AIR-TIGHT INDUSTRIAL FURNACE ALLOWING PROTECTIVE GAS TO BE INTRODUCED THEREINTO, IN PARTICULAR, CHAMBER FURNACE, PUSHER FURNACE AND ROTARY HEARTH FURNACE OR RING-TYPE HEARTH FURNACE

摘要

PROBLEM TO BE SOLVED: To provide an air-tight industrial furnace which ensures an even and high-quality heat treatment process of a batch comprising a plurality of metal works and permits energy saving of heat treatment.SOLUTION: An industrial furnace which is used for performing heat treatment of a batch comprising a plurality of metal works and allows protective gas to be introduced thereinto includes: an inlet air lock (a) which is disposed on an inlet of a heat treatment chamber, contains a first air-tight closure device and can perform tight closure with respect to the surrounding by means of the first air-tight closure device; and a third air-tight closure device (b) arranged between the heat treatment chamber and a hardening facility located on the downstream of the heat treatment chamber. Thereby, the industrial furnace is configured such that, during the loading and taking-out of the batch, a pressure of the protective gas introduced into the heat treatment chamber can be retained.