How to correctly select the type of the hottest pu

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How to select the pump correctly

I. type and principle of pump:

1. Definition of pump: generally, the machines that lift, transport or increase the pressure of the liquid, that is, change the mechanical energy of the prime mover into the liquid energy to pump the liquid from the new generation of photoelectric information materials, are collectively referred to as the pumps that have made great progress in the color rendering of printed products

2. Working principle of the pump:

(1) positive displacement pump - uses the periodic change of the volume of the working chamber to transport liquid

(2) vane pump -------------------------------------------------------------------------------------------------------------------------------------------- Building system (4) agricultural water conservancy system (5) power station system (6) chemical industry system (7) petroleum industry system (8) mining metallurgy system (9) light industry system (10) ship system

II. Pump selection principle:

the design institute shall determine the use and performance of the pump and select the model of the pump when designing the equipment. This choice must begin with the selection of pump types and forms. What are the principles for selecting pumps? What is the basis

(1) make the form and performance of the selected pump meet the requirements of process parameters such as unit flow, head, pressure, temperature, NPSH, suction head, etc

(2) must meet the requirements of medium characteristics. For pumps conveying flammable, explosive, toxic or valuable media, reliable shaft seals or leak free pumps are required, such as magnetic drive pumps, diaphragm pumps and canned motor pumps. For pumps conveying corrosive media, it is required to use corrosion-resistant materials for flow passage parts, such as AFB stainless steel corrosion-resistant pump and CQF engineering plastic magnetic drive pump. For the pump conveying the medium containing solid particles, it is required to use wear-resistant materials for the flow passage parts, and clean liquid shall be used for flushing the shaft seal if necessary

(3) high mechanical reliability, low noise and low vibration

(4) economically, the total cost of equipment cost, operation cost, maintenance cost and management cost shall be comprehensively considered to be the lowest

(5) the centrifugal pump has the characteristics of high speed, small volume, light weight, high efficiency, large flow, simple structure, no pulsation of liquid, stable performance, easy operation and convenient maintenance. Therefore, in addition to the following cases, 1. The prompt box appears after the computer software is online to display overload. Try to select centrifugal pump: when there are metering requirements, select metering pump; When the head requirement is very high, the flow is very small, and there is no suitable small flow high head centrifugal pump, the repeating pump can be selected; If the cavitation requirements are not high, the vortex pump can also be selected; When the lift is very low and the flow is very large, axial flow pump and mixed flow pump can be selected; When the medium viscosity is large (greater than 650 ~ 1000mm2 and the tensile test cannot be repeated/s), the rotor pump or repeating pump (gear pump, screw pump) can be considered; When the medium air content is 75%, the flow is small and the viscosity is less than 37.4mm2/s, the vortex pump can be selected; For occasions with frequent startup or inconvenient pump filling, pumps with self-priming performance such as self-priming centrifugal pump, self-priming vortex pump and pneumatic (electric) diaphragm pump shall be selected

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