General Mechanical Equipment Pump Selection steps and methods
The first section selection principle Pump is a wide range of general-purpose machinery and equipment, widely used in petroleum, chemical, power metallurgy, mining, ship selection, light industry, agriculture, civil and defense departments, occupy an important position in the national economy. According to 79 statistics, China's pump production reached 1.256 million units. The electricity consumption of the pump accounts for more than 21% of the national electricity consumption. Therefore, reducing the pump energy consumption, the use of energy conservation is of great significance. In recent years, we have designed and manufactured many energy-efficient products in the pump industry, such as IHF, CQB, FSB, UHB and other pump products, which have played a positive role in reducing the pump energy consumption. However, at present, in all fields of the national economy, due to the irrational selection, many pumps are in an unreasonable operating condition, and their operation efficiency is low, thus wasting a lot of energy. Some pump because the selection is not reasonable, can not be used, or the use of maintenance costs increase, low economic benefits. Thus it can be seen that the rational selection of pumps is equally important for energy conservation. The so-called rational selection of pumps, is to comprehensively consider the pump unit and pumping station investment and operating costs and other comprehensive technical and economic indicators, to make it in line with economic, security and applicable principles. Specifically, there are the following aspects: 1, must meet the flow and lift requirements, requiring the pump operating point (the intersection of device characteristic curve and the pump performance curve) often remain in the high-efficiency range of operation, so that both the power and not easy to damage the mechanical parts. 2, the selected pump should not only small size, light weight, low cost, but also have good characteristics and high efficiency. 3, with good anti-cavitation performance, this will not only reduce the depth of the excavation of the pump room, but also to pump cavitation, smooth operation, long life. 4, according to the selected pump built pumping station, less project investment, low operating costs. The second section selection steps First, list the basic data: 1, the characteristics of the media: media name, specific gravity, viscosity, corrosive, toxic and so on. 2, contained in the media due to the body particle diameter, content how much. 3, medium temperature: (℃) 4, the required flow General industrial pumps in the process can ignore the leakage in the pipeline system, but must consider the impact of process changes on the flow. Agricultural pumps if the use of open channel water, but also must consider the leakage and evaporation. 5, pressure: suction tank pressure, drainage tank pressure, pressure drop in the piping system (head loss). 6, the piping system data (diameter, length, type and number of pipe fittings, water tank to the pressure tank geometric elevation, etc.). In the design and layout of the pipeline, we should note the following: A, a reasonable choice of pipe diameter, pipe diameter, the same flow, the flow velocity is small, the resistance loss is small, but the high price, the pipe diameter is small, will lead to a sharp increase in resistance loss, so that the selected pump lift, with With increased power, cost and operating costs have increased. Therefore, it should be considered technically and economically. B, discharge pipe and its fittings should consider the maximum pressure that can bear. C, pipe layout should be arranged as straight pipe, pipe fittings to minimize and minimize the length of the pipeline, you must turn when bending the elbow bend radius should be 3 to 5 times the pipe diameter, the angle is greater than 90 ℃. D, the discharge side of the pump must be installed valves (ball valve or globe valve, etc.) and check valve. The valve is used to adjust the operating conditions of the pump. The check valve prevents the pump from reversing when the fluid is flowing backwards and prevents the pump from hitting the water hammer. (When the liquid back flow, will produce a huge reverse pressure to pump damage) Second, determine the flow head 1, determine the flow a, if the production process has been given the smallest, normal, maximum flow, should be considered the maximum flow. b, if the production process is only given normal flow, should consider leaving a certain margin. For ns> 100, the high flow rate is low, and the flow margin is 5%. For the low flow rate of ns <50 and the pump, the flow margin is 10% and the pump of 50≤ns≤100 The amount is also taken 5%, poor quality and poor operating conditions of the pump, flow margin should be taken 10%. c, if the basic data only to the weight flow, should be converted into volume flow. Eps Foam Box,Insulated Polystyrene Boxes,Expanded Polystyrene Box,Eps Foam Food Box Taizhou Tianma Plastic Products Co. 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The device characteristics should also be made if necessary.