Method and apparatus for heating a workpiece
AssigneeAllegheny Ludlum Industries, Inc.
InventorWilliam M. Bloom
Life of this patent
Estimating the term…
Abstract
A steel strip such as stainless steel is passed in uncoiled form through a jet recuperator, an intermediate furnace section, and a main fired furnace section in which a fuel such as natural gas is burned. The exit end of the main furnace section has an opening only slightly greater than the cross-section of the strip. The strip is preheated in the jet recuperator by forcing waste gases from top and bottom waste gas chambers through holes in the bottom and top, respectively, of the waste gas chambers against both sides of the strip. The strip is further heated by the waste gases in the unfired intermediate section and brought to final temperature in the main fired section.
Claims14
A method of heating a steel strip which comprises continuously passing uncoiled strip through the heating chamber of a jet recuperator and then through a main heating chamber where heat is provided by burning fuel, preheating the strip in said jet recuperator by taking waste gases from combustion of said fuel through outlet means offset transversely from the center of said recuperator and intermediate the length of said recuperator and forcing said waste gases through spaced holes against the top and bottom of said strip, and then heating the strip to the desired temperature in said main heating chamber.
Apparatus for heating a workpiece which comprises an elongated main furnace section having a main heating chamber through which the workpiece passes from an entry to an exit end;
- fuel burners in said main furnace structure;
- an opening at the entry end of said heating chamber for receiving said workpiece and waste gases from the combustion of said fuel;
- a jet recuperator at the entry end of said main section having a heating chamber communicating with said main heating chamber and through which the workpiece passes to said heating chamber in said main furnace section, said recuperator including a waste gas chamber communicating with said main heating chamber and having a wall adjacent the path of travel of said workpiece in said recuperator heating chamber with holes therethrough, outlet means from said recuperator heating chamber offset transversely from the center thereof intermediate the length thereof, fan means for receiving waste gases from said main furnace section and said recuperator heating chamber through said offset outlet and delivering them through said waste gas chamber and said holes against said workpiece;
- and means for moving said workpiece through said heating chambers and exit end of said main furnace section.
Dependencies are inferred from the claim text.