Abstract: Direct flame preheating section for continuous metal strip processing lines, comprising a connecting zone between an active zone provided with burners capable of operating in “no flame” mode and a recuperative zone for preheating the strip by exchange with combustion fumes originating from the active zone, the connecting zone having chambers capable of orienting the flow of fumes such that they flow head-on relative to the strip when exiting the active zone and entering the recuperative zone depending on the direction of flow of the fumes.