Automatic control system for diaphragm pumps

A method for controlling an air actuated diaphragm pump, having a pump cycle including a discharge stroke and a fill stroke, comprising the steps of:

• a) setting a desired discharge time and a starting air pressure for the diaphragm pump;
• b) beginning the discharge stroke of the diaphragm pump;
• c) measuring the duration of the actual discharge stroke;
• d) comparing the actual discharge stroke with the desired discharge stroke, and
• e) adjusting the air pressure so that a subsequent discharge stroke will have a duration equal to the desired discharge time.

A control system adapted for use with a pneumatically actuated pump including a diaphragm pump including a pump housing, a diaphragm dividing the housing into a pumping chamber and a pump actuating chamber wherein the control system comprises:

• an air pressure supply source adapted to introduce air pressure into the pump actuating chamber to force the diaphragm from a starting position to a finishing position;
• a three-way supply valve adapted to control the introduction of air pressure into the pump actuating chamber, said three-way valve capable of venting the pump actuating chamber to atmosphere;
• a pressure regulator for limiting the air pressure;
• stroke sensing means for sensing movement of the diaphragm between a starting position and a finishing position;
• a central control system for coordinating the operation of said valve and said pressure regulator in response to signals received from said stroke sensing means;
• pressure adjustment means for said pressure regulator comprising a solenoid-operated three-way valve in communication with said central control system and positioned in a branch conduit connecting said air pressure source to said pressure regulator for communicating pressure signals to said pressure regulator, means for venting signal pressure at said pressure regulator to atmosphere to decrease the pressure signal, the central control system adjusting the pressure regulator in accordance with variations in the discharge time of the pump.