SU1763727A1 - Pump - Google Patents

Abstract

Use: for working with liquids having gas inclusions. Invention: screw (4) and centrifugal wheel (5) are mounted on hollow shaft (6). The cavity (7) of the shaft (6) is connected by slotted holes (8) with inter-blade channels (9) of the screw (4) and zone (10) before entering the screw (4). The discharge elements are installed in the cavity (7). Inlet nozzles (13) are connected to the vortex chamber

Description

The invention relates to the field of engineering and can be used in the design of pumps for use with liquids having gas inclusions.

A centrifugal pump is known (for Germany No. 3538081, 1986, cf. F 04 D 29/70), comprising a housing with a pressure line, an impeller, and a coaxially mounted vortex chamber with axial and tangential nozzles. This technical solution provides separation of phases (solid and liquid) before entering the impeller, but does not prevent the occurrence of cavitation on the blades of the centrifugal pump.

The closest technical solution is a pump (ac. USSR No. 881368, 1980, m.kl. F 04 D 3/00), comprising a housing with axial inlet and outlet nozzles, an auger, a centrifugal wheel mounted on a hollow shaft, the cavity of which is communicated by means of slotted openings with inter-blade auger channels and a zone in front of the auger entrance, and pressure elements installed in the shaft cavity This technical solution provides protection against pump cavitation as a result of an increase in the static pressure of homogeneous fluid in the auger inter-blade channels. However, it is not reliable when pumping liquids with gas inclusions, since in this case cavitation may occur.

The aim of the invention is to improve the reliability of the pump when pumping liquid with gas inclusions by improving anti-cavitation properties. The drawing shows a pump, side view. The pump includes a housing 1 with an axial inlet 2 and an outlet 3 with nozzles, an auger 4 and a centrifugal wheel 5 mounted on

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shaft 6. A cavity 7 is formed inside the shaft, which is connected with slotted holes 8 at the back of the blades with inter-blade channels 9, as well as with zone 10 in front of the auger entrance. The cavity 7 contains longitudinal perforated partitions 11. The pump is equipped with a vortex chamber 12c with additional inlet pipes 13 tangentially connected to it. A hollow confuser nozzle 14 with a concave spherical perforated screen 15 is mounted on the shaft, on the surface of which there are cylindrical grooves 16, with the perforation holes located in the grooves.

The pump works as follows. The gas with gas inclusions, entering through the axial inlet 2 into the chamber 12, under the action of the flow of liquid supplied through the tangential nozzles 13, is twisted in the circumferential direction. The gas inclusions contained in the inlet flow remain in zone 10 before entering the screw 4, and the main part of the fluid, under the action of centrifugal forces, is thrown away from the periphery of the chamber 12 and then proceeds along the diffusion channel formed by the pump housing 1 and the hollow confused nozzle 14, mounted in front of the screw 4 on the shaft 6. The diffuser channel allows increasing the fluid pressure at the screw inlet. Part of the liquid spreads over the concave spherical perforated screen 15, filling the cylindrical grooves 16. The gas-liquid mixture passing through the central part of the discharge line brakes at the screen 15, gas bubbles are suppressed in the liquid layer at the cylindrical grooves 16. As a result, a more uniform liquid passes through the perforations the screen 15 into the cavity 7 inside the shaft 6, where the further alignment of the fluid composition (suppression of gas inclusions) occurs. This alignment in the pressure zones during interaction of the fluid flow and the longitudinal perforated partitions 11 rotating together with the shaft 6. The holes in the partitions allow the liquid to flow from the pressure zones to the reduced ones, which prevents the erosion effect of gas bubbles on the partitions, since the latter are covered with a sufficient layer liquids as well poe

to that the collapse (or suppression) of bubbles occurs in the liquid, and not on the surface of the septum. From the valgus cavity, the liquid enters through the slit holes 8 to the backs of the blades of the screw 4, which allows a substantial increase in pressure in these, as is known, most dangerous zones from the point of view of possible cavitation breakdown. Thus, it is possible to improve the anti-cavitation properties of not only the screw 4, but also the centrifugal wheel 5 of the pump, since the indicated properties of the screw are crucial for the entire pump.

Significantly increases the reliability of the pump when pumping liquids with gas inclusions through the use of fairly simple devices - a screw with a confusing nozzle, having slotted holes and longitudinal perforated partitions. Uniformity (almost homogeneous composition) of a liquid with gas inclusions is achieved without using special additional devices - degassing and so on

Claims (1)

Claim of the invention. A pump comprising a housing with axial inlet and outlet nozzles, auger v centrifugal wheel mounted on a hollow shaft, the cavity of which is communicated through slotted openings to the auger interloop channels and a zone in front of the screw inlets, and the pressure elements mounted in the shaft cavity, distinguishing and so that, in order to increase the reliability in operation when pumping liquid with gas inclusions by improving the anti-cavitation properties, the pump is equipped with a vortex chamber, additional inlet nozzles, connected to the vortex chamber tangentially, and fixed on the shaft in front of the auger by a hollow confused nozzle with a concave spherical perforated screen, on the surface of which cylindrical grooves are facing the vortex chamber, E holes are located in the perforation opening, grooves are made in the form of the longitudinal perforated partitions, the shaft cavity and the nozzle are interconnected, and the slotted apertures are located on the back of the auger blades. / i 2 b o