Mathematical modelling of thin-layer drying according to particle size distribution in crushed feed rice

• Drying model considering the particle size distribution of crushed rice was proposed.
• The model assumed a Rosin–Rammler distribution was validated successfully.
• To assess the effect of particle size distribution, a stochastic model was developed.
• Uniform drying could be achieved by increasing the drying temperature.

A thin-layer drying model taking into account the particle size distribution of crushed feed rice was developed to simulate moisture content during high-temperature drying. The model was based on the Page equation, which was regarded as a suitable empirical equation to describe the thin-layer drying of rice. The proposed model, with an assumed a Rosin–Rammler distribution, successfully predicted the mean moisture content of rice during drying experiments with a mean error of 0.5% dry basis at 60, 70, and 80 °C. In order to investigate the effect of particle size distribution of rice on the drying process, a stochastic model based on Monte Carlo simulations was developed. The model developed here could provide useful information on the drying behaviour of rice particles, individually and collectively, in a thin layer bed. It was clear that uniform drying could be achieved by increasing the drying temperature.