Simulation of convective drying of a cylindrical iron ore pellet

Abstract

Purpose

The purpose of this paper is to numerically model convective drying of a two‐dimensional iron ore pellet subjected to turbulent flow.

Design/methodology/approach

Simulations of the iron ore pellet drying process are carried out with commercial computational fluid dynamics software. The moisture distribution inside the pellet is calculated from a diffusion equation and drying due to evaporation at the surface is taken into account.

Findings

The results show an initial warm up phase with a succeeding constant rate drying period. Constant drying rate will only be achieved if the surface temperature is constant. The falling rate period will subsequently start at the forward stagnation point when the minimum moisture content is reached, while other parts of the surface still provide enough moisture to allow surface evaporation. The phases will thus coexist for a period of time.

Research limitations/implications

Owing to the complex physical processes involved in iron ore pellet drying, some parameters in the model are based on estimations. The effective diffusivity should, for example, in the future be investigated more thoroughly. It is also important to extend the model so that the falling rate drying period is also included. The model is at present undergoing further validation.

Practical implications

The simulations can provide detailed information on some key fluid dynamics and physical processes that an iron ore pellet undergoes during drying.

Originality/value

The simulations enhance the understanding of iron ore pellet drying and the model provides a complement to experimental investigations when optimizing the drying process.

Citation

Ljung, A., Staffan Lundström, T. and Tano, K. (2011), "Simulation of convective drying of a cylindrical iron ore pellet", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 21 No. 6, pp. 703-716. https://doi.org/10.1108/09615531111148464