Abstract The variables concerning the heat engineering of a flame furnace may be clas-sified into three groups: (1) the design and operation variables; (2) thermopro-cess variables and (3) the performance variables, which have been studied compre-hensively using an analytical method. In several typical cases, the results weredrawn on charts and set on tables to make clear on the performance of flamefurnace. An empirical method has also been proposed for studying the relationshipbetween the 1st and 3rd groups of variables and many production furnaces havebeen analysed. The principal ways of saving furnace fuel were pointed out. Theempirical method here introduced is entirely based on the production data. simplic-ity itself, and no measuring tool is necessary.
