Steel reheating furnace

A furnace for heating a steel slab as it moves longitudinally through various regions in the furnace, said furnace including a pair of elongated, longitudinally extending rails each having a top surface for supportingly engaging the bottom surface of the slab, characterized by said top surfaces being generally coplanar, each rail including a first and a second primary portion each laterally offset from one another for engaging, respectively, a first and second area of said bottom surface, each of the first primary portions being in a different region than that of the second primary portions, and heating means disposed vertically below said top surfaces for selectively heating the second areas when the slab is moved from supporting engagement by the second primary portions and has its first areas supported by the first primary portions.

A steel reheating furnace characterized by a plurality of elongated, longitudinally extending, heating elements and associated skid rails, each rail having laterally offset primary portions with each portion supporting either a respective first or second area on the bottom of a slab as it passes through the furnace, the areas being side-by-side, the heating elements directing their heat at the associated first area when the second area is supported by the associated rail portion, whereby to eliminate skid marks caused by rail portions otherwise shielding the slab from heat in the furnace.

A furnace for heating a steel slab as it moves through the furnace between an inlet to an outlet, said furnace including a pair of elongated, longitudinally extending rails each having a top surface for supportingly engaging the bottom surface of the slab, characterized by each rail including a first, second and third portion, the first and third portions being proximate, respectively, to the outlet and the inlet for engaging a first area of its slab and the second portions being laterally offset from its first and third portions for engaging a second area of its slab, first heating means adjacent to the second portions for actively heating said first areas to prevent heat sink formation caused by said first areas being supported by said third portions and second heating means adjacent to the outlet for actively heating said second areas to eliminate heat sink formation on said second areas caused when second areas were supported by said second portions.

An elongated furnace chamber through which a slab to be heated is fed in a feeding direction and supported by at least one rail, characterized by a radially apertured pipe having a central bore which defines a pressurizable chamber for combustible gases, said rail having an elongated first portion overlying the pipe and an elongated second portion, each said portion for supporting laterally offset first and second areas on the bottom of the slab as the slab is moved between successive areas in the furnace, means for supplying and mixing natural gas and air to form a combustible gas mixture in the chamber, and ignition means for igniting the combustible gas mixture, the products of combustion being discharged from the slots and directed at the first areas when the second portions support the second areas.