Anti-cavitation centrifugal pump set

Abstract

The anti-cavitation centrifugal pump set comprises a pump body, the pump body is connected with a fluid inlet pipe and a fluid outlet pipe, the fluid inlet pipe is provided with an axial liquid inlet channel, the fluid inlet pipe is provided with an air ejector, and the air ejector is communicated with the axial liquid inlet channel; the fluid outlet pipe is provided with a radial liquid outlet channel, an impeller is arranged between the axial liquid inlet channel and the radial liquid outlet channel, the attack angle of a blade inlet of the impeller is 5-15 degrees, the impeller is connected with a power mechanism, an inducer is arranged in the axial liquid inlet channel, and the inducer is connected with the power mechanism. According to the self-priming centrifugal pump, the inducer and the air ejector are additionally arranged, and the attack angle of a blade inlet of the impeller is adjusted, so that a common self-priming centrifugal pump has high cavitation resistance and rapid self-priming capacity, has wide applicability under the working conditions of high altitude, low air pressure, plain, suction depth and pressurization, has wide application space and use value, and is suitable for popularization and application. The device is particularly suitable for conveying light fuel oil, water or media with similar properties.

Description

Technical Field

[0001] This invention belongs to the field of fluid machinery technology, and specifically relates to an anti-cavitation centrifugal pump set. Background Technology

[0002] A pump is a machine that converts the mechanical energy of a prime mover into the energy of the pumped liquid. There are many types of pumps, and they have a wide range of applications, playing a vital role in all sectors of the national economy. Among the various types of pumps, centrifugal pumps account for more than 75% of the total, and are widely used in power, petrochemical, water conservancy, aerospace, and other fields. Centrifugal pumps work by using the centrifugal motion of an impeller to cause water to move centrifugally. Before starting the pump, the pump casing and suction pipe must be filled with water. Then, the motor is started, causing the pump shaft to drive the impeller and water to rotate at high speed. The water undergoes centrifugal motion, being thrown towards the outer edge of the impeller and flowing into the pump's discharge pipe through the flow channel of the volute casing.

[0003] Cavitation, also known as pitting corrosion, is a phenomenon where cave-like corrosion occurs on metal surfaces in contact with fluids under conditions of high-speed flow and pressure changes. It commonly occurs in high-speed decompression zones, such as at the tips of centrifugal pump blades, where cavities form. These cavities are then crushed in high-pressure zones, generating impact pressure that destroys the protective film on the metal surface, accelerating corrosion. Cavitation is characterized by the initial formation of numerous tiny pits on the metal surface, which gradually expand into cavities. In centrifugal pumps, when the static pressure of the liquid near the impeller is equal to or lower than the saturated vapor pressure of the liquid at the pumping temperature, the liquid vaporizes, producing bubbles. When liquid carrying bubbles enters the high-pressure zone of the impeller, the bubbles rapidly condense or burst. The disappearance of the bubbles creates a local vacuum, causing surrounding liquid to flow at extremely high speeds into the space previously occupied by the bubbles, generating significant local impact force. Under the repeated action of this impact force, the centrifugal pump impeller suffers cavitation damage.

[0004] Existing self-priming centrifugal pumps rely on their own gas-liquid separation chamber and reflux hole to achieve self-priming. For example, Chinese patent document CN215170819U discloses a self-priming centrifugal pump set, which has two sealed water tanks at the inlet of the centrifugal pump: a main water tank and an auxiliary water tank. The inlet of the centrifugal pump is connected to the lower part of the main water tank; the upper part of the main water tank is connected to a water pool via a suction pipe; the upper part of the auxiliary water tank is connected to the upper part of the main water tank via an upper connecting pipe; the lower part of the auxiliary water tank is connected to the lower part of the main water tank via a lower connecting pipe; valves are respectively installed on the upper and lower connecting pipes; the centrifugal pump, main water tank, and auxiliary water tank are all fixed to the base with bolts. The self-priming centrifugal pump set of this invention adopts a dual-tank structure at the pump inlet, one main and one auxiliary. When the main water tank does not meet the upper vacuum requirement, the connecting pipe between the main water tank and the auxiliary water tank can be opened, maintaining the vacuum in the tank without stopping the pump, ensuring long-term safe and reliable operation of the pump.

[0005] National standards stipulate that self-priming centrifugal pump sets, under normal temperature and a suction depth of four meters in plains areas, should complete suction and enter normal operation within 240 seconds. While existing self-priming centrifugal pump sets can meet this standard at normal temperature and in plains areas, they cannot complete suction and enter normal operation at a suction depth of four meters in high-altitude, low-pressure environments. Because the working environment at high altitudes places extremely demanding requirements on self-priming centrifugal pumps, existing pumps are prone to cavitation in high-altitude regions, affecting their normal operation and failing to meet the requirements for all-weather, multi-environment use. Therefore, developing self-priming centrifugal pumps capable of rapid start-up and normal operation under various harsh conditions to meet the requirements of high-altitude areas is currently a key focus of development and research in the self-priming centrifugal pump industry. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-cavitation centrifugal pump unit to solve the above-mentioned problems existing in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an anti-cavitation centrifugal pump set, comprising a pump body, wherein the pump body is connected to a fluid inlet pipe and a fluid outlet pipe, the fluid inlet pipe is provided with an axial liquid inlet channel, and an air ejector is provided in the fluid inlet pipe, the air ejector being connected to the axial liquid inlet channel; the fluid outlet pipe is provided with a radial liquid outlet channel, an impeller is provided between the axial liquid inlet channel and the radial liquid outlet channel, the blades of the impeller having an inlet angle of attack of 5°-15°, the impeller being connected to a power mechanism, and an inducer wheel is provided in the axial liquid inlet channel, the inducer wheel being connected to the power mechanism.

[0008] This invention provides an anti-cavitation centrifugal pump set. Based on the traditional self-priming centrifugal pump, it adds an inducer and an air ejector, and adjusts the impeller blade inlet angle, giving the ordinary self-priming centrifugal pump high anti-cavitation performance and rapid self-priming capability. It retains the high reliability, stable performance, and long replacement cycle of parts of the self-priming centrifugal pump, while enhancing the anti-cavitation performance of the centrifugal pump set. It significantly shortens the suction depth time of the centrifugal pump set and has wide applicability in high altitude, low air pressure and plains, and suction depth and pressurization conditions. It has a wide application space and use value, and is particularly suitable for conveying light fuel oil, water or similar media.

[0009] As an optional design structure of the above technical solution, the impeller includes a disk and blades. The blades include multiple long blades and multiple short blades. The multiple long blades and multiple short blades are spirally spaced on the disk, and the ends of the long blades and short blades extend to the edge of the disk.

[0010] As an optional design structure of the above technical solution, the wrap angle of the long blade is in the range of 250°-300°, and the wrap angle of the short blade is in the range of 100°-130°.

[0011] As an optional design structure of the above technical solution, the impeller is made of titanium alloy.

[0012] As an optional design structure of the above technical solution, the inducer wheel includes a wheel shaft and helical blades. The wheel shaft is connected to the wheel disc, and the helical blades are disposed on the surface of the wheel shaft. The ends of the helical blades adopt a rounded streamlined surface and are smoothly connected to the impeller.

[0013] As an optional design structure of the above technical solution, the hub ratio of the inlet end and the outlet end of the helical blade is equal.

[0014] As an optional design structure for the above technical solution, the helical blades are made of aluminum alloy.

[0015] As an optional design structure for the above technical solution, the blade exit angle of the impeller is 30°-40°.

[0016] As an optional design structure of the above technical solution, the power mechanism includes a power source, the power source is connected to a transmission mechanism, the output end of the transmission mechanism is provided with a main shaft, and the impeller and the inducer are both mounted on the main shaft.

[0017] As an optional design structure of the above technical solution, the transmission mechanism includes a gearbox, in which a driving gear and a driven gear mesh with each other are provided. The driving gear is connected to a power source, and the driven gear is connected to a main shaft.

[0018] As an optional design structure of the above technical solution, a locking bolt is provided at the end of the main shaft, which is used to axially fix the inducer wheel.

[0019] The beneficial effects of this invention are as follows: 1. The anti-cavitation centrifugal pump unit of this invention achieves both rapid self-priming and high cavitation resistance. The entire process is simple and easy to control, and the self-priming time and high-altitude cavitation resistance are significantly optimized. During operation, the inducer and impeller rotate synchronously at the same speed, requiring no separate control. The inducer functions automatically as long as the centrifugal pump unit is running, improving its cavitation resistance and solving cavitation problems under various operating conditions. Furthermore, the centrifugal pump unit itself meets national standards, possessing a self-priming capability within 240 seconds. Under normal operating conditions, it can operate normally without activating the air ejector. When rapid startup is required, simply opening the air ejector completes the self-priming task in a very short time, enabling the centrifugal pump unit to operate normally. The entire centrifugal pump unit is simple, convenient, and safe to control, with significantly improved self-priming and cavitation resistance, which is of great significance in practical applications.

[0020] 2. The core working parts of the anti-cavitation centrifugal pump unit of this invention are the impeller and the inducer, both of which are connected to the main shaft via a key. Key transmission is inherently a rigid transmission, with high transmission efficiency and reliable and stable operation. The air ejector does not require additional power. Simply connect the compressed air tank to the air ejector, and the operation of the air ejector can be controlled by a valve. In the entire control process, it is only necessary to ensure the pressure and storage capacity of the compressed air tank; no other external power is required, and no other unnecessary losses will occur.

[0021] 3. The anti-cavitation centrifugal pump unit of this invention has a compact structure and reasonable design. Based on a conventional self-priming centrifugal pump, it adds an inducer and an air ejector. The inducer is installed before the impeller and inside the fluid inlet pipe, without increasing the overall size of the centrifugal pump unit. The inducer is fixed to the main shaft using only locking bolts and locking washers, without any additional structure or design. The air ejector design is even smaller; the fluid inlet pipe does not need to be modified, and the air ejector can be installed on the pre-reserved mounting platform in the fluid inlet pipe, occupying very little space. The entire centrifugal pump unit has a compact structure and reasonable design.

[0022] 4. The anti-cavitation centrifugal pump set of this invention has strong adaptability and can be used in a modular manner. The air ejector and inducer wheel have high versatility, and the inducer wheel can be used on centrifugal pump sets of similar types and models. In particular, the air ejector, as a rapid self-priming module, can not only be used on self-priming centrifugal pumps, but also in any working condition that requires self-priming. Its structure is compact and simple, easy to use, and has good consistency.

[0023] 5. The cavitation-resistant centrifugal pump unit of this invention has high reliability and long service life. All transmission components of the centrifugal pump unit have undergone lifespan and safety calculations, with sufficient safety margins, allowing for safe operation even under conditions with large power fluctuations. The inducer wheel, installed inside the fluid inlet pipe, has strong cavitation resistance and a large strength margin in its design, enabling it to operate normally under cavitation conditions. Therefore, the entire centrifugal pump unit is safe, reliable, has a long service life, operates stably, and is easy to replace. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an anti-cavitation centrifugal pump unit according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the impeller and the inducer in one embodiment of the present invention.

[0025] In the diagram: 1-Pump body; 2-Fluid inlet pipe; 3-Fluid outlet pipe; 4-Air ejector; 5-Impeller; 6-Inducer wheel; 7-Disc; 8-Long blade; 9-Short blade; 10-Shaft; 11-Helical blade; 12-Main shaft; 13-Gearbox; 14-Driving gear; 15-Driven gear; 16-Locking bolt; 17-Mechanical seal. Detailed Implementation

[0026] like Figure 1 and Figure 2 As shown, this embodiment provides an anti-cavitation centrifugal pump set, including a pump body 1. The pump body 1 is connected to a fluid inlet pipe 2 and a fluid outlet pipe 3. The fluid inlet pipe 2 is located on the left side of the pump body 1, and the fluid outlet pipe 3 is located on the top side of the pump body 1. The fluid inlet pipe 2 is provided with an axial liquid inlet channel and an air ejector 4, which communicates with the axial liquid inlet channel.

[0027] The air ejector 4, as a core component for improving the self-priming time of the centrifugal pump set, is installed directly above the fluid inlet pipe 2. A connecting hole for the air ejector 4 is located above the fluid inlet pipe 2. The fluid inlet pipe 2 and the air ejector 4 are fixed together by studs, and then the fluid inlet pipe 2 is installed on the pump body 1. When the centrifugal pump set starts, compressed air is introduced into the air ejector 4. The high-speed, high-pressure gas expels the air from the fluid inlet pipe 2, allowing the centrifugal pump set to draw up the medium. The entire process is extremely short, and the self-priming time changes with the compressed air pressure; the higher the pressure, the shorter the self-priming time. Users can adjust the compressed air pressure to control the self-priming time according to actual needs.

[0028] The fluid outlet pipe 3 is provided with a radial liquid outlet channel. An impeller 5 is provided between the axial liquid inlet channel and the radial liquid outlet channel. The blade inlet angle of attack of the impeller 5 is 5°-15°, preferably 12°. The impeller 5 is connected to a power mechanism. The blade inlet angle of attack of the impeller 5 is set to 5°-15°, which can effectively reduce the bending of the blades, increase the inlet flow area of ​​the blades, and reduce the blade displacement, thereby improving the anti-cavitation performance of the centrifugal pump set. Furthermore, when the flow rate of the centrifugal pump set increases, the inlet relative liquid flow angle increases, which can avoid the occurrence of negative angle of attack when the centrifugal pump set operates at high flow rates, so that the centrifugal pump set has better anti-cavitation performance.

[0029] Cavitation, also known as pitting corrosion, is a phenomenon where cave-like corrosion occurs on metal surfaces in contact with fluids under conditions of high-speed flow and pressure changes. It commonly occurs in high-speed decompression zones, such as at the tips of centrifugal pump blades, where cavities form. These cavities are then crushed in high-pressure zones, generating impact pressure that destroys the protective film on the metal surface, accelerating corrosion. Cavitation is characterized by the initial formation of numerous tiny pits on the metal surface, which gradually expand into cavities. In centrifugal pumps, when the static pressure of the liquid near the impeller is equal to or lower than the saturated vapor pressure of the liquid at the pumping temperature, the liquid vaporizes, producing bubbles. When liquid carrying bubbles enters the high-pressure zone of the impeller, the bubbles rapidly condense or burst. The disappearance of the bubbles creates a local vacuum, causing surrounding liquid to flow at extremely high speeds into the space previously occupied by the bubbles, generating significant local impact force. Under the repeated action of this impact force, the centrifugal pump impeller suffers cavitation damage.

[0030] An inducer wheel 6 is installed within the axial inlet channel, and the inducer wheel 6 is connected to the power mechanism. The inducer wheel 6 is installed in front of the impeller 5. When the working medium flows through the inducer wheel 6, it is pressurized. Since the pressurized medium already possesses a vaporization pressure exceeding that at ambient temperature, cavitation will not occur at the impeller 5, thus preventing it from affecting the performance of the core working component, the impeller 5. At the inducer wheel 6, localized cavitation may occur, but due to the structure of the inducer wheel 6, the bubbles generated by cavitation quickly burst and disappear at the rim of the inducer wheel 6. Furthermore, the inducer wheel 6 has a strong flow capacity, and the generated localized bubbles will not affect the flow rate of the inducer wheel 6. Therefore, installing the inducer wheel 6 within the axial inlet channel can increase the cavitation resistance of the centrifugal pump unit.

[0031] The impeller 5 is made of titanium alloy, which has good cavitation resistance. The blade outlet angle of attack of the impeller 5 is 30°-40°. The inlet and outlet angles of attack of the long blades 8 and the short blades 9 are the same, which can reduce separation and diffusion losses in low-specific-speed pumps with low flow rates. In this embodiment, the impeller 5 includes a disk 7 and blades. The blades include multiple long blades 8 and multiple short blades 9, which are spirally spaced on the disk 7, and the ends of the long blades 8 and short blades 9 extend to the edge of the disk 7. The twisting direction of the multiple long blades 8 and multiple short blades 9 is consistent, which improves the flow uniformity within the impeller 5 and improves the working efficiency of the centrifugal pump set. The wrap angle of the long blades 8 is in the range of 250°-300°, and the wrap angle of the short blades 9 is in the range of 100°-130°, which will not affect the normal operation of the centrifugal pump set and can meet the requirements of long-term cavitation-resistant operation of the centrifugal pump set.

[0032] Specifically, the inducer wheel 6 includes a shaft 10 and helical blades 11. The shaft 10 is connected to the impeller 7, and the helical blades 11 are disposed on the surface of the shaft 10. The ends of the helical blades 11 adopt a rounded streamlined surface for smooth transition with the impeller 5, which can reduce inlet impact loss and improve the cavitation resistance of the impeller 5. The hub ratios of the inlet and outlet ends of the helical blades 11 are equal, and the helical blades 11 are made of aluminum alloy material, which improves the service life of the inducer wheel 6.

[0033] In this embodiment, the power mechanism includes a power source connected to a transmission mechanism. The output end of the transmission mechanism is provided with a main shaft 12, and the impeller 5 and the inducer wheel 6 are both mounted on the main shaft 12. The power source is a motor, and the transmission mechanism is a gear mechanism. The motor drives the main shaft 12 to rotate through the transmission mechanism. The inducer wheel 6 and the impeller 5 on the main shaft 12 can rotate together with the main shaft 12, thereby allowing the fluid to enter the radial outlet channel from the axial inlet channel.

[0034] The transmission mechanism includes a gearbox 13, which contains a driving gear 14 and a driven gear 15 that mesh with each other. The driving gear 14 is connected to a power source, and the driven gear 15 is connected to a main shaft 12. The main shaft 12 extends into an axial fluid inlet channel, and a mechanical seal 17 is provided on the main shaft 12, located between the pump body 1 and the main shaft 12. A locking bolt 16 is provided at the end of the main shaft 12 for axially fixing the inducer wheel 6.

[0035] The main shaft 12 has a certain length, on which the impeller 5 and the inducer 6 are mounted. The inducer 6 is driven to the main shaft 12 by a key. Then, the inducer 6 is pressed and fixed to the main shaft 12 by locking washers and locking bolts 16. The fluid inlet pipe 2 is then installed on the pump body 1 and fixed with bolts. Finally, the air ejector 4 is pressed and fixed to the fluid inlet pipe 2 with studs. The air ejector 4 is connected to the compressed air tank, and the input of compressed air is controlled by a valve. To prevent the working medium flowing through the impeller 5 from flowing out of the gap between the pump body 1 and the main shaft 12, a mechanical seal 17 is added between the main shaft 12 and the pump body 1. During operation, the impeller 5 and the inducer 6 rotate simultaneously with the main shaft 12. The working medium flows into the fluid inlet pipe 2, is pressurized by the inducer 6, and then enters the impeller 5. After being accelerated and pressurized by the impeller 5, it enters the fluid outlet pipe 3 and is finally discharged from the outlet end of the fluid outlet pipe 3.

[0036] The anti-cavitation centrifugal pump unit of this invention is based on a traditional self-priming centrifugal pump, with the addition of an inducer 6 and an air ejector 4, and the adjustment of the blade inlet angle of the impeller 5. This gives the ordinary self-priming centrifugal pump high cavitation resistance and rapid self-priming capability. The inducer 6 uses helical blades 11, which inherently have the characteristics of large flow rate, low head, and low loss. Due to its large flow area, the bubbles generated when local cavitation occurs inside the inducer 6 will not have a significant impact on the overall flow rate, and will not block the flow, causing a sharp drop in the working flow rate and head of the centrifugal pump unit. Moreover, the generated bubbles are thrown to the rim of the inducer 6 and collapse and rupture under the action of centrifugal force, and will not remain in the flow channel of the inducer 6 blades for a long time, nor will they be transported to the centrifugal pump unit impeller 5 with the medium. Therefore, the inducer 6 can resist cavitation and can work under cavitation conditions. Therefore, the inducer 6 is installed before the impeller 5. The medium enters the blades after being pressurized by the inducer 6, avoiding vaporization due to the medium pressure being lower than the local ambient vaporization pressure, which would affect the normal operation of the centrifugal pump unit. The air ejector 4 discharges excess gas from the fluid inlet pipe 2 of the centrifugal pump group, which can achieve the purpose of rapid start-up. It is especially suitable for conveying light fuel oil, water or similar media in high-altitude, low-pressure environments or in conditions where the suction depth is greater than four meters.

[0037] Compared with the prior art, the present invention has the following advantages: 1. The anti-cavitation centrifugal pump set of this invention achieves both rapid self-priming and high cavitation resistance. The entire process is simple and easy to control, and the self-priming time and high-altitude cavitation resistance are significantly optimized. During operation, the inducer 6 and impeller 5 rotate synchronously at the same speed, requiring no separate control. The inducer 6 functions automatically as long as the centrifugal pump set is running, improving its cavitation resistance and solving cavitation problems under various operating conditions. Furthermore, the centrifugal pump set itself meets national standards, possessing a self-priming capability within 240 seconds. Under normal operating conditions, it can operate normally without activating the air ejector 4. When rapid startup is required, simply opening the air ejector 4 completes the self-priming task in a very short time, enabling the centrifugal pump set to operate normally. The entire centrifugal pump set is simple, convenient, and safe to control, with significantly improved self-priming and cavitation resistance, which is of great significance in practical applications.

[0038] 2. The core working parts of the anti-cavitation centrifugal pump unit of this invention are the impeller 5 and the inducer 6, both of which are connected to the main shaft 12 via a key. Key transmission itself is a rigid transmission, with high transmission efficiency and reliable and stable operation. The air ejector 4 does not require additional power. As long as the compressed air tank is connected to the air ejector 4, the operation of the air ejector 4 can be controlled by a valve. In the entire control process, it is only necessary to ensure the pressure and storage capacity of the compressed air tank. No other external power is required and no other unnecessary losses will occur.

[0039] 3. The anti-cavitation centrifugal pump unit of the present invention has a compact structure and reasonable design. Based on a conventional self-priming centrifugal pump, it adds an inducer wheel 6 and an air ejector 4. The inducer wheel 6 is installed before the impeller 5 and inside the fluid inlet pipe 2, without increasing the overall size of the centrifugal pump unit. The inducer wheel 6 is fixed to the main shaft 12 using only locking bolts 16 and locking washers, without any additional structure or design. The air ejector 4 has a smaller design structure; the fluid inlet pipe 2 does not need to be modified, and the air ejector 4 can be installed on the pre-reserved mounting boss in the fluid inlet pipe 2, occupying very little volume. The entire centrifugal pump unit has a compact structure and reasonable design.

[0040] 4. The anti-cavitation centrifugal pump set of this invention has strong adaptability and can be used in a modular manner. The air ejector 4 and the inducer 6 have high versatility. The inducer 6 can be used on centrifugal pump sets of similar models. In particular, the air ejector 4, as a fast self-priming module, can not only be used on self-priming centrifugal pumps, but also in any working condition that requires self-priming. Its structure is compact and simple, easy to use, and has good consistency.

[0041] 5. The cavitation-resistant centrifugal pump unit of this invention has high reliability and long service life. All transmission components of the centrifugal pump unit have undergone lifespan and safety calculations, with a safety margin, allowing for safe operation even under conditions with large power fluctuations. The inducer wheel 6, installed inside the fluid inlet pipe 2, has strong cavitation resistance and a large strength margin in its design, enabling it to operate normally under cavitation conditions. Therefore, the entire centrifugal pump unit is safe, reliable, has a long service life, operates stably, and is easy to replace.

[0042] In the description of this invention, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. They can refer to fixed connections, detachable connections, or integral connections; they can be mechanical or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this invention. Furthermore, the specific features and structures described in the embodiments are included in at least one implementation method. Those skilled in the art can combine features from different implementation methods without contradiction. The scope of protection of this invention is not limited to the specific implementation methods described above. Based on the basic technical concept of this invention, implementation methods that can be conceived by those skilled in the art without creative effort are all within the scope of protection of this invention.

Claims

1. A cavitation-resistant centrifugal pump unit, comprising a pump body (1), characterized in that, The pump body (1) is connected to a fluid inlet pipe (2) and a fluid outlet pipe (3). The fluid inlet pipe (2) is provided with an axial liquid inlet channel and an air ejector (4). The air ejector (4) is connected to the axial liquid inlet channel. The fluid outlet pipe (3) is provided with a radial liquid outlet channel. An impeller (5) is provided between the axial liquid inlet channel and the radial liquid outlet channel. The blade inlet angle of the impeller (5) is 5°-15°. The impeller (5) is connected to a power mechanism. An inducer wheel (6) is provided in the axial liquid inlet channel. The inducer wheel (6) is connected to the power mechanism.

2. The anti-cavitation centrifugal pump set according to claim 1, characterized in that, The impeller (5) includes a disk (7) and blades. The blades include multiple long blades (8) and multiple short blades (9). The multiple long blades (8) and multiple short blades (9) are spirally spaced on the disk (7), and the ends of the long blades (8) and the short blades (9) extend to the edge of the disk (7).

3. The anti-cavitation centrifugal pump set according to claim 2, characterized in that, The long blade (8) has an enclosing angle range of 250°-300°, and the short blade (9) has an enclosing angle range of 100°-130°.

4. The anti-cavitation centrifugal pump set according to claim 1, characterized in that, The impeller (5) is made of titanium alloy.

5. The anti-cavitation centrifugal pump set according to claim 2, characterized in that, The inducer wheel (6) includes a wheel shaft (10) and a spiral blade (11). The wheel shaft (10) is connected to the wheel disk (7). The spiral blade (11) is disposed on the surface of the wheel shaft (10). The end of the spiral blade (11) is smoothly connected to the impeller (5) with a rounded streamline surface.

6. The anti-cavitation centrifugal pump set according to claim 5, characterized in that, The hub ratio of the inlet end and the outlet end of the spiral blade (11) is equal, and the spiral blade (11) is made of aluminum alloy.

7. The anti-cavitation centrifugal pump set according to claim 1, characterized in that, The blade exit angle of the impeller (5) is 30°-40°.

8. The anti-cavitation centrifugal pump set according to claim 1, characterized in that, The power mechanism includes a power source, which is connected to a transmission mechanism. The output end of the transmission mechanism is provided with a main shaft (12), and the impeller (5) and the inducer (6) are both mounted on the main shaft (12).

9. The anti-cavitation centrifugal pump set according to claim 8, characterized in that, The transmission mechanism includes a gearbox (13), which has a driving gear (14) and a driven gear (15) meshing with each other. The driving gear (14) is connected to a power source, and the driven gear (15) is connected to a main shaft (12).

10. The anti-cavitation centrifugal pump set according to claim 9, characterized in that, The end of the main shaft (12) is provided with a locking bolt (16), which is used to axially fix the inducer wheel (6).

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