PEBBLE HEATER, A HIGH-TECH APPROACH FOR BLAST PREHEATING

Reduction of coke consumption is a major issue for many integrated mil ls, as coke ovens are aging and replacement is very capital intensive, as well as environmentally sensitive. Coke substitution by pulverized coal, natural gas or fuel-oil is increasing every year. Levels as hig h as 200 kg/thm of pulverized coal have been achieved in industrial pr actice in several mills, and 250 kg/thm is the new target. At the same time, coke rates have reached 320 kg/thm. Independently to coke repla cement, a way to reduce coke consumption is to increase the blast temp erature. A new type of stove has been developed to allow higher blast temperature without high capital expenditure.