Some clients cannot tell difference of fixed speed centrifuge and fix speed centrifuge, they wonder while price for each so difference.
Centrifuge itself for the 2 types is the same. The different lies in electric control panel.For a fixed speed centrifuge, usually, a smaller control panel mounted on the pedestal of centrifuge, to control its on and off, and for emergency stop.In some condition, clients, want better explosion proof and do not want hydraulic drive, they will require a bigger box for fixed speed.
Variable speed centrifuge mainly used for liquid-mud plant and waste management. it uses a big VFD control panel. The control is too big to set on the same skid with centrifuge.Beside control on and off, if also offer control speed of main dirve, back drive, and sometime, feeding pump.