Anti-cavitation centrifugal impeller assembly capable of adjusting lift according to rotating speed

Abstract

The invention relates to the technical field of centrifugal pumps, and discloses an anti-cavitation centrifugal impeller assembly capable of adjusting the lift according to the rotating speed, the anti-cavitation centrifugal impeller assembly comprises a center shaft, the center shaft is provided with a first-stage impeller assembly and a second-stage impeller disc, the first-stage impeller assembly comprises a first-stage impeller disc, and the second-stage impeller disc comprises a second-stage impeller disc; arc-shaped short blades and spiral long blades are fixedly installed on the outer side face of the first-stage impeller disc, the multiple sets of arc-shaped short blades are fixedly installed on the first-stage impeller disc in an annular array shape with the circle center of the first-stage impeller disc as the center, and a gap is formed between every two adjacent sets of arc-shaped short blades. The multiple sets of spiral long blades are fixedly installed between every two adjacent sets of arc-shaped short blades. When the pressure sensing reaction sheet on the spiral long blade senses that the pressure in the pump is lower than the local medium saturated vapor pressure, the pulse nozzle receives an induction signal and emits pulse waves, bubbles and cavitation bubbles generated in a low-pressure area in the pump are subjected to pulse cutting fracture, the cavitation bubbles are prevented from entering a high-pressure area to be extruded and fractured, and the pressure in the pump is reduced. And the effect of preventing the interior and the shell of the centrifugal pump from being damaged is achieved.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump technology, and more particularly to an anti-cavitation centrifugal impeller assembly with adjustable head based on rotational speed. Background Technology

[0002] The working principle of a centrifugal pump is that the rotation of the impeller generates centrifugal force, which pushes the fluid towards the edge of the impeller. The fluid is then compressed and discharged through the spiral channel of the pump casing, thus achieving fluid transportation. Centrifugal pumps are widely used in industrial, agricultural, and construction fields, such as in water treatment, water supply systems, and chemical processes.

[0003] Centrifugal pumps are prone to cavitation problems under low pressure. Cavitation refers to the phenomenon that when a liquid is flowing, the local pressure drops below the liquid's saturated vapor pressure, causing the liquid to vaporize and form bubbles. When these bubbles move with the fluid to the high-pressure area, they will quickly burst, generating shock waves with local high temperature and high pressure, which will damage the pump's metal surface.

[0004] Therefore, we propose an anti-cavitation centrifugal impeller assembly with adjustable head based on rotational speed. Summary of the Invention

[0005] The present invention mainly solves the technical problem of cavitation in centrifugal pumps under low pressure conditions, and provides an anti-cavitation centrifugal impeller assembly with adjustable head according to rotational speed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an anti-cavitation centrifugal impeller assembly with adjustable head according to rotational speed, comprising a central shaft, wherein the central shaft is provided with a primary impeller assembly and a secondary impeller disk;

[0007] The first-stage impeller assembly includes a first-stage impeller disk. Arc-shaped short blades and spiral long blades are fixedly installed on the outer surface of the first-stage impeller disk. Multiple sets of arc-shaped short blades are fixedly installed on the first-stage impeller disk in a circular array with the center of the first-stage impeller disk as the center. A gap is provided between two adjacent sets of arc-shaped short blades. Multiple sets of spiral long blades are fixedly installed between two adjacent sets of arc-shaped short blades.

[0008] The second impeller disk is provided with a second bushing at its center. The second impeller disk is fixedly installed on the central shaft through the second bushing. The second impeller disk is provided with multiple fixed blades. The multiple sets of fixed blades are arranged in a ring array with the center of the second impeller disk as the center.

[0009] The outer end of the fixed blade is provided with a U-shaped groove, and an elastic connector is provided inside the U-shaped groove. One end of the elastic connector is fixedly connected to the inner wall of the U-shaped groove, and an expansion blade is fixedly spliced ​​to the free end of the elastic connector.

[0010] Preferably, the first-stage impeller disk is provided with a first bushing, the first-stage impeller disk is fixedly connected to the central shaft through the first bushing, and a protruding cover plate is provided at the center of the outer side of the first-stage impeller disk.

[0011] Preferably, multiple sets of the arc-shaped short blades and multiple sets of spiral long blades are alternately distributed on the first-stage impeller disk. One end of the spiral long blade is fixedly installed on the outer surface of the first-stage impeller disk near the edge. The free end of the spiral long blade extends outward in a spiral manner and is distributed in a suspended manner. The free ends of multiple sets of spiral long blades are intertwined in a suspended manner, presenting a spiral shape.

[0012] Preferably, the fixed blade has a larger width on the side closer to the center of the secondary impeller disk, and the width of the fixed blade gradually decreases on the side closer to the edge of the secondary impeller disk.

[0013] Preferably, the inner wall surface of the spiral blades is provided with pressure-sensitive reaction plates, and the inner wall surface of the spiral blades is provided with multiple pulse nozzles at equal intervals.

[0014] Preferably, the inner wall of the U-shaped groove is provided with a sliding groove, and the left and right side walls of the expansion blade are provided with sliders, which are slidably distributed in the corresponding sliding grooves.

[0015] Preferably, both the primary impeller assembly and the secondary impeller disk are located inside the centrifugal pump casing. The primary impeller assembly is located inside the pump casing near the outer inlet, and the secondary impeller disk is located inside the pump casing near the inner side.

[0016] Beneficial effects

[0017] This invention provides an anti-cavitation centrifugal impeller assembly with adjustable head based on rotational speed. It offers the following advantages:

[0018] (1) When the pressure-sensitive reaction plate on the spiral blades senses that the pressure inside the pump is lower than the local saturated vapor pressure of the medium, the pulse nozzle receives the sensing signal and emits a pulse wave to cut and break the bubbles and cavitation bubbles generated in the low-pressure area of ​​the pump, preventing the cavitation bubbles from entering the high-pressure area and being squeezed and broken, thus avoiding damage to the inside of the centrifugal pump and the casing.

[0019] (2) The anti-cavitation centrifugal impeller assembly with adjustable head according to rotation speed controls the rotation speed of the central shaft, thereby controlling the rotation speed of the first-stage impeller assembly and the second-stage impeller disk. When the rotation speed of the second-stage impeller disk is higher, the centrifugal force generated on the fixed blades is greater. At this time, the expansion blades expand towards the elastic connector and extend outward under the centrifugal action. Conversely, the expansion blades retract under the pulling force of the elastic connector. By controlling the extension state of the expansion blades through the rotation speed of the central shaft, the effect of accurately controlling the fluid head is achieved.

[0020] (3) The anti-cavitation centrifugal impeller assembly with adjustable head according to speed can make the expansion blades relatively active during operation by freely changing the speed of the central shaft, making the secondary impeller disk more suitable for handling high viscosity fluids, thus maintaining the stability and operating performance of the centrifugal pump when handling high viscosity fluids.

[0021] (4) The anti-cavitation centrifugal impeller assembly with adjustable head according to speed has a U-shaped groove that makes the outer end of the fixed blade hollow. The hollow design reduces the overall weight of the secondary impeller disk, thereby reducing the centrifugal force on the secondary impeller disk and bearing. In a high-speed rotating pump, this helps to improve the mechanical stability of the pump and extend its service life.

[0022] (5) The anti-cavitation centrifugal impeller assembly with adjustable head according to speed has a U-shaped groove that makes the outer end of the fixed blade hollow. The hollow design changes the flow characteristics of the fluid on the outer side of the secondary impeller disk, reduces the eddies and flow resistance caused by the outer edge of the fixed blade, and improves the efficiency of the centrifugal pump. Attached Figure Description

[0023] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0024] The structures, proportions, sizes, etc. disclosed in this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0025] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0026] Figure 2 This is a three-dimensional structural diagram of the first-stage impeller assembly of the present invention;

[0027] Figure 3 This is a schematic diagram of the three-dimensional structure of the spiral long blade of the present invention;

[0028] Figure 4 This is a schematic diagram of the fixed blade and the expansion blade positions of the structure of the present invention.

[0029] Legend:

[0030] 1. Central shaft; 2. First shaft sleeve; 3. First stage impeller assembly; 300. First stage impeller disk; 301. Protruding cover plate; 302. Arc-shaped short blade; 303. Spiral long blade; 304. Pressure-sensitive reaction plate; 305. Pulse nozzle; 4. Second shaft sleeve; 5. Second stage impeller disk; 6. Fixed blade; 7. U-shaped groove; 8. Elastic connector; 9. Expansion blade; 10. Slide groove. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: Anti-cavitation centrifugal impeller assembly with adjustable head based on rotational speed, refer to Figure 1 The pump includes a central shaft 1, which is equipped with a primary impeller assembly 3 and a secondary impeller disk 5. The central shaft 1 is fixedly connected to the output end of the motor through a bearing. The primary impeller assembly 3 and the secondary impeller disk 5 are both distributed inside the pump casing. The primary impeller assembly 3 is located inside the pump casing near the outer liquid inlet, and the secondary impeller disk 5 is located inside the pump casing near the inner side. The central shaft 1 is controlled by the motor to rotate freely, and the central shaft 1 rotates together with the primary impeller assembly 3 and the secondary impeller disk 5 inside the pump casing.

[0033] Furthermore, refer to Figure 2 The first-stage impeller assembly 3 includes a first-stage impeller disk 300, on which a first-stage shaft sleeve 2 is provided. The first-stage impeller disk 300 is fixedly connected to the central shaft 1 through the first-stage shaft sleeve 2. A protruding cover plate 301 is provided at the center of the outer side of the first-stage impeller disk 300. Arc-shaped short blades 302 and spiral long blades 303 are fixedly installed on the outer side of the first-stage impeller disk 300. Multiple sets of arc-shaped short blades 302 are fixedly installed in a ring array on the first-stage impeller disk 300 with the center of the first-stage impeller disk 300 as the center. A gap is provided between two adjacent sets of arc-shaped short blades 302. Multiple sets of spiral long blades 303 are fixedly installed between two adjacent sets of arc-shaped short blades 302. Multiple sets of arc-shaped short blades 302 and multiple sets of spiral long blades 303 are alternately distributed on the first-stage impeller disk 300.

[0034] Furthermore, refer to Figure 2One end of the spiral long blade 303 is fixedly installed on the outer surface of the first-stage impeller disk 300 near the edge. The free end of the spiral long blade 303 extends outward in a spiral and is distributed in a suspended manner. The free ends of multiple sets of spiral long blades 303 are interwoven in a suspended manner, presenting a spiral shape. Through this setting, the outer volume structure of the first-stage impeller assembly 3 is smaller, thereby reducing the interference with the flow state inside the pump.

[0035] Furthermore, refer to Figure 3 The inner wall surface of the spiral blades 303 is provided with pressure-sensitive reaction plates 304, and multiple pulse nozzles 305 are equidistantly arranged on the inner wall surface of the spiral blades 303. During operation, when the pressure-sensitive reaction plates 304 sense that the pressure inside the pump is lower than the local saturated vapor pressure of the medium, the pulse nozzles 305 receive the sensing signal and emit pulse waves to pulse-cut and break the bubbles and cavitation generated in the low-pressure area of ​​the pump, preventing the cavitation from entering the high-pressure area and being squeezed and broken, thus avoiding damage to the inside of the centrifugal pump and the casing.

[0036] Example 2, based on Example 1, refers to... Figure 1 and Figure 4 A second bushing 4 is provided at the center of the second-stage impeller disk 5. The second-stage impeller disk 5 is fixedly installed on the central shaft 1 through the second bushing 4. Multiple fixed blades 6 are provided on the second-stage impeller disk 5. Multiple sets of fixed blades 6 are arranged in a ring array with the center of the second-stage impeller disk 5 as the center.

[0037] Furthermore, refer to Figure 4 The fixed blade 6 has a larger width on the side closer to the center of the secondary impeller disk 5, and the width of the fixed blade 6 gradually decreases on the side closer to the edge of the secondary impeller disk 5. The width is controlled to decrease as the fixed blade 6 extends outward, which improves the flow efficiency of the liquid at the secondary impeller disk 5, and at the same time ensures that a high centrifugal force can be generated at the periphery of the secondary impeller disk 5, thereby pushing the liquid outward.

[0038] Furthermore, a U-shaped groove 7 is provided on the outer end of the fixed blade 6, and a sliding groove 10 is provided on the inner wall of the U-shaped groove 7. An elastic connector 8 is provided inside the U-shaped groove 7. One end of the elastic connector 8 is fixedly connected to the inner wall of the U-shaped groove 7, and an expansion blade 9 is fixedly spliced ​​on the free end of the elastic connector 8. The left and right side walls of the expansion blade 9 are provided with sliders, and the sliders are slidably distributed in the corresponding sliding grooves 10. The U-shaped groove 7 makes the outer end of the fixed blade 6 hollow. The hollow design reduces the overall weight of the secondary impeller disk 5, thereby reducing the centrifugal force on the secondary impeller disk 5 and the bearing. In a high-speed rotating pump, this helps to improve the mechanical stability of the pump and extend its service life. The hollow design changes the flow characteristics of the fluid on the outer side of the secondary impeller disk 5, reducing the eddies and flow resistance generated by the outer edge of the fixed blade 6. Especially when dealing with high-viscosity fluids, it improves the efficiency of the centrifugal pump.

[0039] By controlling the rotational speed of the central shaft 1, the rotational speed of the first-stage impeller assembly 3 and the second-stage impeller disk 5 is controlled. The higher the rotational speed of the second-stage impeller disk 5, the greater the centrifugal force generated on the fixed blades 6. At this time, the expanding blades 9 expand and extend outward under the centrifugal force, pulling the elastic connecting member 8. Conversely, the expanding blades 9 retract under the pulling force of the elastic connecting member 8. The extension state of the expanding blades 9 is controlled by the rotational speed of the central shaft 1, thereby precisely controlling the head of the fluid. At the same time, by freely changing the rotational speed of the central shaft 1, the expanding blades 9 are made to be in a relatively active state during operation, making the second-stage impeller disk 5 more suitable for handling high-viscosity fluids, thereby maintaining the stability and operating performance of the centrifugal pump.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A centrifugal impeller assembly with adjustable head based on rotational speed, comprising a central shaft (1), characterized in that: The central shaft (1) is provided with a primary impeller assembly (3) and a secondary impeller disk (5); The first-stage impeller assembly (3) includes a first-stage impeller disk (300). Arc-shaped short blades (302) and spiral long blades (303) are fixedly installed on the outer side of the first-stage impeller disk (300). Multiple sets of arc-shaped short blades (302) are fixedly installed on the first-stage impeller disk (300) in a circular array with the center of the first-stage impeller disk (300) as the center. A gap is provided between two adjacent sets of arc-shaped short blades (302). Multiple sets of spiral long blades (303) are fixedly installed between two adjacent sets of arc-shaped short blades (302). The second-stage impeller disk (5) is provided with a second bushing (4) at its center. The second-stage impeller disk (5) is fixedly installed on the central shaft (1) through the second bushing (4). The second-stage impeller disk (5) is provided with multiple fixed blades (6). The multiple sets of fixed blades (6) are arranged in a ring array with the center of the second-stage impeller disk (5) as the center. The outer end of the fixed blade (6) is provided with a U-shaped groove (7), and an elastic connector (8) is provided inside the U-shaped groove (7). One end of the elastic connector (8) is fixedly connected to the inner wall of the U-shaped groove (7), and an expansion blade (9) is fixedly spliced ​​on the free end of the elastic connector (8).

2. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: The first-stage impeller disk (300) is provided with a first bushing (2), and the first-stage impeller disk (300) is fixedly connected to the central shaft (1) through the first bushing (2). A protruding cover plate (301) is provided at the center of the outer side of the first-stage impeller disk (300).

3. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: Multiple sets of arc-shaped short blades (302) and multiple sets of spiral long blades (303) are alternately distributed on the first-stage impeller disk (300). One end of the spiral long blade (303) is fixedly installed on the outer surface of the first-stage impeller disk (300) near the edge. The free end of the spiral long blade (303) extends outward in a spiral and is distributed in a suspended manner. The free ends of multiple sets of spiral long blades (303) are interwoven in a suspended manner, presenting a spiral shape.

4. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: The fixed blade (6) has a larger width on the side closer to the center of the secondary impeller disk (5), and the width of the fixed blade (6) gradually decreases on the side closer to the edge of the secondary impeller disk (5).

5. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: The inner wall surface of the spiral blade (303) is provided with pressure-sensitive reaction plates (304), and the inner wall surface of the spiral blade (303) is provided with multiple pulse nozzles (305) at equal intervals.

6. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: The inner wall of the U-shaped groove (7) is provided with a sliding groove (10), and the left and right side walls of the expansion blade (9) are provided with sliders, which are slidably distributed in the corresponding sliding grooves (10).

7. The anti-cavitation centrifugal impeller assembly with adjustable head according to speed according to claim 1, characterized in that: The primary impeller assembly (3) and the secondary impeller disk (5) are both located inside the centrifugal pump casing. The primary impeller assembly (3) is located inside the pump casing near the outer liquid inlet, and the secondary impeller disk (5) is located inside the pump casing near the inner side.

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