RU2594247C1 - Mid stage impeller of centrifugal pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to negative displacement pumps, particularly, to impellers of centrifugal pumps. Mid stage impeller of centrifugal pump comprises drive disc, cover disc and vanes arranged therebetween. Cover disc is equipped with additional seal in form of circular ledge, concentric to inner ledge of main seal and forming together with main seal a discharge chamber. In plane perpendicular to axis of impeller, line which connects inlet and outlet edges of blade wheel is inclined to passing through outlet edge of impeller vanes tangent to outer periphery at an angle exceeding by 30-45° exit angle of impeller vanes. Maximum distance from line connecting inlet and outlet edge of blade of impeller to blade in direction perpendicular to said line is 0.15-0.25 of length of line connecting inlet and outlet edges of blade of impeller.

EFFECT: higher efficiency of rotary pump impeller.

3 cl, 2 dwg

Description

The invention relates to pumps of continuous displacement, and in particular to impellers of centrifugal pumps.

It is known that the impeller of the intermediate stage of a centrifugal pump contains a drive disk, a cover disk and vanes located between them, the cover disk having an additional seal in the form of an annular protrusion concentric with the internal protrusion of the main seal and forming an unloading chamber together with the main seal (see a.c SU 1003607, class F04D 1/00, publ. 23.10.1983).

A disadvantage of the known device is the lack of efficiency and complexity of the design of the sealing assembly.

Closest to the invention in technical essence and the achieved result is the impeller of the intermediate stage of a centrifugal pump, containing a drive disk, a cover disk and vanes located between them, the cover disk having an additional seal in the form of an annular protrusion concentric with the inner protrusion of the main seal and forming together with the main seal unloading chamber (see patent RU 2362912, CL F04D 29/22, publ. 07.27.2009).

However, a centrifugal pump with such an impeller does not provide the required performance, which narrows the scope of its use.

The objective of the invention is to remedy these disadvantages.

The technical result is that it is possible to increase the performance of a centrifugal pump.

This problem is solved, and the technical result is achieved due to the fact that the impeller of the intermediate stage of the centrifugal pump contains a drive disk, a cover disk and vanes located between them, and the cover disk is equipped with an additional seal in the form of an annular protrusion concentric with the inner protrusion of the main seal and forming together with the main seal, the unloading chamber, while in the plane perpendicular to the axis of the impeller, the line connecting the input and output edges of the blade of the impeller is inclined to the tangent to the outer circumference of the impeller passing through the outlet edge of the impeller vanes at an angle that is 30 ° -45 ° greater than the outlet angle of the impeller vanes, and the maximum distance from the line connecting the inlet and outlet edges of the impeller vanes the blades in the direction perpendicular to the above line is from 0.15 to 0.25 of the length of the line connecting the input and output edges of the impeller blades.

The impeller preferably contains from 10 to 12 blades.

The impeller preferably contains 11 blades.

In FIG. 1 shows a longitudinal section of the impeller.

In FIG. 2 is a front view of the impeller.

The impeller contains a drive 1 and a cover 2 mounted on a shaft (not shown). Blades 3 are located between the disks 1 and 2. The cover disk 2 is provided with an additional seal in the form of an annular protrusion 4. The protrusion 4 is located on the disk 2 concentrically to the internal protrusion of the main seal. Thus, an unloading chamber 6 is formed between the protrusion 4 and the main seal 5. The chamber 6 serves to quench the velocity head after an additional gap seal, thereby increasing the resistance to overflow.

In the plane perpendicular to the impeller axis, the line connecting the input and output edges of the impeller blade 3 is inclined to the tangent to the outer circumference of the impeller passing through the output edge of the impeller blade 3 at an angle α exceeding the exit angle β by 30 ° -45 ° blades of the impeller, and the maximum distance L from the line connecting the input and output edges of the blades 3 of the impeller to the blades 3 in the direction perpendicular to the above line is from 0.15 to 0.25 of the length of the line connecting the input and the output edge of the blade 3 of the impeller.

The impeller preferably contains from 10 to 12 blades 3.

The impeller preferably contains 11 vanes 3.

The experiments also showed that the hydrodynamic optimum, from the point of view of minimizing hydraulic losses, is the design of the impeller, in which the profile of the impeller blades 3 is formed in the manner described above, and an increase in the efficiency of the impeller was achieved when the number of impeller blades 3 is from 10 to 12 blades 3, while the maximum efficiency is achieved when the number of blades 3 is 11.

The impeller operates as follows.

The pump is pre-filled with the pumped liquid. The rotational force transmitted from the pump motor to the shaft drives the drive disk 1. The disk 1 carries the blades 3 and the cover disk 2. The flow of the pumped working fluid (fluid) through the inlet guide apparatus is pumped into the cavity of the impeller. The specified cavity is formed by channels between the blades 3 and the discs 1 and 2. Through these channels, under the action of centrifugal force, the liquid rushes into the outlet channel.

Claims (3)

1. The impeller of the intermediate stage of a centrifugal pump, comprising a drive disk, a cover disk and vanes located between them, the cover disk having an additional seal in the form of an annular protrusion concentric with the inner protrusion of the main seal and forming an unloading chamber together with the main seal, characterized in that in a plane perpendicular to the axis of the impeller, the line connecting the input and output edges of the impeller blades is inclined to the blade passing through the output edge the impeller tangent to the outer circumference of the impeller at an angle that is 30-45 ° greater than the angle of exit of the impeller blades, and the maximum distance from the line connecting the input and output edges of the impeller blades to the blades in the direction perpendicular to the above line is from 0.15 to 0.25 of the length of the line connecting the input and output edges of the impeller blades. 2. The impeller according to claim 1, characterized in that it contains from 10 to 12 blades. 3. The impeller according to claim 1, characterized in that it contains 11 blades.

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