Shaft furnace bottom, in particular for a blast furnace

摘要

A shaft furnace, e. g., blast furnace for iron manufacture, having liquid cooling of its periphery and air cooling of its bottom which contains a horizontal layer of refractory material with a heat conduction coefficient lambda (cal/m/h/ DEG C) which under operating conditions is higher than 20, includes the improvement that said layer is enclosed between upper and lower layers of refractory of much lower heat conducting coefficient lambda . With the bottom surface cooled to below about 150 DEG C, the thicknesses of said upper and lower layers, depending on their said coefficients, are preferably such that only 20 to 60 percent, more preferably 25 to 40 percent, of the heat discharge through the intermediate layer is transmitted to the lower layer; the periphery of the bottom being kept at about 50 DEG C. The intermediate layer may consist of graphite with a lambda -value of 60 to 100; the lower, of refractory e. g., carbon bricks, of a lambda -vslue of 2 to 5; and the upper layer of refractory, e. g., semi-graphite, may have a lambda -value of 20 to 30.