Process of calcining limestone and the like in vertical kilns fired with lean gas

摘要

246,485. Hauts Fourneaux et AciÚries de' Differdange - St. - Ingbert- Rumelange, Soc. Anon., and Lavandier, E. Jan. 21, 1925, [Convention date]. Shaft furnaces for baking limestone and fritting dolomite are heated by blast furnace or producer gas burnt under pressure in mixing burners C with the amount of air necessary for its complete combustion, the products of combustion being injected into the kiln through nozzles D so as to localize within the kiln a zone E at a temperature of at least 900‹ C. opposite the nozzles. The gas and air are fed under pressure through annular pipes A, B connected to the mixing burners C in which the ignition takes place. According to the temperature required the gas, air or both may be preheated. The kiln is provided at the bottom with outlet holes having doors which prevent admission of air except during the discharging periods.