What are the benefits of reducing pressure regulation by micro vacuum pump and micro air pump?
For example, the flow rate of a micropump is adjusted by electronic control. Because the essence of electronic control is to adjust the pump speed through voltage, under the same load, the lower the speed, the smaller the flow; On the contrary, the higher. However, in general, in order to avoid burning out the pump motor due to high voltage, the electric control will generally reduce the voltage to adjust the flow.
Examples are as follows:
Due to the need of instrument production, we hope to adjust the flow of micro air pump in our instrument through electric adjustment. We adjust the flow by changing the working voltage of micro vacuum pump.
Of course, the working voltage of the pump can only be lower than the rated voltage, not higher than the rated voltage, otherwise it may burn out the motor. Through the test of VAA6005-24V miniature vacuum pump produced by Chengdu Weicheng Company, it is found that the flow rate decreases with the decrease of working voltage, and it is close to linear relationship.
For example, the rated voltage is 24V, and when it drops to 20V, the flow rate is about 4L/MIN；. ; When it is reduced to 15V, the flow rate is about 2.5L/MIN.
(The premise is that the pump can withstand it! See the analysis below for details). This is basically consistent with their published voltage-flow curve.
However, this method can only adjust the flow in a small range, and a large range of adjustment (for example, adjusting to several hundred ml/Min) still needs to be completed by adding a flow regulating valve at the pumping end of the pump.
In addition, when the operating voltage is lower than the rated value, the pump may not be started. It is found that the larger the load, the higher the starting voltage required for the pump to reach the rated value, and the undervoltage can be started when the load is small.
Pump running under pressure has many advantages: noise is obviously reduced; The service life is obviously prolonged. Long-term experiments show that the lower the voltage, the more obvious these two advantages are. The disadvantage is that when the voltage is low to a certain extent, the pulsation of pump flow appears, which can be monitored by rotating flowmeter.
We have been running the pump of Chengdu Weicheng Company around the clock for three consecutive months. In the test, the performance of the pump is very stable and reliable, and no other disadvantages caused by undervoltage operation are found. However, other domestic brands did not perform well in the same test, or some pumps failed after several days of continuous operation, or they were unstable and frequently failed.
PS: One thing must be noted in undervoltage operation: the pump must be able to start normally when the load is hung! Otherwise, the input electric energy can not be converted into kinetic energy, but can be completely converted into heat energy, so that the motor will continue to heat up until it burns down. Of course, different loads will have different starting voltages, and the lowest starting voltage should be determined according to their own load conditions.