SU981684A1 - Hydraulic testing bed - Google Patents

Description

one

The invention relates to hydraulic engineering and can be used in hydraulic testing of centrifugal pumps.

Known hydraulic test stand, contents of the supply tank, a pump with a pressure pipe connected to the tank, and a venturi tube t1J.

The disadvantage of the known stand is the long duration of the preparation of the working fluid to it: test.

The closest to the invention of the technical essence and the achieved result is a hydraulic test bench containing a supply tank with a vertical pipe, the upper ring of which is located above the liquid level in the tank, and the lower one is brought out through its bottom to the outside, a pump with a pressure pipe, a wire connected to the lower end of the nozzle, and the venturi t2J. A disadvantage of the known test bench is that during cavitation tests of the pump, the liquid is diluted with gas. The required accuracy is not ensured.

The purpose of the invention is to improve the accuracy of testing during tests of a pump for liquids with dissolved gas.

Claims (2)

This goal is achieved by the fact that the Venturi tube is located at the point of connection of the pressure pipe of the pipeline to the nozzle and is provided with a critical section installed in its critical section; with a central axial displacement, the central body, in the socket at the outlet, the Venturi tubes are fitted with screw-2 vanes, and at the upper end there is a narrowing nozzle, and the end of the socket is perforated. The drawing shows schematically the hydraulic test bench “The hydraulic test wall contains a supply tank 1 with a vertical one, a branch pipe 2, the upper end of which is located above the liquid level in the tank 1, and the lower one is brought out through its bottom 3 to the outside, the pump 4 with a pressure pipe S connected to the lower end of the nozzle 2 and the Venturi tube 6, the Venturi tube 6 is located at the point of connection of the pressure pipe 5 to the nozzle 2 and is equipped with a centrally mounted axially displaceable section fired body 7, in the pipe 2 on the outlet tube 6 Ventoux When set screw blade 8, and at its upper end a tapered nozzle 9 and the adjacent portion of pipe 10 2 is perforated,. version 11. The stand is equipped with the necessary measuring devices 12, 13 and the regulating body H, and the supply tank 1 is equipped with a pressure control system 15 and a drain valve 16. The stand works as follows. Start pump A and set the required frequency of shaft rotation. pump,% of the flow rate of the pumped liquid and the pressure at the inlet by means of the regulator k and the pressure control system 15, respectively. The desired operation mode of the Venturi tube 6 is established by changing the position body 7. In the critical section of the tube 6. In this case, a venturi forms a cavitation zone and the fluid passing through this zone is actively degassed. The two-phase gas-liquid mixture thus obtained is twisted in a spiral with the help of screw blades 8. The required degree of twist is achieved by choosing the angle of installation of the blades 8 at the exit and the thickness of the blades of the blades 8, which is greater than one. Due to the twist, the gas is separated to the center of the vertical pipe 2 and in the form of a thin cord goes through the tapering nozzles 9 into the gas cavity of the tank 1, the degassed liquid through the holes 11 is drained below the level of the liquid in the tank 1 3 diameters of D nozzle 2. In this case, the capture of free gas bubbles by the liquid is prevented. The degassed liquid flows from tank 1 to the pump inlet. After testing pump 4 in one mode, the latter is changed. Cavitation tests on the proposed stand are carried out on the degassed liquid, which increases their accuracy. Claims of the Invention A hydraulic test bench containing a supply tank with a vertical tube, the upper end of which is located above the liquid level in the tank, and the bottom end is brought out through its bottom to the outside, a pump with a pressure pipe connected to the lower end of the tube, and a venturi that, in order to increase the accuracy when conducting cavitation tests of a pump for liquids with dissolved gas, the Venturi tube is located at the point of pressure pipe connection to the nozzle and is fitted with With its critical section, with the possibility of axial movement of the central body, the helical blades are installed on the venturi tubing, and on. its upper end is narrowing nozzles, and the adjacent branch of the nozzle is made perforated. Sources of information taken into account during the examination 1, USSR Author's Certificate No. 802610, cl. F 04 B 51/00, 1977. 2.Pilipenko V.V. et al. Investigation of high-frequency cavitation auto-oscillations in the hydraulic system of the Venturi tube, - Coll. articles Cavitational autodog | 8 pumping systems, t, 11, Kiev, Naukova Dumka, 1976, p. 104, fig. 1. L / fc I I I l I I I