Prediction of the Heat Transfer and Flow Characteristics in Rotary Combustor

A numerical analysis model is developed to evaluate heat transfer and fluid flow characteristics of a through-flow-type-rotary system. The numerical domain is divided into three parts, waste layer, gas phase above the layer and rotary grate, and these are modeled, respectively. The analytical results of CO concentration in gas at outlet, peak temperature of rotary grate and heat-recovering rate correspond with the experimental those, which shows validity of the numerical model. The maximum temperature of the layer, heat recovering rate and NO concentration in gas at outlet rise in proportion to O₂ concentration in air into combustion zone, and unburned carbon in combustion residue and CO concentration at outlet and decrease at a fixed rate. In case that flue gas is recirculated from the top of incinerator into combustion zone, NO concentration in gas at the outlet decreases in proportion to the flow rate of recirculating gas.