Double casing multistage centrifugal pump discharge cover

Abstract

The utility model discloses a double -shell multistage centrifugal pump discharge cover relates to centrifugal pump technical field, including first discharge cover casing and second discharge cover casing, install the flow mechanism between first discharge cover casing and second discharge cover casing, in the utility model, the high pressure medium after the last stage guide vane pressure boost enters annular chamber from the center inlet of first discharge cover casing, and the drainage vane captures the cyclone, and the circular motion is decomposed into axial propulsion, and the guide vane divides the wide gap into the narrow flow channel, and the medium diffusion is inhibited to form the large -scale vortex, and under the cyclone guidance of drainage vane and the flow channel restraint cooperation of guide vane, along the axial uniformity passes through the cylindrical array, and the flow rate uniformity promotes, and the local pressure loss reduces, and the conveying cylinder of alternate distribution, the drainage vane and the guide vane inhibit medium pulsation, and the flow state is stabilized, and the operation efficiency of pump is improved.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pump technology, and in particular to a discharge cover for a double-casing multi-stage centrifugal pump. Background Technology

[0002] Double-casing multistage centrifugal pumps are a common type of pump, typically used in applications requiring high pump head and high discharge pressure. They are widely used in petroleum, chemical, and power industries. When the pump is working, the medium being pumped enters the final stage guide vane through the centrifugal force of the final stage impeller. After flowing out of the final stage guide vane, the medium is discharged from the pump through the discharge cover and transported to the required location.

[0003] In the prior art, most discharge covers adopt a structure with multiple holes machined in the circumferential direction of the discharge cover. When the medium flows through the holes of the discharge cover, its flow state will change significantly due to the structural characteristics of the circular flow holes. The drastic contraction of the flow channel cross section will cause local eddies and sudden changes in flow velocity, resulting in some kinetic energy being converted into useless turbulent loss, which will reduce the pump operating efficiency. Utility Model Content

[0004] The purpose of this invention is to solve the problem that most discharge covers in the prior art adopt a structure with multiple holes machined in the circumferential direction of the discharge cover. The drastic contraction of the flow channel cross section will cause local eddies and sudden changes in flow velocity, resulting in a decrease in pump operating efficiency. Therefore, this invention proposes a discharge cover for a double-casing multi-stage centrifugal pump.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a discharge cover for a double-shell multi-stage centrifugal pump, comprising a first discharge cover shell and a second discharge cover shell, wherein a flow-through mechanism is installed between the first discharge cover shell and the second discharge cover shell, the flow-through mechanism comprising a conveying cylinder, the two ends of the conveying cylinder being fixedly connected to opposite sides of the first discharge cover shell and the second discharge cover shell respectively, a gap being provided between two adjacent conveying cylinders, the first discharge cover shell and the second discharge cover shell, a flow-guiding blade being fixedly connected to the outer surface of the conveying cylinder, and a reinforcing mechanism being provided on the outside of the conveying cylinder.

[0006] Preferably, a guide vane is fixedly connected between the first discharge cover housing and the second discharge cover housing, and the guide vane is spaced apart from the conveying cylinder and disposed inside the gap.

[0007] Preferably, the reinforcing mechanism includes a sleeve ring, the inner ring surface of which is fixedly connected to the outer surface of the conveying cylinder, and the opposite sides of the two sleeve rings are respectively fixedly connected to the two ends of the guide vane.

[0008] Preferably, a support column is fixedly connected to the other side of each of the two sleeve rings, and multiple support columns are arranged in a uniform ring array with the center line of the sleeve ring as the axis. Positioning holes are opened on the opposite side of the first discharge cover housing and the second discharge cover housing, and the support columns are inserted into the interior of the positioning holes.

[0009] Preferably, the inner rings of the multiple support columns are fixedly connected with sealing rings, and two sealing rings are respectively installed at the connection between the conveying cylinder and the first discharge cover housing and at the connection between the conveying cylinder and the second discharge cover housing.

[0010] Preferably, the outer surface of the conveying cylinder is fixedly connected with an insert block, and multiple insert blocks are arranged in a uniform ring array with the center line of the conveying cylinder as the axis.

[0011] Preferably, a reinforcing rib is fixedly connected between the two sleeve rings, and multiple reinforcing ribs are arranged in a uniform ring array with the center line of the conveying cylinder as the axis, and multiple reinforcing ribs are fixedly connected to the inner side of the drainage blade.

[0012] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0013] 1. In this utility model, the high-pressure medium after being pressurized by the final stage guide vane enters the annular cavity from the central inlet of the first discharge cover shell. The guide vane captures the swirling flow, decomposing the circular motion into axial propulsion. The guide vane divides the wide gap into a narrow flow channel, suppressing the diffusion of the medium and forming a large-scale vortex. Under the synergistic guidance of the swirling flow of the guide vane and the flow channel constraint of the guide vane, the medium passes through the cylindrical array uniformly along the axis, improving the uniformity of the flow velocity and reducing local pressure loss. The alternating distribution of the conveying cylinder, guide vane and guide vane suppresses the pulsation of the medium and stabilizes the flow state.

[0014] 2. In this utility model, the sleeve ring and the reinforcing rib form an annular hoop and radial rib, which disperse the radial load of the conveying cylinder, reduce the stress concentration coefficient at the root, resist deformation, and the support column and positioning hole precisely constrain the position of the conveying cylinder, maintain the uniformity of the flow gap, the insert block covers the scouring area, reduces the wear rate, and the sealing ring is deformed by the pressure of the medium, filling the assembly gap and reducing leakage. Attached Figure Description

[0015] Figure 1 A three-dimensional structural diagram of a discharge cover for a double-shell multi-stage centrifugal pump is provided for this utility model;

[0016] Figure 2 This utility model provides a partial structural connection diagram of the discharge cover of a double-shell multi-stage centrifugal pump;

[0017] Figure 3 This utility model provides a partial structural disassembly diagram of the discharge cover of a double-casing multi-stage centrifugal pump;

[0018] Figure 4This utility model presents a schematic diagram of a sleeve ring connection structure for the discharge cover of a double-shell multi-stage centrifugal pump.

[0019] Legend: 1. First discharge cover housing; 2. Flowing mechanism; 21. Conveying cylinder; 22. Drain vane; 23. Guide vane; 3. Reinforcing mechanism; 31. Insert block; 32. Sleeve ring; 33. Positioning hole; 34. Reinforcing rib; 35. Support column; 36. Sealing ring; 4. Second discharge cover housing. Detailed Implementation

[0020] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0022] Example 1: As Figure 1 - Figure 4 As shown, this utility model provides a discharge cover for a double-casing multi-stage centrifugal pump, including a first discharge cover housing 1 and a second discharge cover housing 4. A flow-through mechanism 2 is installed between the first discharge cover housing 1 and the second discharge cover housing 4. The flow-through mechanism 2 includes a conveying cylinder 21, with its two ends fixedly connected to opposite sides of the first discharge cover housing 1 and the second discharge cover housing 4, respectively. A gap is provided between two adjacent conveying cylinders 21 and between the first discharge cover housing 1 and the second discharge cover housing 4. A guide vane 22 is fixedly connected to the outer surface of the conveying cylinder 21, and a reinforcing mechanism 3 is provided on the outside of the conveying cylinder 21. A guide vane 23 is fixedly connected between the first discharge cover housing 1 and the second discharge cover housing 4, and the guide vane 23 is spaced apart from the conveying cylinder 21 and is disposed inside the gap.

[0023] After being pressurized by the final stage guide vane, the high-pressure medium enters the annular cavity from the central inlet of the first discharge cover shell 1. The guide vane 22 captures the swirling flow, decomposing the circular motion into axial propulsion. The guide vane 23 divides the wide gap into a narrow flow channel, suppressing the diffusion of the medium and forming a large-scale vortex. Under the synergistic guidance of the swirling flow of the guide vane 22 and the flow channel constraint of the guide vane 23, the medium passes through the cylindrical array uniformly along the axis, improving the uniformity of the flow velocity and reducing local pressure loss. The alternating distribution of the conveying cylinder 21, the guide vane 22 and the guide vane 23 suppresses the pulsation of the medium and stabilizes the flow state.

[0024] Example 2: Figure 1 - Figure 4As shown, the reinforcing mechanism 3 includes a sleeve ring 32, the inner ring surface of which is fixedly connected to the outer surface of the conveying cylinder 21. The opposite sides of the two sleeve rings 32 are respectively fixedly connected to the two ends of the guide vane 22. Support columns 35 are fixedly connected to the other sides of both sleeve rings 32. Multiple support columns 35 are arranged in a uniform ring array around the center line of the sleeve ring 32. Positioning holes 33 are provided on the opposite sides of the first discharge cover housing 1 and the second discharge cover housing 4, and the support columns 35 are inserted into the positioning holes 33. The inner rings of the multiple support columns 35 are fixedly connected to the outer surface of the conveying cylinder 21. A sealing ring 36 is fixedly connected, and two sealing rings 36 are respectively installed at the connection between the conveying cylinder 21 and the first discharge cover housing 1 and the connection between the conveying cylinder 21 and the second discharge cover housing 4; an inlay block 31 is fixedly connected to the outer surface of the conveying cylinder 21, and multiple inlay blocks 31 are arranged in a uniform ring array with the center line of the conveying cylinder 21 as the axis; a reinforcing rib 34 is fixedly connected between the two sleeve rings 32, and multiple reinforcing ribs 34 are arranged in a uniform ring array with the center line of the conveying cylinder 21 as the axis, and multiple reinforcing ribs 34 are fixedly connected to the inner side of the drainage blade 22.

[0025] The connecting ring 32 and the reinforcing rib 34 form an annular hoop and radial ribs, which disperse the radial load of the conveying cylinder 21, reduce the stress concentration coefficient at the root, and resist deformation. The support column 35 and the positioning hole 33 precisely constrain the position of the conveying cylinder 21 and maintain the uniformity of the flow gap. The insert block 31 is in direct contact with the medium, and its wear-resistant material resists particle erosion and avoids the increase in flow resistance caused by surface wear of the conveying cylinder 21. The sealing ring 36 is deformed by the pressure of the medium, fills the assembly gap, and reduces leakage.

[0026] The operating method and working principle of this device are as follows: When the centrifugal pump is working, the motor drives the impeller, and the medium is pressurized in the last stage guide vane. The medium carries the particles and rushes towards the discharge cover in a swirling state. It enters the annular flow cavity formed by the first discharge cover housing 1 and the second discharge cover housing 4 from the center inlet of the first discharge cover housing 1, and prepares to enter the flow channel. The medium first contacts the guide vanes 22 on the outer surface of the conveying cylinder 21. The spiral guide vanes 22 capture the swirling component in the medium and decompose the disordered motion in the circumferential direction into axial propulsion force, reducing the kinetic energy loss caused by the swirling flow and making the medium initially form a directional flow. Then the medium enters the gap between adjacent conveying cylinders 21. The guide vanes 23 divide the wide gap into a narrow flow channel and forcibly constrain the diffusion trend of the medium. The sleeve ring 32 and the reinforcing rib 34 form a rigid frame and are attached to the inner side of the guide vanes 22 to jointly disperse the radial load generated by the impact of the medium. The support column 35 is inserted into the positioning hole 33 to constrain the circumferential position of the conveying cylinder 21 and maintain the flow stability.

[0027] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A discharge cover for a double-casing multistage centrifugal pump, comprising a first discharge cover housing (1) and a second discharge cover housing (4), characterized in that: A flow-through mechanism (2) is installed between the first discharge cover housing (1) and the second discharge cover housing (4). The flow-through mechanism (2) includes a conveying cylinder (21). The two ends of the conveying cylinder (21) are fixedly connected to the opposite sides of the first discharge cover housing (1) and the second discharge cover housing (4). A gap is provided between two adjacent conveying cylinders (21), the first discharge cover housing (1) and the second discharge cover housing (4). A guide vane (22) is fixedly connected to the outer surface of the conveying cylinder (21). A reinforcing mechanism (3) is provided on the outside of the conveying cylinder (21).

2. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 1, characterized in that: A guide vane (23) is fixedly connected between the first discharge cover housing (1) and the second discharge cover housing (4). The guide vane (23) is spaced apart from the conveying cylinder (21) and is located inside the gap.

3. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 1, characterized in that: The strengthening mechanism (3) includes a sleeve ring (32), the inner ring surface of which is fixedly connected to the outer surface of the conveying cylinder (21), and the opposite sides of the two sleeve rings (32) are fixedly connected to the two ends of the guide vane (22).

4. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 3, characterized in that: Each of the two sleeve rings (32) is fixedly connected to a support column (35) on the other side. Multiple support columns (35) are arranged in a uniform ring array with the center line of the sleeve ring (32) as the axis. Positioning holes (33) are opened on the opposite side of the first discharge cover housing (1) and the second discharge cover housing (4). The support columns (35) are inserted into the inside of the positioning holes (33).

5. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 4, characterized in that: The inner rings of the multiple support columns (35) are fixedly connected with sealing rings (36), and two sealing rings (36) are respectively installed at the connection between the conveying cylinder (21) and the first discharge cover housing (1) and at the connection between the conveying cylinder (21) and the second discharge cover housing (4).

6. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 1, characterized in that: The outer surface of the conveying cylinder (21) is fixedly connected with an inlay block (31), and multiple inlay blocks (31) are arranged in a uniform ring array with the center line of the conveying cylinder (21) as the axis.

7. The discharge cover of a double-casing multi-stage centrifugal pump according to claim 3, characterized in that: A reinforcing rib (34) is fixedly connected between the two sleeve rings (32). The multiple reinforcing ribs (34) are arranged in a uniform ring array with the center line of the conveying cylinder (21) as the axis. The multiple reinforcing ribs (34) are fixedly connected to the inner side of the drainage blade (22).

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