Centrifuge with automatic sampling and control and method thereof

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 the bowl drive motor;
• a conveyor VFD operatively arranged to drive the screw conveyor drive motor;
• a pump VFD operatively arranged to drive the pump drive motor;
• a first analysis assembly;
• and,
• at least one computer electrically connected to the bowl VFD, the conveyor VFD, the pump VFD, and the first analysis assembly, wherein:
• the first analysis assembly is configured to:
• automatically sample a liquid effluent discharged from the centrifuge;
• and,
• automatically transmit first data, characterizing the liquid effluent, to the at least one computer;
• and,
• the at least one computer is configured to:
• calculate respective control schemes for the bowl VFD, the conveyor VFD and the pump VFD using the first data;
• transmit respective control signals to the bowl VFD, the conveyor VFD and the pump VFD to operate the bowl VFD, the conveyor VFD and the pump VFD according to the respective control schemes;
• receive a first input quantifying a torque load on the conveyor motor;
• vary a first differential speed between the bowl and the conveyor until the torque load increases by a first degree at a second differential speed between the bowl and the conveyor;
• calculate a third differential speed based on the second differential speed;
• and,
• operate the bowl and conveyor motors to maintain the third differential speed.

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 the bowl drive motor;
• a conveyor VFD operatively arranged to drive the screw conveyor drive motor;
• a pump VFD operatively arranged to drive the pump drive motor;
• a first analysis assembly connected to a section of pipe connecting the pump and the bowl;
• a second analysis assembly;
• and,
• at least one computer electrically connected to the bowl VFD, the conveyor VFD, the pump VFD, and the first and second analysis assemblies, wherein:
• the first analysis assembly is configured to:
• automatically sample a slurry pumped through the first section of pipe;
• and,
• automatically transmit first data, characterizing the slurry, to the at least one computer;
• the second analysis assembly is configured to:
• automatically sample a liquid effluent discharged from the centrifuge;
• and,
• automatically transmit first data, characterizing the liquid effluent, to the at least one computer;
• and,
• the at least one computer is configured to:
• calculate respective control schemes for the bowl VFD, the conveyor VFD and the pump VFD using the first and second data;
• and,
• transmit respective control signals to the bowl VFD, the conveyor VFD and the pump VFD to operate the bowl VFD, the conveyor VFD and the pump VFD according to the respective control schemes;
• receive a first input quantifying a torque load on the conveyor motor;
• vary a first differential speed between the bowl and the conveyor until the torque load increases by a first degree at a second differential speed between the bowl and the conveyor;
• calculate a third differential speed based on the second differential speed;
• and,
• operate the bowl and conveyor motors to maintain the third differential speed.

A method for centrifuging a slurry using a centrifuge including 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 the bowl drive motor, a conveyor VFD operatively arranged to drive the screw conveyor drive motor, a pump VFD operatively arranged to drive the pump drive motor, a first analysis assembly connected to a first section of pipe connecting the pump and the bowl, a second analysis assembly, and at least one computer electrically connected to the bowl VFD, the conveyor VFD, the pump VFD, and the first and second analysis assemblies, the method comprising:

• automatically sampling, using the first analysis assembly, a slurry pumped through the first section of pipe;
• automatically transmitting, using the first analysis assembly, first data, characterizing the slurry, to the at least one computer;
• automatically sampling, using the second analysis assembly, a liquid effluent discharged from the centrifuge;
• automatically transmitting, using the second analysis assembly, second data, characterizing the liquid effluent, to the at least one computer;
• calculating, using the at least one computer, respective control schemes for the bowl VFD, the conveyor VFD and the pump VFD using the first and second data;
• transmitting, using the at least one computer, respective control signals to the bowl VFD, the conveyor VFD and the pump VFD;
• operating the bowl VFD, the conveyor VFD and the pump VFD according to the respective control schemes;
• receiving, using the at least one computer, a first input quantifying a torque load on the conveyor motor;
• varying, using the at least one computer, a first differential speed between the bowl and the conveyor until the torque load increases by a first degree at a second differential speed between the bowl and the conveyor;
• calculating, using the at least one computer, a third differential speed based on the second differential speed;
• and,
• operating, using the at least one computer, the bowl and conveyor motors to maintain the third differential speed.