A vertical multi-stage mud pump

Abstract

The present invention discloses a vertical multi-stage mud pump, which relates to the technical field of mud pumps, including a pump body and a volute installed at the bottom of the pump body, and also includes a guide baffle, which is installed in the volute, and the volute is internally formed with an inner flow channel and an outer flow channel through the guide baffle, and a discharge port is provided on one side of the volute, one end of the guide baffle is in the inner cavity of the volute, and the other end is in the inner cavity of the discharge port, and the end is elastically hinged with a diversion buffer, a noise reduction buffer cavity, which is installed on the inner wall of the volute, and a partition tongue is installed at the internal connection between the volute and the discharge port, and the partition tongue is located between the diversion buffer and the cavity mouth of the noise reduction buffer cavity, and a plurality of opening and closing pressure regulating parts are hinged on the outside of the noise reduction buffer cavity. The present invention divides the internal space of the volute into two areas, the inner flow channel and the outer flow channel, by arranging the guide baffle, balances the radial force of the impeller, and makes the flow velocity on both sides of the discharge port more uniform, and the diversion buffer can also play a buffering role when the fluid impacts the discharge port.

Description

Technical Field

[0001] The invention relates to the technical field of mud pumps, in particular to a vertical multi-stage mud pump. Background Art

[0002] As an important fluid conveying equipment, vertical multi-stage mud pump is used to extract and convey mud medium containing solid particles. When ships are dredging in rivers, ports and other waters, vertical mud pumps can be used to extract mud from the riverbed or seabed and convey it to the designated area.

[0003] The patent publication number of the existing patent application is: CN206309647U, and the publication date is July 7, 2017. The name of the patent is "A double volute centrifugal pump". In the patent, the outlet end of the partition is located in the range from the middle section of the diffuser to the horizontal section of the volute. The patent optimizes the position of the outlet end of the partition in the volute, effectively balancing the radial force of the impeller, and improves the characteristic curve of the double volute centrifugal pump, that is, the head at the small flow point is reduced and the head at the large flow point is increased, so that the characteristic curve changes from steep to relatively gentle, and the hydraulic efficiency is improved. The preferred solution of the patent further increases the flow cross-sectional area of ​​the outer flow channel of the partition, which not only makes the characteristic curve of the double volute centrifugal pump more gentle, but also reduces the casting difficulty of the volute, which is conducive to improving the casting quality of the flow channel surface and further improving the hydraulic efficiency. This advantage is particularly prominent for low-speed double volute centrifugal pumps with small flow and high head, which is conducive to the development and application of such double volute centrifugal pumps.

[0004] The above application has shortcomings. When the mud contains larger particles or impurities, it is easy to cause blockage and wear of the internal parts of the pump body, and also increase the noise during operation. Although the noise can be reduced to a certain extent by the baffle tongue, the dynamic and static interference between the impeller and the volute baffle tongue in the centrifugal pump will cause the fluid to produce unstable flow and pressure pulsation in the volute, which is a major factor affecting the stable operation of the centrifugal pump. Summary of the invention

[0005] The object of the present invention is to provide a vertical multi-stage mud pump to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A vertical multi-stage mud pump comprises a pump body and a volute mounted on the bottom of the pump body, and also comprises a guide baffle mounted in the volute, wherein the interior of the volute is provided with an inner flow channel and an outer flow channel through the guide baffle, a discharge port is provided on one side of the volute, one end of the guide baffle is in the inner cavity of the volute, and the other end is in the inner cavity of the discharge port, and a diversion buffer is elastically hinged at this end, and a noise reduction buffer cavity is mounted on the inner wall of the volute, a partition tongue is installed at the internal connection between the volute and the discharge port, the partition tongue is located between the diversion buffer and the cavity opening of the noise reduction buffer cavity, and a plurality of opening and closing pressure regulating parts are hinged on the outside of the noise reduction buffer cavity.

[0008] Preferably, a motor fixing seat is installed on the top of the pump body, and the motor fixing seat is in an inverted cone shape.

[0009] Preferably, the diversion buffer member comprises an arc-shaped baffle elastically hinged to one end of the guide baffle, the arc-shaped baffle is located in the middle of the discharge port, and a plurality of diversion grooves are formed on the arc-shaped baffle.

[0010] Preferably, the opening area of ​​the noise reduction buffer cavity is larger than the area of ​​the partition tongue, and the cavity body of the noise reduction buffer cavity gradually narrows along the water flow inflow direction.

[0011] Preferably, the partition tongue is slidably connected to a filter screen on one side close to the discharge port, the filter screen is fixedly connected to a push rod on one side, and a slider is symmetrically fixedly connected to the other side, a slide groove matching the slider is provided on the partition tongue, and an elastic member is also installed between the filter screen and the partition tongue.

[0012] Preferably, a cleaning brush is installed on one side of the partition tongue between the two slide grooves, and the cleaning brush is in contact with the back side of the filter screen.

[0013] Preferably, the widths of the plurality of opening and closing pressure regulating parts gradually narrow from the cavity opening of the noise reduction buffer cavity, and the width of a preceding opening and closing pressure regulating part is greater than the width of a succeeding opening and closing pressure regulating part.

[0014] Preferably, the opening and closing pressure regulating member comprises an arc-shaped spacer elastically hinged to the outside of the noise reduction buffer cavity, and one side of the arc-shaped spacer is fixedly connected with a protrusion in the noise reduction buffer cavity.

[0015] Preferably, a connecting kit is installed between the volute and the pump body, the inner wall of the volute is provided with a mounting groove adapted to one end of the connecting kit, and an impeller cavity is provided inside the volute, and the diameter of the impeller cavity is smaller than the diameter of the mounting groove.

[0016] Preferably, a buffer pad is installed in the outer flow channel, one side of the buffer pad is respectively connected to the noise reduction buffer chamber and the inner wall of the volute, and the other side of the buffer pad is embedded with a plurality of buffer strips.

[0017] In the above technical scheme, the internal space of the volute is divided into two areas, the inner flow channel and the outer flow channel, by setting a guide baffle, so as to balance the radial force of the impeller and make the flow velocity on both sides of the discharge port more uniform. The diversion buffer can also play a buffering role when the fluid impacts the discharge port and the baffle tongue, so that the baffle tongue and the noise reduction buffer chamber together form an effective noise absorption area. Moreover, the fluid entering the noise reduction buffer chamber can squeeze a plurality of opening and closing pressure regulating parts, so that the fluid in the noise reduction buffer chamber interacts with the fluid in the flow channel, thereby protecting the inner wall of the volute to allow the fluid to be smooth and suppressing the generation of noise.

[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0019] This application document provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of the overall structure of a vertical multi-stage mud pump of the present invention;

[0022] Figure 2 It is a schematic diagram of the connection between the pump body and the volute in a vertical multi-stage mud pump of the present invention;

[0023] Figure 3 A bottom view of a volute in a vertical multi-stage mud pump of the present invention;

[0024] Figure 4 It is a cross-sectional view of a volute in a vertical multi-stage mud pump of the present invention;

[0025] Figure 5 for Figure 4 A magnified view of the structure at A;

[0026] Figure 6 It is a schematic diagram of the connection between the diaphragm tongue and the filter screen in a vertical multi-stage mud pump of the present invention;

[0027] Figure 7 It is a structural schematic diagram of a diaphragm tongue in a vertical multi-stage mud pump of the present invention;

[0028] Figure 8The present invention is a schematic structural diagram of a flow guide baffle and a flow diversion buffer in a vertical multi-stage mud pump.

[0029] Description of reference numerals:

[0030] 1. Pump body; 10. Partition tongue; 2. Volute; 3. Guide baffle; 4. Inner flow channel; 5. Outer flow channel; 6. Discharge port; 8. Diverter buffer; 81. Arc-shaped baffle; 82. Diverter slot; 9. Noise reduction buffer chamber; 91. Opening; 12. Opening and closing pressure regulating part; 121. Arc-shaped baffle; 122. Protrusion; 13. Motor fixing seat; 14. Filter; 15. Push rod; 16. Slider; 17. Slide; 18. Cleaning brush; 19. Connection kit; 20. Mounting slot; 21. Impeller chamber; 22. Buffer pad; 23. Buffer strip; 24. Elastic part. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0032] See also Figure 1-8 A vertical multi-stage mud pump provided by an embodiment of the present invention includes a pump body 1 and a volute 2 installed at the bottom of the pump body 1, and also includes a guide baffle 3, which is installed in the volute 2. An inner flow channel 4 and an outer flow channel 5 are formed inside the volute 2 through the guide baffle 3. A discharge port 6 is provided on one side of the volute 2. One end of the guide baffle 3 is in the inner cavity of the volute 2, and the other end is in the inner cavity of the discharge port 6, and the end is elastically hinged with a diverter buffer 8 and a noise reduction buffer cavity 9, which is installed on the inner wall of the volute 2. A partition tongue 10 is installed at the internal connection between the volute 2 and the discharge port 6. The partition tongue 10 is located between the diverter buffer 8 and the cavity opening of the noise reduction buffer cavity 9. A plurality of opening and closing pressure regulating parts 12 are hinged on the outside of the noise reduction buffer cavity 9.

[0033] Specifically, a volute 2 is firmly installed at the bottom of the pump body 1, and the interior of the volute 2 is divided into an inner flow channel 4 and an outer flow channel 5 by a guide baffle 3, ensuring that the fluid forms an orderly flow inside the volute 2 after entering from the bottom inlet of the volute 2. One end of the guide baffle 3 is in the inner cavity of the volute 2, and the other end extends to the inner cavity of the discharge port 6. When the vertical multi-stage mud pump is working, the fluid enters the volute 2 under the action of the impeller, and is guided by the guide baffle 3 to enter the inner flow channel 4 and the outer flow channel 5 respectively, thereby achieving a balanced distribution of the fluid inside the volute 2 and effectively reducing the radial force on the impeller. The guide baffle 3 is elastically hinged at the discharge port 6 with a diversion buffer 8, which can effectively absorb the impact force of the fluid when it impacts the discharge port 6 and the partition tongue 10. The noise reduction buffer chamber 9 is fixedly installed on the inner wall of the volute 2, and is connected to the discharge port 6 and the partition tongue 10. 0 constitutes a key area for absorbing noise, and the baffle 10 is firmly installed at the internal connection between the volute 2 and the discharge port 6, and is located between the diversion buffer 8 and the cavity mouth of the noise reduction buffer chamber 9, playing the role of guiding the fluid, and the opening and closing pressure regulating part 12 at the bottom of the noise reduction buffer chamber 9 can be opened and closed appropriately with the change of fluid pressure, and the fluid entering the noise reduction buffer chamber 9 is used to squeeze the multiple opening and closing pressure regulating parts 12, so that the fluid in the noise reduction buffer chamber 9 and the fluid in the flow channel interact with each other, while protecting the inner wall of the volute 2 to make the fluid flow smoother, and suppressing the generation of noise. This interaction not only protects the inner wall of the volute 2 and makes the fluid flow smoother, but also effectively suppresses the generation of noise by adjusting the fluid pressure and flow rate, thereby realizing the high-efficiency and low-noise operation of the vertical multi-stage mud pump.

[0034] Compared with the prior art, the embodiment of the present invention divides the internal space of the volute 2 into two areas, the inner flow channel 4 and the outer flow channel 5, by setting a guide baffle 3, so as to balance the radial force of the impeller and make the flow velocity on both sides of the discharge port 6 more uniform. The diverter buffer 8 can also play a buffering role when the fluid impacts the discharge port 6 and the baffle 10, so that the baffle 10 and the noise reduction buffer chamber 9 together form an effective noise absorption area. Moreover, the fluid entering the noise reduction buffer chamber 9 can squeeze the multiple opening and closing pressure regulating parts 12, so that the fluid in the noise reduction buffer chamber 9 interacts with the fluid in the flow channel, thereby protecting the inner wall of the volute 2 to allow the fluid to be smooth and suppressing the generation of noise.

[0035] In a further embodiment of the present invention, a motor fixing seat 13 is installed on the top of the pump body 1, and the motor fixing seat 13 is in an inverted cone shape. Specifically, the motor fixing seat 13 effectively reduces the vibration and noise propagation generated during the operation of the motor through its inverted cone structural characteristics, thereby further improving the working efficiency and quietness performance of the vertical multi-stage mud pump.

[0036] In a further embodiment of the present invention, the diversion buffer member 8 includes an arc-shaped baffle 81 elastically hinged to one end of the guide baffle 3, a torsion spring is installed between the arc-shaped baffle 81 and the guide baffle 3, the arc-shaped baffle 81 is located in the middle of the discharge port 6, and a plurality of diversion grooves 82 are provided on the arc-shaped baffle 81. Specifically, when the fluid flows to the discharge port 6, it will encounter the arc-shaped baffle 81 located in the middle thereof. The arc-shaped baffle 81 can not only guide the fluid more effectively due to its shape, but also further disperse the fluid through the diversion grooves 82 provided thereon, thereby reducing the direct impact of the fluid on the discharge port 6, thereby enhancing the buffering effect. Since the diversion groove 82 is located in the middle of the discharge port 6, it does not completely cover the discharge port 6, and will not cause silt accumulation to cause blockage. At the same time, the noise absorption area formed by the noise reduction buffer cavity 9 and the partition tongue 10 continues to play its role, absorbing the noise generated by the dispersed fluid, so that the noise reduction effect is significantly improved under multiple coordination.

[0037] In a further embodiment of the present invention, the cavity opening area of ​​the noise reduction buffer cavity 9 is larger than the area of ​​the partition tongue 10, and the cavity body of the noise reduction buffer cavity 9 gradually narrows along the water flow inflow direction. Specifically, the noise reduction buffer cavity 9, as a key noise reduction component, has a cavity opening area designed to be larger than the area of ​​the partition tongue 10 to ensure that more fluid can smoothly enter the noise reduction buffer cavity 9 for noise reduction processing. In addition, the cavity body of the noise reduction buffer cavity 9 gradually narrows along the water flow inflow direction. This design not only helps to enhance the noise reduction effect, but also can further increase the fluid pressure in the noise reduction buffer cavity 9 through the compression of the fluid, thereby more effectively suppressing the noise generated when the fluid flows in the flow channel.

[0038] In a further embodiment of the present invention, a filter screen 14 is slidably connected to one side of the partition tongue 10 near the discharge port 6, a push rod 15 is fixedly connected to one side of the filter screen 14 near the discharge port 6, and a slider 16 is symmetrically fixedly connected to the other side. A slide groove 17 matching the slider 16 is provided on the partition tongue 10, and an elastic member 24 is also installed between the filter screen 14 and the partition tongue 10. Specifically, during the operation of the vertical multi-stage mud pump, the fluid is guided by the guide baffle 3 and the arc baffle 81, passes through the inner flow channel 4 and the outer flow channel 5, and finally flows to the discharge port 6. In this process, the filter screen 14 can effectively intercept impurities in the fluid and reduce the amount of impurities between the partition tongue 10 and the impeller. The mud and sand that enter the noise reduction buffer chamber 9 through the gap can also slide stably on the partition tongue 10 through the cooperation of the slider 16 and the slide groove 17. When the impurities accumulated on the filter screen 14 reach a certain level, the gap between the partition tongue 10 and the impeller becomes narrower due to the blockage of impurities. The fluid in the inner flow channel 4 can more strongly impact the filter screen 14 and the push rod 15 on the filter screen 14, and while cleaning the filter screen 14, force the filter screen 14 to move along the surface of the partition tongue 10 toward the discharge port 6 under certain circumstances to prevent the impurities on the filter screen 14 from affecting the normal operation of the mud pump. If some of the impurities on the filter screen 14 are washed away, the filter screen 14 will move back and reset under the action of the elastic member 24.

[0039] In a further embodiment of the present invention, a cleaning brush 18 is installed on one side of the partition tongue 10 between the two slide grooves 17, and the cleaning brush 18 contacts the back of the filter screen 14. Specifically, when the filter screen 14 slides on the partition tongue 10, the cleaning brush 18 can automatically clean the filter screen 14 and brush away the impurities and dirt accumulated on the filter screen 14. When the filter screen 14 is close to the discharge port 6, the cleaning brush 18 is hidden in the area between the filter screen 14 and the partition tongue 10, which not only ensures its effective cleaning of the filter screen 14, but also avoids interference with the flow of the fluid.

[0040] In a further embodiment of the present invention, the widths of several opening and closing pressure regulating parts 12 gradually narrow from the cavity mouth of the noise reduction buffer chamber 9, and the width of the previous opening and closing pressure regulating part 12 is greater than the width of the subsequent opening and closing pressure regulating part 12. Specifically, the noise reduction buffer chamber 9 and the opening and closing pressure regulating part 12 jointly play the role of regulating fluid pressure and suppressing noise. Since the width of the opening and closing pressure regulating part 12 gradually narrows from the cavity mouth of the noise reduction buffer chamber 9, the width of the previous opening and closing pressure regulating part 12 is greater than the width of the subsequent opening and closing pressure regulating part 12. This makes the forces exerted on the fluid by each opening and closing pressure regulating part 12 different from each other, thereby more gently adjusting the fluid pressure in the noise reduction buffer chamber 9 and the fluid pressure in the flow channel.

[0041] In a further embodiment of the present invention, the opening and closing pressure regulating member 12 includes an arc-shaped spacer 121 elastically hinged to the outside of the noise reduction buffer chamber 9, one side of the arc-shaped spacer 121 is fixedly connected with a protrusion 122 in the noise reduction buffer chamber 9, and an opening 91 for accommodating the arc-shaped spacer 121 is provided on the outside of the noise reduction buffer chamber 9. One side of the inner wall of the opening 91 is inclined against one side of the arc-shaped spacer 121. Specifically, when the fluid flows through the noise reduction buffer chamber 9, the fluid pressure acts on the protrusion 122 on the arc-shaped spacer 121, so that it can be flexibly opened and closed around the hinge point, and the protrusion 122 plays a guiding role when the arc-shaped spacer 121 is opened and closed. The arc-shaped partition 121 is forced to flip toward the flow channel in the volute 2, and the fluid entering the flow channel will impact the arc-shaped partition 121 from the opposite direction. The two fluids interact with each other through the arc-shaped partition 121, which not only avoids the fluid in the flow channel from directly impacting the inner wall of the volute 2, but also prevents the fluid from being stirred between the impellers. When the arc-shaped partition is in the opening, it is blocked by one side of the opening, and the fluid in the flow channel cannot impact and flip the arc-shaped partition into the noise reduction buffer chamber, thereby reducing the disturbance force and turbidity vortex of the fluid in the pump on the impeller. Even if the flow rate in the flow channel is too large, the flow rate and head of the pump can be guaranteed to be stable, thereby improving the operating stability of the pump.

[0042] In a further embodiment of the present invention, a connecting kit 19 is installed between the volute 2 and the pump body 1, and a mounting groove 20 adapted to one end of the connecting kit 19 is provided on the inner wall of the volute 2. An impeller cavity 21 is provided inside the volute 2, and the diameter of the impeller cavity 21 is smaller than the diameter of the mounting groove 20. Specifically, during the operation of the vertical multi-stage mud pump, the fluid is sucked into the impeller cavity 21, and obtains energy and speed under the rotation of the impeller, and is finally discharged from the pump body 1. The connecting kit 19 serves as a connecting component between the volute 2 and the pump body 1, and the volute 2 The inner wall is also provided with a mounting groove 20 matched with one end of the connecting kit 19, ensuring that the connecting kit 19 can be accurately embedded in the volute 2 and form a tight connection with the volute 2, ensuring that the volute 2 can be firmly installed on the pump body 1. At the same time, the diameter of the impeller cavity 21 is designed to be smaller than the diameter of the mounting groove 20. Such a design ensures that the impeller cavity 21 has enough space to accommodate the impeller and allow it to operate efficiently, and avoids the formation of vortexes or leakage of the fluid in the mounting groove 20 area, thereby improving the overall efficiency and performance of the pump.

[0043] In a further embodiment of the present invention, a buffer pad 22 is installed in the outer flow channel 5, and one side of the buffer pad 22 is respectively connected to the noise reduction buffer chamber 9 and the inner wall of the volute 2, and the other side of the buffer pad 22 is embedded with multiple buffer strips 23. Specifically, during the operation of the vertical multi-stage mud pump, the fluid flows through the outer flow channel 5 and the inner flow channel 4 in sequence under the guidance of the guide baffle 3 and the arc baffle 81. When the fluid flows through the outer flow channel 5, it will come into contact with the buffer pad 22 and the buffer strips 23 thereon, which can effectively absorb the impact of the fluid on the noise reduction buffer chamber 9 and reduce the vibration and noise generated by the fluid, thereby further reducing the noise level generated by the vertical multi-stage mud pump during operation. At the same time, the connection between the buffer pad 22 and the noise reduction buffer chamber 9 further enhances the noise reduction effect of the noise reduction buffer chamber 9, so that the overall noise reduction performance of the vertical multi-stage mud pump is significantly improved.

[0044] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A vertical multi-stage mud pump, comprising a pump body (1) and a volute (2) mounted at the bottom of the pump body (1), characterized in that: Also includes: A flow guide baffle (3) is installed in the volute (2); an inner flow passage (4) and an outer flow passage (5) are formed in the volute (2) through the flow guide baffle (3); a discharge port (6) is provided on one side of the volute (2); one end of the flow guide baffle (3) is located in the inner cavity of the volute (2); the other end of the flow guide baffle (3) is located in the inner cavity of the discharge port (6) and is elastically hinged with a flow diversion buffer (8); A noise reduction buffer chamber (9) is installed on the inner wall of the volute (2); a partition tongue (10) is installed at the internal connection between the volute (2) and the discharge port (6); the partition tongue (10) is located between the flow diversion buffer component (8) and the cavity opening of the noise reduction buffer chamber (9); and a plurality of opening and closing pressure regulating components (12) are hingedly connected to the outer side of the noise reduction buffer chamber (9).

2. A vertical multi-stage mud pump according to claim 1, characterized in that: A motor fixing seat (13) is mounted on the top of the pump body (1), and the motor fixing seat (13) is in an inverted cone shape.

3. A vertical multi-stage mud pump according to claim 1, characterized in that: The flow diversion buffer (8) comprises an arc-shaped baffle (81) elastically hinged to one end of the flow guide baffle (3); the arc-shaped baffle (81) is located in the middle of the discharge port (6); and a plurality of flow diversion grooves (82) are provided on the arc-shaped baffle (81).

4. A vertical multi-stage mud pump according to claim 1, characterized in that: The opening area of ​​the noise reduction buffer cavity (9) is larger than the area of ​​the partition tongue (10), and the cavity body of the noise reduction buffer cavity (9) gradually narrows along the water flow inflow direction.

5. A vertical multi-stage mud pump according to claim 1, characterized in that: A filter screen (14) is slidably connected to one side of the partition tongue (10) near the discharge port (6); a support rod (15) is fixedly connected to one side of the filter screen (14); and a slider (16) is symmetrically fixedly connected to the other side. A slide groove (17) matching the slider (16) is provided on the partition tongue (10); and an elastic member (24) is also installed between the filter screen (14) and the partition tongue (10).

6. A vertical multi-stage mud pump according to claim 5, characterized in that: A cleaning brush (18) is installed on one side of the partition tongue (10) between the two slide grooves (17), and the cleaning brush (18) is in contact with the back side of the filter screen (14).

7. A vertical multi-stage mud pump according to claim 1, characterized in that: The widths of the plurality of opening and closing pressure regulating pieces (12) gradually narrow from the cavity opening of the noise reduction buffer cavity (9), and the width of a preceding opening and closing pressure regulating piece (12) is greater than the width of a succeeding opening and closing pressure regulating piece (12).

8. A vertical multi-stage mud pump according to claim 7, characterized in that: The opening and closing pressure regulating member (12) comprises an arc-shaped spacer (121) elastically hinged to the outside of the noise reduction buffer cavity (9), and one side of the arc-shaped spacer (121) is fixedly connected to a protrusion (122) in the noise reduction buffer cavity (9).

9. A vertical multi-stage mud pump according to claim 1, characterized in that: A connection kit (19) is installed between the volute (2) and the pump body (1); an installation groove (20) adapted to one end of the connection kit (19) is provided on the inner wall of the volute (2); an impeller cavity (21) is provided inside the volute (2); and a diameter of the impeller cavity (21) is smaller than a diameter of the installation groove (20).

10. A vertical multi-stage mud pump according to claim 1, characterized in that: A buffer pad (22) is installed in the outer flow channel (5), one side of the buffer pad (22) is connected to the noise reduction buffer cavity (9) and the inner wall of the volute (2), and the other side of the buffer pad (22) is embedded with a plurality of buffer strips (23).

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