Exhaust system for a magnetic centrifugal pump

Abstract

The application discloses a magnetic centrifugal pump exhaust system, which comprises a motor, wherein the motor drives an outer magnetic cylinder to rotate through a motor coupling, the outer magnetic cylinder drives an inner magnetic cylinder and a positioning sleeve in an isolation cover to rotate synchronously through magnetic force, the positioning sleeve drives a pump shaft to rotate through a key, and the pump shaft drives an impeller to rotate through an impeller key, so as to convert low-pressure medium passing through the impeller into high-pressure medium. The application is characterized in that an exhaust hole is formed in the center of the pump shaft at the highest point of the rotating part of the pump. The gas at the highest point can be pressed from the hole of the pump shaft at the highest point to the low-pressure impeller inlet by the high-pressure fluid in the pump shell, and then is discharged from the pump outlet through the action of the impeller, so that the problems of difficult exhaust of the magnetic centrifugal pump and effective medium circulation cooling of the sliding bearing are solved.

Description

Technical Field

[0001] This utility model relates to the field of magnetic centrifugal pump technology, and in particular to an internal exhaust system for a magnetic centrifugal pump. Background Technology

[0002] Magnetic drive pumps achieve contactless torque transmission thanks to their unique magnetic coupling. When the electric motor drives the outer magnetic rotor to rotate, the inner magnetic rotor and impeller rotate synchronously under the influence of the magnetic field, thus smoothly pumping the liquid. Particularly noteworthy is that because the liquid is safely enclosed within a stationary isolation sleeve, the magnetic drive pump is a statically sealed, leak-free pump type, ideal for high-end applications such as conveying flammable or hazardous media like strong acids, strong alkalis, and new energy liquids.

[0003] Currently, under the general environment of energy conservation, emission reduction, and carbon emission reduction, the new energy market has begun to boom. Many magnetic pumps that were originally used for pumping water are now used to pump new energy liquids such as methanol and liquid ammonia, which have poor lubricity. Because they do not have a forced exhaust channel at the highest position, they have difficulty venting. In severe cases, this can cause air binding and prevent them from working. In milder cases, because the gas cannot be completely discharged, the sliding bearings cannot be fully lubricated and circulated for cooling, leading to the burnout of the pump bearings. Utility Model Content

[0004] To address the problems in related technologies, this application discloses a method in which an exhaust hole is machined at the center of the pump shaft at the highest point of the pump's rotating parts. The gas at the highest point can be forced from the high-pressure fluid inside the pump casing through the exhaust hole of the pump shaft to the low-pressure impeller inlet, and then discharged from the pump outlet by the action of the impeller. This solves the problems of difficult exhaust and medium circulation cooling of the sliding shaft sleeve in magnetic centrifugal pumps.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] An internal exhaust system for a magnetic centrifugal pump includes a motor that drives an external magnetic cylinder connected to a motor coupling to rotate. The external magnetic cylinder drives an internal magnetic cylinder and a positioning sleeve inside an isolation cover to rotate synchronously via magnetic force. The positioning sleeve drives the pump shaft to rotate via a key. The pump shaft drives the impeller to rotate via an impeller key, thereby converting the low-pressure medium passing through the impeller into a high-pressure medium.

[0007] A nut is fastened to the top of the pump shaft;

[0008] The impeller is provided with a pump casing on its outer side, the pump casing is provided with a medium inlet and outlet, and the rear end of the pump casing is provided with a rear cover;

[0009] The radial force of the impeller is borne by the pump shaft that fixes the impeller through the upper and lower sliding bushings fixed in the bearing housing. The axial force of the impeller is borne and axially limited by the two pairs of dynamic thrust rings that rotate together with the pump shaft and the static thrust rings fixed in the bearing housing.

[0010] The rear cover is provided with a horizontally arranged rear cover drainage hole, which connects the inside and outside of the rear cover;

[0011] The bearing housing is provided with a vertically arranged bearing housing drainage hole. One end of the bearing housing drainage hole is connected to the drainage hole of the rear cover, and the other end is connected to the gap between the isolation cover and the inner magnetic cylinder.

[0012] The pump shaft has a pump shaft vent hole at its center, and the nut has a nut drain hole. The pump shaft vent hole is connected to the nut drain hole. The top of the pump shaft vent hole is connected to the air trapping area inside the isolation cover. The nut drain hole is connected to the inner cavity of the pump casing.

[0013] As a further aspect of this application: the bearing housing has a through hole on its side, one end of which is connected to the drainage hole of the bearing housing, and the other end of which is connected to the gap between the pump shaft and the sliding bushing.

[0014] As a further aspect of this application: the bearing housing is provided with a horizontally arranged external vent hole, one end of which is connected to the drain hole of the bearing housing, and the other end is connected to the outside of the bearing housing.

[0015] As a further aspect of this application, the outlet end of the nut drainage hole is positioned facing the medium inlet direction.

[0016] In summary, the beneficial effects of this application are as follows:

[0017] The magnetic centrifugal pump is equipped with a self-circulating exhaust system. The highest rotating component of the centrifugal pump is the pump shaft, which has a through exhaust hole machined in its center. This allows the gas in the highest area inside the isolation casing to communicate with the exhaust hole on the pump shaft. The high-pressure liquid at the impeller outlet enters the isolation casing through the drainage holes in the rear cover and bearing housing. The high-pressure liquid forces the gas inside the isolation casing out of the exhaust hole on the pump shaft to the low-pressure area at the impeller inlet. The gas then mixes with the liquid in the impeller and is discharged to the pump casing outlet by the action of the impeller. This solves the problems of exhaust difficulties caused by the lack of a forced exhaust hole in the magnetic centrifugal pump and the problem of medium circulation cooling the sliding shaft sleeve, thus improving the safety and reliability of the magnetic pump. Attached Figure Description

[0018] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0019] In the attached diagram:

[0020] Figure 1 This is a cross-sectional view of the magnetic centrifugal pump of this application.

[0021] Figure 2This is a liquid exhaust route diagram for the magnetic centrifugal pump of this application.

[0022] Figure label annotations:

[0023] 1. Pump casing; 2. Impeller; 3. Rear cover; 4. Bearing housing; 5. Isolation cover; 6. Inner magnetic cylinder; 7. Positioning sleeve; 8. Outer magnetic cylinder; 9. Pump shaft; 10. Motor coupling; 11. Motor base; 12. Motor; 13. Impeller key; 14. Key; 15. Nut; 16. Washer; 17. Wear ring; 18. Dynamic thrust ring; 19. Static thrust ring; 20. Sliding bushing;

[0024] 3.1 Rear cover drainage hole; 4.1 Bearing housing drainage hole; 4.2 Bearing housing external vent hole; 9.1 Pump shaft vent hole; 15.1 Nut drainage hole;

[0025] AT, the trapped air zone inside the isolation enclosure; TL, the exhaust route; S, the start of the exhaust route; E, the end of the exhaust route. Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects disclosed in this embodiment as detailed in the appended claims.

[0027] It should be noted that all directional indicators in the embodiments (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Furthermore, the use of terms such as "first" and "second" in the embodiments is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit this application. It is merely to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0029] To further understand the content, features, and effects of this application, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0030] like Figure 1 Cross-sectional view of the magnetic centrifugal pump shown:

[0031] The motor 12 drives the outer magnetic cylinder 8, which is connected to the motor coupling 10, to rotate. The outer magnetic cylinder 8 drives the inner magnetic cylinder 6, which is completely isolated from the outside world inside the isolation cover 5, and the connected positioning sleeve 7 to rotate synchronously through magnetic force. The positioning sleeve 7 drives the pump shaft 9 to rotate through the key 14. The pump shaft 9 drives the impeller 2 to rotate through the impeller key 13, thereby converting the low-pressure medium passing through the impeller 2 into a high-pressure medium.

[0032] The radial force of the impeller 2 is borne by the pump shaft 9 that fixes the impeller 2 through the upper and lower sliding bushings 20 fixed in the bearing housing 4. The axial force of the impeller 2 is borne and axially limited by the two pairs of dynamic thrust rings 18 that rotate together with the pump shaft 9 and the static thrust rings 19 fixed in the bearing housing 4.

[0033] The rear cover 3 is provided with a rear cover drainage hole 3.1, which connects the inside and outside of the rear cover 3.

[0034] The bearing housing 4 has a vertically arranged bearing housing drain hole 4.1 and a horizontally arranged bearing housing external vent hole 4.2.

[0035] One end of the bearing housing drainage hole 4.1 is connected to the drainage hole 3.1 of the rear cover, and the other end is connected to the gap between the isolation cover 5 and the inner magnetic cylinder 6.

[0036] One end of the external vent hole 4.2 of the bearing housing is connected to the drain hole 4.1 of the bearing housing, and the other end is connected to the outside of the bearing housing 4.

[0037] The pump shaft 9 has a pump shaft exhaust hole 9.1 at its center, and the nut 15, which axially positions the impeller 2 on the pump shaft 9, has a nut drain hole 15.1. The outlet end of the nut drain hole 15.1 is set towards the medium inlet direction.

[0038] The pump shaft exhaust port 9.1 is connected to the nut drain hole 15.1, the top of the pump shaft exhaust port 9.1 is connected to the trapped air zone AT inside the isolation cover, and the nut drain hole 15.1 is connected to the inner cavity of the pump casing 1.

[0039] The bearing housing 4 has a through hole on its side. One end of the through hole is connected to the bearing housing drain hole 4.1, and the other end of the through hole is connected to the gap between the pump shaft 9 and the sliding bushing 20.

[0040] like Figure 2 The liquid exhaust path diagram of the magnetic centrifugal pump shown is as follows:

[0041] Figure 2The exhaust route TL is a dashed line. The high-pressure medium at the impeller outlet starts from point S of the exhaust route TL, passes through the rear cover drain hole 3.1 and the bearing seat drain hole 4.1. A small portion enters the gap between the sliding sleeve 20 and the pump shaft 9 through the through hole on the bearing seat 4 to lubricate the sliding sleeve 20. The other portion enters the trapped gas zone AT inside the isolation cover through the gap between the isolation cover 5 and the inner magnetic cylinder 6. Thus, the gas trapped in the trapped gas zone AT inside the isolation cover is discharged to the impeller 2 inlet E through the pump shaft exhaust hole 9.1 and the nut drain hole 15.1.

[0042] The discharged gas mixes with the inlet liquid at the impeller inlet, is pressurized by the impeller 2, and then discharged outside the pump casing 1. This process is repeated until the gas trapped in the gas trap zone AT inside the isolation shroud is completely discharged. Similarly, the liquid inside the pump, from the exhaust path TL at point S to point E, achieves forced circulation and convection, thereby improving the lubrication and circulating cooling of the sliding bushing 20 and the dynamic thrust ring 18.

[0043] For applications requiring accelerated venting and sometimes horizontal placement, the external vent 4.2 of the bearing housing can serve as a manual venting port and inspection port.

[0044] The magnetic centrifugal pump is equipped with a self-circulating exhaust system. The highest rotating component of the centrifugal pump is the pump shaft, which has a through exhaust hole machined in its center. This allows the gas in the highest area inside the isolation casing to communicate with the exhaust hole on the pump shaft. The high-pressure liquid at the impeller outlet enters the isolation casing through the drainage holes in the rear cover and bearing housing. The high-pressure liquid forces the gas inside the isolation casing out of the exhaust hole on the pump shaft to the low-pressure area at the impeller inlet. The gas then mixes with the liquid in the impeller and is discharged to the pump casing outlet by the action of the impeller. This solves the problems of exhaust difficulties caused by the lack of a forced exhaust hole in the magnetic centrifugal pump and the problem of medium circulation cooling the sliding shaft sleeve, thus improving the safety and reliability of the magnetic pump.

[0045] Finally, it should be noted that the above disclosure is merely a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. The scope of this application is limited only by the appended claims.

Claims

1. An internal exhaust system for a magnetic centrifugal pump, comprising a motor (12), wherein the motor (12) drives an external magnetic cylinder (8) connected to a motor coupling (10) to rotate, the external magnetic cylinder (8) drives an internal magnetic cylinder (6) and a positioning sleeve (7) within an isolation cover (5) to rotate synchronously by magnetic force, the positioning sleeve (7) drives a pump shaft (9) to rotate by a key (14), and the pump shaft (9) drives an impeller (2) to rotate by an impeller key (13), thereby converting the low-pressure medium passing through the impeller (2) into a high-pressure medium; The pump shaft (9) is fastened with a nut (15) at its top end; The impeller (2) is provided with a pump casing (1) on its outer side. The pump casing (1) is provided with a medium inlet and outlet. The pump casing (1) is provided with a rear cover (3) at its rear end. The radial force of the impeller (2) is borne by the pump shaft (9) that fixes the impeller (2) through the upper and lower sliding bushings (20) fixed in the bearing housing (4). The axial force of the impeller (2) is borne and axially limited by the two pairs of dynamic thrust rings (18) that rotate together with the pump shaft (9) and the static thrust rings (19) fixed in the bearing housing (4). Its features are: The rear cover (3) is provided with a horizontally arranged rear cover drainage hole (3.1), which connects the inside and outside of the rear cover (3); The bearing housing (4) is provided with a vertically arranged bearing housing drain hole (4.1). One end of the bearing housing drain hole (4.1) is connected to the drain hole (3.1) of the rear cover, and the other end is connected to the gap between the isolation cover (5) and the inner magnetic cylinder (6). The pump shaft (9) is provided with a pump shaft exhaust hole (9.1) at its center, and the nut (15) is provided with a nut drain hole (15.1). The pump shaft exhaust hole (9.1) is connected to the nut drain hole (15.1). The top of the pump shaft exhaust hole (9.1) is connected to the trapped air zone (AT) inside the isolation cover. The nut drain hole (15.1) is connected to the inner cavity of the pump casing (1).

2. The internal exhaust system of a magnetic centrifugal pump according to claim 1, characterized in that: The bearing housing (4) has a through hole on its side. One end of the through hole is connected to the drainage hole (4.1) of the bearing housing, and the other end of the through hole is connected to the gap between the pump shaft (9) and the sliding bushing (20).

3. The internal exhaust system of a magnetic centrifugal pump according to claim 1, characterized in that: The bearing housing (4) is provided with a horizontally arranged external vent hole (4.2). One end of the external vent hole (4.2) is connected to the drain hole (4.1) of the bearing housing, and the other end is connected to the outside of the bearing housing (4).

4. The internal exhaust system of a magnetic centrifugal pump according to claim 1, characterized in that: The outlet end of the nut drain hole (15.1) is oriented towards the medium inlet.

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