METHOD OF TREATING FURNACE CHARGE,IN PARTICULAR STEEL WIRE BUNDLES OR STEEL STRIP BUNDLES IN INTERMITTENTLY OPERATING INDUSTRIAL FURNACES,IN PARTICULAR IN BELL-TYPE ANNEALING FURNACES

摘要

In a process of heating and cooling charges in batch-process industrial furnaces, particularly in a process of cooling coils of steel wire or strip steel in bell-type annealing furnaces, the charge is heated and cooled in contact with circulated protective gas. The cooling time is shortened and the power input to the circulating fan is reduced by changing the composition of the protective gas so as to decrease the specific gravity of the protective gas just before the beginning of the cooling period and/or during the cooling period.