ANALYSIS OF THE FEASIBILITY OF COPROCESSING OF INDUSTRIAL WASTES IN CEMENT KILNS THROUGH COMPUTATIONAL MODEL FOR DETERMINING THERMAL PARAMETERS
George Patton de Oliveira Silva1; Juan Guilherme Renó Sarto1; Genésio José Menon1; Rogério José da Silva1
1 Universidade Federal de Itajubá
doi:10.20906/CPS/CILAMCE2017-1022
Resumo
This work presents a computational method developed in FORTRAN language for the determination of thermal parameters necessary for the evaluation of the thermal destruction efficiency of hazardous substances present in industrial waste in the activity of coprocessing in rotary kilns of cement factories. The technique of industrial waste coprocessing consists of the partial substitution of fossil fuels, such as mineral coal and petroleum coke, by used tires, oily wastes, petrochemical wastes, chemical wastes, among others, which can be thermally destroyed, taking advantage of their calorific value in the process, and its ashes incorporated into the clinker. The industrial wastes must be destroyed with a high destruction efficiency, above 99.99%. For the determination of parameters such as flame temperature, residence time, gas volume, average flow rates and velocities, a computational model was constructed, tested with the operational data of a clinker production facility. This installation has a rotary kiln with a four-stage preheater, precalciner with separate tertiary air duct parallel to the kiln and grill cooler. The model allows the balancing of the combustion equations, from the calorific value and compositions of the fuels used, as well as the proportion in which they were used in a mixture of fuels. The flame temperatures are calculated in the firing region of the kiln and inside the precalciner, taking into account the feed rates of the raw mix and their composition, besides the reaction heats in the formation of clinker compounds and the necessary heat for the heating of the solids up to the reaction temperatures. The model, implemented in FORTRAN language, uses matrices and vectors for the calculations and also the bisection method for the determination of the flame temperatures. Simulating different mixtures of fuels, one can analyze the emission of pollutants generated and their volumes. Finally, through an estimate for the temperature inside the rotary kiln, one can evaluate whether a particular unde
Palavras-chave: Industrial Wastes; Cement Kiln; Computational Model; Thermal Parameters; Clinker Production