Improving the heating system and structure of shaft furnaces for roasting limestone

Improvements in the thermal system of counterflow shaft furnaces—including the heating systems, burners, gas-distribution units, and control algorithms—are described, for new and reconstructed furnaces producing lime containing 92–96% (CaO + MgO)_act. The burnout is no more than 1%, and the quantities of CO and NO _x are significantly below the permitted values.