Patent ID: 8490416

Claim:
A method of cooling a metal strip traveling through a cooling section in a continuous heat treatment line, wherein the method consists in projecting a refrigerant medium into the cooling section ( 4 ) onto a surface of the strip ( 1 ) to be cooled, the medium being constituted by a phase-change substance that passes into the gaseous phase at a temperature that is lower than the temperature of the strip ( 1 ) and without oxidizing said strip so that energy is exchanged within an endothermic process by a change in the phase of said phase-change substance, wherein the refrigerant medium is a fluid, in particular in the form of fine droplets, presenting a normal boiling temperature that is higher than the temperature of the outside ambient medium, the endothermic process taking place with said refrigerant medium evaporating at the surface of the strip ( 1 ) to be cooled and wherein the normal sublimation temperature of the refrigerant medium is equal or inferior up to 5 K to the temperature of the outside ambient medium, so that said refrigerant medium can be recondensed at a pressure equal to atmospheric pressure.