A water pump is a machine that delivers or pressurizes a liquid. It transfers the mechanical energy of the prime mover or other external energy to the liquid, and increases the energy of the liquid. It is mainly used to transport liquids including water, oil, acid and alkali, emulsion, suspoemulsion and liquid metal, and also to transport liquids and gas mixtures. And a liquid containing suspended solids. The selection of the pump should be based on the process flow, water supply and drainage requirements, from five aspects, including liquid delivery, device head, liquid properties, piping layout and operating conditions.
1. Flow rate is one of the important performance data of the pump selection, which is directly related to the production capacity and conveying capacity of the entire device. For example, the normal, minimum and maximum flow rates of the pump can be calculated in the design of the design institute. When the pump is selected, the normal flow rate is based on the maximum flow rate. When there is no maximum flow rate, 1.1 times the normal flow rate can be taken as the maximum flow rate.
2. The head required for the device system is another important performance data of the pump selection. Generally, the head should be selected by amplifying the 5%-10% balance.
3. Liquid properties, including liquid media name, physical properties, chemical properties and other properties, physical properties are temperature c density d, viscosity u, solid particle diameter and gas content in the medium, etc., which involves the lift of the system, effective gas Calculation of the amount of eclipse and the type of suitable pump: chemical properties, mainly refers to the chemical corrosiveness and toxicity of the liquid medium, is an important basis for the selection of the pump material and the type of shaft seal.
4. The piping arrangement conditions of the equipment system refer to the data feeding height, liquid feeding distance, liquid feeding direction, suction side, minimum liquid level, discharge side maximum liquid level, and other data and pipe specifications and length, material, pipe fittings specifications and quantity. Etc., in order to carry out the calculation of the combing process and the checking of the NPSH.
5. Operating conditions have a lot of content, such as liquid operation T saturated steam force P, suction side pressure PS (absolute), discharge side container pressure PZ, altitude, ambient temperature operation is gap or continuous, pump position is fixed Still removable.
