Dew point reduction method for annealing furnace atmosphere gas, the manufacturing method of the device and a cold-rolled annealed steel sheets

摘要

Part of an atmosphere gas in a heating zone 1 and/or a soaking zone is sucked out and is cooled through a high-temperature gas passage of a heat exchanger 9 by heat exchange with a gas in a low-temperature gas passage, is then further cooled by mixing with part of an atmosphere gas in a cooling zone 2, is then further cooled through a gas cooler 10, is then dehumidified to a dew point of -45°C or less in a dryer 11, is then heated through the low-temperature gas passage of the heat exchanger 9 by heat exchange with a gas in the high-temperature gas passage, and is returned to the heating zone 1 and/or the soaking zone. These can achieve a low dew point of -45°C or less with high energy efficiency.