Centrifugal pump mechanical seal cavity capable of preventing medium accumulation and centrifugal pump

Abstract

The utility model relates to a centrifugal pump machine seal cavity of preventing medium accumulation and centrifugal pump belongs to the mechanical seal technical field of centrifugal pump. Among them, the centrifugal pump machine seal cavity of preventing medium accumulation includes: rotating shaft, impeller, fixed mounting is in rotating shaft, friction pair, installs on rotating shaft, cover, fixed mounting is on friction pair, to with part friction pair fixed, the first end of machine seal chamber is close to impeller and sets up, the second end is close to cover and sets up with the abutment of cover, with the direction of medium flow is front, and machine seal chamber is located the front side of impeller, wherein, machine seal chamber includes the body portion formed with cavity and at least one separator arranged in the body portion, the separator separates at least part of the cavity into at least two separate cavities, and is suitable for blocking the rotating flow of medium in the cavity. Through the above-mentioned mode, the continuous friction of solid particles and machine seal cavity, friction pair can be avoided, the wear of solid particles to machine seal cavity and friction pair is reduced, so as to improve the service life of machine seal cavity and centrifugal pump whole.

Description

Technical Field

[0001] This utility model relates to the field of mechanical seal technology for centrifugal pumps, and in particular to a centrifugal pump mechanical seal cavity and centrifugal pump for preventing media accumulation. Background Technology

[0002] Centrifugal pumps transport liquids using the centrifugal force generated by the rotation of an impeller. During operation, the impeller rotates at high speed inside the pump casing, causing the medium entering the casing through the suction pipe to rotate as well. Under the action of centrifugal force, the medium is thrown towards the outer edge of the impeller and flows through the flow channels of the pump casing to the discharge pipe. Simultaneously, a vacuum is created at the center of the impeller due to the medium being thrown out, and under the action of atmospheric pressure, the medium is drawn into the impeller along the suction pipe. This process of continuously drawing in and discharging the medium continues.

[0003] In the centrifugal pump process described above, due to the unavoidable gap between the impeller and the mechanical seal cavity, some of the medium will enter the mechanical seal cavity through the gap under the action of centrifugal force. If the medium contains solid particles, these particles will accumulate in the mechanical seal cavity. Furthermore, since the medium enters the mechanical seal cavity from the back of the impeller, and the inlet pressure is greater than the pressure inside the mechanical seal cavity, the medium inside the mechanical seal cavity will generate eddies as the impeller rotates. The solid particles in the mechanical seal cavity will swirl along with the medium. During the swirling process in the mechanical seal cavity, the solid particles will continuously rub against the outer wall of the mechanical seal cavity and the friction pair. The mechanical seal cavity is constantly rubbed by the rotating solid particles, and the outer wall of the mechanical seal cavity will be worn down quickly, as will the friction pair, thus shortening the service life of the centrifugal pump. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a centrifugal pump sealing chamber for preventing media accumulation, comprising: Rotation axis; The impeller is fixedly mounted on the rotating shaft and rotates with the rotating shaft; A friction pair is mounted on the rotating shaft; The cover is fixedly installed on the friction pair to secure part of the friction pair. The mechanical seal chamber has a first end and a second end that are arranged opposite to each other. The first end is located near the impeller, and the second end is located near the cover so as to abut against the cover. With the direction of medium flow as the front, the mechanical seal chamber is located in front of the impeller. The mechanical seal chamber includes a body portion having a cavity and at least one partition member disposed within the body portion. The partition member divides at least a portion of the cavity into at least two partition chambers, which are adapted to prevent the medium from rotating and flowing within the cavity.

[0005] In one embodiment, the cavity includes a first cavity disposed near the impeller and a second cavity disposed near the cover; The second cavity has a flow guiding surface with the direction of medium flow as the front. The flow guiding surface is inclined from back to front toward the rotation axis, which is suitable for guiding the medium from the second cavity to the first cavity. The partition is disposed in the first cavity and divides the first cavity.

[0006] In one embodiment, the guide surface has a first end near the impeller and a second end near the cover, the friction pair has a first shortest distance to the first end and a second shortest distance to the second end, and the ratio of the first shortest distance to the second shortest distance is less than or equal to 2.

[0007] In one embodiment, the line connecting the first end and the end of the first cavity near the impeller has a first slope, and the guide surface has a second slope, wherein the first slope is greater than the second slope.

[0008] In one embodiment, the separator is integrally formed with the mechanical seal chamber.

[0009] In one embodiment, the separator is arranged perpendicular to the axial centerline of the mechanical seal chamber.

[0010] In one embodiment, the diameter of the first end decreases towards the second end; The friction pair has a first linear distance from the first end and a second linear distance from the second end, wherein the ratio of the second linear distance to the first linear distance is greater than or equal to one-half.

[0011] In one embodiment, the ratio of the second straight-line distance to the first straight-line distance is greater than or equal to one-third.

[0012] In one embodiment, the friction pair has a first axial distance from the impeller, and the cover has a second axial distance from the impeller, wherein the ratio of the first axial distance to the second axial distance is less than or equal to 0.2.

[0013] This utility model also provides a centrifugal pump, which includes at least the centrifugal pump seal cavity for preventing media accumulation as described above.

[0014] The beneficial effects of this utility model are reflected in the fact that the mechanical seal chamber includes a main body portion forming a cavity and at least one partition member disposed within the main body portion. The partition member divides at least a portion of the cavity into at least two partition chambers, so that solid particles entering the mechanical seal chamber are blocked by the partition member and cannot form continuous eddies in the cavity, thereby avoiding continuous friction between solid particles and the mechanical seal chamber and friction pair, reducing the wear of solid particles on the mechanical seal chamber and friction pair, and improving the service life of the mechanical seal chamber and the centrifugal pump as a whole. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the sealing chamber of a centrifugal pump used in the prior art to prevent media accumulation. Figure 2 This is a schematic diagram of the pump body provided by this utility model; Figure 3 A schematic diagram of the centrifugal pump sealing cavity for preventing media accumulation provided by this utility model; Figure 4 for Figure 3 Partial structural diagram; Figure 5 A schematic diagram of the medium flow direction in the sealing cavity of the centrifugal pump for preventing medium accumulation provided by this utility model; Figure 6 for Figure 2 A schematic diagram of the mechanical seal chamber in the middle; Figure 7 for Figure 6 A cross-sectional schematic diagram; Figure 8 for Figure 6 The front view.

[0016] Figure label: 1-Pump casing; 11-Suction inlet; 12-Discharge outlet; 2-Mechanical seal cavity; 21-Rotating shaft; 22-Impeller; 23-Mechanical seal chamber; 231-First cavity; 232-Second cavity; 233-Separator; 234-Guide surface; 24-Friction pair; 241-Rotating ring; 242-Stationary ring; 243-Stationary ring seat; 25-Cover. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example 1: Reference Figures 2-8 A centrifugal pump according to a preferred embodiment of the present invention includes a pump body, a transmission device, and a drive device, wherein the drive device drives the pump body to operate through the transmission device. The drive device can be a motor, and the transmission device can be a gearbox, etc., which are conventional structures and are not specifically limited herein, but are determined according to the actual situation.

[0019] The pump body includes a pump casing 1 and a centrifugal pump seal 2 connected to the pump casing 1 to prevent media accumulation. The pump casing 1 has a suction port 11 and a pressure outlet 12. When the drive device drives the pump body to run, the pressure inside the pump casing 1 is lower than the external pressure, which causes the medium to enter the pump casing 1 through the suction port 11 and be thrown towards the pressure outlet 12 under the action of centrifugal force, so that the medium flows out of the pump casing 1 from the pressure outlet 12.

[0020] Specifically, the centrifugal pump mechanical seal chamber 2 for preventing media accumulation includes a rotating shaft 21, an impeller 22, a friction pair 24, a cover 25, and a mechanical seal chamber 23. The impeller 22 is fixedly mounted on the rotating shaft 21 and rotates with it. The rotating shaft 21 is connected to an external drive device, which drives it to rotate, thereby rotating the impeller 22. The external drive device can be a drive motor, etc., a conventional structure, and is not specifically limited here, depending on the actual situation.

[0021] Friction pair 24 is the core working component of the sealing system, forming the main sealing surface to prevent media leakage. Friction pair 24 is mounted on rotating shaft 21 and includes rotating ring 241 and stationary ring 242. Rotating ring 241 is fixedly connected to rotating shaft 21 to rotate with rotating shaft 21, while stationary ring 242 is clamped and fixed in a specific position (such as a groove or step) inside the cover 25 to ensure that stationary ring 242 remains stationary during operation and to prevent stationary ring 242 from rotating or moving axially.

[0022] The stationary ring 242 includes a stationary ring body and a stationary ring seat 243. The stationary ring seat 243 is fixedly connected to the cover 25 and abuts against and clamps the stationary ring body, preventing the stationary ring body from moving. The stationary ring 242 also includes an anti-rotation pin to further ensure that the stationary ring 242 remains stationary during operation, thereby ensuring the sealing performance of the friction pair 24.

[0023] The friction pair 24 relies on a spring to provide an initial sealing force, ensuring a tight fit between the rotating ring 241 and the stationary ring 242. The spring force is then transmitted through the cover 25 to the stationary ring 242. In other words, when the cover 25 is connected to the stationary ring 242, the spring needs to be stressed to apply a force towards both the stationary ring 242 and the rotating ring 241, ensuring a tight fit and thus achieving a seal.

[0024] As described above, the cover 25 is fixedly mounted on the friction pair 24 to partially secure the friction pair 24. Therefore, the contact surface between the cover 25 and the stationary ring 242 is sealed to prevent leakage of the medium from the position between the cover 25 and the stationary ring 242.

[0025] The mechanical seal chamber 23 has a first end and a second end arranged opposite to each other. The first end is located near the impeller 22, and the second end is located near the cover 25 to abut against the cover 25. With the direction of medium flow as the front, the mechanical seal chamber 23 is located in front of the impeller 22. In this embodiment, the medium is a fluid medium. When the application scenario is a chemical scenario, solid particles may be present in the fluid medium. Therefore, when the drive device drives the pump body to operate, due to the rotation of the impeller 22, the pressure inside the pump casing 1 is less than the pressure outside the pump casing 1, and the fluid medium enters the pump casing 1 from the suction port 11.

[0026] However, due to the unavoidable gap between the rotating space of the impeller 22 and the mechanical seal cavity 2, some fluid medium will enter the mechanical seal cavity 2 through the gap during pump operation. As mentioned above, when the application scenario is a chemical scenario, the fluid medium may contain solid particles. Therefore, after the fluid medium enters the mechanical seal cavity 2, the solid particles will accumulate in the mechanical seal cavity 2. The fluid medium enters the mechanical seal cavity 2 from the back of the impeller 22. Since the inlet pressure is greater than the pressure inside the mechanical seal cavity 2, the fluid medium inside the mechanical seal cavity 2 will generate eddies as the impeller 22 rotates. The solid particles inside the mechanical seal cavity 2 will swirl along with the fluid medium. During the swirling process inside the mechanical seal cavity 2, the solid particles will continuously rub against the outer wall of the mechanical seal chamber 23 and the friction pair 24. The mechanical seal cavity 2 will be worn down quickly by the continuous friction of the rotating solid particles, and the outer wall of the mechanical seal chamber 23 will also be worn down, thereby reducing the service life of the entire centrifugal pump.

[0027] To address the aforementioned technical problems, the mechanical seal chamber 23 in this embodiment includes a main body portion forming a cavity and at least one partition 233 disposed within the main body portion. The partition 233 divides at least a portion of the cavity into at least two partitioned chambers, suitable for preventing the medium from rotating and flowing within the cavity. By dividing at least a portion of the cavity into at least two partitioned chambers through the partition 233, the fluid medium within the cavity cannot form a continuous vortex due to the obstruction of the partition 233. Therefore, continuous friction between solid particles and the mechanical seal chamber 2 and the friction pair 24 can be avoided, reducing the wear of solid particles on the mechanical seal chamber 2 and the friction pair 24, thereby improving the service life of the mechanical seal chamber 2 and the centrifugal pump as a whole.

[0028] In this embodiment, there are four separators 233. The four separators 233 form four separate cavities in the cavity, which reduces the rotation radius of solid particles in the mechanical seal cavity 2 and further reduces the wear between solid particles and mechanical seal cavity 2 and friction pair 24.

[0029] In other embodiments, the number of separators 233 can also be other, such as one, two, three, five, etc., and is not specifically limited here, depending on the actual situation. It is worth noting that, theoretically, the more separators 233 there are, the more partition cavities are formed, and therefore the smaller the rotation radius of solid particles in the mechanical seal cavity 2. However, when the space of the partition cavity is narrower, solid particles are more likely to accumulate in the partition cavity, which will still cause wear of the mechanical seal cavity 2 and the friction pair 24 by the solid particles. Therefore, in the actual design of the number of separators 233, it is necessary to reduce the wear of solid particles on the mechanical seal cavity 2 and the friction pair 24, while also avoiding solid particles from contacting each other in the partition cavity.

[0030] Specifically, the cavity includes a first cavity 231 located near the impeller 22 and a second cavity 232 located near the cover 25. The second cavity 232 has a guide surface 234, which is inclined from back to front toward the rotating shaft 21 with the direction of medium flow as the front, suitable for guiding the medium from the second cavity 232 into the first cavity 231. A separator 233 is disposed in the first cavity 231 and separates the first cavity 231. According to the flow path of the fluid medium, since the fluid medium enters the mechanical seal cavity 2 from the gap between the outer edge of the impeller 22 and the mechanical seal cavity 2, the fluid medium will first enter the first cavity 231 and rotate in the first cavity 231. The separator 233 is provided in the first cavity 231, which reduces the flow radius of the solid medium that enters the mechanical seal cavity 2 with the fluid medium, thus reducing the wear between solid particles and the mechanical seal cavity 2 and the friction pair 24.

[0031] Even if a small amount of fluid medium enters the second cavity 232, due to the presence of the guide surface 234 and the vortex rotation of the fluid medium in the mechanical seal chamber 23, the fluid medium in the second cavity 232 can flow to the first cavity 231 through the guide surface 234, reducing the accumulation of fluid medium in the second cavity 232 and further reducing the wear between solid particles and the mechanical seal chamber 2 and the friction pair 24.

[0032] To ensure the strength of the separator 233 and prevent it from separating from the mechanical seal chamber 23 under the impact of fluid flow, thus avoiding the problem of insufficient wear between solid particles and the mechanical seal chamber 23 and friction pair 24, in this embodiment, the separator 233 and the mechanical seal chamber 23 are integrally formed. The integrally formed separator 233 and mechanical seal chamber 23 ensure the strength of the separator 233 and further reduce wear between solid particles and the mechanical seal chamber 23 and friction pair 24.

[0033] Furthermore, the separator 233 is positioned perpendicular to the axial centerline of the mechanical seal chamber 23. The purpose of this arrangement is to ensure that the angle between the separator 233 and the inner wall of the mechanical seal chamber 23 is a right angle, rather than an obtuse or acute angle, thus preventing solid particles from accumulating at this location and causing wear.

[0034] Please see Figure 1 In the existing technology, there is also a problem that the distance between the friction pair 24 and the mechanical seal chamber 2 is too short, causing solid particles to accumulate at point K in the figure. This results in severe wear between the solid particles and the mechanical seal chamber 23 and the friction pair 24, which seriously affects the sealing performance of the pump mechanical seal. In more serious cases, it may cause the pumped medium fluid to leak through the mechanical seal device onto the main shaft, affecting the life of the main shaft and causing liquid corrosion to the bearing housing. This has a great impact on the maintenance of the entire pump.

[0035] To avoid the aforementioned problems, in this embodiment, the guide surface 234 has a first end near the impeller 22 and a second end near the cover 25. The friction pair 24 has a first shortest distance to the first end and a second shortest distance to the second end, with the ratio of the first shortest distance to the second shortest distance being less than or equal to 2. This arrangement increases the distance between the friction pair 24 and the second end of the guide surface 234, making it at least half the distance between the friction pair 24 and the first end of the guide surface 234. This allows the fluid medium to drive the solid particles to rotate and flow through the guide surface 234 into the first cavity 231, thus preventing excessive solid particles from contacting the friction pair 24 and the guide surface 234.

[0036] Specifically, the line connecting the first end and the end of the first cavity 231 near the impeller 22 has a first slope, and the guide surface 234 has a second slope, with the first slope being greater than the second slope. The first slope being greater than the second slope is based on the first cavity 231. In this case, the line connecting the first end and the end of the first cavity 231 near the impeller 22 slopes from upper left to lower right, and the guide surface 234 also slopes from upper left to lower right. The purpose of this arrangement is that solid particles can be more easily guided into the first cavity 231 via the guide surface 234, while solid particles located in the first cavity 231 are less likely to flow into the second cavity 232 due to the gentler slope, further reducing the accumulation of solid particles at point K.

[0037] As mentioned above, the mechanical seal chamber 23 has a first end and a second end, with the diameter decreasing from the first end to the second end; the friction pair 24 has a first straight-line distance from the first end and a second straight-line distance from the second end, and the ratio of the second straight-line distance to the first straight-line distance is greater than or equal to one-half, thereby increasing the volume of the friction pair 24 and the mechanical seal chamber 23 at point K and reducing the possibility of solid particles accumulating at point K.

[0038] Preferably, the ratio of the second straight-line distance to the first straight-line distance is greater than or equal to one-third.

[0039] The friction pair 24 has a first axial distance from the impeller 22, and the cover 25 has a second axial distance from the impeller 22. The ratio of the first axial distance to the second axial distance is less than or equal to 0.2, so that the friction pair 24 can be set close to the impeller 22, thereby increasing the space of the mechanical seal chamber 23 and making it easier to prevent solid particles from accumulating near the friction pair 24.

[0040] In summary: By providing the mechanical seal chamber 23, which includes a body portion having a cavity and at least one partition 233 disposed within the body portion, the partition 233 divides at least a portion of the cavity into at least two partition chambers. This prevents solid particles entering the mechanical seal chamber 23 from forming continuous eddies within the cavity due to the obstruction of the partition 233. This avoids continuous friction between solid particles and the mechanical seal chamber 2 and the friction pair 24, reduces wear on the mechanical seal chamber 2 and the friction pair 24 by solid particles, and improves the service life of the mechanical seal chamber 2 and the centrifugal pump as a whole.

[0041] In the description of the embodiments of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "center," "top," "bottom," "top," "bottom," "inner," "outer," "inner side," and "outer side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. "Inner side" refers to the interior or enclosed area or space. "Outer perimeter" refers to the area surrounding a specific component or specific area.

[0042] In the description of embodiments of this utility model, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] In the description of the embodiments of this utility model, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0045] In the description of the embodiments of this utility model, it should be understood that "-" and "~" represent a range of two values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0046] In the description of the embodiments of this utility model, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0047] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A centrifugal pump sealing chamber for preventing media accumulation, characterized in that, include: Rotation axis; The impeller is fixedly mounted on the rotating shaft and rotates with the rotating shaft; A friction pair is mounted on the rotating shaft; The cover is fixedly installed on the friction pair to secure part of the friction pair. The mechanical seal chamber has a first end and a second end that are disposed opposite to each other. The first end is disposed near the impeller, and the second end is disposed near the cover so as to abut against the cover. With the direction of medium flow as the front, the mechanical seal chamber is located on the front side of the impeller. The mechanical seal chamber includes a body portion having a cavity and at least one partition member disposed within the body portion. The partition member divides at least a portion of the cavity into at least two partition chambers, which are adapted to prevent the rotational flow of the medium within the cavity.

2. The centrifugal pump sealing chamber for preventing media accumulation according to claim 1, characterized in that, The cavity includes a first cavity disposed near the impeller and a second cavity disposed near the cover; The second cavity has a flow guiding surface with the direction of medium flow as the front. The flow guiding surface is inclined from back to front toward the rotation axis, which is suitable for guiding the medium from the second cavity to the first cavity. The partition is disposed in the first cavity and divides the first cavity.

3. The centrifugal pump sealing chamber for preventing media accumulation according to claim 2, characterized in that, The guide surface has a first end near the impeller and a second end near the cover. The friction pair has a first shortest distance to the first end and a second shortest distance to the second end. The ratio of the first shortest distance to the second shortest distance is less than or equal to 2.

4. The centrifugal pump sealing chamber for preventing media accumulation according to claim 2, characterized in that, The line connecting the first end and the end of the first cavity near the impeller has a first slope, and the guide surface has a second slope, wherein the first slope is greater than the second slope.

5. The centrifugal pump sealing chamber for preventing media accumulation according to any one of claims 1 to 4, characterized in that, The separator is integrally formed with the mechanical seal chamber.

6. The centrifugal pump sealing chamber for preventing media accumulation according to any one of claims 1 to 4, characterized in that, The separator is arranged perpendicular to the axial centerline of the mechanical seal chamber.

7. The centrifugal pump sealing chamber for preventing media accumulation according to any one of claims 1 to 4, characterized in that, The diameter decreases from the first end to the second end; The friction pair has a first linear distance from the first end and a second linear distance from the second end, wherein the ratio of the second linear distance to the first linear distance is greater than or equal to one-half.

8. The centrifugal pump sealing chamber for preventing media accumulation according to claim 7, characterized in that, The ratio of the second straight-line distance to the first straight-line distance is greater than or equal to one-third.

9. The centrifugal pump sealing chamber for preventing media accumulation according to any one of claims 1 to 4, characterized in that, The friction pair has a first axial distance from the impeller, and the cover has a second axial distance from the impeller. The ratio of the first axial distance to the second axial distance is less than or equal to 0.

2.

10. A centrifugal pump, characterized in that, It includes at least the centrifugal pump seal cavity for preventing media buildup as described in any one of claims 1 to 9.

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