Patent ID: 7387602

Claim:
A centrifuge for centrifuging a slurry, comprising: a bowl driven by a bowl drive motor; a screw conveyor driven by a screw conveyor drive motor; a pump driven by a pump motor; a bowl variable frequency drive unit (VFD) operatively arranged to drive said bowl drive motor; a conveyor VFD operatively arranged to drive said screw conveyor drive motor; a pump drive unit operatively arranged to drive said pump drive motor; and, a general-purpose computer (GC) arranged to interactively control said bowl VFD and said conveyor VFD, wherein said GC is configured to maintain a constant differential speed between said bowl and said screw conveyor during acceleration and deceleration of said bowl by calculating, in an iterative process, an instantaneous conveyor motor speed and direction and supplying a speed reference and direction command to said conveyor VFD responsive to said instantaneous bowl speed and desired conveyor speed.