Centrifugal pump

Description

[0001] Technical field

[0002] The utility model relates to pump engineering, in particular to a centrifugal pump, which is designed for pumping fluids, in particular oil, water, water-oil mixture, water-gas-oil mixture in oil and gas wells, in oilfield transport systems and installations for oil and gas treatment.

[0003] Technology Level

[0004] A screw-centrifugal pump is known in the prior art (see patent RU 2314436), comprising a housing and an auger and diffuser mounted on a shaft.

[0005] The prior art knows a technical solution adopted as the closest analogue, a centrifugal pump containing a housing and a screw and diffuser mounted on a shaft (see https: / / www.manualslib.com / manual / 3086797 / DesmiNslv.html?page=42#manual).

[0006] The magnetic clutch and hydrodynamic bearing ensure slow rotation of the auger, creating an uneven flow and causing vortices and separation zones. Uneven flow causes damage to the flow path components.

[0007] The disadvantage of known solutions is large hydraulic losses, which reduce the efficiency of the pump and worsen the cavitation reserve.

[0008] The technical result is to increase the reliability of the centrifugal pump.

[0009] The technical result is achieved by a centrifugal pump comprising a housing, a diffuser, a shaft, and an auger mounted on the shaft. A radial clearance is provided between the inner surface of the diffuser and the outer surface of the auger blades, with the clearance ranging from 0.3 to 0.5 mm. The inner surface of the diffuser is coated with an antifriction coating. The thickness of the antifriction coating ranges from 0.005 to 0.015 mm.

[0010] Brief description of drawings

[0011] The claimed utility model is explained by an illustration.

[0012] The figure shows a longitudinal section of a centrifugal pump,

[0013] where 1 is the housing; 2 is the impeller; 3 is the shaft; 4 is the diffuser; 4.1 is the inner surface of the diffuser; 5 is the auger; 5.1 is the auger blade.

[0014] Implementation of a utility model

[0015] The centrifugal pump comprises a casing 1, which ensures the pump's seal and directs the fluid flow. Inside casing 1 is an impeller 2 mounted on shaft 3, which is secured to casing 1. A diffuser 4 and auger 5 are mounted on shaft 3. Auger 5 is a screw shaft with spiral blades that mix the fluid. Diffuser 4 is installed in the pump casing and serves to convert the kinetic energy of the fluid flow into static pressure. The rotation of auger 5 on shaft 3 increases the pressure before entering impeller 2. As auger 5 rotates, the spiral blade captures the fluid and moves it axially. The auger also ensures a more uniform flow, which reduces pulsation and pressure fluctuations in the system. This is especially important in high-speed pumps, where flow stability is critical to prevent damage to flow path components due to cavitation.

[0016] A radial clearance of 0.3 to 0.5 mm is provided between the inner surface of diffuser 4.1 and the outer surface of auger blades 5.1. A radial clearance of less than 0.3 mm may result in contact between the auger blades and the inner surface of the diffuser, which can lead to friction, overheating, and possibly jamming. A radial clearance greater than 0.5 mm increases crossflow due to uneven flow, which reduces pump pressure and efficiency and reduces the positive suction head.Maintaining a radial clearance of 0.3 to 0.5 mm ensures optimal operation of the pump's flow path by reducing the cross-sectional area between the inner surface of the diffuser and the outer surface of the auger blades, which reduces losses during the conversion of the mechanical energy of the rotor's rotation into the hydraulic energy of the pumped medium, increases the pressure at the impeller inlet, which leads to increased pressure and more efficient operation of the pump, as well as an increase in the positive suction head, extending the service life of the pump's flow path elements.

[0017] The inner surface of the diffuser is preferably coated with an antifriction coating. PTFE is used as the antifriction coating. The thickness of the antifriction coating is from 0.005 to 0.015 mm. When the antifriction coating is applied less than 0.005 mm, the wear of the protected surface is accelerated due to the erosive effect of solid particles of the pumped medium. When applying an antifriction coating greater than 0.015 mm, there is a risk of coating peeling. It is preferable to apply an antifriction coating with a thickness of 0.005 mm to 0.015 mm, which ensures the formation of a sliding film, leading to reduced hydraulic losses and increased efficiency. As a result, less energy is required to pump liquid. The application of an antifriction coating improves the cavitation properties of the inner wall of the centrifugal pump diffuser, reduces erosive effects and increases resistance to cavitation destruction.

Claims

1. A centrifugal pump comprising a housing, a diffuser, a shaft and a screw mounted on the shaft, characterized in that a radial gap is provided between the inner surface of the diffuser and the outer surface of the screw blades, wherein the value of the radial gap is from 0.3 to 0.5 mm.

2. A centrifugal pump according to paragraph 1, characterized in that the inner surface of the diffuser is made with an antifriction coating.

3. A centrifugal pump according to paragraph 2, characterized in that the thickness of the antifriction coating is from 0.005 to 0.015 mm.

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