Simulation of lime burning in rotary kilns
F. Herz, Hochschule Anhalt, Köthen, E. Specht, Otto von Guericke University Magdeburg, Magdeburg, Germany
In addition to the higher requirements for lime quality, the investment and operating costs play a critical role in the dimensioning and optimization of lime rotary kilns. In order to optimize existing rotary kilns and to design new furnaces with respect to economic factors, the calcination process needs to be carried out precisely. Experience regarding the effect of changing significant process parameters is especially vital. For this reason, a mathematical model was developed to simulate the process of lime burning in directly fired rotary kilns. In this model, the temperature, reaction and filling degree curves along the rotary kiln are calculated and additional data regarding the exhaust gas composition, heat loss through the wall, the specific energy demand and the lime quality are determined. In the first phase, a model is developed for an industrial rotary kiln that is fired with lignite. In the bounds of a parameter study, the effects of adjustments to the natural gas firing on the lime quality are shown. The potential of this simulation model is presented with the aid of further parameter variation with the goal of process optimization after the fuel substitution process. Here, the influences of the primary energy input and the throughput rate are especially clearly shown.
Summary CEMENT INTERNATIONAL 03/2017 pp 40-49
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