FREMGANGSMAATE OG SMELTEOVN FOR SMELTING AV TUNGTSMELTENDEMETALLSKROT.

摘要

A process for melting metal scrap, particularly steel scrap or such high-melting charge material in a shaft furnace operated in cokeless manner by means of fluid fuels is described. The furnace shaft used for carrying out the process is separated from the furnace hearth connected to the bottom thereof by means of a cooled grate arrangement. The burners issue substantially vertically to the longitudinal axis of the shaft into the furnace and the combustion air is recuperatively preheated by means of the shaft furnace waste gases. The amount of heat introduced into the melting unit by means of the burners is subdivided in dosable manner into a component drawn off from the furnace shaft and a component remaining in the furnace hearth. For this purpose the radiating surface of the wall lining in the furnace hearth is between 1.5 and 3.5 m2, particularly 2 and 2.8 m2 ton of molten metal produced. The radiation-active, average layer thickness of the gas in the furnace hearth is between 1.5 and 3.5 m, particularly 2 and 2.5 m and the inlet temperature of the waste gas into the recuperator is controlled as a function of the charge material bed height in the furnace shaft.