Abstract: A regenerative thermal oxidizer in which contaminated air is first passed through a hot heat-exchange bed and into a communicating high temperature oxidation (combustion) chamber, and then through a relatively cool second heat exchange bed. The apparatus includes a number of internally insulated, ceramic filled heat recovery columns topped by an internally insulated combustion chamber. From the combustion chamber, the air flows vertically downward through another column containing heat exchange media, thereby storing heat in the media for use in a subsequent inlet cycle when the flow control valves reverse. Temperature is sensed within the bed of heat exchange media in order to monitor the temperature profile and control a bypass of hot combustion gases should the temperature exceed a predetermined level.

Abstract: A single bed thermal oxidizer for oxidizing a contaminate in a gas (air) stream has a plenum above the bed containing burners for gaseous fuel and means for injecting excess air. The burners are activated to initially heat the adjacent top bed portion. The burners are then turned off and a mixture of gaseous fuel and air is passed down into and through the bed which oxidizes the gaseous fuel and transfers the hot portion of the bed downward to preheat the central region of the bed. At that point, the gaseous fuel is terminated and the contaminated gas stream is introduced into the preheated bed for oxidation of the contaminate.

Abstract: A regenerative bed incinerator 10 is provided with a gas recirculation duct 80 through which a controlled amount of gaseous fuel is injected in the contaminated process exhaust gases 3 prior to admission to the regenerative bed incinerator 10 to increase the heating value of the process exhaust gases 3 so as to improve overall contaminated destruction efficiency for process exhaust gases which have a low level of combustible contaminants therein.

Abstract: A regenerative thermal oxidizer for oxidizing a contaminant in an air or other gas stream includes a heat transfer material which heats the incoming air and collects heat from the exiting air. The direction of flow of the air through the oxidizer is periodically reverse for the regenerative heat exchange. When flow is reversed, a quantity of untreated air in the oxidizer which would otherwise be discharged to the atmosphere is collected in a purge chamber which surrounds the lower portion of the discharge stack. The untreated air enters the bottom of the chamber and the air already in the chamber is forced out from vent holes in the top of the chamber into the stack. The untreated air in the chamber is fed back to the oxidizer through the inlet of the blower feeding the oxidizer while clean air is drawn into the chamber from the stack through the vent holes.

Abstract: A catalytic regenerative oxidizer (18) comprises a closed casing (24) having upper and lower ends, an input port (20) at the lower end and an output port (22) at the upper end. The casing contains a plurality of stacked layers or beds, including upper (34), lower (32), and central beds (40) of silica gravel or the like. Two catalyst layers (36, 38) are provided in the stack, one between the lower and central gravel beds, and the other between the upper and central gravel beds. A heating element (42) is situated in the central bed, for maintaining at least one of the catalyst layers at an activation temperature in the range of about 500-1000 deg.F. The catalyst layers are formed by a multiplicity of ceramic pellets on which is deposited a catalyst material, such as precious metal. The contaminated gas stream enters the casing through the lower port and passes vertically through the stacked beds and layers.

Abstract: In a regenerative bed incinerator 10 of type wherein the direction of gas flow through the bed 14 is periodically switched via a gas switching valve 30, a controller 80 is provided to periodically activate the gas switching valve 30 to reverse the direction of gas flow through the bed 14 in response to the temperature of the cooled incinerated process exhaust gases 5 as measured by gas sensing means 90.

Abstract: A regenerative bed incinerator 10 is provided with a gas recirculation duct 80 through which a controlled amount of incinerated process exhaust gases 7 are recirculated to the regenerative bed incinerator 10 to again pass through the combustion zone within the bed 14 housed therein so as to improve overall hydrocarbon destruction efficiency without exceeding permissible temperature limits.