Abstract: A process heater system (10) for an industrial envelope (11) comprises a main combustion chamber (20), an afterburner (30), and an exhaust stack (40). Retrofitted heat-recovery piping (50) receives combustion gas downstream of the afterburner (30) and uses it as a heat source for the industrial envelope. When the industrial load in the main combustion chamber (20) is paint, powder coating, varnish, epoxy, grease and/or oil, the secondary materials burned in the afterburner 30 can be considered alternative fuel, not solid wastes.

Abstract: A pyrolysis furnace is described enabling removal of solid and liquid organic contaminants from various metal parts in a continuous manner. A novel furnace contruction employing a rotating retort vessel is described together with its method of continuous operation.

Abstract: A batch-type pyrolysis furnace burns a load of organic combustibles on metal parts without a significant risk of explosion because of a combination of two necessary conditions: (a) a primary water spray is maintained during a large portion of the burn cycle while the main burner is neither turned off nor attenuated until a major portion of the load is combusted; and, (b) the temperature in the main chamber is controlled by a "micro-ramped" programmable temperature controller (PC). By setting the ramp for micro-steps of no more than 2.degree. F. per minute, and actuating the primary water spray to maintain the set-point temperature while it is ramped upward, the criticality of the location for the single thermocouple is obviated, and it is unnecessary to measure the temperature in the throat. The micro-steps eliminate soak periods during the ramp. The main "burn" progresses during the ramp, and at the upper set-point of the ramp (say 800.degree.) with normal fuel supply to the main burner ("high-fire").

Abstract: A method of operating a batch-type pyrolysis furnace to burn organic combustibles so that the effluent from its exhaust stack is essentially free of smoke. This is accomplished without the aid of any catalyst or catalytic device to purify the smoke. For its main heat source, the furnace uses a gas burner or electric heating coil in combination with an afterburner to burn volatiles generated in the furnace's main chamber. A single thermocouple (throat TC) senses the instantaneous temperature in the throat of the furnace and in cooperation with a programmable controller (PC), maintains a preselected ramp and soak temperature profile over the entire burn cycle. When the temperature required by the profile is exceeded, a single water spray is actuated by a signal from the PC to lower the temperature below the profile. The throat TC thus maintains a fire under controlled temperature conditions in the main chamber without an explosion, using a single-stage system.

Abstract: A batch-type pyrolysis furnace fired by a main heat source such as a gas burner or an electric heating coil in combination with an afterburner to burn volatiles generated in the furnace's main chamber, is operated to incinerate high-polymer loads smokelessly, yet is effectively safeguarded from explosions. A single thermocouple (zone TC) senses the instantaneous temperature in a critical sensitive zone (CSZ) of the furnace and in cooperation with a programmable controller (PC), maintains a preselected ramp and soak temperature profile over the entire burn cycle. The CSZ has been found to be within about 1' (foot) from the upper edge of the throat, and not lower than about 6" (inches) from the ceiling of the main chamber. When the temperature required by the profile is exceeded, a single water spray actuated by a signal from the PC lowers the temperature below the profile.

Abstract: A batch-type pyrolysis furnace fired by a main heat source such as a gas burner or an electric heating coil in combination with an afterburner to burn volatiles generated in the furnace's main chamber, is operated to incinerate high-polymer loads smokelessy, yet is effectively safeguarded from explosions. A single thermocouple (throat TC) senses the instantaneous temperature in the throat of the furnace and in cooperation with a programmable controller, maintains a preselected ramp and soak temperature profile over the entire burn cycle. When the temperature required by the profile is exceeded, a single water spray actuated by a signal from the PC lowers the temperature below the profile. The throat TC thus maintains a fire under controlled temperature conditions in the main chamber without an explosion, using a single-stage system.

Abstract: A batch-type pyrolysis furnace fired by a main gas burner and an afterburner, is effectively safeguarded from explosions and runaway fires due to an undue build-up of flammable vapors within its main chamber, by the simple expedient of maintaining a fire under controlled temperature conditions in the main chamber. This is done by a dual-stage control system requiring three thermocouples, one (first) in the main chamber, a second in the exhaust stack downstream of the afterburner, and a third upstream of the afterburner in the vent passage ("throat") connecting the main chamber with the afterburner chamber. The first thermocouple in the main chamber senses the ambient, essentially instantaneous temperature at that location. The effectiveness of the control system, in large measure, derives from the unexpected difference in temperatures sensed by the first and third thermocouples.