Multi-stage centrifugal vortex shield pump
By adopting a combined design of centrifugal impeller and vortex impeller in a multi-stage pump and adding a shielding structure to the tail of the pump, the existing multi-stage pumps are solved, and the problem of high lift, leakage-free and cavitation-resistant problems are difficult to meet the problems of high head, no leakage and anti-cavitation at the same time, achieving efficient and safe medium transportation.
Patent Information
- Application Number
- CN202421991869.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-16
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-08-16
AI Technical Summary
Existing multi-stage pumps are difficult to meet the requirements of high lift, leakage-free and cavitation resistance at the same time, especially when transporting flammable, explosive, volatile or toxic media.
A multi-stage centrifugal vortex shielding pump is designed. The first stage impeller adopts a centrifugal impeller, and the second stage to the last stage impeller are all vortex impellers. A shielding pump structure is designed at the tail of the pump to achieve leakage-free.
It realizes a small size, high head and leak-free pump, reduces operating noise and vibration, and is suitable for medium transportation in various industries.
Smart Images
Figure CN222894385U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of multi-stage pumps, in particular to a multi-stage centrifugal vortex canned pump. Background Art
[0002] The pump is a general-purpose machine with a wide range of applications. It is required in various industries such as petroleum, chemical industry, agriculture, mining, and electric power.
[0003] Among them, centrifugal pumps have become the most widely used and largest-output pumps in modern times due to their high speed, low NPSH, stable performance, simple structure, etc. However, in order to achieve high lift, centrifugal pumps need to use impellers with large diameters or connect many impellers in series to meet the demand. Both of these situations will make the centrifugal pump very large and require sufficient space for installation.
[0004] The vortex pump is the simplest high-lift pump. Compared with the centrifugal pump of the same size, its head is 2 to 4 times higher; compared with the volumetric pump of the same head, its size is much smaller and its structure is much simpler. However, the vortex pump has poor anti-cavitation performance and has high requirements for on-site use conditions.
[0005] And with the development of chemical industry and the improvement of people's awareness of environment and safety, the requirements for chemical pumps are getting higher and higher. In some occasions, such as conveying flammable, explosive, volatile, toxic or precious media, the pump used is required to be absolutely leak-free, so a leak-free pump is needed.
[0006] However, it is difficult for current multi-stage pumps to meet the above requirements at the same time, causing troubles in practical applications. Utility Model Content
[0007] The main purpose of the utility model is to provide a multi-stage centrifugal vortex canned pump, which can effectively solve the problems mentioned in the background technology.
[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0009] A multi-stage centrifugal vortex canned pump comprises a multi-stage pump, wherein the multi-stage pump is divided into an outer shell at the front end and a motor shell at the rear end, wherein a canned pump structure consisting of a stator and a rotor is arranged inside the motor shell, wherein the front end of the rotor is connected to a pump shaft and extends into the outer shell, wherein the interior of the outer shell is provided with a plurality of groups of front middle shells and rear middle shells assembled together, wherein vortex impellers are arranged inside the front middle shells and the rear middle shells, and the vortex impellers are installed on the pump shaft to form a vortex pump structure, wherein the front end of the pump shaft extends out of the front middle shell and the rear middle shell and extends into the first-stage middle shell, and a centrifugal impeller is installed at the front end of the pump shaft to form a centrifugal pump structure.
[0010] Preferably, the stator is wrapped around the outside of the rotor, and a stator shielding sleeve and a rotor shielding sleeve are provided between the stator and the rotor.
[0011] Preferably, a motor housing cover is fixedly installed at the tail of the motor housing, and a rear bearing body is fixedly installed at the outer end of the motor housing cover. A group of sliding bearing assemblies are arranged on the inner wall of the rear bearing body, and the rear bearing body is rotatably connected with the tail shaft of the rotor through the sliding bearing assembly.
[0012] Preferably, an intermediate bearing body is fixedly installed at the connection between the outer shell and the motor shell, and a sliding bearing assembly is also installed at the center of the intermediate bearing body and is rotatably connected to the front end of the rotor, while the pump shaft and the rotor are integrated components.
[0013] Preferably, throttling sealing rings are added to the upper and lower end surfaces of the vortex impeller, and a tortuous gap channel is provided between the shells of the front middle section shell and the rear middle section shell.
[0014] Preferably, the front middle section shell at the front end is assembled and connected with the first middle section shell through a front bearing body, and a sliding bearing assembly is also installed at the center position of the front bearing body to be rotatably connected with the front end of the pump shaft.
[0015] Preferably, the front end of the pump shaft extends into the first-stage middle section housing, and a centrifugal impeller is fixedly installed at the end by bolts, the rear end of the centrifugal impeller is also equipped with a guide vane, and the front end of the first-stage middle section housing is equipped with a suction cover, and the suction cover is also fixedly connected to the intermediate bearing body by a screw.
[0016] Preferably, two suction ports are provided on the front middle section shell, and two discharge ports are provided on the rear middle section shell, and the suction ports and the discharge ports are cross-symmetrically distributed.
[0017] Preferably, a central support seat of an integrated structure is provided at the center of the pump body of the multi-stage pump.
[0018] Compared with the prior art, the utility model has the following beneficial effects:
[0019] In the utility model, a new structural composition is designed to innovatively assemble a centrifugal pump, a vortex pump and a shielded pump together to form a new multi-stage pump structure, wherein the first-stage impeller of the multi-stage pump adopts a centrifugal impeller, and the second-stage to the last-stage impellers are all vortex impellers, which solves the problem of poor cavitation resistance of the vortex pump. After the medium is pressurized by the centrifugal impeller, the cavitation requirement of the subsequent vortex impeller is met, and the vortex impeller can work normally. After the medium is pressurized by multiple vortex impellers, a high head is achieved. At the same time, the shielded pump structural design at the tail can achieve complete leakage-free, thereby achieving a small volume while achieving a high head, no leakage, and low operating noise and vibration, which can meet the needs of various industries. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a cross-sectional view of the overall structure of the utility model;
[0021] Figure 2 This is a schematic diagram of the structure of the throttling sealing ring on the centrifugal impeller of the utility model;
[0022] Figure 3 This is a schematic diagram of the position distribution of the suction port and the discharge port of the utility model;
[0023] Figure 4 This is a schematic diagram of the installation position of the central support seat of the utility model.
[0024] In the figure: 1. outer shell; 2. suction cover; 3. first-stage middle shell; 4. centrifugal impeller; 5. guide vane; 6. front bearing body; 7. sliding bearing assembly; 8. front middle shell; 9. vortex impeller; 10. rear middle shell; 11. intermediate bearing body; 12. stator; 13. rotor; 14. stator shielding sleeve; 15. rotor shielding sleeve; 16. motor shell; 17. motor shell cover; 18. rear bearing body; 19. pump shaft; 20. throttling sealing ring; 21. suction port; 22. discharge port; 23. center support seat; 24. multi-stage pump. DETAILED DESCRIPTION
[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.
[0026] like Figure 1 As shown, a multi-stage centrifugal vortex shielded pump, the multi-stage pump 24 is divided into an outer casing 1 at the front end and a motor casing 16 at the rear end, a shielded pump structure consisting of a stator 12 and a rotor 13 is arranged inside the motor casing 16, the front end of the rotor 13 is connected to a pump shaft 19 and extends into the outer casing 1, and the interior of the outer casing 1 is provided with a plurality of groups of front middle section casings 8 and rear middle section casings 10 assembled together, and vortex impellers 9 are assembled inside the front middle section casing 8 and the rear middle section casing 10, and the vortex impellers 9 are installed on the pump shaft 19 to form a vortex pump structure, the front end of the pump shaft 19 extends out of the front middle section casing 8 and the rear middle section casing 10 and extends into the first-stage middle section casing 3, and a centrifugal impeller 4 is installed at the front end of the pump shaft 19 to form a centrifugal pump structure.
[0027] like Figure 1As shown, in the shielded pump structure, the stator 12 is wrapped around the outside of the rotor 13, and a stator shielding sleeve 14 and a rotor shielding sleeve 15 are provided between the stator 12 and the rotor 13. A motor housing cover 17 is fixedly installed at the tail of the motor housing 16, and a rear bearing body 18 is fixedly installed at the outer end of the motor housing cover 17. A group of sliding bearing assemblies 7 are provided on the inner wall of the rear bearing body 18, and the rear bearing body 18 is rotatably connected to the tail shaft of the rotor 13 through the sliding bearing assembly 7. The rear bearing body 18 is also fixedly connected to the intermediate bearing body 11 through a screw structure.
[0028] like Figure 1-Figure 2 As shown, in the vortex pump structure, a throttling sealing ring 20 is added to the upper and lower end surfaces of the vortex impeller 9, and a tortuous gap channel is formed between the front middle section housing 8 and the rear middle section housing 10. Because the general vortex pump needs to minimize the axial leakage, the gap between the upper and lower end surfaces of the impeller and the housing is very small, usually 0.07-0.15mm, which requires high precision in processing and assembly. In this embodiment, a throttling sealing ring 20 structure is added to the upper and lower end surfaces of the vortex impeller 9. This structure requires the medium to pass through a narrow and tortuous channel when leaking from the high-pressure area at the edge of the vortex impeller 9 to the low-pressure area in the middle, which increases the loss of the medium along the way and hinders the flow of the medium. It can reduce the axial leakage and improve the flow rate and efficiency of the pump.
[0029] Preferably, the front middle section housing 8 at the front end is assembled and connected with the first middle section housing 3 through the front bearing body 6, and a sliding bearing assembly 7 is also installed at the center position of the front bearing body 6 and is rotatably connected to the front end of the pump shaft 19.
[0030] like Figure 1 As shown, in the centrifugal pump structure, the front end of the pump shaft 19 extends into the first-stage middle section housing 3, and the centrifugal impeller 4 is fixedly installed at the end by bolts, and the rear end of the centrifugal impeller 4 is also equipped with a guide vane 5, and the front end of the first-stage middle section housing 3 is equipped with a suction cover 2, and the suction cover 2 is also fixedly connected to the intermediate bearing body 11 by a screw. The reason why the first-stage impeller uses a centrifugal impeller 4 and the second-stage to the last-stage impellers are all vortex impellers 9 is that the required cavitation margin of the centrifugal impeller 4 is low. Placing the centrifugal impeller 4 in the first stage can solve the problem of poor cavitation resistance of the vortex pump. After the medium is pressurized by the centrifugal impeller, the cavitation requirements of the subsequent vortex impeller 9 are met, and the vortex impeller 9 can work normally. After the medium is pressurized by multiple vortex impellers 9, it reaches a high head.
[0031] like Figure 3As shown, two suction ports 21 are provided on the front middle section housing 8, and two discharge ports 22 are provided on the rear middle section housing 10, and the suction ports 21 and the discharge ports 22 are cross-symmetrically distributed. This can balance the radial force generated when the vortex impeller 9 works on the medium, reduce vibration and noise during pump operation, extend the service life of the sliding bearing, and ensure that the pump can operate smoothly for a long time.
[0032] like Figure 4 As shown, the pump body of the multistage pump 24 is provided with a central support seat 23 of an integrated structure at the center position. Compared with ordinary multistage pumps, the double shell structure of the outer shell 1 and the motor shell 16 reduces the sealing points. The middle shell of each stage of ordinary multistage pumps is a sealing point, which reduces the risk of leakage when the pump is running at high pressure. Ordinary multistage pumps use foot support. Assuming that the center displacement of its expansion change is a, the maximum displacement is 2a. In this embodiment, a central support seat 23 is used, and its expansion change center remains unchanged, with a maximum displacement of a. Therefore, the central support structure can avoid the problem that the pump body expands under high temperature and high pressure, resulting in the pump rotor and the shell are not on the same horizontal line, so that the pump can operate normally under high temperature and high pressure conditions.
[0033] In actual use, after the junction box on the motor housing 16 is powered on, the rotor 13 starts to rotate and synchronously drives the pump shaft 19 to rotate, thereby driving the vortex impeller 9 and the centrifugal impeller 4 to rotate and work, and the transported medium enters from the flange interface at the front end of the multistage pump 24, is transported to the inside after the centrifugal impeller 4 does work, and then continues to be pressurized by the vortex impeller 9, and finally discharged from the flange interface at the top of the multistage pump 24 to complete the medium transportation. The entire pump has a compact structure design, small size, high head, high temperature and high pressure resistance, low noise and vibration, and zero leakage, and toxic and harmful media will not pollute the environment.
[0034] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.
Claims
1. A multi-stage centrifugal vortex canned motor pump, comprising a multi-stage pump (24), characterized in that: The multistage pump (24) is divided into an outer casing (1) at the front end and a motor casing (16) at the rear end. A shielded pump structure composed of a stator (12) and a rotor (13) is arranged inside the motor casing (16). The front end of the rotor (13) is connected to a pump shaft (19) and extends into the outer casing (1). The outer casing (1) is provided with a plurality of groups of front middle casings (8) and rear middle casings (10) assembled together. A vortex impeller (9) is installed inside the front middle casing (8) and the rear middle casing (10), and the vortex impeller (9) is installed on the pump shaft (19) to form a vortex pump structure. The front end of the pump shaft (19) extends out of the front middle casing (8) and the rear middle casing (10) and extends into the first-stage middle casing (3). A centrifugal impeller (4) is installed at the front end of the pump shaft (19) to form a centrifugal pump structure.
2. The multi-stage centrifugal vortex canned motor pump according to claim 1, characterized in that: The stator (12) is wrapped around the outside of the rotor (13), and a stator shielding sleeve (14) and a rotor shielding sleeve (15) are provided between the stator (12) and the rotor (13).
3. The multi-stage centrifugal vortex canned motor pump according to claim 2, characterized in that: A motor housing cover (17) is fixedly mounted on the rear portion of the motor housing (16), and a rear bearing body (18) is fixedly mounted on the outer end of the motor housing cover (17). A group of sliding bearing assemblies (7) are arranged on the inner wall of the rear bearing body (18), and the rear bearing body (18) is rotatably connected to the tail shaft of the rotor (13) through the sliding bearing assemblies (7).
4. The multi-stage centrifugal vortex canned motor pump according to claim 3, characterized in that: An intermediate bearing body (11) is fixedly mounted at the connection between the outer shell (1) and the motor shell (16), and a sliding bearing assembly (7) is also mounted at the center of the intermediate bearing body (11) and is rotatably connected to the front end of the rotor (13), while the pump shaft (19) and the rotor (13) are integral components.
5. The multi-stage centrifugal vortex canned motor pump according to claim 4, characterized in that: A throttling sealing ring (20) is added to the upper and lower end surfaces of the vortex impeller (9), and a tortuous gap channel is formed between the shells of the front middle section shell (8) and the rear middle section shell (10).
6. The multi-stage centrifugal vortex canned motor pump according to claim 5, characterized in that: The front middle section housing (8) at the front end is assembled and connected with the first middle section housing (3) through the front bearing body (6). A sliding bearing assembly (7) is also installed at the center position of the front bearing body (6) and is rotatably connected with the front end of the pump shaft (19).
7. The multi-stage centrifugal vortex canned motor pump according to claim 6, characterized in that: The front end of the pump shaft (19) extends into the first-stage middle section housing (3), and a centrifugal impeller (4) is fixedly installed at the end by bolts. The rear end of the centrifugal impeller (4) is also equipped with a guide vane (5). The front end of the first-stage middle section housing (3) is equipped with a suction cover (2), and the suction cover (2) is also fixedly connected to the intermediate bearing body (11) by means of screws.
8. The multi-stage centrifugal vortex canned motor pump according to claim 1, characterized in that: The front middle section shell (8) is provided with two suction ports (21), and the rear middle section shell (10) is provided with two discharge ports (22), wherein the suction ports (21) and the discharge ports (22) are cross-symmetrically distributed.
9. The multi-stage centrifugal vortex canned motor pump according to claim 1, characterized in that: A central support seat (23) of an integrated structure is arranged at the center of the pump body of the multi-stage pump (24).