Abstract: A method for operating a blast furnace includes feeding metallic charge materials, alloy elements and energy carriers in the upper part of the furnace shaft. An oxidizing agent is fed in the lower part of the shaft. Filler material, namely, alloy elements, metal chips, carbon, sands, dust are fed individually or in combination into the melting zone in at least one burst jet. Fuels may be introduced additionally into the first jet. The oxygen is fed at a high speed into the melting zone in at least one separate jet and the conditions of introducing the materials in the first jet and the oxygen in the second jet are controlled so that no flame can be formed.

Abstract: A cooling tunnel for cooling a continuously running belt or partial belt section by means of a low boiling liquefied gas to a predetermined temperature has its cover in the form of a chamber which has a connection near the tunnel entrance for supplying the liquid cooling agent and a connection near the tunnel exit for discharging evaporated cooling agent with at least one pipeline for returning the evaporated cooling agent to the cooling tunnel.