The Research On Numerical Simulation And Structure Improvement Of Rotary Kiln Of Roasting The Vanadium-containing Shale

Roasting was an important process of vanadium extraction process,and rotary kilnhad become the main type furnace for roasting vanadium shale. It was necessary tostudy about rotary kiln because rotary kiln exsits that quality of product is not stable,equipment operation rate, the disadvantage of low and high energy consumption. Themethod of numerical simulation had become the major means to study the workingcondition of the rotary kiln and optimize rotary kiln.A three-dimensional model of the rotary kiln was established.By using Fluentsoftware, this paper choosed the standard k-ε turbulence model and the premixedcombustion model, and calculates the temperature field of the gas, materials and wallsurface, and the velocity field of the gas in rotary kiln. The results not only showed thatthe flame shape was a good wooden club shaped in the rotary kiln, and the temperaturedistribution was gradient descending in the kiln wall and material surface,which wereconform with the practical operating conditions, but also provided the guidance for theoptimization of structure process parameters of the rotary kiln using for roasting thevanadium-containing shale.Then temperature field that was calculated using Fluent software was importedthe Ansys results for node interpolation, and calculating the thermal stress of rotary kiln.The results showed that in the rotary kiln closed to flame thermal stress was bigger. Theanalysis results provided the guarantee for the research of rotary kiln temperature andthermal stress, thermal stress evaluation of hazardous, as well as the optimization designof rotary kiln cylinder provided theoretical guidance.In conclusion, the structure of rotary kiln with identical diameter was improved byexpanding the diameter at different position of the rotary kiln with inner diameter toform rotary kiln with variable diameters.And the effect of temperature in rotary kiln of variable diameter size and variable diameter locations was analysed，then the optimalrotary kiln with variable diameters was gotten; The temperature and thermal stress werecompared between rotary kiln of an identical diameter and rotary kiln with variablediameters. The results showed that roasting zone of rotary kiln with variable diameterswhose diameter changes at suitable location was longer than rotary kiln of an identicaldiameter, so it was beneficial to improving the oxidation of low valence of vanadium invanadium-containing shale.