Process control systems and methods for use with filters and filtration processes

A process control system comprising:

• a microfiltration unit;
• a single-pass tangential flow filter having an inlet, a permeate outlet and a retentate outlet;
• a feed pump with an inlet connected to the microfiltration unit and an outlet connected to the inlet of the filter;
• a permeate pump with an inlet connected to the permeate outlet of the filter;
• and a control system coupled to the permeate pump and adapted to control the permeate pump to vary a flow reduction factor, where the flow reduction factor is a ratio of feed flow into the inlet of the single-pass tangential flow filter to retentate flow out of the retentate outlet of the single-pass tangential flow filter,
• and wherein the control system is adapted to control the permeate pump to vary the flow reduction factor to achieve a target volume reduction factor, where the volume reduction factor is a ratio of cumulative feed volume of the feed flow to cumulative retentate volume of the retentate flow.