Oxygen enriched hot air blast cupola iron melting

In cupola iron melting the beneficial effects of using separately the hot air blast or oxygen enriched ambient air blast are well known. A study undertaken to know the extents of benefits obtained by using simultaneously the oxygen and the hot air blast has shown that for every 100°C increase in temperature of the air blast along with every one percent enrichment of air blast by oxygen, the molten metal temperature increases by 30 to 40°C temperature of air blast. Beyond the optimum range, the utility of oxygen decreases and the erosion of the furnace lining is severe. (Shri R. Santokh Singh and Shri P.S. Virdhi, Scientists, National Metallurgical Laboratory)