Skid mark erasure system

In a reheating furnace of the type having a charging end and a discharge end and a hearth extending between said ends and walls defining a plurality of combustion zones above and below said hearth and extending a distance from said charging end, a soaking zone above said hearth adjacent said discharge end, a plurality of reheat combustion burners in each of said zones directed toward said charging end and a plurality of parallel spaced-apart, water-cooled support rails longitudinally extending along said hearth adapted to support semi-finished metal shapes thereon, wherein the improvement comprises:

• high thrust burner means positioned in a wall of the furnace spaced above the hearth and comprising a plurality of high velocity burners aligned in a longitudinally extending, spaced-apart array positioned above each of the water-cooled support rails and adapted to direct a high velocity flame on a top surface of said metal shapes directly above each of said longitudinally extending support rails supporting said metal shapes;
• sensing and control means for the high thrust burner means to detect the presence of cold skid marks and permit selective activation of a number of high velocity burners positioned above metal shapes having cold skid marks detected thereon and for selective deactivation of a number of high velocity burners positioned above the metal shapes having no skid marks detected thereon;
• said high thrust burner means including a plurality of spaced burner pairs, each of said burner pairs aligned in a converging manner such that a flame developed by each overlaps one another to produce a high temperature flame impingement sport on said metal shape;
• and
• additional high thrust burner means positioned below the hearth and longitudinally aligned along each of said support rails adapted to direct high velocity flames on a bottom surface of said metal shapes adjacent said support rails supporting said metal shapes.