Lift-off means and method for use with a horizontal continuous hearth roll furnace for the treatment of metallic strip

Improved means and method are provided for the guidance of metallic strip in a horizontal continuous furnace having hearth rolls and wherein the strip temperature and furnace atmosphere are such as to promote the transfer of metal, oxides, dirt and the like from the metallic strip to some at least of the hearth rolls. At least one lifting hearth roll is provided in an elevated position wherein it lifts the metallic strip from those critical hearth rolls subject to contamination transfer. The elevated position of the lifting roll and its diameter are so chosen to assure a wrap-around contact between the metallic strip and the lifting roll in its elevated position. In practice the metallic strip is fed through the furnace and continuous operation is begun. The lifting roll, in its elevated position, maintains the metallic strip out of contact with the critical hearth rolls.