Patent ID: 9657366
Date: 2017-05-23
CPC Classifications: C21D,F27B,F27D

Claim:
1. An apparatus that reduces a dew point of an atmosphere gas in a continuous annealing furnace that anneals a metal strip in a reducing atmosphere by passing the metal strip through a heating zone and a cooling zone in this order or through a heating zone, a soaking zone, and a cooling zone in this order, comprising: a circulator including a heat exchanger that exchanges heat between a low-temperature gas and a high-temperature gas, a gas cooler that cools a gas, a dryer that dehumidifies a gas to a dew point of −45° C. or less by utilizing a desiccant or compressor, and a gas distributor, wherein the apparatus further includes a first gas passage extending from the heating zone and/or the soaking zone through a gas passage to a high-temperature gas passage which is installed in the heat exchanger and through the gas cooler to the dryer, a second gas passage extending from the dryer through the gas distributor to a low-temperature gas passage of the heat exchanger and from the heat exchanger to the heating zone and/or the soaking zone, and a third gas passage that returns part of gas flowing from the dryer toward the low-temperature gas passage of the heat exchanger directly to the cooling zone through the gas distributor but without passing through the heat exchanger.