Abstract: A process and apparatus for removing volatile contaminants from scrap metal is disclosed. The process is carried out in a furnace maintained at a relatively constant temperature and having a first zone in which volatiles contained on the surface of the metal are vaporized and a second zone in which carbon contained on the surface of the metal is pyrolyzed. The furnace also has a conveyor for transporting metal therethrough at a specific speed to ensure complete vaporization and pyrolysis of the contaminants. The process includes the steps of sufficiently vaporizing the volatiles without oxidizing the metal, the vaporizing producing fumes containing unburned hydrocarbons. The hydrocarbon fumes are then burned to produce hot gas which is recirculated to the furnace. The hot gas contacts the incoming metal and vaporizes the volatiles contained thereon.

Abstract: A process and apparatus is disclosed for removing volatile contaminants from scrap metal. The process is carried out in a furnace maintained at a relatively constant temperature having a first zone in which volatiles contained on the surface of the metal are vaporized and a second zone in which carbon contained on the surface of the metal is pyrolyzed. The furnace also has a vibrating conveyor for transporting metal therethrough at a specific speed. The process includes the step of vaporizing and fluidizing the volatiles to produce fumes containing unburned hydrocarbons without oxidizing the metal. The hydrocarbon fumes are then burned to produce hot gas which is recirculated to the furnace so as to contact new incoming scrap metal.

Abstract: A process and apparatus for removing volatile contaminants from scrap metal is disclosed. The process is carried out in a furnace maintained at a relatively constant temperature and having a first zone in which volatiles contained on the surface of the metal are vaporized and a second zone in which carbon contained on the surface of the metal is pyrolyzed. The furnace also has a conveyor for transporting metal therethrough at a specific speed to ensure complete vaporization and pyrolysis of the contaminants. The process includes the steps of sufficiently vaporizing the volatiles without oxidizing the metal, the vaporizing producing fumes containing unburned hydrocarbons. The hydrocarbon fumes are then burned to produce hot gas which is recirculated to the furnace. The hot gas contacts the incoming metal and vaporizes the volatiles contained thereon.

Abstract: A process for removing hydrocarbon combustibles from the surface of metal particles and recovering the heat content therefrom is disclosed. The process is carried out in a system having a smoke collection zone, a heating zone and burner means supplied with fuel and air. The process includes charging the metal particles into a moving molten metal bath contained in the smoke collection zone. The charging generates smoke and vaporizes the hydrocarbon combustibles to provide unburned hydrocarbon fumes. A burner means is fired to draw transporting gas into the smoke collection zone to entrain and transport the smoke and fumes from the smoke collection zone to a jet stream exiting the burner means. The smoke and fumes are incinerated in the jet stream to provide hot gas. The transporting gas also contains oxygen for incinerating the smoke and fumes. The hot gas provided by incinerating the smoke and fumes is then jetted via the jet stream into the heating zone where its heat content is recovered.

Abstract: Scrap metal contaminated with hydrocarbon combustibles is reclaimed by vaporizing the hydrocarbon combustibles contaminating the metal in a kiln so as to produce partially unburned fumes in said kiln. The fumes are separated from the metal as the metal is discharged from the kiln, and the separated fumes are then transported to a heat generating means having a burner means secured therein. The fumes are incinerated in the heat generating means by the flame of said burner means so as to provide hot gas which is recirculated to the kiln for purposes of conducting the aforementioned vaporization step. The firing rate of the burner means is regulated to maintain the recirculating hot gas close to a predetermined temperature, and the air to fuel ratio supplied to the burner means is varied to maintain the concentration of oxygen in the recirculating hot gas close to a predetermined level.