A general treatment of the behaviour of glass furnaces is given, which is based on an earlier fundamental description of processes involving three heat reservoirs, i.e. three temperature levels. For glass furnaces, these three temperature levels (referred to the ambient temperature) are: the adiabatic temperature of the furnace atmosphere, and the exit temperatures of melt and offgas, respectively. The furnace performance is essentially determined by the irreversible (non-recoverable) shares of heat involved in batch melting and by the heat losses through the furnace lining. The treatment yields a relation between pull rate and overall energy demand, which can be used to determine optimal configurations of process parameters yielding maximum energy exploitation efficiency.
