Patent ID: 6092389
Filing Date: 2000-07-25
Classification: C21D,F27B,F27D

Abstract:
Rapid-cooling oven, forming part of a plant comprising treatment stations, especially stations for the heat treatment of products in strip form, through which a metal strip runs continuously, the rapid cooling being obtained by spraying onto the strip a jet of atmosphere gas consisting of a nitrogen/hydrogen mixture having a hydrogen content which is greater than 15%, and preferably close to 50%, the atmosphere gas being recirculated using a circuit of recirculation ducts comprising at least one fan and at least one gas/water exchanger located in an enclosure, the various ducts comprising compensators made in the form of a series of corrugations allowing all the ducts to expand, wherein the enclosure, in which the exchanger or exchangers are housed and into which the atmosphere-gas recirculation ducts emerge, comprises:a main flow area via which the cooling gas flows through the exchangers, this flow area being provided with a register upstream of the said exchanger or exchangers;bypass flow areas allowing the flow of cooling gas to be diverted in the event of the main flow area being closed, so that this flow does not pass through the exchanger or exchangers, the bypass flow areas being provided with registers andactuators with a very short response time, i.e. of less than five seconds, these being tripped by means for detecting a break in the strip, a break in a compensator corrugation and a break in the power supply.