CN205064391U - Anti -cavitation structure of semi -open impeller centrifugal pump - Google Patents

Abstract

The utility model provides an anti-cavitation structure of a semi-open impeller centrifugal pump, which comprises a semi-open impeller, a volute and a front pump wall of the volute, and a metal insert including an integrated smooth Connected outer ring and inner ring; the outer ring is a horizontal ring; the inner ring is an inclined ring; the metal insert is fixed on the front pump wall of the volute and is coaxial with the semi-open impeller ; The width of the inner ring is greater than or equal to the length of the front streamline of the blade of the semi-open impeller. The anti-cavitation structure not only reduces the hydraulic loss and improves the flow state of the medium inside the semi-open impeller, but also significantly improves the anti-cavitation performance of the front pump wall of the volute of the semi-open impeller centrifugal pump, and improves the performance of the centrifugal pump. Working efficiency and service life; the anti-cavitation method described in the utility model is simple and convenient to implement, which greatly reduces the transformation cost of the centrifugal pump.

Description

Anti-cavitation structure of a semi-open impeller centrifugal pump

technical field

The utility model belongs to the technical field of centrifugal pumps, in particular to an anti-cavitation structure of a semi-open impeller centrifugal pump.

Background technique

Cavitation has seriously restricted the development of engine cooling water pumps. As an important part of the engine water cooling system, the engine cooling water pump is limited by its structural size and works under high temperature, variable speed, and large flow conditions, which is prone to cavitation damage. At the same time, the engine cooling water pump is usually equipped with a semi-open impeller. The semi-open impeller has no cover plate on the side of the suction port, and the backflow at the edge of the blade is relatively large, which aggravates the possibility of cavitation. Due to the complex structure and small size of the engine cooling water pump, the pump body is mostly cast, so that the cavitation damage in the front pump wall and flow channel of the volute has not been well resolved, except for improving the anti-cavitation performance through conventional optimized hydraulic design In addition, it is urgent to find a new technology and method to prevent cavitation damage. The utility model patent with application number 201410394785.5 discloses an anti-cavitation water pump impeller. An anti-cavitation zinc-nickel layer is provided on the surface of the blade, hub seat and fixed shaft hole, and the anti-cavitation zinc-nickel layer is monitored through the sensing layer under the coating. The anti-cavitation performance of the semi-open impeller is improved by the shedding of the layer, but it has the following disadvantages: since the semi-open impeller is a rotating part, the anti-cavitation coating is easy to fall off, and the stability of the monitoring device is also greatly tested.

Utility model content

Aiming at the defect that the anti-cavitation damage ability of the volute front pump wall of the semi-open impeller centrifugal pump in the prior art is insufficient, the utility model provides an anti-cavitation structure of the semi-open impeller centrifugal pump, the purpose of which is to significantly improve The anti-cavitation performance of the pump wall in front of the volute, thereby improving the efficiency and service life of the centrifugal pump.

The utility model realizes above-mentioned technical purpose by following technical means.

An anti-cavitation structure of a semi-open impeller centrifugal pump, including a semi-open impeller, a volute and a front pump wall of the volute, and a metal insert including an integrated and smoothly connected outer ring and the inner ring; the outer ring is a horizontal ring; the inner ring is an inclined ring; the metal insert is fixed on the front pump wall of the volute and is coaxial with the semi-open impeller; the inner ring The width of the ring is greater than or equal to the length of the front streamline of the blade of the semi-open impeller.

Preferably, the inner ring is parallel to the front streamline of the blade.

Preferably, the distance between the inner ring and the front streamline of the blade is not greater than 1mm.

Preferably, the thickness of the metal insert is 1-3mm.

Preferably, the material of the metal insert is stainless steel, alloy steel, cast manganese, bronze or high-nickel alloy.

Preferably, the outer ring is provided with a plurality of holes, and the outer ring is screwed to the front pump wall of the volute.

When cavitation occurs in the semi-open impeller centrifugal pump, the air bubbles move along the outlet direction of the semi-open impeller blades. When the air bubbles move to the high-pressure area near the pump wall in front of the volute, they will shrink and collapse. The instantaneous impact force acts on the metal insert fixed on the front pump wall of the volute, which prevents the pump wall from being damaged by cavitation before the volute.

The beneficial effects of the utility model:

The anti-cavitation structure of the semi-open impeller centrifugal pump described in the utility model not only reduces the hydraulic loss, but also improves the half The flow state of the medium inside the open impeller not only improves the cavitation resistance of the front wall of the volute of the semi-open impeller centrifugal pump, but also improves the working efficiency and service life of the centrifugal pump.

Description of drawings

Fig. 1 is a structural diagram of the anti-cavitation device of the semi-open impeller centrifugal pump of the present invention.

Fig. 2 is a top view of the metal insert of the present invention.

The reference signs are explained as follows:

1-metal insert, 2-semi-open impeller, 3-volute front pump wall, 4-volute, 5-outer ring, 6-hole, 7-inner ring.

detailed description

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the utility model is not limited thereto.

As shown in Figures 1 and 2, an anti-cavitation structure of a semi-open impeller centrifugal pump includes a semi-open impeller 2, a volute 4 and a front pump wall 3 of the volute, and also includes a metal insert 1. The material of the metal insert 1 is stainless steel, alloy steel, cast manganese, bronze or high-nickel alloy, and the thickness of the metal insert 1 is 1-3 mm, which prevents deformation of the metal insert and reduces cost.

The metal insert 1 includes an outer ring 5 and an inner ring 7; the outer ring 5 is a horizontal ring, and the outer ring 5 is provided with a plurality of holes 6, and bolts and nuts are placed in the holes 6, and the outer ring 5 is horizontal. The circular ring 5 is threadedly connected with the front pump wall 3 of the volute, and is used for fixing the metal insert 1 .

The inner ring 7 is an inclined ring, that is, the outer edge and the inner edge of the inner ring 7 are not on the same horizontal plane, and its side view is a slanted line; the outer ring 5 and the inner ring 7 are integrated and smoothly connected to form Metal insert 1; the metal insert 1 is fixed on the front pump wall 3 of the volute and is coaxial with the semi-open impeller 2. The inner ring 7 is parallel to the front flow line of the blade, and the width of the inner ring 7 is greater than or equal to the length of the front flow line of the blade of the semi-open impeller 2, so that the front pump wall 3 of the volute can be protected in a larger range from the inlet to the Cavitation damage in the outlet area; the distance between the inner ring 7 and the front streamline of the blade is not greater than 1mm. The utility model not only reduces the hydraulic loss and improves the flow state of the medium inside the semi-open impeller, but also significantly improves the anti-cavitation performance of the front pump wall of the volute of the semi-open impeller centrifugal pump, and improves the working efficiency of the centrifugal pump and service life; the anti-cavitation method described in the utility model is simple and convenient to implement, which greatly reduces the transformation cost of the centrifugal pump.

The anti-cavitation method utilizing the anti-cavitation structure comprises the following steps:

S1: An annular step is processed on the pump wall 3 in front of the volute, and the height of the step is 1-2 mm greater than the thickness of the outer ring 5;

S2: Machining a plurality of holes 6 on the outer ring 5, and then machining an integrated and smoothly connected outer ring 5 and inner ring 7 to form a metal insert 1;

S3: thread the outer ring 5 of the metal insert 1 described in step S2 to the step of the front pump wall 3 of the volute;

S4: Install the semi-open impeller 2 coaxially on the rear end of the metal insert 1, so that the inner ring 7 is parallel to the front streamline of the blade, and the distance is not greater than 1mm.

When cavitation occurs in the semi-open impeller centrifugal pump, the air bubbles move along the outlet direction of the semi-open impeller 2 blades. When the air bubbles move to the high-pressure area near the pump wall 3 in front of the volute, they will shrink and collapse. The instantaneous impact force generated by the extinguishing acts on the fixed metal insert 1 of the front pump wall 3 of the volute, which prevents the front pump wall 3 of the volute from being damaged by cavitation.

Described embodiment is the preferred implementation of the present utility model, but the present utility model is not limited to above-mentioned embodiment, under the situation of not departing from the essential content of the present utility model, any obvious improvement that those skilled in the art can make , replacement or modification all belong to the protection scope of the present utility model.

Claims (6)

1. An anti-cavitation structure of a semi-open impeller centrifugal pump, comprising a semi-open impeller (2), a volute (4) and a volute front pump wall (3), characterized in that it also includes a metal insert (1), the metal insert (1) includes an integrated smooth outer ring (5) and an inner ring (7); the outer ring (5) is a horizontal ring; the inner ring ( 7) is an inclined ring; the metal insert (1) is fixed on the front pump wall (3) of the volute, and is coaxial with the semi-open impeller (2); the width of the inner ring (7) is greater than or equal to The length of the front streamline of the blades of the semi-open impeller (2). 2. The anti-cavitation structure of a semi-open impeller centrifugal pump according to claim 1, characterized in that, the inner ring (7) is parallel to the front streamline of the blade. 3. The anti-cavitation structure of a semi-open impeller centrifugal pump according to claim 2, characterized in that the distance between the inner ring (7) and the front flow line of the blade is not greater than 1mm. 4. The anti-cavitation structure of a semi-open impeller centrifugal pump according to claim 1, characterized in that the thickness of the metal insert (1) is 1-3mm. 5. The anti-cavitation structure of a semi-open impeller centrifugal pump according to claim 1, wherein the material of the metal insert (1) is stainless steel, alloy steel, cast manganese, bronze or high nickel alloy. 6. The anti-cavitation structure of a semi-open impeller centrifugal pump according to claim 1, characterized in that, the outer ring (5) is provided with a plurality of holes (6), and the outer ring (5) (5) is threadedly connected with the front pump wall (3) of the volute.