Discrete and Continuous Modeling of Heat and Mass Transport in Drying of a Bed of Iron Ore Pellets

A.-L. Ljung, B.D. Marjavaara, T.S. Lundström, V. Frishfelds
Taylor & Francis
Drying Technology: An International Journal
Boiling, Drying, evaporation, Heat and Mass Transport, Pellets, Porous media, Voronoi discretization

Drying of a porous bed of iron ore pellets is here considered by modeling a discrete two-dimensional system of round pellets. As a complement to the two-dimensional model, a continuous one-dimensional model enabling fast calculations is developed. Results from the discrete model show that the temperature front advances faster in areas with large distances between the pellets. In areas with low flow speed, the temperature of the pellets increases with a relatively slow rate. The water inside these pellets will therefore remain for a long time. The continuous model fits the discrete model very well for a regular distribution of equal-sized particles. A discrete model with irregular packing will, compared to the continuous model, show a larger variation in the distribution of temperature and moisture content in the final phase of drying.

Keywords: Boiling, Drying, Evaporation, Heat and mass transport, Pellets, Porous media, Voronoi discretization

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