Raymond J Burda

US Patent:

54794340, Dec 26, 1995

Filed:

Mar 11, 1994

Appl. No.:

8/212581

Inventors:

Raymond J. Burda - Cheswick PA

Assignee:

Mannesmann Aktiengesellschaft - Dusseldorf

International Classification:

F27D 2300

US Classification:

373 78

Abstract:

A double furnace installation having two arc furnaces connected via a line, a power supply, a device for charging material, and an arrangement for extraction and purification of gas is operated by connecting a first one of the furnaces with the power supply for melting a charge located therein, isolating a second one of the furnaces from the power supply, charging the second furnace with charging material, and closing the second furnace with a cover. Flue gas generated during a melting phase of the first furnace is sucked therefrom and introduced into the second furnace through a first interior bay region of the second furnace. The flue gas entering the second furnace in this manner passes substantially horizontally through the charging material in the second furnace because it is sucked therefrom through a second interior bay region disposed diametrically opposite the first interior bay region.

US Patent:

55419526, Jul 30, 1996

Filed:

Jun 21, 1994

Appl. No.:

8/263922

Inventors:

Ulrich F. H. Genge - Pittsburgh PA
Raymond J. Burda - Cheswick PA
John W. Brandon - Pine Township PA

Assignee:

Mannesmann Demag Corporation - Coraopolis PA

International Classification:

F27D 2300

US Classification:

373 9

Abstract:

Apparatus and methods of abating the objectionable emissions of volatile hydrocarbons generated during the preheating cycle of a twin vessel electric arc furnace steelmaking operation wherein the vessels cycle between a powered or melting state and an unpowered state. During the unpowered state, scrap charged to the non-powered vessel is preheated. The spent off-gases from the non-powered vessel may contain toxic and/or noxious hydrocarbons therein by virtue of certain plastics and/or grease/oils mixed with the scrap being preheated. The spent off-gas from the preheat vessel is delivered to a combustion chamber to be mixed with a hot off-gas diverted from the powered vessel. The temperature of the mixed off-gases in the combustion chamber is raised to a critical temperature to burn/crack the objectionable hydrocarbons, which may include dioxins and furans. The temperature of the spent off-gas can be increased more rapidly during initial melting stages by employing burners in the preheat vessel and/or by decreasing the size of the scrap charge and increasing the molten heel left in the non-powered vessel after tapping.