Hydraulic power sealing device for fluid medium conveying

Abstract

The hydraulic power sealing device for fluid medium conveying comprises a pump shell and a pump cover which are connected with each other, an impeller is arranged in the pump shell, a pump shaft and a magnetic driver are arranged in the pump cover, the impeller is fixedly installed at the end, facing the pump shell, of the pump shaft, and the magnetic driver is fixedly installed at the end, facing the pump shell, of the pump shaft. The other end of the pump shaft is connected with the magnetic driver; impeller back blades are fixedly mounted on the side, away from the pump shell, of the impeller; a hydraulic sealing cavity is formed between the impeller back blade and the magnetic driver, the hydraulic sealing cavity is filled with pressurized liquid, the pressure of the pressurized liquid is higher than that of a pump inlet, power sealing is formed through cooperation of the pump cover and the impeller back blade, fluid is prevented from being conveyed into the pump cover, and the pump cover and the impeller back blade can form a pressure head. Due to the fact that the pressure of liquid with pressure in the hydraulic sealing cavity is higher than the pressure of a pump inlet, conveying fluid in a pump flow channel cannot enter the hydraulic sealing cavity, and sealing reliability and economical efficiency are effectively improved.

Description

Technical Field

[0001] The present application relates to the field of fluid medium transportation, and particularly to a hydraulic power seal device for fluid medium transportation. Background Art

[0002] In the aspect of fluid medium transportation, especially in the petrochemical industry, many petrochemical raw materials, finished products or semi-finished products are in a fluid state, and they usually have high-risk characteristics such as flammable, explosive, toxic and strongly corrosive. If they leak during transportation, it is extremely easy to cause safety accidents and environmental pollution. Therefore, the sealing of such high-risk fluids during transportation needs to be extremely reliable without the slightest negligence.

[0003] Generally, fluid media are transported by pumps, and the seals of pumps usually include mechanical seals, dry gas seals and dynamic seals, etc. In addition, there are magnetic pumps and canned pumps in a shaftless seal form.

[0004] However, mechanical seals cannot guarantee absolute sealing; shaftless pumps cannot transport media containing solid particles due to their bearings, shielding sleeves and isolating sleeves; while both dynamic seals and dry gas seals are moving seals, their seals become effective during operation, and a shutdown seal needs to be configured when stopping. Therefore, although their seals are more reliable than mechanical seals, their structures are complex and maintenance and repair are inconvenient. Summary of the Utility Model

[0005] The embodiments of the present application provide a hydraulic power seal device for fluid medium transportation to solve the problems that the existing sealing structures and shaftless pumps are not convenient for transporting complex and highly hazardous fluids.

[0006] The embodiments of the present application provide a hydraulic power seal device for fluid medium transportation, including a pump housing and a pump cover connected to each other. An impeller is arranged inside the pump housing, and a pump shaft and a magnetic driver are arranged inside the pump cover. The impeller is fixedly installed at one end of the pump shaft facing the pump housing, and the other end of the pump shaft is connected to the magnetic driver;

[0007] An impeller back vane is fixedly installed on the side of the impeller away from the pump housing;

[0008] There is a hydraulic seal chamber between the impeller back vane and the magnetic driver, and the hydraulic seal chamber is filled with a pressurized liquid, and the pressure of the pressurized liquid is higher than the pump inlet pressure.

[0009] In a feasible implementation manner, an impeller seal ring is fixedly installed on the side of the impeller away from the pump housing. The impeller back vane is located between the impeller and the impeller seal ring, and the hydraulic seal chamber is between the impeller seal ring and the magnetic driver;

[0010] One end of the inner wall of the pump cover facing the pump housing is fixedly installed with a pump cover sealing ring. The pump cover sealing ring is coaxially arranged with the impeller sealing ring, and the impeller sealing ring is located inside the pump cover sealing ring.

[0011] In a feasible implementation manner, a sealing liquid inlet and a sealing liquid outlet are opened on the pump cover, and both the sealing liquid inlet and the sealing liquid outlet are communicated with the hydraulic sealing cavity.

[0012] In a feasible implementation manner, the magnetic drive includes an inner magnetic steel, an isolation sleeve, an outer magnetic steel and a magnetic drive housing. The inner magnetic steel is connected to the other end of the pump shaft. The isolation sleeve is arranged outside the inner magnetic steel and connected to the pump cover. The outer magnetic steel is arranged outside the isolation sleeve, and the magnetic drive housing is arranged outside the outer magnetic steel and connected to the pump cover;

[0013] A hydraulic sealing cavity is formed between the impeller sealing ring and the isolation sleeve.

[0014] In a feasible implementation manner, the cross-section of the isolation sleeve is U-shaped.

[0015] In a feasible implementation manner, the impeller sealing ring and the pump cover sealing ring are in clearance fit.

[0016] In a feasible implementation manner, a thrust bearing and a sliding bearing are further provided at one end of the pump shaft close to the pump housing, and the thrust bearing and the sliding bearing are located in the hydraulic sealing cavity.

[0017] In a feasible implementation manner, the pressurized liquid is a liquid without solid particles.

[0018] In a feasible implementation manner, the pump housing and the pump cover are connected by bolts.

[0019] In a feasible implementation manner, the impeller and the impeller back blades are integrally formed.

[0020] A hydraulic dynamic sealing device for fluid medium transportation provided by an embodiment of the present application forms a dynamic seal through the mutual cooperation of the pump cover and the impeller back blades, offsets the head generated by the impeller to prevent the transported fluid from entering the inside of the pump cover, and the two can form a pressure head to increase the total head of the impeller. In addition, since the pressure of the pressurized liquid in the hydraulic sealing cavity is higher than the pump inlet pressure, the transported fluid in the pump flow channel cannot enter the hydraulic sealing cavity, effectively improving the sealing reliability and economy. Brief Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of a hydraulic dynamic sealing device for fluid medium transportation provided by an embodiment of the present application.

[0022] Description of the drawing reference numerals:

[0023] 1 - pump casing; 2 - impeller; 3 - back vane of impeller; 4 - impeller seal ring; 5 - pump cover seal ring; 6 - pump cover; 7 - thrust bearing; 8 - sliding bearing; 9 - pump shaft; 10 - inlet of sealing liquid; 11 - outlet of sealing liquid; 12 - inner magnetic steel; 13 - isolation sleeve; 14 - outer magnetic steel; 15 - housing of magnetic drive. Detailed implementation manners

[0024] In order to enable those skilled in the art to better understand the technical solutions in this application, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0025] Since the petrochemical industry is essential in daily life and industrial production, and in recent years, the national and even global requirements for the safe production and environmental protection of the petrochemical industry have become increasingly high, the sealing performance of fluid transportation equipment in the petrochemical industry has accordingly been required to be improved. Therefore, it is necessary to design a sealing method that has good sealing performance, preferably absolute sealing performance, is relatively easy to implement, is applicable to various complex and highly hazardous fluids, and has a relatively simple structure and is convenient for maintenance and repair. Such a sealing method will undoubtedly effectively improve the safety of transporting complex and highly hazardous fluids, and thus improve the safe production and environmental protection of the petrochemical industry.

[0026] Figure 1 is a schematic structural diagram of a hydraulic dynamic sealing device for fluid medium transportation provided by an embodiment of this application. Refer to Figure 1 As shown, an embodiment of this application provides a hydraulic dynamic sealing device for fluid medium transportation, including a pump casing 1 and a pump cover 6 that are connected to each other. An impeller 2 is provided inside the pump casing 1, and a pump shaft 9 and a magnetic drive are provided inside the pump cover 6. The impeller 2 is fixedly installed at one end of the pump shaft 9 facing the pump casing 1, and the other end of the pump shaft 9 is connected to the magnetic drive;

[0027] A back vane 3 of the impeller is fixedly installed on a side of the impeller 2 away from the pump casing 1;

[0028] A hydraulic sealing cavity is formed between the back vane 3 of the impeller and the magnetic drive, and a pressurized liquid is filled in the hydraulic sealing cavity, and the pressure of the pressurized liquid is higher than the pump inlet pressure.

[0029] It should be noted that the pump casing 1 and the pump cover 6 are connected by bolts, the impeller 2 and the back vane 3 of the impeller are integrally formed, and the impeller 2 and the pump shaft 9 are connected by a key.

[0030] It is easy to understand that before the pump starts, the sealing liquid should fill the hydraulic sealing cavity, and the sealing liquid in the hydraulic sealing cavity should have a certain pressure, that is, pressurized liquid, and ensure that its pressure is higher than the pump inlet pressure.

[0031] In the above embodiment, sealing is achieved by combining dynamic sealing and liquid pressure difference, which is mainly used for transporting liquids containing solid particle impurities, such as shaftless pumps, magnetic pumps or canned motor pumps, etc. When the back vane 3 of the impeller rotates, it will generate a certain pressure, and the direction of this pressure is opposite to the head generated by the impeller 2, so as to offset the head generated by the impeller 2 and make the pressure on the back of the impeller 2 extremely low or negative pressure, which can prevent the pressure generated by the impeller 2 from entering the back of the impeller 2, so as to prevent the liquid containing solid particle impurities from leaking to the back of the impeller 2, thus realizing dynamic sealing. Then, by using the pressurized liquid and the characteristic that the liquid pressure difference determines its flow direction, the liquid containing solid particle impurities can be controlled at a certain position, which can effectively protect components such as the magnetic drive, and can also increase the total head of the impeller 2 for transporting the liquid containing solid particle impurities, improving the liquid transportation efficiency.

[0032] Since the pressure of the pressurized liquid in the hydraulic sealing cavity is higher than the pressure on the back of the impeller 2, the pressurized liquid will have losses. To solve the above problems, in a feasible implementation manner, an impeller seal ring 4 is fixedly installed on the side of the impeller 2 away from the pump casing 1, the back vane 3 of the impeller is located between the impeller 2 and the impeller seal ring 4, and a hydraulic sealing cavity is formed between the impeller seal ring 4 and the magnetic drive;

[0033] One end of the pump cover 6 facing the inner wall of the pump casing 1 is fixedly installed with a pump cover seal ring 5. The pump cover seal ring 5 is coaxially arranged with the impeller seal ring 4, and the impeller seal ring 4 is located inside the pump cover seal ring 5.

[0034] It is easy to understand that the impeller seal ring 4 and the pump cover seal ring 5 can adopt an interference fit method to ensure that the gap between the two is small enough.

[0035] In the above embodiment, the pump cover seal ring 5 and the impeller seal ring 4 jointly form a clearance seal, which can prevent the pressurized liquid in the hydraulic sealing cavity from flowing into the pump flow channel, thereby reducing the loss of the pressurized liquid, reducing the operating cost, and being beneficial to the economy of the sealing device.

[0036] In a feasible implementation manner, a sealing liquid inlet 10 and a sealing liquid outlet 11 are opened on the pump cover 6, and both the sealing liquid inlet 10 and the sealing liquid outlet 11 are communicated with the hydraulic sealing cavity.

[0037] In the above embodiments, the pressurized liquid in the hydraulic seal cavity can be kept in a flowing state through the seal liquid inlet 10 and the seal liquid outlet 11, which is beneficial to reducing the temperature of components such as the magnetic drive.

[0038] It is easy to understand that the seal liquid inlet 10 is connected to a liquid delivery power device to fill the hydraulic seal cavity with liquid and ensure that the liquid in the hydraulic seal cavity has a certain pressure. The seal liquid outlet 11 can be connected to a cooler, and the cooler is then connected to the inlet of the liquid delivery power device to form a loop, which can quickly cool the liquid.

[0039] In a feasible embodiment, the magnetic drive includes an inner magnetic steel 12, an isolation sleeve 13, an outer magnetic steel 14, and a magnetic drive housing 15. The inner magnetic steel 12 is connected to the other end of the pump shaft 9. The isolation sleeve 13 is arranged outside the inner magnetic steel 12 and connected to the pump cover 6. The outer magnetic steel 14 is arranged outside the isolation sleeve 13, and the magnetic drive housing 15 is arranged outside the outer magnetic steel 14 and connected to the pump cover 6;

[0040] The hydraulic seal cavity is between the impeller seal ring 4 and the isolation sleeve 13.

[0041] It should be noted that the cross-section of the isolation sleeve 13 is U-shaped, and the outer magnetic steel 14 is fixedly installed on the output shaft of the motor, thereby providing power for the inner magnetic steel 12. The motor is not shown in the figure.

[0042] In the above embodiments, the inner magnetic steel 12 drives the pump shaft 9 to rotate to enable the normal operation of the impeller 2. The gap between the impeller seal ring 4 and the isolation sleeve 13 is the hydraulic seal cavity for accommodating the pressurized liquid.

[0043] In a feasible embodiment, a thrust bearing 7 and a sliding bearing 8 are further provided at one end of the pump shaft 9 close to the pump housing 1. The thrust bearing 7 and the sliding bearing 8 are located in the hydraulic seal cavity.

[0044] It is easy to understand that the thrust bearing 7 is used to bear the axial thrust of the pump shaft 9, and the sliding bearing 8 is used to support the pump shaft 9. Here, it will not be elaborated too much.

[0045] In the above embodiments, the liquid in the hydraulic seal cavity can lubricate the thrust bearing 7 and the sliding bearing 8, extend their service life, and ensure the stability and low resistance of the operation of the pump shaft 9 and the impeller 2.

[0046] In a feasible embodiment, the pressurized liquid is the same as the pump delivery medium and does not contain solid particles.

[0047] In the above embodiments, even if a small portion of the pressurized liquid flows towards the impeller 2 side, it is possible to avoid affecting the composition of the liquid transported by the pump. The absence of solid particles can ensure that the components immersed therein can be fully lubricated and cooled, and the working performance will not decline due to solid particles.

[0048] During use, when the pump is shut down, the pressure on the back of the impeller 2, that is, on the side of the back vane 3 of the impeller, is equivalent to the pump inlet pressure. The pressure of the pressurized liquid in the hydraulic seal cavity is slightly higher than the pressure on the back of the impeller 2. The medium containing solid particle impurities in the pump flow channel cannot flow into the hydraulic seal cavity. The liquids in the thrust bearing 7, the sliding bearing 8, the inner magnetic steel 12, and the isolation sleeve 13 are all clean and free of impurities. When the pump starts, the pump shaft 9 drives the impeller 2 to rotate to generate a head, and the pressure in the pump flow channel rises. However, since the back vane 3 of the impeller and the pump cover 6 cooperate to form a dynamic seal, a certain pressure head can also be formed. The head generated by the impeller 2 cannot enter the back of the impeller 2. The pressure on the back of the impeller 2 is only equivalent to the pump inlet pressure, and the pressure head can increase the total head of the impeller 2 and improve the conveying efficiency of the medium. Components such as the thrust bearing 7, the sliding bearing 8, and the inner magnetic steel 12 are still in a liquid that is clean and free of impurities, ensuring safety. And due to the provision of a clearance seal, the flow of the liquid in the hydraulic seal cavity towards the impeller 2 side is very small or blocked. Therefore, the sealing economy is also ensured.

[0049] The embodiment of the present application provides a hydraulic dynamic sealing device for fluid medium transportation, which uses the principle that the flow direction of a liquid is determined by the liquid pressure magnitude to perform sealing. At the same time, it utilizes the characteristics of the dynamic seal to effectively reduce the pressure on the back of the impeller 2 and take effect with the operation of the pump to maintain the pressure on the back of the impeller 2 moderately at a condition basically the same as the pump inlet pressure, and adopts a clearance seal for cooperation to achieve the purpose of effectively reducing the sealing liquid pressure and enabling it to have a relatively accurate value, thereby effectively improving the sealing reliability and economy.

[0050] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application based on several embodiments provided by the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0051] The above specific implementation manners further elaborate in detail the purpose, technical solutions, and beneficial effects of the embodiments of the present application. It should be understood that the above is only the specific implementation manners of the embodiments of the present application and is not used to limit the protection scope of the embodiments of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A hydraulic power sealing device for fluid medium transportation, characterized in that: The invention comprises a pump casing (1) and a pump cover (6) which are connected to each other, wherein an impeller (2) is arranged inside the pump casing (1), and a pump shaft (9) and a magnetic transmission device are arranged inside the pump cover (6), wherein the impeller (2) is fixedly mounted on one end of the pump shaft (9) facing the pump casing (1), and the other end of the pump shaft (9) is connected to the magnetic transmission device; An impeller back blade (3) is fixedly mounted on a side of the impeller (2) away from the pump casing (1); A hydraulic sealing cavity is provided between the impeller back blade (3) and the magnetic transmission device, and the hydraulic sealing cavity is filled with pressurized liquid, the pressure of which is higher than the pump inlet pressure.

2. The hydraulic power sealing device for fluid medium transportation according to claim 1, characterized in that: An impeller sealing ring (4) is fixedly mounted on a side of the impeller (2) away from the pump casing (1); the impeller back blade (3) is located between the impeller (2) and the impeller sealing ring (4); and a hydraulic sealing chamber is formed between the impeller sealing ring (4) and the magnetic actuator; A pump cover sealing ring (5) is fixedly mounted on one end of the pump cover (6) facing the inner wall of the pump casing (1); the pump cover sealing ring (5) is coaxially arranged with the impeller sealing ring (4), and the impeller sealing ring (4) is located inside the pump cover sealing ring (5).

3. The hydraulic power sealing device for fluid medium transportation according to claim 1, characterized in that: The pump cover (6) is provided with a sealing liquid inlet (10) and a sealing liquid outlet (11), and both the sealing liquid inlet (10) and the sealing liquid outlet (11) are communicated with the hydraulic sealing chamber.

4. The hydraulic power sealing device for fluid medium transportation according to claim 2, characterized in that: The magnetic transmission device comprises an inner magnetic steel (12), an isolating sleeve (13), an outer magnetic steel (14) and a magnetic transmission device housing (15); the inner magnetic steel (12) is connected to the other end of the pump shaft (9); the isolating sleeve (13) is arranged outside the inner magnetic steel (12) and connected to the pump cover (6); the outer magnetic steel (14) is arranged outside the isolating sleeve (13); and the magnetic transmission device housing (15) is arranged outside the outer magnetic steel (14) and connected to the pump cover (6); A hydraulic sealing chamber is provided between the impeller sealing ring (4) and the isolation sleeve (13).

5. The hydraulic power sealing device for fluid medium transportation according to claim 4, characterized in that: The cross section of the isolation sleeve (13) is U-shaped.

6. The hydraulic power sealing device for fluid medium transportation according to claim 2, characterized in that: The impeller sealing ring (4) and the pump cover sealing ring (5) are clearance-matched.

7. The hydraulic power sealing device for fluid medium transportation according to any one of claims 1 to 6, characterized in that: A thrust bearing (7) and a sliding bearing (8) are also provided at one end of the pump shaft (9) close to the pump housing (1); the thrust bearing (7) and the sliding bearing (8) are located in the hydraulic sealing chamber.

8. The hydraulic power sealing device for fluid medium transportation according to any one of claims 1 to 6, characterized in that: The pressurized liquid is a liquid without solid particles.

9. The hydraulic power sealing device for fluid medium transportation according to any one of claims 1 to 6, characterized in that: The pump casing (1) and the pump cover (6) are connected by bolts.

10. The hydraulic power sealing device for fluid medium transportation according to any one of claims 1 to 6, characterized in that: The impeller (2) and the impeller back blades (3) are integrally formed.

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