Development of a method for determining moisture diffusivity of alfalfa grind under surface condensation

A method, referred to as the “ring stack” method, based on one–dimensional diffusion in a semi–infinite cylinder has been developed to measure the moisture diffusivity of a powder material like ground alfalfa when exposed to steam. This method and the diffusion model associated with it have been evaluated using regression statistics. Through the lack–of–fit test, it was found statistically (. = 0.05) that the diffusion model associated with the “ring stack” method represented very well the experimental data on ground alfalfa under steam condensation. Moisture diffusivity of ground alfalfa measured by the “ring stack” method was 5.90 U 10–8 µ4.72 U 10–9 m2/s, which compared favorably with published data.