A centrifugal multistage pump

Abstract

The present invention belongs to the technical field of centrifugal pumps, and specifically relates to a centrifugal multistage pump, comprising a pump body, wherein a driving shaft in a tube cavity of the pump body is sleeved with an intake impeller group and a discharge impeller group arranged along the length direction, the intake impeller group and the discharge impeller group are symmetrically arranged, and a transition component is provided in the smooth tube cavity of the pump body to divide its chamber into an intake chamber and a discharge chamber. By setting the transition component, the intake impeller group will inhale materials from a feed port and guide them to the discharge chamber through the transition component, and the discharge impeller group in the discharge chamber will guide the materials in the discharge chamber to the outside of the discharge port of the pump body through the transition component. The feed port is located at one end of the pump, and the discharge port is located in the middle of the pump body. The area occupied by the other end of the pump will be reduced, so that the pump can be installed in a smaller space, which is more convenient to install and has a wide range of uses. At the same time, the overall friction loss efficiency and the pumping material loss efficiency are small, thereby achieving performance stability.

Description

Technical Field

[0001] The invention belongs to the technical field of centrifugal pumps, and in particular relates to a centrifugal multistage pump. Background Art

[0002] A pump is an energy device that converts the energy output by the prime mover into medium pressure energy. Pumps are mainly used to transport liquids including water, oil, acid and alkali liquids, emulsion liquids, liquid metals, etc. Pumps can also transport gas mixtures and liquids containing suspended solids. Pumps can be used in agriculture, chemical industry, petroleum production, mining and metallurgical industries, power industry, etc., and are often limited by installation space in these application areas. Traditional centrifugal pumps are difficult to install in a small space due to structural problems. There are usually annular protrusions on the pump body, and the feed and discharge ports of the pump are usually located at both ends of the pump body. The feed and discharge ports need to occupy a large space, which will cause the pump to occupy a large space, and the pump body cannot be installed in a small space, which is inconvenient to disassemble and assemble. At the same time, due to the complex structure, the economic benefits are low. Summary of the invention

[0003] The object of the present invention is to provide a centrifugal multistage pump, which reduces the volume occupied by the pump by arranging a transition component in the pump cavity, reasonably arranging the structure in the pump cavity, shortening the distance between the feed port and the discharge port, making it easier to install and having a wide range of use.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a centrifugal multistage pump, including a pump body, a driving shaft in the tube cavity of the pump body is sleeved with an intake impeller group and a discharge impeller group arranged along the length direction, the intake impeller group and the discharge impeller group are symmetrically arranged, a transition component is provided in the smooth tube cavity of the pump body to divide its chamber into an intake chamber and a discharge chamber, the intake impeller group and the discharge impeller group are respectively placed in the intake chamber and the discharge chamber, the intake impeller group sucks the material from the feed port and guides it to the discharge chamber through the transition component, and the discharge impeller group guides the material in the discharge chamber to the outside of the discharge port of the pump body through the transition component.

[0005] Preferably, the transition assembly includes a transition ring that forms a sealing fit with the smooth inner wall of the cylindrical pump body. The transition ring is sleeved on the drive shaft and is provided with a positive flow channel connecting the suction chamber and the discharge chamber, and a reverse flow channel connecting the discharge chamber and the outside of the pump body.

[0006] Preferably, the inlets of the positive flow channel and the reverse flow channel are smaller than their respective outlets, and the inner cavities of both are gradually enlarged.

[0007] Preferably, the positive flow channel and the reverse flow channel are evenly distributed in the circumferential direction of the transition ring in multiple numbers and the number of the two is equal, and the positive flow channel and the reverse flow channel are staggered in arrangement.

[0008] Preferably, the transition ring is divided into a small diameter section and a large diameter section in a stepped shape, and the small diameter section and the large diameter section have a smooth curve transition, wherein the small diameter section is on the side of the suction impeller group, and the large diameter section is on the side of the discharge impeller group, and a sealing fit is formed between the large diameter section and the inner wall of the cylindrical pump body; the inlet of the positive flow channel is located on the end face of the small diameter section and close to the middle, and the outlet is located on the end face of the large diameter section and close to the edge; the inlet of the reverse flow channel is located on the end face of the large diameter section and close to the middle, and the outlet is located at the transition position between the small diameter section and the large diameter section.

[0009] Preferably, the inlet to the outlet of the positive flow channel and the reverse flow channel are both smoothly curved transitions; the cross-sections of the positive flow channel and the reverse flow channel are trapezoidal as a whole, and the inner sides are larger than the outer sides; the end face of the transition ring at the inlet of the positive flow channel is concave, and the end face of the transition ring at the inlet of the reverse flow channel is also concave.

[0010] Preferably, an intake impeller shell is provided on the outside of the intake impeller group to separate the inner wall of the pump body from the intake impeller group, and the two ends of the intake impeller shell are respectively abutted against the end face of the small diameter section of the transition ring and the inner end cover of the pump body; the gap formed between the intake impeller shell and the pump body is connected to the outlet of the reverse flow channel.

[0011] Preferably, a discharge impeller shell is provided on the outside of the discharge impeller group to separate the inner wall of the pump body from the discharge impeller group, and the gap formed between the discharge impeller shell and the inner wall of the pump body is connected to the discharge cavity where the discharge impeller group is set; the outlet of the positive flow channel is located at the gap between the discharge impeller shell and the inner wall of the pump body.

[0012] Preferably, the inlet of the positive flow channel is adjacent to the impeller position of the suction impeller assembly; the inlet of the reverse flow channel is adjacent to the impeller position of the discharge impeller assembly.

[0013] Preferably, a sealing groove is provided on the outer peripheral surface of the large diameter section of the transition ring, and an O-ring is provided in the sealing groove; a throttling bushing is provided between the transition ring and the drive shaft, and a lug is provided at one end of the throttling bushing, and a through hole is provided on the lug, and a bolt passes through the through hole to fix the throttling bushing to the transition ring.

[0014] The beneficial effects of the present invention are:

[0015] 1) By setting a transition component, the suction impeller group will suck the material from the feed port and guide it to the discharge chamber through the transition component. The discharge impeller group in the discharge chamber will guide the material in the discharge chamber through the transition component to the discharge port of the pump body. The structure in the pump chamber is reasonably arranged, which does not affect the function of the pump and shortens the distance between the feed port and the discharge port. In this embodiment, the feed port is located at one end of the pump, and the discharge port is located in the middle of the pump body. The area occupied by the other end of the pump will be reduced, that is, the feed port and the discharge port only occupy half of the position of the pump body, so that the pump can be installed in a smaller space, which is more convenient to install and has a wide range of use. At the same time, the overall friction loss efficiency and the pumping material loss efficiency are small, thereby achieving performance stability.

[0016] 2) The outer ring surface of the transition ring fits tightly against the inner wall of the pump body, isolating the suction chamber from the discharge chamber. By setting the positive flow channel and the reverse flow channel, the suction and discharge of the pump are reasonably separated, so that the suction and discharge materials of the pump do not interfere with each other.

[0017] 3) The kinetic energy of the material can be converted into pressure energy, that is, the suction impeller group in the suction chamber introduces the material from the entrance of the positive flow channel at high speed. As the inner cavity of the channel of the positive flow channel gradually increases, the material gradually converts the kinetic energy into pressure energy and reaches the discharge chamber. The material forms an extremely high pressure in the discharge chamber, which is convenient for the discharge impeller group to discharge the material from the discharge chamber, thereby improving the discharge efficiency; the discharge impeller group in the discharge chamber introduces the material from the entrance of the reverse flow channel at high speed. As the inner cavity of the channel of the reverse flow channel gradually increases, the material gradually converts the kinetic energy into pressure energy and reaches the discharge port, thereby forming an extremely high pressure, which is convenient for meeting the working requirements of small flow and high lift.

[0018] 4) There are multiple positive flow channels and reverse flow channels evenly distributed in the circumferential direction of the transition ring, and the number of the two is equal. The positive flow channels and the reverse flow channels are arranged in a staggered manner. On the one hand, the pumping speed and flow rate of the pump are guaranteed, and the radial force of the pump is offset when the positive flow channels and the reverse flow channels are diverted. On the other hand, it is further ensured that the suction and discharge materials of the pump do not interfere with each other.

[0019] 5) The space between the outlet of the reverse flow channel and the discharge port is increased within the limited pump cavity space of the pump body. The gap formed between the suction impeller shell and the pump body can introduce more materials, so that the working requirements of small flow and high head are further guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 It is a partial structural schematic diagram of the transition assembly of the present invention;

[0022] Figure 3 is a schematic diagram of the structure of the transition ring;

[0023] Figure 4 for Figure 3 Schematic diagram of the BB cross-section structure. DETAILED DESCRIPTION

[0024] For ease of understanding, the invention is described in detail below with reference to the accompanying drawings.

[0025] A centrifugal multistage pump comprises a pump body 10, wherein a driving shaft 13 in a tube cavity of the pump body 10 is sleeved with an intake impeller group 21 and a discharge impeller group 22 arranged along the length direction, wherein the intake impeller group 21 and the discharge impeller group 22 are symmetrically arranged, wherein a transition assembly 30 is provided in the smooth tube cavity of the pump body 10 for dividing the cavity into an intake cavity 11 and a discharge cavity 12, wherein the intake impeller group 21 and the discharge impeller group 22 are respectively disposed in the intake cavity 11 and the discharge cavity 12, wherein the intake impeller group 21 inhales material from a feed port 40 and guides the material to the discharge cavity 12 through the transition assembly 30, and wherein the discharge impeller group 22 guides the material in the discharge cavity 12 to the outside of a discharge port 50 of the pump body 10 through the transition assembly 30. By setting the transition component 30, the suction impeller group 21 will suck the material from the feed port 40 and guide it to the discharge chamber 12 through the transition component 30, and the discharge impeller group 22 in the discharge chamber 12 will guide the material in the discharge chamber 12 through the transition component 30 to the discharge port 50 outside the pump body 10. The structure in the pump chamber is reasonably arranged, which does not affect the function of the pump and shortens the distance between the feed port 40 and the discharge port 50. In this embodiment, the feed port 40 is located at one end of the pump, and the discharge port 50 is located in the middle of the pump body. The area occupied by the other end of the pump will be reduced, that is, the feed port 40 and the discharge port 50 only occupy half of the position of the pump body, so that the pump can be installed in a smaller space, which is more convenient to install and has a wide range of use. At the same time, the overall friction loss efficiency and the pumping material loss efficiency are small, thereby achieving performance stability.

[0026] More specifically, the transition assembly 30 includes a transition ring 31 that forms a seal with the smooth inner wall of the cylindrical pump body 10. The transition ring 31 is sleeved on the drive shaft 13. The transition ring 31 is provided with a positive flow channel 311 connecting the suction chamber 11 and the discharge chamber 12, and a reverse flow channel 312 connecting the discharge chamber 12 and the outside of the pump body 10. The outer annular surface of the transition ring 31 is tightly fitted with the inner wall of the pump body 10, isolating the suction chamber 11 from the discharge chamber 12. By setting the positive flow channel 311 and the reverse flow channel 312, the suction and discharge of the pump are reasonably separated, so that the suction material and the discharge material of the pump do not interfere with each other.

[0027] The inlets of the positive flow channel 311 and the reverse flow channel 312 are both smaller than their respective outlet sizes, and the inner cavities of both are gradually enlarged, which can convert the kinetic energy of the material into pressure energy, that is, the suction impeller group 21 in the suction chamber 11 introduces the material from the inlet of the positive flow channel 311 at high speed. As the channel inner cavity of the positive flow channel 311 gradually increases, the material gradually converts the kinetic energy into pressure energy and reaches the discharge chamber 12. The material forms an extremely high pressure in the discharge chamber 12, which is convenient for the discharge impeller group 22 to discharge the material from the discharge chamber 12, thereby improving the discharge efficiency; the discharge impeller group 22 in the discharge chamber 12 introduces the material from the inlet of the reverse flow channel 312 at high speed. As the channel inner cavity of the reverse flow channel 312 gradually increases, the material gradually converts the kinetic energy into pressure energy and reaches the discharge port 50, thereby forming an extremely high pressure, which is convenient for meeting the working requirements of small flow and high lift.

[0028] There are multiple positive flow channels 311 and reverse flow channels 312 evenly distributed in the circumferential direction of the transition ring 31, and the number of the two channels is equal. The positive flow channels 311 and the reverse flow channels 312 are arranged in a staggered manner. Such a setting, on the one hand, ensures the pumping speed and flow rate of the pump, ensures that the positive flow channels 311 and the reverse flow channels 312 offset the radial force of the pump when guiding the flow, and on the other hand, further ensures that the suction and discharge materials of the pump do not interfere with each other.

[0029] The transition ring 31 is divided into a stepped small diameter section 313 and a large diameter section 314, and there is a smooth curve transition between the small diameter section 313 and the large diameter section 314, wherein the small diameter section 313 is located on the suction impeller group 21 side, and the large diameter section 314 is located on the discharge impeller group 22 side, and the large diameter section 314 and the inner wall of the cylindrical pump body 10 form a sealing fit; the inlet of the positive flow channel 311 is located on the end face of the small diameter section 313 and close to the middle, and the outlet is located on the end face of the large diameter section 314 and close to the edge; the inlet of the reverse flow channel 312 is located on the end face of the large diameter section 314 and close to the middle, and the outlet is located at the transition position between the small diameter section 313 and the large diameter section 314.

[0030] The entrance to the exit of the positive flow channel 311 and the reverse flow channel 312 are both smoothly curved, so that the material is more stable when flowing at high speed in the flow channel, and there is no impact force on the flow channel; the cross-section of the positive flow channel 311 and the reverse flow channel 312 is trapezoidal as a whole, and the inner side is larger than the outer side; the end face of the transition ring 31 at the entrance of the positive flow channel 311 is concave, and the end face of the transition ring 31 at the entrance of the reverse flow channel 312 is also concave. The concave setting allows part of the impeller of the suction impeller group 21 or the discharge impeller group 22 to extend into the concave area of ​​the transition ring 31, which is more convenient for the impeller group to pump the material.

[0031] The outside of the suction impeller group 21 is provided with a suction impeller shell 211 that separates the inner wall of the pump body 10 from the suction impeller group 21. The two ends of the suction impeller shell 211 respectively abut against the end surface of the small diameter section 313 of the transition ring 31 and the inner end cover 14 of the pump body 10; the gap formed between the suction impeller shell 211 and the pump body 10 is connected to the outlet of the reverse flow channel 312. Such a setting increases the space between the outlet of the reverse flow channel 312 and the discharge port 50 within the limited pump cavity space of the pump body 10. The gap formed between the suction impeller shell 211 and the pump body 10 can introduce more materials, so that the working requirements of small flow and high head are further guaranteed.

[0032] The discharge impeller assembly 22 is provided with a discharge impeller shell 221 outside to separate the inner wall of the pump body 10 from the discharge impeller assembly 22. The gap formed between the discharge impeller shell 221 and the inner wall of the pump body 10 is connected to the discharge chamber 12 where the discharge impeller assembly 22 is provided. The outlet of the positive flow channel 311 is located at the gap between the discharge impeller shell 221 and the inner wall of the pump body 10. Consistent with the above principle, the space of the discharge chamber 12 is increased, so that the material in the discharge chamber 12 has a greater pressure, which facilitates the discharge impeller assembly 22 to discharge the material from the discharge chamber 12, improves the discharge efficiency, and further guarantees the working requirements of small flow and high head.

[0033] The inlet of the positive flow channel 311 is adjacent to the impeller position of the suction impeller assembly 21 ; the inlet of the reverse flow channel 312 is adjacent to the impeller position of the discharge impeller assembly 22 .

[0034] A sealing groove 315 is provided on the outer peripheral surface of the large diameter section 314 of the transition ring 31, and an O-ring is provided in the sealing groove 315, which further ensures that the transition ring 31 isolates the suction chamber 11 from the discharge chamber 12, improves the sealing effect, isolates the high and low pressures of the two chambers, and makes the pump more stable; a throttling bushing 60 is provided between the transition ring 31 and the drive shaft 13, and a lug 61 is provided at one end of the throttling bushing 60, and a through hole is provided on the lug 61. The bolt passes through the through hole to fix the throttling bushing 60 to the transition ring 31. The setting of the throttling bushing 60 also achieves the purpose of completely isolating the suction chamber 11 from the discharge chamber 12. At the same time, the setting of the lug 61 makes the connection between the throttling bushing 60 and the transition ring 31 completely sealed, and there is a throttling gap between the throttling bushing 60 and the remaining rotating parts. This throttling gap serves the purpose of throttling sealing and preventing dynamic and static friction.

Claims

1. A centrifugal multistage pump, comprising a pump body (10), wherein a drive shaft (13) in a tube cavity of the pump body (10) is sleeved with a suction impeller assembly (21) and a discharge impeller assembly (22) arranged along a length direction, characterized in that: The suction impeller assembly (21) and the discharge impeller assembly (22) are symmetrically arranged. A transition assembly (30) is arranged in the smooth tube cavity of the pump body (10) to divide the cavity into a suction cavity (11) and a discharge cavity (12). The suction impeller assembly (21) and the discharge impeller assembly (22) are respectively arranged in the suction cavity (11) and the discharge cavity (12). The suction impeller assembly (21) sucks material from the feed port (40) and guides the material to the discharge cavity (12) through the transition assembly (30). The discharge impeller assembly (22) guides the material in the discharge cavity (12) through the transition assembly (30) to the outside of the discharge port (50) of the pump body (10); The transition assembly (30) comprises a transition ring (31) which forms a sealing fit with the smooth inner wall of the cylindrical pump body (10); the transition ring (31) is sleeved on the drive shaft (13); the transition ring (31) is provided with a positive flow channel (311) connecting the suction chamber (11) and the discharge chamber (12), and a reverse flow channel (312) connecting the discharge chamber (12) and the outside of the pump body (10); The inlets of the positive flow channel (311) and the reverse flow channel (312) are both smaller than their respective outlets, and the inner cavities of both are gradually enlarged; The transition ring (31) is divided into a small diameter section (313) and a large diameter section (314) in a stepped shape, and a smooth curve transition is formed between the small diameter section (313) and the large diameter section (314), wherein the small diameter section (313) is located on the side of the suction impeller assembly (21), and the large diameter section (314) is located on the side of the discharge impeller assembly (22), and a sealing fit is formed between the large diameter section (314) and the inner wall of the cylindrical pump body (10); the inlet of the positive flow channel (311) is located on the end surface of the small diameter section (313) and close to the middle, and the outlet is located on the end surface of the large diameter section (314) and close to the edge; the inlet of the reverse flow channel (312) is located on the end surface of the large diameter section (314) and close to the middle, and the outlet is located at the transition position between the small diameter section (313) and the large diameter section (314); The inlet and outlet of the positive flow channel (311) and the reverse flow channel (312) are both smoothly curved transitions; the cross-sections of the positive flow channel (311) and the reverse flow channel (312) are overall trapezoidal, with the inner side being larger than the outer side; the end face of the transition ring (31) at the inlet of the positive flow channel (311) is concave, and the end face of the transition ring (31) at the inlet of the reverse flow channel (312) is also concave; An intake impeller shell (211) is provided outside the intake impeller assembly (21) to separate the inner wall of the pump body (10) from the intake impeller assembly (21); two ends of the intake impeller shell (211) respectively abut against the end surface of the small diameter section (313) of the transition ring (31) and the inner end cover (14) of the pump body (10); and a gap formed between the intake impeller shell (211) and the pump body (10) is communicated with the outlet of the reverse flow channel (312).

2. A centrifugal multistage pump according to claim 1, characterized in that: A plurality of the positive flow channels (311) and the reverse flow channels (312) are evenly distributed in the circumferential direction of the transition ring (31), and the number of the positive flow channels (311) and the reverse flow channels (312) are equal. The positive flow channels (311) and the reverse flow channels (312) are arranged in a staggered manner.

3. A centrifugal multistage pump according to claim 1, characterized in that: A discharge impeller shell (221) is provided outside the discharge impeller assembly (22) to separate the inner wall of the pump body (10) from the discharge impeller assembly (22); a gap formed between the discharge impeller shell (221) and the inner wall of the pump body (10) is communicated with a discharge chamber (12) in which the discharge impeller assembly (22) is provided; and an outlet of the positive flow channel (311) is located at the gap between the discharge impeller shell (221) and the inner wall of the pump body (10).

4. A centrifugal multistage pump according to claim 3, characterized in that: The inlet of the positive flow channel (311) is adjacent to the impeller position of the suction impeller assembly (21); and the inlet of the reverse flow channel (312) is adjacent to the impeller position of the discharge impeller assembly (22).

5. A centrifugal multistage pump according to claim 1, characterized in that: A sealing groove (315) is provided on the outer circumferential surface of the large diameter section (314) of the transition ring (31), and an O-type sealing ring is provided in the sealing groove (315); a throttling bushing (60) is provided between the transition ring (31) and the drive shaft (13); a lug (61) is provided at one end of the throttling bushing (60), and a through hole is provided on the lug (61), and a bolt passes through the through hole to fix the throttling bushing (60) to the transition ring (31).

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