Simulation of rotary cement kilns using a one-dimensional model

Abstract

Rotary kilns are used to convert calcineous raw meal into cement clinkers. In this paper we present a one-dimensional model to simulate key processes occurring in solid bed of cement kilns. Solid-solid reactions occurring in cement kilns were modelled with a pseudo-homogeneous approximation. Variation of bed height and melt formation in burner zone within the kiln was accounted for. Energy balance (including conductive, convective and radiative heat transfer) was solved based on a quasi-steady state approximation. The mathematical model was first applied to a rotary calciner. The model predictions were verified by comparing them with the published experimental data. The model was then used to simulate performance of three industrial kilns. Numerical experiments were carried out to investigate influence of key operating and design parameters on energy consumption of kilns. The model was also used to explore the possibility of manipulating temperature profile within the kiln to reduce energy consumption in kiln per ton of clinker. Apart from providing a computationally efficient tool to simulate kiln performance, the model and the results discussed here will provide a useful basis for the development of comprehensive three-dimensional models of rotary cement kilns.