Fluid viscosity is a very important parameter in pump selection. Flow diagram refers to the flow curve of water transported at an atmospheric pressure. Viscosity affects the pump speed, efficiency, power and so on. When the viscosity of the liquid reaches a certain value, the pumping efficiency will be reduced due to the limited suction capacity of the hose. At the same pump speed, the flow rate of the viscous liquid will be smaller than the flow rate when pumping water. The higher the viscosity, the more the flow rate will decrease.
Viscosity is the physical property of fluid, any fluid has viscosity, the viscosity of water is 1CP, the following is the viscosity table of other common liquids for reference:
1CP=1mPa*s
Influence of suction and head on flow of basic peristaltic pump
Peristaltic pump suction concept:
Peristaltic pump has a strong self-priming ability, in theory, the large suction range of water transmission under a large air can reach 9.8 meters, but due to the influence of the surface tension of the medium in the pipeline resistance, the actual situation of the peristaltic pump flow will be attenuated, and every meter of suction, the flow of the peristaltic pump will be attenuated by 15%. Suction and pump head hose and media are related, if there is a high demand for suction, you can choose a thinner inner diameter, thicker wall hose, while choosing a higher speed drive.
Basic peristaltic pump flow hose model:
Head refers to the vertical height of the peristaltic pump pump head to the liquid outlet, such as the wall thickness of 1.6mm hose, its working pressure (continuous) 0.17(Mpa), that is, 1.7*9.8 meters, the head can reach 16.7 meters. When a larger head is needed, you only need to choose a hose with the right pressure bearing capacity according to your actual needs.
Selection of hoses - chemical compatibility, life, hardness
The chemical compatibility, life and hardness of the pump tube all affect the efficiency of the peristaltic pump.
The material of the hose determines the chemical compatibility of the hose. When choosing a peristaltic pump for pumping aggressive fluids, the choice of hose material is critical. The service life of different materials and specifications of hoses will also be different, and the hose that is suitable for life needs to be selected according to the use situation. PharmedBPT tube has a longer life and better air tightness than domestic silicone tube. For example, when doing anaerobic bacteria culture experiments, the air tightness of the pump tube is very important to prevent outside oxygen from entering the culture through the pipeline.
In addition, the imported pump pipe in addition to chemical compatibility and life is better than the domestic silicone pipe, the hardness will be higher. Therefore, when selecting the pump tube and the driver selection, the influence of the pump tube hardness on the driver should also be considered. If the selected drive torque is too small, it may not be able to pressure the inlet pump pipe.
