Choosing a chemical pump is actually very simple

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How to select a chemical pump? Chemical pumps are a type of general-purpose mechanical equipment that is widely used across various sectors such as petroleum, chemicals, power and metallurgy, mining, shipbuilding, light industry, agriculture, civil applications, and defense. They hold an important position in the national economy. Commonly available on the market are magnetic drive pumps, low-speed slurry transfer pumps, high-temperature resistant low-speed slurry transfer pumps, fluorinated lining liquid centrifugal pumps, fluorinated lining self-priming pumps, stainless steel magnetic drive pumps, stainless steel centrifugal pumps, and so on. However, at present in various sectors of the national economy, due to improper selection, many pumps are operating under suboptimal conditions, resulting in low efficiency and significant energy waste. There are also pumps that cannot be used at all due to improper selection, or whose operation and maintenance costs increase. It is evident that proper pump selection is equally important for energy conservation. 1. List the basic data. Properties of the medium: medium name, specific gravity, viscosity, corrosivity, toxicity, etc. The particle diameter and concentration of the impurities contained in the medium. Medium temperature: (°C). The required flow rate. In general industrial pumps, the leakage in the piping system can be ignored within the process flow, but the impact of process changes on flow rate must be taken into account. Pressure: pressure in the water intake tank, pressure in the water discharge tank, pressure drop (head loss) in the piping system. Piping system data (pipe diameter, length, types and quantities of piping accessories, geometric parameters from the suction tank to the pressure tank, etc.). If necessary, the device characteristic curve should also be prepared. Second, when designing and arranging pipes, the following points should be noted. The discharge pipe and its fittings should take into account the maximum pressure they can withstand. The pipe diameter should be selected carefully. A larger pipe diameter results in a lower flow velocity at the same flow rate, thereby reducing frictional losses; however, it increases the cost. On the other hand, a smaller pipe diameter leads to a sharp increase in frictional losses, which in turn requires a pump with higher head pressure, more power to operate, and thus higher costs and operating expenses. Therefore, it should be considered from both technical and economic perspectives. The piping layout should be arranged as straight as possible, with as few fittings as feasible and a minimal pipe length. When bends are necessary, the radius of curvature of the elbows should be 3 to 5 times the diameter of the pipe, and the angle should be as large as possible, exceeding 90°. A valve (such as a ball valve or globe valve) and a check valve must be installed on the discharge side of the water pump. Valves are used to adjust the operating point of the pump, while check valves prevent the pump from rotating in reverse when fluid flows backward, thus protecting the pump from water hammer effects. (When the liquid flows back, a huge reverse pressure is generated, which can damage the pump.) Third, if minimum, normal, and maximum flow rates are specified in the production process, the maximum flow rate should be taken into account. If only the normal flow rate is specified in the production process, a certain margin should be considered. For high-flow, low-head pumps with ns>100, a flow margin of 5% is adopted, for ns