Computer controlled waste heat reclaimer

Claim 1

A control device for a heat reclaiming unit, which heat reclaiming unit is of the type which includes: a primary heat exchanger for receiving waste gases from a stack or other source and for receiving cool water from a primary source of water and for mixing said gases and water to heat the primary water while cooling the gases, a secondary heat exchanger having a secondary flow of water, means for delivering the heated primary water to the secondary heat exchanger and into heat exchanging relation with the secondary flow of water to heat the secondary flow of water, means for delivering waste gases to said primary heat exchanger, said control unit including: means for sensing the temperature of said gases being delivered to said primary heat exchanger and for creating a signal indicative of said temperature, means for sensing the temperatures of said secondary flow of water both before it enters heat exchanging relation with said primary flow and after it leaves such heat exchanging relation and for creating electrical signals indicative of said termperatures, means for sensing the flow pressure of said secondary flow of water and for creating an electrical signal indicative of said flow pressure, means for sensing the flow pressure of the heated primary water and for creating an electrical signal indicative of said flow pressure, logic and control means for receiving said signals and displaying indications of the flow pressures and temperatures, said logic and control further including means responsive to the sensed temperature of the gases being delivered to the primary heat exchanging means for warning an operator if the gases are below a given low temperature and for shutting off said means for delivering waste gases and said means for delivering primary water if said temperature is above a given high temperature, means for warning the operator if the flow pressure in either said means for delivering waste gases or said means for delivering primary water is below a given level indicative that the respective flow has ceased, means responsive to said signals indicative of the temperatures and flow pressure of the secondary source of water for calculating the rate of heat energy gain in said secondary flow of water as a result of passing through said secondary heat exchanger, and for displaying the rate of heat energy gain calculated means for indicating to an operator that said heat gain amount is below a given amount, and means to display an indication of the time since a particular component of said unit has been serviced.