Patent ID: 6748881
Filing Date: 2004-06-15
Classification: F23C,F23G,F23L,F23N

Abstract:
A continuous method to remove organic contaminants from metal parts in a pyrolysis furnace having an enclosure physically divided into a main combustion chamber connected to inlet and exhaust chambers, a rotating retort vessel extending thru said enclosure to enable continuous passage of contaminated metal parts thru said pyrolysis furnace, an adjustable heating rate burner to directly heat air ducted into said enclosure, and multiple supplemental combustion chambers in open communication with said furnace enclosure and vented to the atmosphere with each containing an auxiliary burner, said method comprising:(a) operating said main combustion chamber at a positive chamber pressure while concurrently operating both inlet and exhaust chambers at a negative chamber pressure, said operation being conducted with temperature sensing means in combination with control means including programmable temperature control means to maintain continuous operation of said adjustable heating rate burner with (i) a normal fuel supply necessary to maintain full combustion of said organic contaminants in the presence of excess oxygen during a major portion of the pyrolysis cycle, said excess oxygen being relative to the amount required to burn the fuel in said burner, and (ii) a diminished supply of fuel sufficient to maintain fuel-starved combustion during the final portion of the pyrolysis, also in the presence of excess oxygen, (b) activating a water spray within said furnace enclosure responsive to said temperature sensing means for operative cooperation with said adjustable heating rate burner to regulate operating temperatures within said furnace enclosure in accordance with a preselected heating schedule, (c) employing multiple auxiliary burners to complete combustion of the volatized organic contaminants being transported from said furnace enclosure within said supplemental combustion chambers, and (d) continuously supplying said contaminated metal parts to the retort vessel in said pyrolysis furnace.