Vertical direct fired strip heating furnaces

Claim 1

In a vertical direct fired strip heating furnace for heating steel strips and of the type including at least two vertical and parallelly arranged heating chambers each having strip entrance and exit ends, with a steel strip to be heated passing in a vertical path through the entrance and exit ends of an upstream-most said heating chamber and then in successive vertical paths through the entrance and exit ends of the remainder of said heating chambers, and guide rolls located adjacent the exit end of said upstream-most heating chamber and adjacent the entrance and exit ends of said remainder of said heating chambers, at least the downstream-most of said heating chambers being provided therein with burners to directly heat the steel strip passing therethrough, the improvement comprising: a horizontal flue connecting a said exit end and an adjacent said entrance end of successive adjacent of said heating chambers; adjacent each said horizontal flue and separate therefrom, a respective guide roll chamber housing the respective said guide rolls adjacent the said ends of said heating chambers connected by the respective said horizontal flue; said steel strip passing horizontally through each said guide roll chamber but not through said horizontal flues, and said horizontal flues providing free communication of exhaust gases from said burners between said heating chambers, but said exhaust gases being substantially isolated from said guide roll chambers; and means for adjusting the temperature within said guide roll chambers.