Patent 6991041 was granted and assigned to Hale Products, Inc. on January, 2006 by the United States Patent and Trademark Office.
A compressed air foam system for use in extinguishing fire includes a conduit, a water flow sensor, a foam proportioning apparatus, an air conduit, an air flow sensor, an air flow control valve and a system controller. The water flow sensor is configured to sense a water flow rate through the conduit. The air flow sensor is configured to sense an air flow rate through the air conduit. The system controller has a user adjustable ratio input. The system controller is configured to receive the sensed water flow rate, to receive the sensed air flow rate, to output a first control signal to the air flow control valve and to output a second control signal to the foam proportioning apparatus. The system controller automatically adjusts the first and second control signals to maintain a ratio of air flow to foam flow based upon the user adjustable ratio input.