Anti-cavitation flow channel assembly and self-suction pump

Abstract

The utility model belongs to self -priming pump technical field especially, a kind of anti-cavitation runner and self-priming pump, to the uneven pressure of impeller inlet caused by gas-liquid mixing disorder of existing self-priming pump, easy to produce cavitation and collapse, to cause the problem of erosion components, vibration and performance decline, present and propose the following scheme, it includes pump body, impeller and shaft, pump body liquid inlet is sequentially connected gas-liquid chamber and buffer tube;Gas-liquid chamber inner wall is equipped with spiral protrusion, shaft end is equipped with variable pitch inducer, both cooperate with fluid premixing and pressurization;Buffer tube inner diameter is gradually expanded and inner wall is equipped with multiple blind holes, in the utility model, fluid pressure is improved by the above-mentioned cooperation structure and flow state is organized, then gradually expanding runner stabilizes pressure, reduces flow rate, and makes small gas bubble collapse at blind hole to dissipate impact, to improve the fluid condition of entering impeller, system inhibits cavitation, improves running stability and durability.

Description

Technical Field

[0001] This utility model relates to the field of self-priming pump technology, and in particular to an anti-cavitation flow channel component and a self-priming pump. Background Technology

[0002] A self-priming pump is a type of pump that does not require priming before startup and can automatically expel air from the suction line and establish normal liquid delivery function. Its basic structure usually includes a pump body, an impeller, and a liquid separation chamber. During operation, the liquid pre-stored in the pump mixes violently with the suction air in the impeller. The resulting gas-liquid mixture is discharged into the separation chamber. In the separation chamber, due to the reduced flow velocity and increased space, the gas rises due to its lower density and is discharged from the exhaust port, while the liquid sinks and flows back, mixing with fresh air again. This cycle continues until the suction line is evacuated to a vacuum, and liquid is continuously introduced, completing the self-priming process.

[0003] However, the core problem facing current self-priming pump technology lies in the inherent contradictions in the dynamics of its gas-liquid mixing and transport process, which easily induces and exacerbates cavitation hazards. Specifically, in the initial stage of self-priming, the turbulent fluid with high gas content directly impacts the impeller inlet, resulting in extremely unstable flow patterns and severely uneven pressure distribution in this area. This easily leads to the formation of instantaneous local low-pressure points. When the pressure is lower than the liquid's saturated vapor pressure, the liquid locally vaporizes, generating a large number of cavitation bubbles. These cavitation bubbles, after entering the high-pressure zone of the impeller or pump casing with the mainstream, will instantly collapse, generating micro-jet streams and shock waves with pressures up to hundreds of megapascals. These waves continuously act on the metal surface. This physical erosion not only causes material fatigue spalling on the surfaces of flow-through components such as the impeller and pump casing, forming honeycomb-like pits, but in severe cases, it can even lead to component perforation and failure. At the same time, the periodic generation and collapse of bubbles can also cause high-frequency vibration and harsh noise in the unit, and cause the pump's flow rate, head, and other external characteristic curves to drop sharply at the critical point, making it difficult to guarantee operating efficiency and stability. Therefore, we propose an anti-cavitation self-priming pump to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing self-priming pumps, such as cavitation induced by the gas-liquid mixing process, which leads to uneven impeller inlet pressure, cavitation bubbles, and cavitation bubble collapse erosion of components, causing vibration and noise, resulting in decreased pump performance and unstable operation. Therefore, this invention proposes an anti-cavitation flow channel component and a self-priming pump.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An anti-cavitation flow channel assembly includes a pump body, an impeller disposed within the pump body, and a shaft for driving the impeller. The pump body's liquid inlet is connected to the gas-liquid chamber via a buffer pipe; The inner wall of the gas-liquid chamber is provided with a spiral protrusion. One end of the rotating shaft extends into the gas-liquid chamber and is fixedly installed with a variable pitch inducer. The blades of the variable pitch inducer and the spiral protrusion form a spirally converging flow channel. The inner wall of the buffer tube has multiple blind holes.

[0006] In one possible design, the inner diameter of the buffer tube gradually increases from its inlet end to its outlet end.

[0007] In one possible design, the number of blind holes per unit area on the inner wall of the buffer tube gradually decreases along the fluid flow direction.

[0008] In one possible design, the pitch of the variable pitch inducer decreases continuously from its inlet side to its outlet side.

[0009] In one possible design, the helical direction of the helical protrusion is opposite to the direction of the fluid motion propelled by the rotation of the variable pitch inducer.

[0010] In one possible design, a self-priming pump includes an anti-cavitation flow channel assembly as described in any of the above technical solutions, and further includes a base and a drive mechanism. The pump body is fixed on the base, and the drive mechanism includes a motor and a coupling. The motor is fixedly mounted on the top of the base, and the motor is connected to a rotating shaft via the coupling.

[0011] In this application, firstly, the fluid enters the gas-liquid chamber. Inside the gas-liquid chamber, the rotating shaft drives the variable pitch inducer wheel to start rotating, creating a spatial fit with the spiral protrusion fixed on the inner wall. This fit allows the fluid to achieve circumferential rotational motion while moving forward axially, thereby achieving preliminary mixing and pre-pressurization of the gas and liquid. This process increases the fluid pressure, which helps to suppress the generation of bubbles from the source. Subsequently, the pretreated fluid enters the buffer tube. The inner diameter of the buffer tube gradually expands from its inlet end to its outlet end, which reduces the fluid velocity and converts some kinetic energy into static pressure energy, further increasing the fluid pressure and stabilizing the flow field. When flowing through the inner wall of the buffer tube, multiple blind holes distributed on the wall surface play a role, providing a place for the collapse of any tiny bubbles that may exist in the fluid. The shock wave generated by the collapse of the bubbles is reflected, interfered with and dissipated multiple times in the limited space of the blind holes, avoiding the energy from being concentrated on the tube wall. After the fluid has been stabilized and buffered, it smoothly enters the pump inlet through the outlet of the buffer pipe and reaches the impeller chamber. At this point, the fluid has a relatively uniform pressure distribution and flow pattern. Driven by the rotating shaft, the main impeller performs the final pressurization and delivery of the fluid. Due to the pretreatment of the upstream flow channel, the fluid conditions acting on the main impeller are improved, the pressure pulsation at the impeller inlet is reduced, and the low-pressure zone is not easy to form. This allows the main impeller to work under better conditions, ensuring efficiency and significantly reducing the risk of cavitation corrosion.

[0012] Beneficial effects: In this utility model, the anti-cavitation flow channel component and self-priming pump, through the spatial cooperation between the spiral protrusions set on the inner wall of the gas-liquid chamber and the variable pitch inducer installed at the extended end of the rotating shaft, can achieve the effect of pre-organizing and primary pressurizing the gas-liquid mixture entering the pump. The spiral protrusions guide the fluid, while the variable pitch inducer does work on it. The synergistic work of the two makes the gas-liquid mixing more uniform, increases the fluid kinetic energy, and raises the pressure, effectively improving the state of the fluid before entering the main impeller, laying a good foundation for the subsequent process. In this invention, the anti-cavitation flow channel assembly and self-priming pump, through a buffer tube with a gradually expanding inner diameter and multiple blind holes distributed on the inner wall, located between the gas-liquid chamber and the pump body inlet, can achieve the effects of stabilizing the pressure, reducing the speed, and dissipating microscopic energy of the fluid. The gradually expanding flow channel slows down the fluid, converting kinetic energy into pressure energy, thereby increasing the static pressure of the fluid. The array of blind holes on the inner wall can capture and buffer tiny bubbles in the fluid. When a bubble collapses near a blind hole, the impact energy it generates is reflected and dispersed multiple times by the hole wall, weakening the direct erosion effect on the flow channel base material, thereby protecting the flow components. In this invention, the anti-cavitation flow channel assembly and self-priming pump utilize a three-stage progressive flow channel consisting of a gas-liquid chamber, a buffer pipe, and an impeller connected in sequence. This achieves the effect of systematically suppressing cavitation and improving overall operational stability. The fluid sequentially undergoes pretreatment pressurization, flow stabilization and buffering, and finally performs work, resulting in smoother pressure changes throughout the process and avoiding drastic pressure fluctuations. This structure ensures that the fluid reaches a high and stable pressure and uniform flow pattern upon reaching the main impeller, significantly reducing the risk of cavitation in the main impeller and guaranteeing the long-term, efficient, and stable operation of the pump. In this invention, the spiral protrusions of the gas-liquid chamber, in conjunction with the variable pitch inducer, pre-organize and initially pressurize the gas-liquid mixture, improving the fluid state entering the main impeller. The gradually expanding structure of the buffer tube and the array of blind holes on its inner wall achieve pressure stabilization, velocity reduction, and microscopic energy dissipation, protecting the flow components from direct cavitation corrosion. The three-stage progressive flow channel, consisting of the gas-liquid chamber, buffer tube, and impeller, ensures smooth pressure changes, resulting in stable pressure and uniform flow upon reaching the main impeller. This systematically suppresses cavitation and improves the pump's operational stability and durability. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural schematic diagram of an anti-cavitation flow channel component and a self-priming pump proposed in this utility model. Figure 2 This is a three-dimensional structural diagram of a partially exploded anti-cavitation flow channel component and a self-priming pump proposed in this utility model. Figure 3This is a partial cross-sectional three-dimensional structural schematic diagram of an anti-cavitation flow channel component and a self-priming pump proposed in this utility model.

[0014] In the diagram: 1. Pump body; 2. Shaft; 3. Impeller; 4. Gas-liquid chamber; 401. Spiral protrusion; 5. Buffer tube; 501. Blind hole; 6. Variable pitch inducer; 7. Base; 8. Motor; 9. Coupling. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0016] In one embodiment: Refer to Figure 1-3 A cavitation-resistant flow channel assembly includes a pump body 1, a rotating shaft 2, an impeller 3, a gas-liquid chamber 4, a buffer pipe 5, and a variable pitch inducer 6. The components work together to achieve the functions of cavitation prevention and self-priming conveying. The pump body 1 is fixed on the base 7. An impeller 3 is installed inside the pump body 1. A rotating shaft 2 passes through the pump body 1, and one end of the rotating shaft 2 is fixedly connected to the impeller 3, thereby driving the impeller 3 to rotate and complete the final pressurization and delivery of the fluid. Furthermore, the liquid inlet of the pump body 1 is connected to the gas-liquid chamber 4 through a buffer pipe 5. The fluid needs to be pre-treated by the gas-liquid chamber 4 and the buffer pipe 5 before entering the pump body 1. The pre-treatment of the upstream flow channel can improve the fluid conditions acting on the impeller 3, reduce the pressure pulsation at the inlet of the impeller 3, make it less likely for a low-pressure zone to form, allow the impeller 3 to work under better conditions, and reduce its risk of cavitation corrosion. The inner wall of the gas-liquid chamber 4 is provided with a spiral protrusion 401. The end of the rotating shaft 2 away from the impeller 3 extends into the gas-liquid chamber 4, and a variable pitch inducer 6 is fixedly installed at this end. A reasonable operating gap is maintained between the outer edge of the blades of the variable pitch inducer 6 and the inner edge of the spiral protrusion 401. The two are not in contact and together define a spiral flow channel with a gradually changing pitch. When the rotating shaft 2 drives the variable pitch inducer 6 to rotate, this engagement allows the fluid to achieve circumferential rotational motion while advancing axially, thereby realizing the initial mixing and pre-pressurization of gas and liquid. This process can increase the fluid pressure, which helps to suppress the generation of bubbles from the source. At the same time, it can make the gas-liquid mixing more uniform, increase the fluid kinetic energy, improve the state of the fluid before entering the impeller 3, and lay a good foundation for the subsequent process. Preferably, the pitch of the variable pitch inducer 6 decreases continuously from its inlet side to its outlet side. This structure can further enhance the pressurization effect on the fluid and improve the uniformity of gas-liquid mixing. Preferably, the helical direction of the spiral protrusion 401 is opposite to the direction of the fluid movement driven by the rotation of the variable pitch inducer 6. Based on this, the disturbance and guidance effect on the fluid can be enhanced, improving the efficiency of pre-pressurization and gas-liquid mixing. Furthermore, the buffer tube 5 is connected between the gas-liquid chamber 4 and the inlet of the pump body 1. The inner wall of the buffer tube 5 has multiple blind holes 501. When there are tiny bubbles in the fluid, the blind holes 501 can serve as the collapse site of the bubbles. The shock wave generated by the collapse of the bubbles can be reflected, interfered with and dissipated multiple times within the limited space of the blind holes 501, avoiding the energy from being concentrated on the tube wall body, thereby weakening the direct erosion effect on the base material of the buffer tube 5. Specifically, the inner diameter of the buffer tube 5 gradually expands from its inlet to its outlet. As the fluid flows through this expanding channel, its velocity decreases, and some of its kinetic energy is converted into static pressure energy. This further increases the fluid pressure and stabilizes the flow field, making the fluid pressure change smoother and avoiding drastic pressure fluctuations. Furthermore, along the fluid flow direction, the number of blind holes 501 per unit area on the inner wall of the buffer tube 5 gradually decreases from its inlet to its outlet. This is because after the initial buffering at the inlet, the internal bubble content has been reduced. Reducing the number of blind holes 501 at the outlet can reduce the flow resistance while ensuring the anti-cavitation effect. This application can be used in the field of self-priming pump technology, or in other fields applicable to this application.

[0017] In another embodiment: Reference Figure 1-2 Based on Embodiment 1, an improvement is made to an anti-cavitation flow channel assembly and a self-priming pump, which is applied in the field of self-priming pump technology. The structure of this embodiment is basically the same as the aforementioned embodiment, except that: on this basis, the anti-cavitation self-priming pump is also equipped with a drive mechanism, which includes a motor 8 and a coupling 9. The motor 8 is fixedly mounted on the top of the base 7, and the motor 8 is connected to the rotating shaft 2 through the coupling 9. After the motor 8 starts, it can drive the rotating shaft 2 to rotate through the coupling 9, thereby synchronously driving the variable pitch inducer 6 and the impeller 3 to operate, realizing the step-by-step processing and transportation of fluid. The three-stage progressive flow channel, which is composed of the gas-liquid chamber 4, the buffer pipe 5 and the impeller 3 connected in sequence, allows the fluid to pass through pretreatment pressurization, flow stabilization buffering and final work in sequence, so that the fluid has a relatively uniform pressure distribution and flow state when it reaches the impeller 3, which significantly reduces the risk of cavitation of the impeller 3 and ensures the long-term efficient and stable operation of the pump. Unlike the above embodiments, in some application scenarios, the material of the buffer tube 5 can be adjusted. Preferably, the buffer tube 5 is made of an anti-cavitation alloy material, which can further improve the corrosion resistance of the buffer tube 5 and extend its service life. Specifically, the buffer tube 5 is connected to the gas-liquid chamber 4 and the liquid inlet of the pump body 1 by flanges. This connection method can improve the sealing of the connection of each component and the convenience of disassembly and assembly, which facilitates subsequent maintenance. After long-term treatment of fluids that are prone to cavitation or contain impurities, the buffer tube 5 and the gas-liquid chamber 4 are the components that require key inspection and maintenance. They can be cleaned or replaced through the inspection port on them.

[0018] However, as is well known to those skilled in the art, the working principle and wiring method of motor 8 are conventional means or common knowledge, and will not be described in detail here. Those skilled in the art can make any selections according to their needs or convenience.

[0019] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0020] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cavitation-resistant flow channel assembly, comprising a pump body (1), an impeller (3) disposed within the pump body (1), and a shaft (2) for driving the impeller (3), characterized in that, The inlet of the pump body (1) is connected to the gas-liquid chamber (4) through a buffer pipe (5); The inner wall of the gas-liquid chamber (4) is provided with a spiral protrusion (401). One end of the rotating shaft (2) extends into the gas-liquid chamber (4) and is fixedly installed with a variable pitch inducer wheel (6). A spirally constricted flow channel is formed between the blades of the variable pitch inducer wheel (6) and the spiral protrusion (401). The inner wall of the buffer tube (5) has multiple blind holes (501).

2. The anti-cavitation flow channel assembly according to claim 1, characterized in that, The inner diameter of the buffer tube (5) gradually increases from its inlet end to its outlet end.

3. The anti-cavitation flow channel assembly according to claim 1, characterized in that, The number of blind holes (501) per unit area on the inner wall of the buffer tube (5) gradually decreases along the fluid flow direction.

4. The anti-cavitation flow channel assembly according to claim 1, characterized in that, The pitch of the variable pitch inducer (6) decreases continuously from its inlet side to its outlet side.

5. The anti-cavitation flow channel assembly according to claim 1, characterized in that, The spiral direction of the spiral protrusion (401) is opposite to the direction of the fluid motion driven by the variable pitch inducer wheel (6) when it rotates.

6. A self-priming pump, characterized in that, The anti-cavitation flow channel assembly according to any one of claims 1-5 further includes a base (7) and a drive mechanism, wherein the pump body (1) is fixed on the base (7), and the drive mechanism includes a motor (8) and a coupling (9), wherein the motor (8) is fixedly disposed on the top of the base (7), and the motor (8) is connected to the rotating shaft (2) through the coupling (9).

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