When to use a centrifugal or a Positive Displacement pump (“PD Pump”) is not always a clear choice. Usually we use a positive displacement pump to feed for decanter centrifuge, it is called single screw pump.
The major benefit to use a positive displacement pump other than centrifugal pumpis that, it will not break the fine solids to smaller, so the centrifuge can separate the solids easily. Centrifugal force of centrifugal pump will cut the solids to smaller, it is not good for centrifuge’s operation.
How to operate a screw pump when feeding to decanter centrifuge?
1 Full fill the pump chamber with drilling fluids , if the media is too viscosity, then inject into other liquids; Inject the mud from the pump inlet connection, and rotate the pump by hand along the running direction of the motor to make the mud full fill the suction chamber.
2 Open the screw pump inlet valve and outlet valve (the valve is fully opened to prevent overload or no load suction), start the motor.
3 The pump should be started under the condition of fully opening the Inhale row valve and bypass valve to minimize the start load. Gradually close the bypass valve after the motor reaching the rated revolution.
4 Check the shaft seal when the pump is running, drop-shaped leakage and small amount of leakage is allowed, Leakage not exceeding 20-30 seconds / drop is considered normal. Check the pump discharge capacity, vibration as well as noise. Any abnormal, should stop the pump and eliminate immediately.
If you need a positive displacement pump (screw pump) or you have any technical problem with a screw pump when used it for a decanter centrifuge, pls contact GN solids control for communication.