Research And Application Of Heating Process Simulation In The Rotary Kiln

Sintering process takes an important place in alumina production inchina. Rotary kiln is the most important part in the sintering technology,but the thermodynamic parameters inside the rotary kiln can not bedetected accurately because of the complexity of sintering process and theimperfectness of detecting means. Higher alumina quality is required withthe raising of the yield in alumina industry. Hence it is important both intheories and practices to understand influence factors in heat engineeringprocess and grasp the pivotal temperature parameters of sintering process,which will result in great improvement of the clinker quality.Based on the heat balance calculation, heat-transfer process in therotary kiln was studied in this paper, a 2D heat transfer model of the kilnwall was established, and the temperature distribution in radial wall andthe time-varying of the inner wall surface temperature were calculated.The heat-transfer process among combustion gas, kiln wall and solidparticle burden was simulated. Assuming that the granular size wasuniform, the solid burden temperature profiles in different sections withdifferent particle diameter were calculated. According to the numericalsimulation results, the feasibility of a 1D thermal mathematical modelused to calculate the temperature distribution of gas, solid in the rotarykiln was discussed.An on-line simulation model of heat-transfer process was establishedwith purpose of optimizing operation parameters. Based on heat balancecalculation and the measurement parameters, the length and temperaturedistribution of each zone in the rotary kiln were studied and analyzed bycomputer simulation technology. According to the practical performance,the model was calculated in different operating conditions, the impact ofimportant parameters such as excess air coefficient, coal quantity on thelength and temperature distribution of each zone in the rotary kiln wereanalyzed.The simulation results were applied in the sintering process, anon-line simulation system was established which can realize on-linedisplay of the length and temperature distribution of each zone, on-line diagnosis of sintering status. The system provides reliable guidance forthe operation optimization. It is shown that the thermal regulation in thekiln is stable, the goal of improving the clinker quality, reducing theproduction costs is achieved.