THE HEAT-BALANCE STUDY OF CERAMIC KILNS1

The elements of the heat-balance study and calculation of the thermal efficiency of ceramic kilns are summarized, and an outline of a heat-balance method is given. The CO₂ in the flue gases of the kilns studied was measured automatically and continuously by an electric CO₂ meter making use of the thermal conductivity method, and some of the resulting CO₂percentage curves are given and interpreted. A complete heat-balance of a 30-foot round downdraft facebrick kiln fired with wood is given, together with various data and conclusions on the use of wood in firing ceramic kilns. A complete heat-balance of a Hoffman continuous coal fired kiln is given, together with temperature-gradient curves and other data of this and two other Hoffman kilns.