Patent ID: 7189196

Claim:
A method of using a centrifuge to separate a light material that is within an input mixture from a heavy material that is within the input mixture, while at the same time independently controlling a speed of rotation of the centrifuge and a speed of removal of the heavy material from the centrifuge, comprising the steps of: providing a first and a second arm assembly aligned on an arm-axis and that are rotatable in a plane extending generally perpendicular to a rotation-axis; providing that each of said first and second arm assemblies includes a tubular-housing having a closed outer end, an intermediate tube having an open outer end, and an inner tube having an open outer end; providing that said inner tube of each arm assembly is of a given length; providing that said intermediate tube of each arm assembly is of a length that is less than said given length; providing that an outer end of said tubular-housing of each arm assembly is spaced from said outer end of said intermediate tube and from said outer end of said inner tube; providing an input mixture flow path that communicates with a cylindrical space between said intermediate tube and said inner tube of each arm assembly; providing a heavy material flow path that communicates with a space within said inner tube of each arm assembly; providing a light material flow path that communicates with a cylindrical space between said intermediate tube and said tubular-housing of each arm assembly; providing a conveyer screw within the inner tube of each arm assembly; providing first speed controllable drive means connected to effect rotation of said first and second arm assemblies about said rotation-axis; and providing second speed controllable drive means connected to effect rotation of said conveyer screws.