Selection of pump head
Thread Content
Our company selected a pump for the filter press; it has a head of 50 meters. Excessive current is generated during use, and the pump manufacturer stated that the low pressure at the pump’s outlet leads to an increased flow rate, thereby increasing the load. At the initial stage of liquid feeding into the filter press, the resistance is low, with a pressure of only 0.1 Pa; as the filter cake thickens, the resistance increases and the pressure rises accordingly. I would like to ask my friends: Is what the pump manufacturers say reasonable? If so, how should the pump head be selected?
It is best to use a positive displacement pump for the pump connected to the filter press. It is necessary to know the maximum pressure at the inlet of the filter press; together with the pressure losses resulting from the distance from the pump to the filter press and any height differences, this value determines the outlet pressure of the pump
The manufacturer is right; a stop valve (which functions as a control valve) can be installed at the pump outlet to regulate the pressure and current at the pump outlet, thereby controlling the pump flow rate without affecting the pressure at the filter press inlet.
Positive displacement pumps cannot have their outlet valves used for regulation; backflow or variable frequency is the proper approach
The existing process should have an outlet valve and a return valve; limit the opening degree of these two valves so that they are not opened too wide, and try to see if the desired functionality can be achieved without exceeding the current limits.
Have you used an inverter? The parameter settings for the inverter in this location are different from those in other locations
The pumps we used in the past didn’t have variable frequency control, nor did they have valves to regulate flow rate. I think that apart from the fact that the pump was selected with an excessively high head, there are also certain design issues related to the pump itself that contribute to the overcurrent problem.
If no valve is installed at the pump outlet, then the pump loses its flexibility; this is hard to understand
It is recommended to use frequency conversion or control valves for regulation.
It’s possible; it has nothing to do with the head! Only an outlet throttle valve (control valve) can be added to regulate the flow rate and current!