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Flow Rate and Calculation Method of Peristaltic Pump

Browse:370   Update time:2017-09-18 13:49:00
How to calculate the flow rate of peristaltic pump? A peristaltic pump head can adapt with a variety of pump tubes, and each tube with different inner diameter of the pump tube will cause different flow rate. As for the same peristaltic pump head, the inner diameter is larger, and the flow rate for each turn is bigger, on the contrary it is smaller.
In the ideal state does, without taking into account the impact of liquid viscosity on the flow, the peristaltic pump generate the same flow rate each tur. Then if the pump generate 10ml each, the flow rate is 10ml / min, if the pump turn N /min, the flow rate is 10N/min.

Of course, there are some differences between the reality and the ideal condition, as below

1.The peristaltic pump sucks liquid according the rebound of the pump tube inhalation of liquid. It will take a certain time for peristaltic pump tube to rebound, the more viscous the pumped liquid is, the longer time the tubes will take to rebound. So the rebound time is less than single-roller distance displacement time (if roller group consists of 2 rollers and the radian is 180 degrees, the time that a roller need take to roll half a circle is single roller displacement time; the higher the speed is , the shorter time will it take). The relationship between the flow rate and the rotary speed is the linear growth. If the time required for the rebound is greater than single-roller distance displacement time, in another word,  the peristaltic pump tube maybe pressed again when it hasn’t fully rebound, so the flow rate for each turn will be smaller than fully rebound. We can ensure that if the peristaltic pump rotary speed is fixed,  the time of each turn will be fixed.

2.the outlet pressure creases, which will cause impact on flow rate and outlet liquid will flow back, because the inner diameter will become bigger with outlet pressure increasing. if the pressure of the outlet is bigger than the pump pressure, then the liquid will cause a complete backflow phenomenon.

Conclusion: Therefore, when calculating the flow rate of the peristaltic pump, we should consider the effect of the increase of the rotary speed and the viscosity of the liquid on the rebound of the tube. If the speed of the peristaltic pump is constantly changing, it can not be calculated exactly as a simple product relationship. In general, we can get from experience that the liquid with a lower gravity can be calculated by product relationship. If the viscosity is very high, the actual rotary speed will reduce.
Chongqing Jieheng Peristaltic Pump Co., Ltd.  Peristaltic pump  constant current pump tube pump