How to calculate the minimum current passed by a centrifugal pump
Thread Content
There are two conditions for stopping the centrifugal pump in the factory. One is the liquid level in the pipe connected to the centrifugal pump, and the other is the current of the centrifugal pump. If the liquid level is too low and the current is too low, the centrifugal pump will automatically stop. But the problem now is that when the current of the centrifugal pump is too low, the liquid in the tanker does not absorb all the liquid and it automatically stops. When it is started again, there is too little liquid in the tanker and the pump cannot fill it with liquid, so it cannot suck up the liquid. So I want to adjust these two conditions and take a look, but I don’t know how to calculate the minimum current that the centrifugal pump can accept. Thank you everyone.
Estimate is the current at minimum continuous flow. Check the performance curve, calculate the shaft power at the flow rate, and then back-calculate the current based on the motor efficiency. In addition, do not operate to the minimum continuous flow rate. Leave some margin. I have no experience in this. suggestion: If the operating flow rate required by the pump process is close to the minimum continuous flow rate, we generally make the actual flow rate of the pump = minimum continuous flow rate + process operating flow rate, and then the minimum continuous flow rate is completely reversed.
Hey, the minimum continuous flow rate on the pump parameter table is 0. It seems that I need to contact the manufacturer. . .
The minimum flow should correspond to the minimum current, right?
There are several flow rates: 1. Minimum flow rate, which is generally required by the process.； 2. The minimum thermally stable flow rate is required by the pump itself, that is, it ensures that the vibration of the pump is within a certain range and the heat generated by the pump is within the allowable range of the pump. The minimum current should be calculated based on the second situation.
Why is there current in this centrifugal pump? You are talking about the motor current that drives the centrifugal pump. Generally, there is an ammeter on site. You close the outlet, open the inlet, start the motor, and observe the current display on the operating column to know the actual minimum current.