GB293326A - Improvements in or relating to the manufacture of steel in the siemens-martin furnace - Google Patents

Abstract

293,326. Siemens Akt.-Ges., F., Durrer, R., Siemens, F. C., and Sprenger, A. Dec. 24, 1926. Open-hearth furnaces ; gases. applying.-In a process for the manufacture of steel in a Siemens- Martin furnace, a layer of gases practically free from hydrogen is formed, at the end of the fining process, between the bath and the heating medium in order to prevent the access to the bath of any oxidizing medium which may get into the furnace or be generated therein. A suitable gas is blast furnace gas or the gas from a tapping producer which works without steam and in which a coal poor in gases, coke or semi-coke is used. In the furnace 1, Fig. 1, in which the air and gas for heating are supplied by conduits 2, 3, the protective gas is introduced by inlets. 7 from pipes 4, 5 into the conduit 3 and spread in a layer over the bath under the flame produced by the air and gas from the conduits 2, 3. In another form, the protective gas is introduced by a separate conduit, and the gas may be produced in a furnace grate connected thereto. In another form, Fig. 9, the gas and air for the heating burner are introduced by pipes 30, 31 and the protective gas through conduits 37, the heating gas being combusted by a burner 33. Additional laterally-arranged nozzles 38 may be provided for the introduction of protective gas. In order to deflect the heating flame down on to the bath the walls of the furnace are lowered at several points such as 23, Fig. 15, the gas and air being introduced through conduits 21, 22. Doors 24 are provided for the removal of slag &c. accumulating in the bottom of the conduit 21. The arches are cooled by a flat water pipe 26, Fig. 17, arranged between the bricks 25 being held in position by distance bricks 27, cooling air being also introduced into the chamber so formed by a pipe 28.