Alternating tangential flow pumping method

An alternating tangential flow pumping method comprising:

• connecting a pneumatic cylinder having a proximal end comprising a center opening, a distal end comprising a piston, and a chamber to a filter sphere base comprising a center opening, lining up the opening of the proximal end with the opening of the sphere base;
• activating the piston with a linear servo;
• and
• moving the piston in and out of the cylinder, creating positive and negative pressure.

An alternating tangential flow pumping system comprising:

• a first pneumatic cylinder having a proximal end and a distal end, and defining a chamber therebetween, the proximal end being connected in series to a first filter system, wherein the proximal end comprises an opening in the center of the proximal end which leads to the chamber;
• a second pneumatic cylinder having a proximal end, a distal end, and containing a chamber, the proximal end being connected in series to a second filter system, wherein the proximal end comprises an opening in the center of the proximal end which leads to the chamber;
• a piston connecting linkage entering the pneumatic cylinder through the distal ends of each of the pneumatic cylinders;
• the filter systems, wherein the systems comprise a hemisphere comprising a diaphragm, the hemisphere connected to the distal end of a cylinder, wherein the proximal end of the cylinder connects to a source of liquid, and wherein the cylinder contains a filter;
• wherein the piston moves to provide pressure to the first filter, creating an equal vacuum on the second filter.

A method of controlling an alternating tangential flow filtration process, the method comprising:

• selecting a volume or size of a diaphragm pump;
• selecting a volume of a fluid to be displaced by the diaphragm pump over a given period of time;
• selecting a duration of a pumping operation, which together with the desired volume of fluid to be displaced over the duration, generates a performance profile appropriate for a specific application;
• actuating the pumping operation by alternating a supply of positive and negative air flow to the diaphragm pump using a linear servo.

A method of actuating a diaphragm pump comprising:

• selecting a volume or size of a diaphragm pump;
• selecting a volume of a fluid to be displaced by the diaphragm pump over a given period of time;
• selecting a duration of a pumping operation, which together with the desired volume of fluid to be displaced over the duration, generates a performance profile appropriate for a specific application;
• actuating the pumping operation by alternating a supply of positive and negative air flow using a piston attached to a linear servo within a chamber connected to the diaphragm pump;
• monitoring the movement of the linear servo to maintain or alter the positive or negative air flow per unit of time chamber;
• optionally, monitoring a position of a diaphragm of the diaphragm pump at one or both ends of its displacement;
• and
• optionally, altering the positive or negative air flow within the chamber to influence either the position of the diaphragm at one or both ends of its displacement or a duration of a partial or full cycle of displacement or both.