Internal combustion engine exhaust filter devices and the like are regenerated by placement in a reclamation or burn-off furnace, raising the temperature to at least about 800° F. to 900° F. and conducting relatively low volumes of low pressure air through the filter media to combust entrapped particulates and other materials residing on the filter media. The reclamation furnace includes an afterburner for combusting materials discharged from the filter devices into the furnace chamber so that complete combustion of materials is accomplished before discharge from the furnace. The flow of combustion air for the filter devices is controlled by manifolding and valving connected to a source and the oxygen content of combustion air may be enhanced by a separate source of oxygen injected into the combustion air flow stream.