Patent ID: 6180933
Filing Date: 2001-01-30
Classification: C23C,H05B

Abstract:
A furnace for heating ferrous metal workpieces, said furnace including the combination of:a plurality of furnace sections including sequential first, second, third, and fourth furnace sections for heating ferrous metal workpieces arranged in an end to end relation to form a continuous supply of workpieces, some of said workpieces requiring heating rates differing from workpiece to workpiece for heating to a desired furnace discharge temperature;a first adjustable furnace controller to control said first furnace section for heating a preselected one of said workpieces at a heating rate different from a heating rate for another said workpieces forming said continuous supply of workpieces for discharge from said first furnace section at correspondingly different workpiece temperatures;a second furnace heating control for said second furnace section to maintain a second furnace operating temperature sufficiently constant to further heat said workpieces to a predetermined required discharge temperature;a third adjustable furnace controller to control said third furnace section for continued heating of said workpieces, said third adjustable furnace controller controlling heating of said preselected one of said workpieces at a heating rate different from a heating rate for other of said workpieces for discharge from said third furnace section at correspondingly different workpiece temperatures; anda fourth furnace heating control operatively coupled to said fourth furnace section for maintaining a fourth furnace operating temperature to continue heating of said workpieces including said preselected one of said workpieces for discharge from said fourth furnace section at a predetermined temperature to metallurgically heat treat said continuous supply of workpieces.