Yancheng Qingquan Pump Industry Co., Ltd.
Contact: Jin Qiang
Address: No. 2, Building 10, Area B, No. 96 Huanghai East Road (Dayang Industrial Park), Tinghu District, Yancheng City
Everyone knows that the self-priming pump has a self-priming function, but we often encounter that the self-priming height cannot be reached after we install the water pump. So what are the factors affecting the self-priming performance of the self-priming pump? Let's briefly introduce:
I. Impact of impeller peripheral speed on self-priming performance
U2 is a necessary condition to promote gas-liquid mixing and gas-liquid flow of the self-priming pump.
The increase of U2 not only promotes the increase of the backflow of the self-priming pump, but also strengthens the role of gas-liquid mixing and improves the self-priming performance.
Second, the gap between the impeller and the pump body
The smaller the gap between the outer circle of the impeller and the tongue, the greater the suction stroke, which is usually controlled within the range of 0.5-lmm.
However, some experimental studies are contrary to this statement. The pump efficiency and suction performance are best under the condition of gap d = 2.5mm.
Self-priming performance is also related to the gap between the rear cover of the impeller and the pump cover.
The gap is greater than 6mm. Regardless of how to adjust other structural geometric parameters, the height of self-priming always does not exceed 3m. After proofreading the drawings and inlaying a wooden board on the pump cover to make the gap d = 2.5mm, the self-priming height exceeds 6m in 100s
Third, the storage chamber volume Vc
The storage volume of the self-priming pump should refer to the volume of the pump body below the lowest point of the pump suction port, that is, the volume of the liquid part that can be stored in the pump body after the pump is stopped.
With the increase of liquid storage, the self-priming time can be shortened gradually. However, if the liquid storage volume is too large, and the liquid storage height is greater than the outlet height of the pressure water chamber diffusion tube, and the water level in the gas-liquid separation chamber is too high, it will affect the smooth discharge of the gas separated from the liquid, and thus also Extend self-priming time.
There are ways to increase the suction range of the self-priming pump
1.A good bottom valve can be installed at the suction port under the inlet pipe pool of the self-priming sewage pump, which can increase the suction distance of about 1 meter. The purpose of installing the bottom valve is to prevent the water in the suction pipe from flowing backward and reduce the self-priming process of the self-priming pump. The water in the middle pipeline is reversed by the atmospheric pressure and affects the self-priming performance of the self-priming pump.
2. Reduce the elbows on the inlet pipe of the self-priming pump. The fewer the number of elbows, the better. The loss of one elbow is about 1 meter.
3.The diameter of the inlet pipe of the self-priming pump can be slightly reduced.For example, the inlet pipe of the pump is 150mm and the outlet is 125mm. You can also use the inlet pipe of 125mm. After the pipe becomes smaller, the air in the pipe will also be reduced. Using a large straw is definitely not as good as a small straw for absorbing water, but it should be noted that the inlet pipe can only be slightly reduced, and the outlet cannot be installed in a configuration that is larger than the inlet, which will cause the consequence of not being able to suck water.