Abrasion and cavitation resistant centrifugal pump

Abstract

The application provides an anti-abrasion and anti-cavitation centrifugal pump, which is characterized by the following technical scheme: a pump body is provided with an impeller, a front cover plate and a rear cover plate of the impeller are respectively provided with a flow guide device in a backflow gap between the cover plate and the pump body, and the flow guide device is used for discharging impurities in the backflow gap through pressurization. The flow guide device comprises a plurality of flow guide components which are uniformly distributed on the back of the front cover plate or the rear cover plate. The flow guide blade component comprises a flow guide rib, a drainage rib and a sand discharge tooth. The flow guide rib and the drainage rib form a flow guide blade contour, and at least one sand discharge tooth is arranged in the flow guide blade contour. A backflow hole is arranged at the edge of the flow guide blade contour, the backflow hole is communicated with a flow channel of the impeller, and is used for discharging the impurities in the backflow gap. The application can reduce the abrasion risk of the front and rear port rings by reducing the fine sand entering the gap between the front and rear port rings, so as to achieve the anti-abrasion effect, and can balance the local pressure by guiding the backflow in the front gap to the back of the blade, so as to achieve the anti-cavitation effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water pumps, in particular to a wear-resistant anti-cavitation centrifugal pump. BACKGROUND

[0002] As an important mechanical equipment, water pump has been widely used in various fields of national production. The wear of the port ring of the centrifugal pump is universal, especially when dealing with sand-containing liquid. When the port ring of the centrifugal pump is severely worn, the performance of the centrifugal pump will be seriously affected, and the efficiency and sealing performance will be reduced. Therefore, in view of the wear problem of the centrifugal pump, a wear-resistant anti-cavitation centrifugal pump is needed.

[0003] The prior art has disclosed a centrifugal pump sealing port ring wear-resistant device, which mainly uses a small flow pump to introduce clean liquid to flush the impeller port ring to avoid wear of the impeller port ring, but the device is only suitable for large pumps or pump stations, and the flushing device needs to be opened in the pump body. The structure of the device is not suitable for conventional small centrifugal pumps. Chinese patent has also disclosed a wear-resistant and corrosion-resistant impeller for centrifugal pump. The invention mainly uses a high-strength wear-resistant alloy material to cast the impeller, and sprays a corrosion-resistant layer on the outer surface of the impeller to achieve the purpose of wear resistance and corrosion resistance. The invention can solve the wear problem of the impeller in a short time, but it cannot fundamentally prevent the continuous wear of the sand and other fine particles on the impeller port ring. Chinese patent has disclosed an anti-cavitation centrifugal pump and manufacturing method. The invention mainly uses the way of water inlet guide vane to stabilize the flow field at the inlet to achieve the effect of anti-cavitation, but this method will increase the resistance of the inlet of the centrifugal pump, and it cannot well solve the cavitation on the back of the centrifugal pump blade.

[0004] The prior art cannot provide an effective solution to the wear of the port ring of the centrifugal pump and the cavitation problem on the back of the blade. Only strengthening the wear resistance of the impeller cannot fundamentally avoid the wear of the fine sand on the impeller, especially at the front and rear port rings, and the conventional means cannot solve the cavitation problem on the back of the centrifugal pump impeller. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a wear-resistant anti-cavitation centrifugal pump, which can reduce the entry of fine sand into the gap between the front and rear port rings to reduce the wear risk of the front and rear port rings to achieve the wear-resistant effect, and guide the backflow in the front gap to the back of the blade to balance the local pressure and achieve the anti-cavitation effect.

[0006] The present application achieves the above technical purpose through the following technical means.

[0007] A wear-resistant anti-cavitation centrifugal pump, a pump body of the centrifugal pump is installed with an impeller, a front cover plate and a rear cover plate of the impeller are respectively provided with a flow guide device in a backflow gap between the pump body, impurities in the backflow gap are discharged by pressurizing through the flow guide device, and the wear of the front port ring and the rear port ring is reduced.

[0008] Further, the flow guide device comprises several flow guide components, which are evenly distributed on the back of the front cover plate or the back cover plate; the flow guide vane component comprises a flow guide rib, a flow guide rib and a sand tooth; the flow guide rib and the flow guide rib constitute the outer contour of the flow guide vane, and at least one sand tooth is arranged in the outer contour of the flow guide vane; a backflow hole is arranged at the edge of the outer contour of the flow guide vane, which is communicated with the flow passage of the impeller, and is used for discharging impurities in the backflow gap.

[0009] Further, the flow guide rib in the outer contour of the flow guide vane is the flow surface, the flow guide rib in the outer contour of the flow guide vane is the backflow surface, one end of the flow guide rib extends to the edge of the front cover plate or the back cover plate along the radial direction of the impeller; one end of the flow guide rib is connected with the flow guide rib.

[0010] Further, the curvature radius R1 of the flow surface of the sand tooth is (0.4-0.6)R 叶轮 , the center of the curvature of the flow surface of the sand tooth is located on the circular ring of 0.47R 叶轮 , and the curvature radius R2 of the backflow surface of the sand tooth is (0.2-0.3)R 叶轮 , wherein R 叶轮 is the radius of the impeller.

[0011] Further, the outlet of the backflow hole points to the back surface of the blade of the impeller.

[0012] Further, the front backflow gap between the front cover plate and the pump body is provided with a front flow guide device, the front flow guide device comprises several front flow guide components, a convex flow resistance ridge is arranged near the front ring of the front cover plate, and the flow resistance ridge is a convex circular ring; the front flow guide vane component comprises a front flow guide rib, a front flow guide rib and a front sand tooth; the front flow guide rib and the front flow guide rib constitute the front flow guide vane contour, and at least one front sand tooth is arranged in the front flow guide vane contour; a front backflow hole is arranged at the edge of the front flow guide vane contour, which is communicated with the flow passage of the impeller.

[0013] Further, one end of the front flow guide rib extends to the edge of the front cover plate along the radial direction of the impeller, the other end of the front flow guide rib is connected with the flow resistance ridge, one end of the front flow guide rib is connected with one end of the front flow guide rib, and the other end of the front flow guide rib is connected with the flow resistance ridge; the root of the front sand tooth is connected with the flow resistance ridge.

[0014] Further, the back backflow gap between the back cover plate and the pump body is provided with a back flow guide device, the back flow guide device comprises several back flow guide components, the back flow guide vane component comprises a back flow guide rib, a back flow guide rib and a back sand tooth; the back flow guide rib and the back flow guide rib constitute the back flow guide vane contour, and at least one back sand tooth is arranged in the back flow guide vane contour; a back backflow hole is arranged at the edge of the back flow guide vane contour, which is communicated with the flow passage of the impeller.

[0015] Further, one end of the rear drainage rib extends to the rear cover plate edge along the radial direction of the impeller, the other end of the rear drainage rib is connected with the rear mouth ring of the rear cover plate, one end of the rear drainage rib is connected with one end of the rear guide rib, the other end of the rear guide rib is connected with the rear mouth ring, and the root of the rear sand tooth is connected with the rear mouth ring.

[0016] Further, a plurality of sand discharge holes are uniformly distributed on the front mouth ring of the front cover plate, and the sand discharge holes are in circular or long strip circular shapes.

[0017] The present application has the following beneficial effects:

[0018] 1. The anti-abrasion and anti-cavitation centrifugal pump provided by the present application is provided with a guide device in the backflow gap between the front cover plate and the rear cover plate of the impeller and the pump body, and the guide device can pressurize and discharge impurities in the backflow gap, so that the risk of abrasion of the front and rear mouth rings caused by fine sand entering the gap between the front and rear mouth rings can be reduced, and the anti-abrasion effect can be achieved.

[0019] 2. The anti-abrasion and anti-cavitation centrifugal pump provided by the present application is provided with a guide vane outer contour formed by the guide rib and the drainage rib, at least one sand tooth is arranged in the guide vane outer contour, a backflow hole is arranged at the edge of the guide vane outer contour, the backflow hole is communicated with the flow passage of the impeller, when the gap is filled with sand, part of the sand can be thrown out of the gap under the action of centrifugal force by the guide vane outer contour, and part of the sand entering the guide vane outer contour can be discharged from the backflow hole through the joint action of the guide vane outer contour and the sand tooth.

[0020] 3. The anti-abrasion and anti-cavitation centrifugal pump provided by the present application is provided with a plurality of sand discharge holes uniformly distributed on the front mouth ring of the front cover plate, when a small amount of sand accidentally enters the gap between the mouth ring of the impeller and the pump body, the sand discharge holes can timely discharge the sand to avoid the continuous abrasion of the mouth ring caused by the sand in the gap, and the further anti-abrasion effect can be achieved.

[0021] 4. The anti-abrasion and anti-cavitation centrifugal pump provided by the present application can balance the pressure on the back surface of the blade through the backflow of the backflow hole, so that the anti-cavitation performance of the pump can be greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. The drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 The anti-abrasion and anti-cavitation centrifugal pump provided by the present application is shown in the structural diagram.

[0024] Figure 2Figure 1 is a schematic diagram of the internal flow direction of the anti-abrasion and anti-cavitation centrifugal pump according to the present application.

[0025] Figure 3 Figure 2 is a partial sectional view of the anti-abrasion and anti-cavitation centrifugal pump according to the present application.

[0026] Figure 4 Figure 3 is a left view of the front cover plate of the anti-abrasion and anti-cavitation centrifugal pump according to the present application.

[0027] Figure 5 Figure 4 is a schematic diagram of the flow around the front cover plate of the anti-abrasion and anti-cavitation centrifugal pump according to the present application.

[0028] Figure 6 Figure 5 is a right view of the rear cover plate of the anti-abrasion and anti-cavitation centrifugal pump according to the present application.

[0029] Figure 7 Figure 6 is an oblique axonometric view of the front cover plate of the impeller according to the present application.

[0030] Figure 8 Figure 7 is an oblique axonometric view of the rear cover plate of the impeller according to the present application.

[0031] In the drawings:

[0032] 1 - pump outlet; 2 - pump body; 3 - pump inlet; 4 - rotating shaft; 5 - impeller; 51 - front cover plate; 510 - front flow guide; 511 - front ring; 512 - flow resistance ridge; 513 - front backflow hole; 514 - sand discharge hole; 515 - front flow guide rib; 516 - front flow guide rib; 517 - front sand discharge tooth; 52 - rear cover plate; 520 - rear flow guide; 521 - rear ring; 522 - rear backflow hole; 525 - rear flow guide rib; 526 - rear flow guide rib; 527 - rear sand discharge tooth; 6 - motor; 70 - main flow direction; 71 - front gap flow direction; 72 - rear gap flow direction. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar reference numerals throughout the drawings denote the same or similar elements or elements having the same or similar functions. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0034] In the description of the present application, it is to be understood by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can be explicitly or implicitly included one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0035] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] As shown in Figure 1 The anti-wear and anti-cavitation centrifugal pump of the present application comprises a pump outlet 1, a pump body 2, a pump inlet 3, a rotating shaft 4, an impeller 5 and a motor 6. The impeller 5 is installed in the pump body 2, the motor 6 drives the impeller 5 to rotate through the rotating shaft 4, and the fluid flowing into the pump inlet 3 is pressurized and transmitted to the pump outlet 1. The front cover plate 51 and the rear cover plate 52 of the impeller 5 are respectively provided with flow guiding devices in the backflow gap between the pump body 2, and the impurities in the backflow gap are discharged by the flow guiding devices, which can reduce the risk of wear of the front ring 511 and the rear ring 521 by reducing the fine sand entering the backflow gap of the front and rear rings to achieve the effect of preventing wear. The front ring 511 is located at the front end of the front cover plate 51, and the rear ring 521 is located at the end of the rear cover plate 52.

[0037] The flow guide device comprises several flow guide components, which are evenly distributed on the back of the front cover plate 51 or the back cover plate 52; the flow guide vane component comprises a flow guide rib, a drainage rib and a sand discharge tooth; the flow guide rib and the drainage rib constitute a flow guide vane outer contour, and at least one sand discharge tooth is arranged in the flow guide vane outer contour; a backflow hole is arranged at the edge of the flow guide vane outer contour, which is communicated with the impeller flow channel and is used for discharging impurities in the backflow gap. The flow guide rib in the flow guide vane outer contour is a flow surface, the drainage rib in the flow guide vane outer contour is a backflow surface, one end of the drainage rib extends to the edge of the front cover plate 51 or the back cover plate 52 along the radial direction of the impeller 5; and one end of the drainage rib is connected with the flow guide rib. The curvature radius R1 of the flow surface of the sand discharge tooth is (0.4-0.6)R 叶轮 , the center of the curvature of the flow surface of the sand discharge tooth is located on a circle ring with a radius of 0.47R 叶轮 , and the curvature radius R2 of the backflow surface of the sand discharge tooth is (0.2-0.3)R 叶轮 , wherein R 叶轮 is the radius of the impeller 5. The outlet of the backflow hole is directed to the back surface of the blade of the impeller 5.

[0038] As shown in Figure 2 , the front gap backflow exists between the front cover plate 51 and the pump body 2, and the flow direction is shown as 71 in the figure. The back gap backflow exists between the back cover plate 52 and the pump body 2, and the flow direction is shown as 72 in the figure. The front gap backflow and the back gap backflow respectively guide a small amount of fluid from the main flow direction 70, and finally flow into the main flow direction 70 through the backflow hole.

[0039] As shown in Figure 3 , Figure 4 and Figure 7As shown, a front guide device 510 is arranged in the front backflow gap between the front cover plate 51 and the pump body 2, the front guide device 510 comprises a plurality of front guide components, a raised flow resistance ridge 512 is arranged near the front mouth ring 511 of the front cover plate 51, the flow resistance ridge 512 is a raised circular ring, the height of the raised flow resistance ridge 512 is less than the width of the front backflow gap; the front guide vane component comprises a front guide rib 515, a front guide rib 516 and a front sand tooth 517; the front guide rib 515 and the front guide rib 516 form a front guide vane profile, at least one front sand tooth 517 is arranged in the front guide vane profile, which is determined according to the size of the impeller diameter and the size of the front guide vane profile; a front backflow hole 513 is arranged at the edge of the front guide vane profile, the front backflow hole 513 is in communication with the flow passage of the impeller. The front backflow hole 513 is arranged in an inclined manner, and the inner part thereof points to the back surface of the blade. One end of the front guide rib 516 extends to the edge of the front cover plate 51 in the radial direction of the impeller 5, the other end of the front guide rib 516 is connected with the flow resistance ridge 512, one end of the front guide rib 516 is connected with one end of the front guide rib 517, the other end of the front guide rib 517 is connected with the flow resistance ridge 512; the root of the front sand tooth 517 is connected with the flow resistance ridge 512.

[0040] In the embodiment, the front sand tooth 517 has a front incident flow surface a and a front back surface b, the radius of curvature R 1前 of the front incident flow surface a is 0.44R 叶轮 , the radius of curvature R 2前 of the front back surface b is 0.21R 叶轮 , and there is one front sand tooth 517 in the front guide vane profile. As shown in Figure 5 , the front guide device 510 can guide part of the fluid to leave the front backflow gap, and guide another part of the fluid to the front backflow hole 513, and further guide the fluid to the back surface of the impeller blade through the front backflow hole 513.

[0041] As shown in Figure 3 , Figure 6 and Figure 8As shown, the rear backflow gap between the rear cover plate 52 and the pump body 2 is provided with a rear flow guide device 520, which includes a plurality of rear flow guide components. The rear flow guide vane component includes a rear flow guide rib 525, a rear flow guide rib 526, and a rear sand tooth 527. The rear flow guide rib 525 and the rear flow guide rib 526 form a rear flow guide vane profile, and at least one rear sand tooth 527 is arranged in the rear flow guide vane profile. A rear backflow hole 522 is arranged at the edge of the rear flow guide vane profile, and the rear backflow hole 522 is in communication with the impeller flow channel. One end of the rear flow guide rib 526 extends to the edge of the rear cover plate 52 along the radial direction of the impeller 5, the other end of the rear flow guide rib 526 is connected with the rear port ring 521 of the rear cover plate 52, one end of the rear flow guide rib 526 is connected with one end of the rear flow guide rib 527, the other end of the rear flow guide rib 527 is connected with the rear port ring 521, and the root of the rear sand tooth 527 is connected with the rear port ring 521.

[0042] In the embodiment, the rear sand tooth 527 has a rear flow face a' and a rear back face b', the radius of curvature R of the rear flow face a' is 0.4R, the radius of curvature R of the rear back face b' is 0.2R, and the number of the rear sand tooth 527 is one in each flow guide device 520. There is one rear sand tooth 527 in the rear flow guide vane profile. 1后 叶轮 2后 叶轮

[0043] In the embodiment, the rotation direction of the impeller is counterclockwise according to the view angle shown. In the embodiment, the number of the impeller 5 blades is 5, and the number of the flow guide components is consistent with the number of the blades, which is 5.

[0044] A plurality of sand discharge holes 514 are uniformly arranged on the front port ring 511 of the front cover plate 51. The sand discharge holes 514 are circular or long-circular in shape. When a small amount of sand accidentally enters the gap between the front port ring 511 and the pump body 2, the sand discharge holes 514 can timely discharge the sand to avoid the sand continuously wearing the port ring in the gap, thereby achieving a further wear prevention effect.

[0045] The working principle is as follows:

[0046] ​​​​​In the gap between the front cover plate 51 and the pump body 2, the effect of preventing wear of the front port ring of the centrifugal pump is achieved by the flow blocking ridge 512, the front flow guide device 510, the front backflow hole 513 and the sand discharge hole 514. When the front gap backflow of the centrifugal pump entrains sand into the gap between the front cover plate 51 and the pump body 2, part of the sand will be thrown out of the gap by the front flow guide blade profile under the action of centrifugal force, and part of the sand in the front flow guide blade profile will be discharged from the backflow hole through the joint action of the front flow guide blade profile and the front sand discharge tooth 517. In addition, when a small amount of sand accidentally enters the gap between the impeller port ring 511 and the pump body 2 at the pump inlet 3, the sand discharge hole 514 arranged on the front port ring 511 can timely discharge the sand to avoid continuous wear of the sand particles in the port ring gap, which can achieve further wear prevention effect.

[0047] The fluid backflowed by the front backflow hole 513 and the rear backflow hole 522 is directed to the back surface of the blade of the impeller 5 to achieve the anti-cavitation effect, because the back surface of the blade is one of the places where cavitation is most likely to occur when the centrifugal pump is working, therefore the fluid backflowed by the front backflow hole 513 and the rear backflow hole 522 can balance the pressure of the back surface of the blade to achieve the anti-cavitation effect of the centrifugal pump.

[0048] It should be understood that although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

[0049] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present application, and are not intended to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A wear-resistant and cavitation-resistant centrifugal pump, wherein an impeller (5) is installed inside the pump body (2) of the centrifugal pump, characterized in that, The front cover plate (51) and rear cover plate (52) of the impeller (5) are provided with flow guiding devices in the reflux gap between the impeller (5) and the pump body (2). The impeller (5) is pressurized by the flow guiding devices to discharge impurities in the reflux gap, thereby reducing the wear of the front inlet ring (511) and the rear inlet ring (521). The flow guiding device includes several flow guiding blade assemblies, which are evenly distributed on the back of the front cover plate (51) or the rear cover plate (52); the flow guiding blade assembly includes flow guiding ribs, flow diversion ribs and sand discharge teeth; the flow guiding ribs and flow diversion ribs form the outer contour of the flow guiding blade, and at least one sand discharge tooth is provided in the outer contour of the flow guiding blade; a return hole is provided at the edge of the outer contour of the flow guiding blade, and the return hole is connected to the impeller flow channel to discharge impurities in the return gap.

2. The anti-wear and anti-cavitation centrifugal pump according to claim 1, characterized in that, The guide rib in the outer contour of the guide vane is the front flow surface, and the guide rib in the outer contour of the guide vane is the back flow surface. One end of the guide rib extends radially along the impeller (5) to the edge of the front cover plate (51) or the rear cover plate (52); one end of the guide rib is connected to the guide rib.

3. The anti-wear and anti-cavitation centrifugal pump according to claim 1, characterized in that, The radius of curvature R1 of the sand-discharging tooth's upstream surface is (0.4~0.6)R. 叶轮 The center of the arc of the sand-discharging tooth's frontal surface is located at 0.47 R. 叶轮 On the annulus, the radius of curvature R2 of the backflow surface of the sand-discharging tooth is (0.2~0.3)R. 叶轮 , where R 叶轮 The radius of the impeller (5) is given.

4. The anti-wear and anti-cavitation centrifugal pump according to claim 1, characterized in that, The outlet of the reflux hole points to the back of the blades of the impeller (5).

5. The anti-wear and anti-cavitation centrifugal pump according to any one of claims 2-4, characterized in that, A front guide device (510) is provided in the front return gap between the front cover plate (51) and the pump body (2). The front guide device (510) includes several front guide blade assemblies. A raised flow-blocking ridge (512) is provided near the front opening ring (511) of the front cover plate (51). The flow-blocking ridge (512) is a raised ring. The front guide blade assembly includes a front guide rib (515), a front guide rib (516), and a front row of sand teeth (517). The front guide rib (515) and the front guide rib (516) form the outline of the front guide blade. At least one front row of sand teeth (517) is provided in the outer outline of the front guide blade. A front return hole (513) is provided at the edge of the outer outline of the front guide blade. The front return hole (513) is connected to the impeller flow channel.

6. The anti-wear and anti-cavitation centrifugal pump according to claim 5, characterized in that, One end of the front guide rib (516) extends radially along the impeller (5) to the edge of the front cover plate (51), and the other end of the front guide rib (516) is connected to the flow-blocking ridge (512). One end of the front guide rib (516) is connected to one end of the front guide rib (517), and the other end of the front guide rib (517) is connected to the flow-blocking ridge (512). The root of the front sand tooth (517) is connected to the flow-blocking ridge (512).

7. The anti-wear and anti-cavitation centrifugal pump according to any one of claims 2-4, characterized in that, A rear guide device (520) is provided in the rear return gap between the rear cover plate (52) and the pump body (2). The rear guide device (520) includes a plurality of rear guide blade assemblies. The rear guide blade assembly includes a rear guide rib (525), a rear guide rib (526), ​​and a rear sand tooth (527). The rear guide rib (525) and the rear guide rib (526) form the outline of the rear guide blade. At least one rear sand tooth (527) is provided in the outer outline of the rear guide blade. A rear return hole (522) is provided at the edge of the outer outline of the rear guide blade. The rear return hole (522) is connected to the impeller flow channel.

8. The anti-wear and anti-cavitation centrifugal pump according to claim 7, characterized in that, One end of the rear drainage rib (526) extends radially along the impeller (5) to the edge of the rear cover plate (52), and the other end of the rear drainage rib (526) is connected to the rear mouth ring (521) of the rear cover plate (52). One end of the rear drainage rib (526) is connected to one end of the rear guide rib (527), and the other end of the rear guide rib (527) is connected to the rear mouth ring (521). The root of the rear sand tooth (527) is connected to the rear mouth ring (521).

9. The anti-wear and anti-cavitation centrifugal pump according to claim 1, characterized in that, A number of sand-discharging holes (514) are evenly distributed on the front opening ring (511) of the front cover plate (51), and the shape of the sand-discharging holes (514) is circular or elongated.

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