Anti-leakage mechanism for centrifugal pump and centrifugal pump

Abstract

The utility model discloses a leakproof mechanism for a centrifugal pump and the centrifugal pump. The centrifugal pump comprises a pump body, a pump shaft, an impeller and a driving mechanism. The pump shaft is rotatably mounted on the pump body, and a sealed cavity is formed in the pump body; the impeller is installed on the pump shaft and located in the sealing cavity, at least one end of the pump shaft is provided with a driving mechanism, the driving mechanism drives the impeller to rotate through the pump shaft, fluid conveying is achieved, the anti-leakage mechanism is located between the pump body and the impeller and comprises a sealing ring, and two threaded holes are formed in the position, below the center line, of the sealing ring. The two screws are installed in the threaded holes from outside to inside respectively, positioning grooves are formed in the positions, corresponding to the heads of the screws, of the pump body, rotation of the sealing ring along with the impeller is limited through matching of the heads of the screws and the positioning grooves, and the screws are prevented from being disengaged from the threaded holes. Compared with the prior art, the anti-leakage mechanism for the centrifugal pump and the centrifugal pump have the advantages that the screw threads are not easy to fall off, and the sealing performance is better.

Description

Technical Field

[0001] This application relates to the field of fluid equipment technology, and in particular to a leak-proof mechanism for a centrifugal pump and the centrifugal pump itself. Background Technology

[0002] like Figure 1 As shown, in the traditional structure of a centrifugal pump, the motor 12 and the pump shaft are connected by a flexible coupling 14 (the coupling 14 is covered by a coupling guard 13). The pump 15 adopts a double-end bearing support structure and requires a shaft seal to isolate the bearing housing from the pump body. Then, the pump shaft is used to connect the impeller, shaft seal, and bearing housing in series. To facilitate on-site installation, the pump and motor are usually mounted as a whole on a common base 11, and the alignment of the pump and motor is adjusted before leaving the factory.

[0003] To reduce leakage from the high-pressure outlet to the low-pressure inlet during pump operation, a leak-proof mechanism is typically installed between the pump body and the impeller. The main component of this mechanism is the sealing ring. Due to the small operating clearance between the sealing ring and the impeller, leakage water continuously erodes the seal, making it a common wear part in centrifugal pumps that requires frequent replacement. Common sealing ring positioning methods include cotter pins or semi-circular groove structures.

[0004] To reduce sand hole defects during the casting process of sealing rings, most casting methods have now been changed to centrifugal casting, and cotter pin positioning is widely used in these standard cylindrical sealing rings. In actual use, although the elastic cylindrical pins made of 65Mn material show no problems in factory testing, they often corrode, lose elasticity, or even break when replacing replacement sealing rings. If cylindrical pins made of 304 stainless steel are used, their elasticity is insufficient, and they are prone to falling off during assembly. When dealing with other more complex media, different materials must be used. Utility Model Content

[0005] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a leak-proof mechanism for centrifugal pumps that is not easily detached, and a centrifugal pump itself.

[0006] The technical solution provided by this utility model is as follows:

[0007] A leak-proof mechanism for a centrifugal pump, the centrifugal pump including a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located in the sealed cavity, and the drive mechanism is mounted on at least one end of the pump shaft, driving the impeller to rotate via the pump shaft to achieve fluid transport; the leak-proof mechanism is located between the pump body and the impeller, including a sealing ring, the sealing ring having two threaded holes below its centerline, two screws respectively installed in the threaded holes from the outside to the inside, the pump body having positioning grooves at the positions corresponding to the screw heads, the screw heads cooperating with the positioning grooves to restrict the sealing ring from rotating with the impeller and to prevent the screws from coming out of the threaded holes.

[0008] Preferably, the screw is an internal hexagon head screw.

[0009] Preferably, the screw surface is provided with a Teflon coating.

[0010] A centrifugal pump includes a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located in the sealed cavity; the pump shaft has a drive mechanism mounted at at least one end, and the impeller is driven to rotate via the drive mechanism to achieve fluid transport; a leakage prevention mechanism as described above is provided between the pump body and the impeller.

[0011] Preferably, the centrifugal pump is a double-suction pump, and the drive mechanism includes axial flux motors installed at both ends of the pump shaft, forming a double-drive double-suction pump.

[0012] Preferably, the axial flux motor includes a bearing housing, a bearing cover, and a drive rotor. The drive rotor is mounted on a pump shaft and has multiple permanent magnets evenly arranged on it. The bearing cover is mounted on the outside of the bearing housing to form a cavity surrounding the drive rotor. Both the bearing cover and the bearing housing are evenly provided with the same number of first winding blocks and second winding blocks as the permanent magnets.

[0013] Preferably, the bearing housing has a first cooling water chamber, which is sealed by a first water seal plate; the bearing cover has a second cooling water chamber, which is sealed by a second water seal plate; and a cooling water coil is also provided between the bearing housing and the drive rotor.

[0014] Preferably, a sealing mechanism is provided between the pump body and the pump shaft. The sealing mechanism includes a mechanical seal rotating ring, a mechanical seal stationary ring, a packing packing, and a packing gland. The mechanical seal rotating ring is fixed to the pump shaft, and the mechanical seal stationary ring is fixed to the pump body. The mechanical seal rotating ring and the mechanical seal stationary ring seal the sealing cavity. The outer end of the mechanical seal stationary ring is provided with a receiving groove for accommodating the packing packing. The packing gland can be installed at the end of the receiving groove and press the packing packing tightly, so that when the mechanical seal between the mechanical seal rotating ring and the mechanical seal stationary ring fails, the packing packing and the packing gland can be installed on the mechanical seal stationary ring to achieve a packing seal.

[0015] Preferably, it further includes an exhaust mechanism, which includes an automatic exhaust valve that connects the high-pressure zone and two low-pressure zones of the pump body sealing cavity. The exhaust mechanism includes a first four-way pipe that is connected to the automatic exhaust valve, the exhaust port of the high-pressure zone of the sealing cavity, and a first pipeline that is connected to the exhaust ports of the two low-pressure zones of the sealing cavity. A check valve is provided on the first pipeline that is connected to the exhaust ports of the two low-pressure zones of the sealing cavity.

[0016] Preferably, a second four-way pipe is provided between the first four-way pipe and the high-pressure exhaust port of the sealing cavity. The second four-way pipe is connected to the mechanical seal through two second pipes and is used to spray water between the dynamic ring and the stationary ring of the mechanical seal.

[0017] Compared to existing technologies, this utility model provides a leak-proof mechanism for centrifugal pumps and a centrifugal pump in which two threaded holes are provided below the center line of the sealing ring, and a screw is engaged with the threaded holes. Compared to existing elastic cylindrical pins that rely on frictional force generated by elastic deformation, the screw threads are less likely to come out, and the sealing performance is better. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an existing centrifugal pump.

[0020] Figure 2 This is a schematic diagram of the centrifugal pump according to an embodiment of the present invention;

[0021] Figure 3 for Figure 2 A schematic diagram of the axial flux motor in the centrifugal pump shown.

[0022] Figure 4 forFigure 3 A cross-sectional view along line CC;

[0023] Figure 5 for Figure 3 A schematic diagram of the driving rotor and permanent magnet in an axial flux motor;

[0024] Figure 6 for Figure 3 A three-dimensional view of the bearing end cover in the axial flux motor shown.

[0025] Figure 7 for Figure 6 A three-dimensional view of the bearing end cap from another angle;

[0026] Figure 8 for Figure 2 A schematic diagram of the sealing mechanism in the centrifugal pump shown.

[0027] Figure 9 for Figure 2 A schematic diagram of the exhaust mechanism in the centrifugal pump shown.

[0028] Figure 10 for Figure 2 A partial enlarged view of the anti-leakage mechanism, pump body, and impeller in the centrifugal pump shown.

[0029] Figure 11 for Figure 10 Side view of the leak-proof mechanism shown. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0034] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0035] like Figures 2 to 11 As shown, this embodiment of the invention provides a centrifugal pump, specifically a double-suction pump, and more specifically a dual-drive double-suction pump. In other embodiments, other centrifugal pumps besides the double-suction pump may also be used.

[0036] This centrifugal pump includes a pump body 2, a pump shaft 3, a sealing mechanism 4, an impeller 5, an axial flux motor 6 (as a drive mechanism), and an exhaust mechanism 7. The pump shaft 3 is rotatably mounted on the pump body 2 via the sealing mechanism 4, forming a sealed cavity inside the pump body 2. The impeller 5 is mounted on the pump shaft 3 and located in the sealed cavity. Axial flux motors 6 are mounted at both ends of the pump shaft 3 to form a dual drive mechanism (in other embodiments, the axial flux motor 6 may be mounted only at one end of the pump shaft 3). The axial flux motor 6 drives the impeller 5 to rotate via the pump shaft 3, thereby achieving fluid transportation. Using an axial flux motor as the drive mechanism eliminates the need for a common base, maintenance alignment, and the pump's own bearing housing, significantly simplifying the overall structure and reducing the footprint.

[0037] Compared to traditional structures, the dual-drive, dual-suction pump using the axial flux motor 6 in this embodiment has the following advantages:

[0038] The axial flux motor 6 directly replaces the bearing housing of the double-suction pump and is installed at both ends of the double-suction pump. It does not require a common base, maintenance alignment, or the bearing housing of the pump itself, which greatly reduces the product's total life cycle cost.

[0039] The axial flux motor 6 has no cooling fan, resulting in lower unit noise. The dual-suction pump structure of this utility model is coaxial, which improves concentricity and reduces product vibration.

[0040] The magnetic field generated by the six coils of the axial flux motor from the inside out can all participate in the work process, so the power density of the radial flux motor is much higher than that of the radial flux motor, and the efficiency is also higher. After reducing the common base, coupling, motor coils, motor heat dissipation and other components in this embodiment, the weight and floor space are reduced by more than 50% compared with the traditional double-suction pump unit, and the construction cost of the pump house is also reduced accordingly;

[0041] It adopts a dual-drive axial flux motor at both ends, and uses the same structure for both clockwise and counterclockwise rotation, which makes it more adaptable and reduces the amount of parts inventory required by the manufacturer.

[0042] The pump adopts a dual-drive axial flux motor with torque input from both sides. The pump shaft 3 can be designed with a shaft diameter of half the maximum torque of the pump, and the material of the shaft can be reduced. After the shaft is reduced, the inlet area of ​​the pump impeller 5 is correspondingly increased, which improves the cavitation performance of the pump.

[0043] The unit adopts a dual-drive axial flux motor, which can meet the power requirements of the unit by running only one side of the motor when the pump speed drops below 75%, resulting in lower energy consumption.

[0044] In summary, the centrifugal pump in this embodiment has the characteristics of high operating efficiency, small footprint, and convenient installation. Compared with the traditional double-suction pump, it is more suitable for prefabricated pump houses, water supply in residential areas, and other fields.

[0045] like Figure 3 , Figure 4 As shown, in this embodiment, the two axial flux motors 6 have identical structures and are arranged in a mirror image at both ends of the pump shaft 3. Each axial flux motor 6 includes a bearing housing 61, a bearing cap 62, and a drive rotor 63. The drive rotor 63 is mounted on the pump shaft 3 and has multiple permanent magnets 64 evenly arranged on it (e.g., ...). Figure 5As shown, this embodiment has 12 blocks, which are embedded in the through holes evenly arranged in the drive rotor. The bearing cover 62 is installed on the outside of the bearing housing 61 to form a cavity surrounding the drive rotor 63. Both the bearing cover 62 and the bearing housing 61 are evenly provided with the same number of first winding blocks (not shown) and second winding blocks 69 as the permanent magnet 64 (the windings of the first winding blocks and the second winding blocks extend out to connect the axial flux motor 6 to the power supply). The permanent magnet 64 cooperates with the first winding blocks and the second winding blocks to form the axial flux motor 6. The bearing housing 61 is also provided with a bearing 66 and a bearing end cover 67, and a locking nut 68 is installed at the end of the pump shaft.

[0046] Using this type of bearing housing component with drive function can reduce coupling components and reduce operating vibration; it eliminates the need for an additional motor, reducing the unit's footprint and making it suitable for applications with size requirements, such as ships and offshore platforms; it is also more suitable for environments powered by power batteries, facilitating use in areas without grid power supply, such as various emergency and mobile facilities.

[0047] Combination Figure 6 , Figure 7 As shown, in this embodiment, the bearing cap 62 has a second cooling water cavity 621, which is sealed by a second water seal plate 622. The second cooling water cavity 621 allows for water inlet and outlet through a second cooling water cavity interface 623. The inner surface of the bearing cap 62 extends inwardly with multiple second protrusions 624, the outer surface of each second protrusion 624 engaging with a corresponding second winding block, and the inner surface having a second recess 625 that serves as part of the second cooling water cavity 621. The bearing seat 61 has a first cooling water cavity 611, which is sealed by a first water seal plate 612. The first cooling water cavity 611 allows for water inlet and outlet through a first cooling water cavity interface 613. The inner end wall of the bearing housing 61 extends outward from the outer surface of a plurality of first protrusions 614, each of which mates with a corresponding first winding block on its outer surface. The inner surface of each protrusion 614 has a first recess that serves as part of a first cooling water chamber 611 (the shapes and structures of the first protrusions 614 and the first recess are similar to those of the second protrusions 624 and the second recess 625, respectively). A cooling water coil 65 is also provided between the bearing housing 61 and the drive rotor 63, adhered to the inner wall of the bearing housing 61 with thermally conductive adhesive, and allows for water inlet and outlet through the cooling water coil interface 651. The first cooling water chamber interface 613, the second cooling water chamber interface 623, and the cooling water coil interface 651 are all connected to the inside of the pump body 2 via a third pipeline, with the pump itself providing the cooling water source. This structure allows for a multi-zone water-cooled arrangement of the bearing components, effectively reducing the impact of winding heat generation.

[0048] like Figure 8As shown, in this embodiment, the sealing mechanism 4 includes a mechanical seal rotating ring 41, a mechanical seal stationary ring 42, a packing packing 43, and a packing gland 44 (a split packing gland is used in this embodiment). The mechanical seal rotating ring 41 is fixed to the pump shaft 3, and the mechanical seal stationary ring 42 is fixed to the pump body 2. The mechanical seal rotating ring 41 and the mechanical seal stationary ring 42 seal the sealing cavity. The outer end of the mechanical seal stationary ring 42 is provided with a receiving groove for accommodating the packing packing 43. The packing gland 44 can be installed at the end of the receiving groove and press the packing packing 43 tightly, so that when the mechanical seal between the mechanical seal rotating ring 41 and the mechanical seal stationary ring 42 fails, the packing packing 43 and the packing gland 44 can be installed on the mechanical seal stationary ring 42 to achieve a packing seal.

[0049] This solution addresses the issue of immediate repair required when existing mechanical seals are damaged, eliminating the need for immediate maintenance. It meets emergency use requirements and allows for replacement of the mechanical seal by notifying the equipment manufacturer's professionals while the seal is in operation. Furthermore, the cost of packing glands and split-packing glands is lower than that of spare mechanical seals, and the installation of these components is less complex. This solution can also be used in special applications such as emergency water supply and marine pumps.

[0050] like Figure 9 As shown, in this embodiment, the venting mechanism 7 includes an automatic venting valve 71, which connects the high-pressure zone (high-pressure water outlet zone) A and two low-pressure zones (low-pressure water inlet zones) B of the sealed cavity of the pump body 2. Specifically, the venting mechanism also includes a first four-way pipe 72, which is connected to the automatic venting valve 71, the high-pressure zone vent of the sealed cavity, and the first pipes 73 that are connected to the vents of the two low-pressure zones of the sealed cavity. The first pipes 73 that are connected to the vents of the two low-pressure zones of the sealed cavity are equipped with check valves 74. This solution can solve the problems of the original automatic venting valve only venting the accumulated air in the high-pressure zone, and the vents of the low-pressure zones being sealed with plugs. During installation and debugging, it is inconvenient to open the vents with a wrench, and the liquid in the pump will also be discharged, which will contaminate the surface of the equipment. This solution achieves the purpose of conveniently venting the accumulated air in the pump, and by setting a check valve, it effectively prevents the liquid in the high-pressure zone from flowing back to the low-pressure zone. A second four-way pipe 75 is also provided between the first four-way pipe 72 and the high-pressure exhaust hole of the sealing cavity. The second four-way pipe 75 is connected to the mechanical seal through two second pipes 76 respectively, and is used to spray water between the mechanical seal dynamic ring 41 and the mechanical seal stationary ring 42 to lubricate, flush and cool the mechanical seal.

[0051] like Figure 10 , Figure 11As shown, in this embodiment, a leak-proof mechanism is provided between the pump body 2 and the impeller 5 to reduce leakage from the high-pressure outlet area to the low-pressure inlet area during pump operation. This leak-proof mechanism includes a sealing ring 8, which has two threaded holes below its centerline. Two screws 9 (in this embodiment, internal hexagonal head screws with a Teflon coating) are installed in the threaded holes from the outside in. The pump body 2 has a positioning groove 21 at the position corresponding to the head of the screw 9. The screw head engages with the positioning groove 21 to restrict the rotation of the sealing ring 8 with the impeller 5 and prevent the screw 21 from coming out of the threaded hole. Simultaneously, during pump operation, the rotation of the impeller 5 causes a high-pressure zone and a low-pressure zone to form within the sealing cavity. The pressure difference between the high-pressure and low-pressure zones keeps the sealing ring 8 tightly pressed against the pump body, thus restricting the axial movement of the sealing ring 8. Compared to existing flexible cylindrical pins that rely on frictional force generated by elastic deformation, threaded screws are less likely to come loose. Existing flexible cylindrical pins have a hollow structure, and drilling through the positioning hole on the sealing ring can easily cause additional leakage. For thin-walled sealing rings, threaded holes provide better sealing. Existing flexible cylindrical pins require elastic materials to be used, limiting their application in corrosive media. However, most materials can be machined into internal hexagonal head screws (in normal use, 316L base material is suitable for most media). Internal hexagonal head screws with a Teflon coating increase corrosion resistance and insulation, effectively reducing the impact of electrochemical corrosion on the screw and lowering the risk of screw breakage.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A leak-proof mechanism for a centrifugal pump, the centrifugal pump comprising a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located within the sealed cavity, and the drive mechanism is mounted at at least one end of the pump shaft, the drive mechanism driving the impeller to rotate via the pump shaft to achieve fluid transport, characterized in that, The anti-leakage mechanism is located between the pump body and the impeller and includes a sealing ring. The sealing ring has two threaded holes below its center line. Two screws are installed in the threaded holes from the outside to the inside. The pump body has a positioning groove at the position of the corresponding screw head. The screw head cooperates with the positioning groove to restrict the sealing ring from rotating with the impeller and prevent the screw from coming out of the threaded hole.

2. The anti-leakage mechanism for a centrifugal pump as described in claim 1, characterized in that, The screw is an internal hexagon head screw.

3. The anti-leakage mechanism for a centrifugal pump as described in claim 1, characterized in that, The screw surface is coated with Teflon.

4. A centrifugal pump, characterized in that, The pump includes a pump body, a pump shaft, an impeller, and a drive mechanism; the pump shaft is rotatably mounted on the pump body, forming a sealed cavity inside the pump body; the impeller is mounted on the pump shaft and located in the sealed cavity; at least one end of the pump shaft is equipped with a drive mechanism, which drives the impeller to rotate via the pump shaft to achieve fluid transport; characterized in that a leak-proof mechanism as described in any one of claims 1 to 3 is provided between the pump body and the impeller.

5. The centrifugal pump as described in claim 4, characterized in that, The centrifugal pump is a double-suction pump, and the drive mechanism includes axial flux motors installed at both ends of the pump shaft, forming a double-drive double-suction pump.

6. The centrifugal pump as described in claim 5, characterized in that, The axial flux motor includes a bearing housing, a bearing cover, and a drive rotor. The drive rotor is mounted on a pump shaft and has multiple permanent magnets evenly arranged on it. The bearing cover is mounted on the outside of the bearing housing to form a cavity surrounding the drive rotor. Both the bearing cover and the bearing housing are evenly provided with the same number of first winding blocks and second winding blocks as the permanent magnets.

7. The centrifugal pump as described in claim 6, characterized in that, The bearing housing has a first cooling water chamber, which is sealed by a first water seal plate; the bearing cover has a second cooling water chamber, which is sealed by a second water seal plate; a cooling water coil is also provided between the bearing housing and the drive rotor.

8. The centrifugal pump as described in claim 4, characterized in that, A sealing mechanism is provided between the pump body and the pump shaft. The sealing mechanism includes a mechanical seal rotating ring, a mechanical seal stationary ring, packing packing, and a packing gland. The mechanical seal rotating ring is fixed to the pump shaft, and the mechanical seal stationary ring is fixed to the pump body. The mechanical seal rotating ring and the mechanical seal stationary ring seal the sealing cavity. The outer end of the mechanical seal stationary ring is provided with a receiving groove for accommodating the packing packing. The packing gland can be installed at the end of the receiving groove and press the packing packing tightly, so that when the mechanical seal between the mechanical seal rotating ring and the mechanical seal stationary ring fails, the packing packing and the packing gland can be installed on the mechanical seal stationary ring to achieve a packing seal.

9. The centrifugal pump as claimed in claim 8, characterized in that, It also includes an exhaust mechanism, which includes an automatic exhaust valve that connects the high-pressure zone of the pump body's sealed cavity to two low-pressure zones. The exhaust mechanism includes a first four-way pipe that is connected to the automatic exhaust valve, the exhaust port of the high-pressure zone of the sealed cavity, and a first pipeline that is connected to the exhaust ports of the two low-pressure zones of the sealed cavity. A check valve is provided on the first pipeline that is connected to the exhaust ports of the two low-pressure zones of the sealed cavity.

10. The centrifugal pump as claimed in claim 9, characterized in that, A second four-way pipe is also provided between the first four-way pipe and the high-pressure exhaust port of the sealing cavity. The second four-way pipe is connected to the mechanical seal through two second pipes, which are used to spray water between the dynamic ring and the stationary ring of the mechanical seal.

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