Centrifugal pump capable of reducing dynamic and static interference effect of centrifugal pump and manufacturing method

Abstract

The invention discloses a centrifugal pump capable of reducing the dynamic and static interference effect of the centrifugal pump and a manufacturing method. A partition tongue of a pump shell is cut and then polished, and the tail edge of a blade is polished; nickel plating is conducted on the positions, corresponding to the blades, of the polished pump shell, and the bonding face of the flexible elastomer is soaked and activated through a silane coupling agent solution; the flexible elastomer in the corresponding shape is bonded and fixed to the tail edge of the blade and the partition tongue of the pump shell through a double-component epoxy resin adhesive, and the flexible elastomer at the tail edge of the blade is exposed out of the outer edge of the cover plate; and the impeller and the pump shell are assembled to finally form the centrifugal pump. According to the centrifugal pump, the flexible elastic body is arranged, vibration and impact generated by dynamic and static interference can be absorbed and buffered through self deformation when the centrifugal pump operates, and the vibration amplitude and impact force are effectively reduced.

Description

Technical Field

[0001] The invention relates to a centrifugal pump capable of reducing dynamic and static interference of the centrifugal pump and a manufacturing method thereof. Background Art

[0002] The negative impact of static-dynamic interference, a key factor restricting the efficient and stable operation of centrifugal pumps, is becoming increasingly prominent. On the one hand, the liquid flow separates at the trailing edge of the blades, generating a wake vortex; on the other hand, the presence of the baffle interferes with the flow pattern at the impeller outlet, leading to pressure pulsation. The interaction of these factors causes the impeller to be subjected to periodic non-uniform forces, causing vibration and noise. Studies have shown that the vibration caused by static-dynamic interference not only exacerbates the wear between the impeller and the pump casing, shortening the service life of key components such as bearings and seals, but may also cause cavitation in the centrifugal pump, further reducing the pump's efficiency and head. Under certain extreme operating conditions, strong static-dynamic interference can even trigger resonance in the equipment, resulting in serious accidents such as impeller breakage and pump damage, bringing huge economic losses and safety hazards to industrial production.

[0003] Traditional methods for solving the problem of dynamic-static interference mainly focus on structural optimization. For example, by changing the outlet angle of the impeller blades, adjusting the placement and shape of the baffles, and precisely controlling the size of the gap between the impeller and the baffles, attempts are made to improve the flow field distribution and reduce pressure pulsation. However, these optimization measures based on rigid structures have certain limitations. On the one hand, due to limitations in machining accuracy and assembly technology, it is difficult to control the gap within the ideal range, and during operation, the gap will change due to factors such as thermal expansion and mechanical deformation; on the other hand, the rigid structure cannot actively adapt to the dynamic changes of the unsteady flow field. Under complex working conditions, the problem of dynamic-static interference still cannot be effectively solved. Summary of the Invention

[0004] The present invention aims to address the aforementioned problems of the prior art by providing a centrifugal pump and manufacturing method that reduces the dynamic-static interference effect of the centrifugal pump. The present invention employs flexible elastomers at the trailing edge of the impeller blades and the diaphragm, aiming to reduce dynamic-static interference from a new perspective and improve the performance and reliability of the centrifugal pump.

[0005] The technical solutions adopted in the present invention are:

[0006] A centrifugal pump for reducing dynamic and static interference of a centrifugal pump comprises a pump casing and an impeller assembled with the pump casing, the impeller comprising blades and cover plates assembled on both sides of the blades and coaxial with the blades, a flexible elastic body is provided at the trailing edge of the blade, the flexible elastic body being exposed from the outer edge of the cover plate;

[0007] The spacer tongue of the pump housing is embedded with a flexible elastic body.

[0008] The Shore hardness of the flexible elastomer is A60-80.

[0009] Furthermore, the flexible elastomer is a polyurethane elastomer or a fluororubber elastomer.

[0010] Furthermore, the flexible elastic body is fixed to the trailing edge of the blade and the tongue of the pump casing by gluing.

[0011] The present invention also discloses a method for manufacturing a centrifugal pump.

[0012] (1) Cut and grind the tongue of the pump casing, and grind the trailing edge of the blade;

[0013] (2) Nickel plating is performed on the corresponding positions of the polished pump casing and the blades, and the bonding surface of the flexible elastomer is activated by soaking in a silane coupling agent solution;

[0014] (3) Using a two-component epoxy resin adhesive, a flexible elastomer of corresponding shape is bonded and fixed to the trailing edge of the blade and the tongue of the pump casing, and the flexible elastomer at the trailing edge of the blade is exposed to the outer edge of the cover plate;

[0015] (4) Assembling the impeller and the pump casing to finally form the centrifugal pump.

[0016] Furthermore, the coating thickness of the two-component epoxy resin glue is 0.1-0.2 mm.

[0017] Furthermore, after the flexible elastomer is bonded, a pressure of 0.1-0.3 MPa is applied; and the mixture is cured at room temperature for 24 hours, or at 60° C. for 2-3 hours.

[0018] The present invention has the following beneficial effects:

[0019] (1) The present invention provides a flexible elastic body, which can absorb and buffer the vibration and impact caused by the dynamic and static interference through its own deformation when the centrifugal pump is running, thereby effectively reducing the vibration amplitude and impact force.

[0020] (2) The flexible elastomer is made of polyurethane or fluororubber with a Shore hardness of 60-80 A, which has good wear resistance and corrosion resistance. It can withstand the long-term impact of the liquid medium in the centrifugal pump, ensure the service life in complex working environments, and maintain the functional stability of reducing dynamic and static interference. It can deform under certain external forces to adapt to the slight displacement and collision between the dynamic and static components, and can withstand the pressure changes during the operation of the centrifugal pump to avoid excessive deformation affecting the performance of the pump. It has good temperature resistance and can maintain stable physical and chemical properties within a certain temperature range generated by the operation of the centrifugal pump, ensuring that the flexible elastomer can play the role of reducing dynamic and static interference under different operating temperatures.

[0021] (3) The flexible elastomer at the trailing edge of the blade is exposed at the outer edge of the cover plate, which can reduce the friction loss of the disc. At the same time, when the trailing edge of the blade sweeps the tongue, the flexible section deforms appropriately, which can change the rotor gap and the flow cross-sectional area and the periodic extrusion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a cross-sectional view of the assembly of the present invention.

[0023] Figure 2 This is the structural diagram of the pump casing.

[0024] Figure 3 This is the structural diagram of the impeller.

[0025] Figure 4 This is the structural diagram of the impeller.

[0026] Figure 5 Time domain diagram of pressure pulsation at the trailing edge of different materials.

[0027] Figure 6 Frequency domain diagram of pressure pulsation at the trailing edge of different materials. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] like Figures 1 to 4 The present invention provides a centrifugal pump for reducing the dynamic and static interference of the centrifugal pump, comprising a pump casing 1 and an impeller 2 assembled with the pump casing, wherein the impeller 2 comprises blades 21 and cover plates 22 assembled on both sides of the blades and coaxial with the blades.

[0030] Depending on the working environment of the centrifugal pump, the rigid structure (i.e., the pump casing, blades, and cover plate 22) is made of cast iron or 316L stainless steel to meet strength and corrosion resistance requirements. A flexible elastomer 3 is provided at the trailing edge of the blade 21, which is exposed at the outer edge of the cover plate. The flexible elastomer is made of polyurethane elastomer with a Shore A hardness of 60-80. In special corrosive working conditions, it can be replaced with fluororubber to ensure elasticity, wear resistance, and weather resistance.

[0031] For the pump casing, the diaphragm is CNC-ground to ensure high-precision molding; the flexible elastomer is formed by a customized high-strength alloy steel mold using an injection molding process to mold the dried polyurethane elastomer at a set temperature and pressure.

[0032] The manufacturing method of the centrifugal pump is:

[0033] The rigid and flexible elastomer connection surfaces are treated separately: the rigid surface is sandblasted and then electrolessly nickel-plated, while the flexible surface is activated by soaking in a silane coupling agent solution. A two-component epoxy resin adhesive (such as 3M Cotch-Weld DP460) is used. This adhesive offers high strength, chemical resistance, and excellent toughness, maintaining stable performance within a temperature range of -40°C to 120°C.

[0034] Use a dispensing machine to evenly apply adhesive to the connection surface between the rigid structure and the flexible elastomer, with a thickness of 0.1-0.2mm. After applying the adhesive, bond the two together and apply a pressure of 0.1-0.3MPa. Cure at room temperature for 24 hours, or at 60°C for 2-3 hours, to allow the adhesive to fully crosslink and form a strong connection layer.

[0035] Install the machined and connected components into the pump body according to process requirements, strictly controlling the axial and radial clearances and coaxiality between the impeller and the flange. Visually inspect the connection quality, and use sensors to conduct no-load and loaded operation tests to monitor parameters such as vibration, noise, pressure, and flow to ensure that the design performance indicators are met.

[0036] like Figure 5 and Figure 6 In order to further verify the feasibility of the technical solution of using bionic flexible materials to replace traditional rigid structures to reduce dynamic and static interference, the impeller rotation process was calculated and analyzed by numerical simulation methods. Specifically, under the same working conditions, the traditional rigid structure impeller and the bionic flexible elastomer impeller were simulated respectively, and the pressure pulsation data at the same position point were monitored. The calculation results show that compared with the traditional rigid structure impeller, the pressure pulsation amplitude measured at the same monitoring point during the rotation of the impeller using bionic flexible elastomer is significantly reduced, effectively suppressing the fluctuation intensity of the fluid pressure (such as Figure 5 In the pressure pulsation frequency domain analysis, the pressure pulsation frequency domain diagram of the bionic flexible elastomer impeller shows that the low-frequency signal amplitude shows a significant downward trend compared with the traditional rigid structure (such as Figure 6 The numerical simulation results above fully demonstrate that the technical solution of using bionic flexible materials proposed in the present invention can effectively reduce the pressure pulsation amplitude and low-frequency signal intensity during the impeller rotation process, thereby reducing dynamic-static interference and significantly improving the stability and reliability of equipment operation.

[0037] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A centrifugal pump for reducing the dynamic and static interference of a centrifugal pump, comprising a pump casing (1) and an impeller (2) assembled with the pump casing, wherein the impeller (2) comprises blades (21) and cover plates (22) assembled on both sides of the blades and coaxial with the blades, characterized in that: A flexible elastic body is provided at the trailing edge of the blade (21), and the flexible elastic body is exposed at the outer edge of the cover plate; The spacer tongue of the pump housing (1) is embedded with a flexible elastic body. The Shore hardness of the flexible elastomer is A60-80.

2. The centrifugal pump for reducing the dynamic and static interference of the centrifugal pump according to claim 1, characterized in that: The flexible elastic body is a polyurethane elastomer or a fluororubber elastomer.

3. The centrifugal pump for reducing the dynamic and static interference of the centrifugal pump according to claim 1, characterized in that: The flexible elastic body is fixed to the trailing edge of the blade and the tongue of the pump casing by gluing.

4. A method for manufacturing a centrifugal pump according to any one of claims 1 to 3, characterized in that: (1) Cut and grind the tongue of the pump casing, and grind the trailing edge of the blade; (2) Nickel plating is performed on the corresponding positions of the polished pump casing and the blades, and the bonding surface of the flexible elastomer is activated by soaking in a silane coupling agent solution; (3) Using a two-component epoxy resin adhesive, a flexible elastomer of corresponding shape is bonded and fixed to the trailing edge of the blade and the tongue of the pump casing, and the flexible elastomer at the trailing edge of the blade is exposed to the outer edge of the cover plate; (4) Assembling the impeller and the pump casing to finally form the centrifugal pump.

5. The manufacturing method according to claim 4, wherein: The coating thickness of the two-component epoxy resin glue is 0.1-0.2 mm.

6. The manufacturing method according to claim 4, wherein: After the flexible elastomer is bonded, a pressure of 0.1-0.3 MPa is applied; and the mixture is cured at room temperature for 24 hours, or at 60° C. for 2-3 hours.

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