What are the advantages and disadvantages of centrifugal pumps and screw pumps?

The advantages of centrifugal pumps:

1, compact structure.

2, wide range of flow and head.

3, a variety of control options

4, uniform flow, smooth operation, low vibration. Do not need special damping foundation.

5, equipment installation, maintenance and repair costs are low.

Disadvantages of centrifugal pumps:

1, there is no self-priming ability, start to fill the liquid, there is air binding phenomenon.

2, for the supply of small flow, large pressure head is not suitable for high viscosity.

Advantages of screw pumps:

1, low speed (generally 20r/min ~ 90r/min), small mechanical wear, will not occur vapor corrosion.

2, the flow channel is wide, can transport water containing solids.

3, the pump body structure is half-open, you can observe the operation of the pump.

4, the suction side of the flow state on the hydraulic performance has little effect on the suction pool, no special requirements for the suction pool, foundation excavation depth is small, the construction of hydraulic buildings is simple, and the cost of civil engineering is less.

Disadvantages of screw pumps:

1, large size, covers a large area.

2, by the mechanical processing conditions, the pump shaft can not be too long, and thus the head is low, generally not more than 10m.

3, suction water surface, the height of the water surface can not be too large a change in height, otherwise it will affect the efficiency of the work, increase energy consumption.

Expanded

By the working principle is divided into the following categories:

1, volumetric pump

Relying on the movement of the working parts caused by the working volume to periodically increase and decrease the suction and discharge of liquids, and rely on the working parts of the extrusion of the pressure of the liquid can be increased directly.

Based on the different ways of moving parts movement is divided into: reciprocating pumps and rotary pumps.

Based on the different structure of moving parts: piston pumps and piston pumps, gear pumps, screw pumps, vane pumps and water ring pumps.

2, impeller pump

Impeller pump is driven by the impeller high-speed rotation of the liquid and the transfer of mechanical energy to the conveyed liquid.

Based on the pump impeller and flow channel structure features of different impeller type can be divided into:

1) centrifugal pump (centrifugalpump)

2) axial pump (axialpump)

3) mixed-flow pump (mixed-flowpump)

4) vortex pump (peripheralpump)

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3, jet pump (jetpump)

It relies on the high speed jet produced by the working fluid to eject the fluid, and then through the exchange of momentum and the energy of the ejected fluid increases.

Baidu Encyclopedia - Centrifugal Pumps

Baidu Encyclopedia - Progressive Cavity Pumps