23. Mechanical seal fastener; 24. Non-drive end bearing housing assembly; 25. Bearing housing fastener; 26. Sealing box fastener; 27. First stage impeller retainer; 28. First stage impeller; 29. ​​Front pump cover fastener. Detailed Implementation

[0013] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings.

[0014] This invention relates to a multistage centrifugal pump designed to reduce cavitation by altering the reflux position of the balancing pipe. The original balancing pipe of the multistage centrifugal pump was led out from the sealed box after the balancing mechanism and refluxed back to the inlet of the suction section (the suction port of the first-stage impeller). The process medium enters from the suction section, flows through the multistage impellers and guide vanes to the balancing mechanism. Rotation, agitation, and friction increase the temperature of the process medium, resulting in high pressure after the balancing mechanism, preventing vaporization. However, when the process medium, nearing its vaporization point, heats up and refluxes back to the inlet of the suction section components in the low-pressure zone, cavitation occurs. Therefore, this invention leads the balancing pipe of the multistage centrifugal pump out from the sealed box after the balancing mechanism and refluxes back to the middle section of the first stage (the discharge port of the first-stage impeller). The relatively high pressure effectively prevents cavitation from occurring when the process medium, near its vaporization point, heats up.

[0015] like Figure 1 As shown, the suction short pipe, cooling water chamber and suction section of this utility model are reliably welded together; Figure 2 As shown, the front pump cover 4 and the spiral wound gasket 5 are installed on the suction section component 11 via the front pump cover fastener 29 to form the stator suction component. After the first-stage impeller 28 and the first-stage impeller retaining sleeve 27 are installed on the pump shaft 1, they are inserted into the stator suction component. The through-bar 8 is passed through the suction section component 11, and the flat washer 10 and nut 9 are installed. The sealing gasket 6 and the sealing ring 12 are installed on the first-stage intermediate section component 7 and then installed together with the stator suction component. The interstage retaining ring 17, impeller 14, guide vane 15, intermediate section component 16, anti-rotation pin 18, and discharge section component 19 are sequentially installed on the pump shaft 1 and the stator suction component, respectively. The through-bar 8 is passed through the discharge section component 19, the flat washer 10 is installed, and the nut 9 is tightened. After installing the balance bushing (pressure sleeve) component 20, the balance drum component 21 is installed. Secure the sealing gland component 22 to the discharge section component 19 using the sealing gland fastener 26. Install the mechanical seal 3 onto the pump shaft 1 (left and right ends, without tightening the mechanical seal fastener 23). Install the drive end bearing body component 2 and the non-drive end bearing body component 24 onto the pump shaft 1 respectively, and adjust the clearance between the drive end bearing body component 2 and the non-drive end bearing body component 24 and the pump shaft 1. Tighten the bearing body fastener 25 (left and right ends) to secure the drive end bearing body component 2 and the non-drive end bearing body component 24. Tighten the mechanical seal fastener 23 (left and right ends) to secure the mechanical seal 3. Install the balance pipe component 13.

Claims

1. A multi-stage centrifugal pump with reduced cavitation, characterized in that, The multistage centrifugal pump's suction short pipe, cooling water chamber, and suction section are welded together; the front pump cover (4) and spiral wound gasket (5) are installed on the suction section component (11) by the front pump cover fastener (29) to form the stator suction component; the first-stage impeller (28) and first-stage impeller retainer (27) are installed on the pump shaft (1) and inserted into the stator suction component for assembly; the through rod (8) passes through the suction section component (11) to install the flat washer (10) and nut (9); the first-stage sealing gasket (6) and sealing ring (12) are installed on the first-stage middle section (7) and installed together with the stator suction component; the interstage retaining ring (17) Impeller (14), guide vane (15), middle section (16), anti-rotation pin (18), and discharge section component (19) are respectively installed on pump shaft (1) and stator suction component; through rod (8) passes through discharge section component (19) to install flat washer (10) and tighten nut (9); sealing box fastener (26) fixes sealing box (22) on discharge section component (19); mechanical seal (3) is installed on pump shaft (1); drive end bearing body component (2) and non-drive end bearing body component (24) are installed on pump shaft (1), and mechanical seal fastener (23) fixes mechanical seal (3).

2. The multi-stage centrifugal pump for reducing cavitation according to claim 1, characterized in that, There is a gap between the drive end bearing body component (2) and the non-drive end bearing body component (24) and the pump shaft (1).

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