APPARATUS FOR CONTROLLING FURNACE PRESSURE IN STRIP CONTINUOUS TREATING FURNACE

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for controlling the furnace pressure in a strip continuous treating furnace with which the excessive increase of the furnace pressure is prevented without providing a pressure releasing valve to keep the furnace pressure properly. SOLUTION: Seal rolls 2A and 2B for preventing the entering of outside air into the furnace by sandwiching the metal strip ST to compress from the front side and the back side and capable of changing the sandwich compression are provided in the inlet of the furnace 1. The furnace pressure is detected by a pressure detector 64 and when the furnace pressure is increased, the sandwich compression of the seal rolls 2A and 2B is decreased by a pressure controller 65 to reduce the furnace pressure to properly keep the furnace pressure. When the furnace pressure is decreased, a pressure controller 66 works to increase the furnace pressure to properly keep the pressure by increasing the feed quantity of the atmospheric gas in the furnace by flow rate control valves 71 and 72.