Treatment of furnace gases

摘要

920,982. Consuming noxious vapours. W. C. HOLMES & CO. Ltd. Jan. 8, 1962 [Jan. 17, 1961], No. 1869/61. Class 51 (1). [Also in Group XXVIII] Gases given off from an electric arc furnace, particularly during the production of steel, are fed to a combustion chamber and completely burned to eliminate carbon monoxide. Gases from the furnace are drawn off through an inlet 2 maintained at a slight vacuum by a stack 3 beyond the gas cleaning equipment, which may have a fan 13. Gases are partly burned within pipes 2 and 6, with air admitted through a slip joint 5, and combustion is completed in a chamber 7, with additional air from a dampened inlet 8. Ignition burners 24 may be arranged at the entrance to the combustion chamber 7. The gases from the chamber 7, after passing baffles 25, are cooled by water sprays in an adjacent chamber 9, and fed to a wet precipitator 20. Sludge from the cooling chamber 9 and the precipitator 20 is fed to a settling tank, and the water recirculated. The water supply to the cooling chamber 9 is controlled in accordance with the temperatures at the outlet of the chamber 9 and the entry to the precipitator 20, and the pressure at the outlet 2 from the furnace roof controls a water-cooled damper 4. The pressure control may have two positions, so that different conditions during the oxygen blowing and refining periods of a steel making furnace. During melting down of oily scrap, appreciable amounts of hydrogen may be given, which is burnt in the chamber 7. A slight pressure in the furnace during the refining period may be obtained by closing the damper 4, or an additional damper may be arranged downstream of the cooling chamber 9. According to the Provisional Specification, the wet precipitator may be replaced by an electrostatic precipitator or by filters.