Circulation of furnace gases to improve - heat transfer

摘要

A more uniform heating of the charge in both batch type and continuous furnaces, including tunnel furnaces, is achieved by mixing combustion gases and circulating them together with the furnace atmosphere through the charge. This is accomplished by having high velocity burners firing alternately from the two sides of the furnace into radiant tubes which are connected by vertical passages at each end with the furnace proper at hearth level. The amount of re-circulated gas is controllable by means of a damper in one of the passages. The charge is stacked on circular stools which have radial ribs to allow penetration of gases underneath and through the charge.