Multi-stage centrifugal pump with sealing ring

Abstract

The multistage centrifugal pump comprises an impeller and the high-pressure-drop sealing ring, a mounting groove is formed in one side of the high-pressure-drop sealing ring, one end of the impeller is arranged in the mounting groove, a radial straight sealing face is arranged on the outer side of the impeller, a first pressure reducing groove is formed in an inner cavity, adjacent to the outer side of the impeller, of the mounting groove, and a second pressure reducing groove is formed in an inner cavity, adjacent to the outer side of the impeller, of the mounting groove. A radial leakage channel is arranged between the first pressure reduction groove and the radial straight sealing face, an axial straight sealing face is arranged at the end, in the mounting groove, of the impeller, and a labyrinth type boss is arranged on the side, adjacent to the axial straight sealing face, of the high pressure drop sealing ring. An axial leakage channel is arranged between the labyrinth type boss and the axial straight sealing face. Through the design of the labyrinth type pressure reducing groove and the backflushing groove which are of a unique structure, the pressure reducing and flow limiting effects can be achieved, and liquid leakage is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of multistage pumps, and specifically relates to a multistage centrifugal pump with a sealing ring. Background Art

[0002] As a key device in the industrial field, multistage centrifugal pumps are widely used in various fluid transportation scenarios. A multistage pump consists of a rotating part and a stator part. There is a gap between the rotating impeller and the pump casing, and the pressure difference on both sides of the gap is very large. If the gap is too large, the liquid coming out of the impeller outlet will return to the suction chamber of the impeller through this gap, which is called internal leakage. The maximum leakage amount can reach 5% of the total liquid volume, resulting in low pump efficiency and wasting more energy. At the same time, during the operation of the pump, the pump casing and the impeller may be scrapped due to excessive wear. Therefore, a sealing ring must be installed between the pump casing and the impeller, which can not only reduce liquid leakage but also bear wear. After wear, only the sealing ring needs to be replaced instead of the relatively expensive impeller and pump casing, extending the service life of the impeller and pump casing and reducing the repair cost.

[0003] At present, when the sealing ring is installed on the impeller, the liquid leakage is large, and at the same time, due to the impact of the liquid leakage flow, the service life of the current sealing ring is not long. Content of the Utility Model

[0004] The purpose of the utility model is to provide a multistage centrifugal pump with a sealing ring, including an impeller and a high-pressure-drop sealing ring. An installation groove is opened on one side of the high-pressure-drop sealing ring, one end of the impeller is arranged in the installation groove, a radial flat sealing surface is arranged on the outer side of the impeller, a first decompression groove is opened in the inner cavity adjacent to the outer side of the impeller in the installation groove, a radial leakage channel is arranged between the first decompression groove and the radial flat sealing surface, an axial flat sealing surface is arranged at one end of the impeller inside the installation groove, a labyrinth boss is arranged on the side adjacent to the axial flat sealing surface of the high-pressure-drop sealing ring, and an axial leakage channel is arranged between the labyrinth boss and the axial flat sealing surface.

[0005] As a further preference, there are several groups of the first decompression grooves, and the first decompression groove is an inclined-tooth triangle, and the angle between the side of the inclined-tooth triangle and the radial flat sealing surface is less than 60°.

[0006] As a further preference, second decompression grooves are opened at the right-angle corners of the radial flat sealing surface and the axial flat sealing surface, and the second decompression groove is specifically square.

[0007] Through the above technical solutions, the beneficial effects of the utility model are as follows:

[0008] The labyrinth decompression groove design with a unique structure of the present utility model: Multiple labyrinth first decompression grooves in the shape of "oblique sawtooth triangles" are designed on the radial sealing end face. When the leakage water flows through the first decompression grooves, a reflected water flow is formed to interact with the direct leakage water flow, reducing the pressure of the leakage water flow. Multiple first decompression grooves are designed to form multiple levels of pressure reduction, and the effect of decompression and flow limiting is obvious.

[0009] The design of the anti-flushing groove with a unique structure: A second decompression groove structure in the shape of a "square" is designed at the corner of the radial sealing surface and the axial sealing surface of the sealing ring. When the leakage water flows from the radial sealing gap into the second decompression groove, a reflected water flow is formed to interact with the direct leakage water flow through the second decompression groove, forming the effect of decompression and flow limiting.

[0010] The design of the multi-step sealing surface: Multiple steps are designed on the axial end face of the sealing ring, and a second decompression groove structure in the shape of a "square" is designed at each corner. Firstly, the sealing area of the sealing ring is increased, and the effect of multi-level decompression and flow limiting is also formed. The decompression effect is more than 50% higher than that of a common flat sealing ring. Description of the drawings

[0011] Figure 1 It is a schematic diagram of the sealing ring structure of the multi-stage centrifugal pump of the present utility model;

[0012] Figure 2 is Figure 1 The enlarged view of the structure at A of

[0013] In the figure: 1 impeller outlet, 2 impeller, 3 high-pressure drop sealing ring, 4 impeller inlet, 5 impeller shaft hole, 6 radial leakage channel, 7 first decompression groove, 8 radial flat sealing surface, 9 second decompression groove, 10 labyrinth boss, 11 axial flat sealing surface, 12 axial leakage channel. Specific implementation manners

[0014] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0015] As Figure 1 shown, the impeller 2 is provided with an impeller shaft hole 5 along the axial direction, and an impeller outlet 1 and an impeller inlet 4 are respectively arranged outside the impeller 2.

[0016] Please refer to Figure 1-2As shown in the figure, the present utility model provides a multi-stage centrifugal pump with a sealing ring, which includes an impeller 2 and a high-pressure-drop sealing ring 3. An installation groove is provided on one side of the high-pressure-drop sealing ring 3, one end of the impeller 2 is arranged in the installation groove, a radial flat sealing surface 8 is arranged on the outer side of the impeller 2, a first decompression groove 7 is provided in the inner cavity adjacent to the outer side of the impeller 2 in the installation groove, a radial leakage channel 6 is arranged between the first decompression groove 7 and the radial flat sealing surface 8, an axial flat sealing surface 11 is arranged at one end of the impeller 2 inside the installation groove, a labyrinth convex platform 10 is arranged on the side of the high-pressure-drop sealing ring 3 adjacent to the axial flat sealing surface 11, and an axial leakage channel 12 is arranged between the labyrinth convex platform 10 and the axial flat sealing surface 11.

[0017] In this embodiment, there are several groups of the first decompression grooves 7, and the first decompression grooves 7 are inclined-tooth triangles, and the angle between the side of the inclined-tooth triangle and the radial flat sealing surface 8 is less than 60°.

[0018] Among them, a plurality of labyrinth first decompression grooves 7 in the shape of "inclined sawtooth triangles" are provided on the radial sealing surface. The angle between the side of the "inclined sawtooth triangle" and the radial flat sealing surface 8 is less than 60°, guiding some of the leakage water flow to change the direction and interact with the direct-flow leakage water, forming turbulent flow and eddy current, consuming pressure, and achieving the purpose of reducing the leakage amount.

[0019] As Figure 2 shown in the figure, second decompression grooves 9 are provided at the right-angle corners of the radial flat sealing surface 8 and the axial flat sealing surface 11, and the second decompression grooves 9 are specifically square.

[0020] Specifically, second decompression groove 8 structures in the shape of "squares" are designed at all right-angle corners of the radial sealing surface of the sealing ring 3 and the axial sealing surface of the impeller. When the leakage water flow leaks from the radial sealing gap to this decompression groove, the leakage water flow forms a reflected water flow in the second decompression groove and interacts with the direct-flow leakage water flow, forming turbulent flow and eddy current, consuming pressure, and achieving the purpose of reducing the leakage amount.

[0021] It can be understood that multiple labyrinth convex platforms 10 are designed on the axial part of the sealing ring 3 and the impeller 2 according to the actual situation, and a second decompression groove 9 structure in the shape of "square" is designed at each corner, forming a step-by-step pressure reduction effect.

[0022] It should be noted that both the first decompression groove 7 and the second decompression groove 9 adopt the hot-melt spraying alloy process. After being processed with ordinary materials, a high-hardness and corrosion-resistant alloy coating is hot-melt sprayed on the surface, which can not only improve the hardness of the material, but also significantly improve the anti-wear and wear-resistant performance of the sealing ring, and the cost is relatively low and the forming is easy.

[0023] Although embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A multistage centrifugal pump with a sealing ring, comprising an impeller (2) and a high-pressure-drop sealing ring (3), characterized in that: On one side of the high-pressure-drop sealing ring (3), an installation groove is formed. One end of the impeller (2) is arranged in the installation groove. A radially flat sealing surface (8) is arranged on the outer side of the impeller (2). A first pressure-reducing groove (7) is formed in the inner cavity adjacent to the outer side of the impeller (2) in the installation groove. A radial leakage channel (6) is arranged between the first pressure-reducing groove (7) and the radially flat sealing surface (8). An axially flat sealing surface (11) is arranged at one end of the impeller (2) inside the installation groove. A labyrinth boss (10) is arranged on one side of the high-pressure-drop sealing ring (3) adjacent to the axially flat sealing surface (11). An axial leakage channel (12) is arranged between the labyrinth boss (10) and the axially flat sealing surface (11).

2. The multistage centrifugal pump with a sealing ring according to claim 1, characterized in that: There are several groups of the first pressure-reducing grooves (7), and the first pressure-reducing grooves (7) are inclined-tooth triangles. The angle between the side of the inclined-tooth triangle and the radially flat sealing surface (8) is less than 60°.

3. The multistage centrifugal pump with a sealing ring according to claim 1, characterized in that: Second pressure-reducing grooves (9) are formed at the right-angle corners of the radially flat sealing surface (8) and the axially flat sealing surface (11), and the second pressure-reducing grooves (9) are specifically square-shaped.

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