Pump control apparatus for cellular filtration systems employing rotating microporous membranes

A system for separating filtrate from a fluid suspension having at least one biological cellular component that is characterized by having a nonrigid cell membrane free of a rigid outer cell wall, the cellular component being thereby subject to trauma when stressed, the system comprising:

• a membrane separation device comprising
• a separation chamber,
• a cellular suspension input for conveying the cellular suspension into the chamber,
• a microporous filter membrane in the chamber having pore openings sized to separate filtrate from the fluid suspension to leave within the chamber a concentrated suspension containing the at least one cellular component that is subject to trauma,
• means rotating the membrane at a selected surface velocity to create movement of the fluid suspension within the chamber without substantial trauma to the cellular component for inducing transport of the cellular component from the membrane while the fluid suspension is transported to the membrane,
• means for withdrawing the filtrate from the chamber through the rotating membrane means, including a filtrate output for discharging the filtrate, and
• a cellular concentrate outlet for discharging the cellular suspension from the chamber, and
• conduit means communication with the membrane separation device and a source of the cellular suspension and including
• input conduit means associated with the cellular suspension input and including inlet pumping means for delivering the cellular suspension from the source into the chamber,
• output conduit means associated with the cellular concentrate outlet and including outlet pumping means for discharging the cellular suspension from the chamber without recirculation back into the chamber, and
• control means interconnecting the input pumping means and the output pumping means for maintaining a selected flow relationship between the input and output pumping means to obtain a desired proportion in the fluid flow rate in the input conduit means in relation to the fluid flow rate in the output conduit means, thereby maintaining a desired optimal flow rate in the filtrate conduit means while the cellular suspension proceeds in a single pass through the membrane separation device.