Abstract: A gas fired furnace system (10) has a controller (14) controlling the supply of gas through a gas valve (12) and air for combustion by means of an induced air draft fan (28), ignition of the gas by means of ignitor (22), the delivery of heated air from a heat exchanger (20) by means of an air blower (34) in response to signals from a thermostat (42). A selected constant flow of air for combustion is provided by controlling the speed of the motor driving the induced motor fan (28) despite changes which may occur in back pressure. Induced draft fan motor parameters proportional to motor torque and motor speed are read on an ongoing basis and inputted to controller (14) which computes a desired voltage and compares that with referenced data stored in the controller memory and makes corrections to the speed of the induced draft fan motor to maintain the constant air flow.

Abstract: A new and improved incinerator steam generation system subjecting to combustion debris such as municipal waste, utilizing the heat derived therefrom to produce steam for steam boiler, electrical generating facilities, heating facility for industrial or commercial plants, and so forth. This is provided with a series of boilers and controls, both manually adjustable and also automatic, whereby the possibility of fire dangers are minimized, created temperature ranges of boiler gases are constrained to desirable limits, dump stack facilities are automatically controlled as to particular effectiveness for differing types of operating conditions, and where safety features are incorporated to shut down gas flow through the boiler during periods of boiler-water deficiency, excess steam generation relative to demand, and other conditions. Within the furnace area proper the pressure conditions are predetermined and are controlled during operation for desired efficiency, vapor removal, and materials' combustion.