Drying model for porous material based on the dynamics of the evaporation front

TL;DR

This paper introduces a receding-front model for drying porous materials, explaining the drying-rate curves through the dynamics of the evaporation front and capturing the linear early-time behavior observed experimentally.

Contribution

It presents a novel numerical model linking evaporation front dynamics to drying-rate curves, especially in the falling-rate period, accounting for porosity-induced resistance.

Findings

The model reproduces the linear early-time drying rate.

Numerical solutions match experimental drying curves.

The model explains the slowing down of the evaporation front.

Abstract

A receding-front model for drying of porous material is proposed that explains their drying-rate curves based on the dynamics of the evaporation front. The falling-rate regime is attributed to the slowing down of the front's propagation inside the medium due to the resistance offered by the disorder generated by porosity. The model is solved numerically and the resulting drying-rate curve is obtained for the falling-rate period. The curve shows a linear behavior at early times in conformance with experiment.