Smokeless pyrolysis furnace with micro-ramped temperature controlled by water-spray

摘要

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° 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°) with normal fuel supply to the main burner ("high-fire"). The final portion of the burn is completed with the main burner being starved of fuel ("low-fire"). The set-point is maintained within the specified narrow range during the main burn with the primary water spray. If the temperature deviates beyond a specified higher temperature (say by 10° F.) a secondary water spray is actuated by the PC. An afterburner burns volatiles generated in the furnace's main chamber. The effluent from the exhaust stack is essentially free of smoke. No catalyst or catalytic device is used to purify the smoke. The main chamber TC and interactive PC thus maintain a fire under controlled temperature conditions in the main chamber without an explosion.