GAS DYNAMIC SEALING METHOD OF CHARGING AND DISCHARGING OPENINGS OF DRAW FURNACE (VERSIONS) Russian patent published in 2012 - IPC F27B9/30 F27D1/18 F27D7/04 

FIELD: metallurgy.

SUBSTANCE: gas dynamic sealing method of charging and discharging openings of draw furnace involves circulation of shielding gas in chambers of the gas seal due to gas pressure drop in each of those chambers; at that, circulation intensity is controlled using the circulation circuit the gas flow in which is performed by a fan the inlet of which is connected to the discharge chamber, and outlet is connected to pressure chamber. According to the first version in gas flow direction after the discharge chamber there created is mixing chamber in which opposite gas and air flows are mixed and there maintained is constant average temperature of discharged mixture of opposite gas and air flows or constant content of oxygen or hydrogen in the discharged mixture at creation of negative pressure in mixing chamber relative to shielding gas in furnace volume and ambient air. According to the second version in gas flow direction before the pressure chamber there created is mixing chamber connected to inlet of additional fan, in which opposite gas and air flows are mixed and pressure is created which is excess relative to ambient air, but less relative to shielding gas in furnace volume. At that, average temperature of discharged mixture of gases from mixing chamber of opposite gas and air flows is set in the range of 0.2-0.9 of shielding gas temperature in the furnace volume adjacent to gas seal; oxygen content in the mixture of gases discharged from mixing chamber of opposite gas and air flows - in the range of 0.1-0.9 of oxygen content in ambient air, and hydrogen content in the discharged mixture of gases from mixing chamber of opposite gas and air flows is in the range of 0.1-0.9 of hydrogen content in shielding gas contained in the furnace volume adjacent to gas seal.

EFFECT: smooth control of the sealing mode of charging or discharging openings at changing the shielding gas pressure in furnace volume in the whole possible range at constant specified losses of shielding gas.

2 cl, 2 dwg