RU1777634C - Device for control of centrifugal pump output - Google Patents

Abstract

Appointment: regulation of centrifugal pumps mainly of hydrotransport installations. SUMMARY OF THE INVENTION: the outlet end of the tube (3), which serves to supply air from the atmosphere to the suction pipe (1), is located in the cavity of the latter at the smaller opening of the confuser nozzle (2) located in the aforementioned pump impeller (7) located in the aforementioned branch pipe (1). The ratio of the area of the inlet (6) of the tube (3) to the area of the smaller opening of the nozzle does not exceed 0.0012. 1 ill. (L C vi vi VI Os GO N GO

Description

The invention relates to pump construction and can be used to control the volumetric flow of centrifugal pumps in hydraulic transport in the metallurgical, coal, chemical and construction industries.

A device (stand) for testing gas separators 1 is known, in which gas is introduced into the liquid through an ejector integrated in the pump discharge line.

The disadvantages of this stand are the impossibility of using bulk materials during the hydrotransport due to the limited passage of the nozzle and the loss of the working pressure of the pump in the ejector.

Closest to the invention is a liquid aeration device 2 comprising a suction nozzle of a centrifugal pump with a confuser nozzle facing its smaller aperture to the impeller, and a tube with an outlet and an inlet end for communicating with the atmosphere.

The disadvantage of this device is a decrease in the stability of the pump from a gradual increase in the flow of air into the pump due to aeration of the liquid in the tank. The consequence of this is the accumulation of air in the pump casing (snail) to a critical value, after which a supply interruption is possible (stops pumping).

The aim of the invention is to ensure stable operation of the pump in control modes.

This object is achieved in that in a device containing a confuser nozzle in the suction nozzle of the pump, facing its smaller aperture to the impeller, and a tube with an inlet and an outlet end, which serves to communicate the nozzle with the atmosphere, according to the invention, the outlet end of the tube is placed in the cavity a suction nozzle at a smaller nozzle opening, wherein the ratio of the area of the inlet of the tube to the area of the smaller nozzle opening does not exceed 0.0012.

The drawing shows a device section.

A device for controlling the flow rate of a centrifugal pump pump contains a suction pipe 1 with a coaxially arranged conical nozzle (confuser) 2, a tube 3, the outlet end of which is located

in the cavity of the suction pipe at the smaller hole, the nozzle, valve 4, cover 5 with a calibration hole 6, a centrifugal pump 7 and a discharge pipe

8.

The device operates as follows.

With the start of the pump 7, open the valve 4. In the suction pipe 1 behind the confuser

rarefaction occurs due to a sharp increase in flow rate when exiting a smaller hole. Under the influence of this discharge through the inlet 6 through the tube 3, air from the atmosphere is sucked

into the cavity of the suction pipe, where it mixes with the fluid flow and enters the pump 7 and then through the pipeline 8 to the place of hydrotransport. The volumetric flow rate of the pump decreases with increasing amount of intake air, which depends on the size of the inlet (calibration) hole in the tube cover. With a smaller opening, the volumetric flow rate of the pump is greater than with a larger inlet. The size of the inlet is limited by the stable operation of the pump in control modes, while the ratio of the area of the inlet of the tube to the area of the smaller aperture of the confuser

the nozzle must not exceed 0.0012. At large values of this ratio, a spontaneous decrease in the volumetric flow occurs over time with a further transition of the pump to the feed cutoff mode

(failure).

Using the proposed device allows for stable operation of the pump in control modes.

Claims (1)

The claims A device for controlling the performance of a centrifugal pump containing confuser nozzles in a suction port of the pump, facing its smaller aperture to the impeller, and a tube with an inlet and an outlet end, which serves to communicate with the atmosphere, characterized in that, in order to ensure stability of the pump in control modes, the outlet end of the tube is placed in the cavity of the suction a nozzle at a smaller nozzle opening, wherein the ratio of the area of the inlet of the tube to the area of the smaller nozzle opening does not exceed 0.0012.