Selection technique of self-priming centrifugal pump
Reasonable selection from suction centrifugal pumps requires careful consideration of comprehensive technical and economic indicators such as pump unit, pump station investment, and operating costs to conform to the economy, safety, and application principles. Specifically, it includes the following aspects:
1), should choose high efficiency, low noise, energy-saving self-priming centrifugal pump, it is strictly forbidden to choose to eliminate the product.
2), You should select the pump according to the design flow rate and the required lift, and you should consider the self-priming centrifugal pump to cause the self-priming centrifugal pump output to decrease due to wear and the like, and you can select the pump by multiplying the calculated head H by the coefficient of 1.05 to 1.10; The self-priming centrifugal pump whose characteristic curve is gradually decreased with the increase of the flow rate should be selected. Such a pump is stable in operation and reliable in parallel operation. The operating point of the self-priming centrifugal pump should be kept in an efficient range so that Energy-saving and not easy to damage the machine.
3). When there is no adjustment facility for the water supply network, it is advisable to use a variable speed pump set or a rated speed pump set to run the water supply. The maximum water output of the pump set should not be less than the design flow of the district water supply and should be checked by fire protection conditions.
4) Selecting the lifting pump of the water tank and water tower should reduce the number of pumps as much as possible, and should use one for each; when the single pump can meet the requirements, it is not suitable to use multiple parallel modes; if you must use multiple parallel operations or large and small pumps In the mode, the model number and number of units should not be too much. The model should not exceed two types. The lift range of the self-priming centrifugal pump should be similar; you should operate each pump in the high-efficiency range in parallel operation.
5), the variable frequency speed control pump (group) design water supply flow should ensure that the maximum design second flow rate in the domestic water supply system is met. The power supply must be reliable (dual power supply or dual loop power supply); the working point of the self-priming centrifugal pump should be selected in the efficient working area of the self-priming centrifugal pump characteristic curve (QH curve) and should not be selected on the extension line of the QH curve. The most unfavorable working point of the design should be at the right end of the high-efficiency section of the characteristic curve of the self-priming centrifugal pump, that is, the point where the self-priming centrifugal pump has the largest amount of water and the head is low but can meet the requirements, that is, self-priming The intersection of the low point of the high-efficiency zone of the centrifugal pump characteristic curve and the pipe characteristic curve. The working range of the self-priming centrifugal pump can be as high as possible in the high-efficiency section of the self-priming centrifugal pump; you should set the speed regulation range between 25% and 100% of the water supply of the self-priming centrifugal pump; the equipment should have the automatic water level control function.
6) The self-priming centrifugal pump unit of the domestic pressurized water supply system shall be provided with a standby pump. The water supply capacity of the standby pump shall be greater than the water supply capacity of the largest self-priming centrifugal pump. The self-priming centrifugal pump shall be automatically switched and alternated. Run.
7) The motor's voltage with the self-priming centrifugal pump should be the same, and the power supply system should be the same as the national power supply system.
Fuan Zhongzhi Pump Co., Ltd
registered the trademark "ZOZHI."
Add:No.155 Shangcun Qinxiyang Industry Zone,Fuan city,Fujian,China
Tel:+86 0593 6532656 Fax: +86 0593 6531158
Mobile: +86.137.0604.0131 E-mail: sales@zz-pump.com
Website: www.zz-pump.com