GB161971A - Improvements in shaft furnaces and the like - Google Patents

Abstract

161,971. ChaudiÞre, E. F. April 19, 1921 Addition to 137,168. Shaft furnaces.-In a shaft furnace of the kind described in the parent Specification, air for cooling the charge is admitted at the base of the shaft, and a variable portion of this air is withdrawn at a level below that of the combustion zone either into the central core or through openings in the outer wall of the furnace. The central core comprises a shaft 2 extending from the base of the furnace to the mouth of the chimney 3, and a casing 8, which is stepped, as shown, to form a support for a refractory lining 6. Air is heated in the space between the shaft 2 and casing 8, and is delivered to the combustion zone through passages 7 in the lining 6, further supplies being also delivered through passages 12 in the outer wall. Air for cooling the charge is admitted to the shaft through the discharge openings, and passes, part to the combustion zone, and part through openings 13 controlled by a damper 15 to the shaft 2. Alternatively the surplus air for the cooling-zone may be withdrawn through openings in the outer wall and the duct 26. The products of combustion may be withdrawn as shown by the arrows through the shaft 2, or if the damper 17 is opened may pass out through the chimney 3. In the latter case the draught may be assisted by the ejector 18.