Numerical analysis of the thermal profile inside the wall of a rotary cement kiln

Abstract

Abstract The present study aimed to evaluate the temperature profile along the inside of the wall of a clinker kiln from a cement industry. The problem was modeled by the equation of transient heat conduction in cylindrical coordinates, considering radial symmetry. Being the wall composed of different materials, even adopting constant physical properties, there is no analytical solution to the problem. The method of the lines was used, being the radial and axial directions discretized by finite differences and the resulting system of ordinary differential equations integrated in time until obtaining the temperature field in steady state. The obtained field was compatible with heat transfer fundamentals and presented a good fit in relation to industrial data. The main limitations of the modeling performed in this study include the fact that the gases and solids contained in the kiln have not been modeled, and the variation in thicknesses of the layers of the kiln wall has not been considered. The program developed in this study can be used to evaluate the performance of different refractories or to infer the refractory wear level from experimental kiln surface temperature profiles.

Keywords

• cement kiln
• temperature profile
• numerical analysis
• method of lines