THE DRYING PROPERTIES OF RAPESEED

The drying properties of rapeseed, Brassica napus have been investigated for the double low variety, Ariana. The experiments were performed using a thin layer technique for air temperatures of 40, 50, 60 and 70·C and initial seed moisture contents of 12-5, 17, 21·5 and 26% d.b. The humidity was controlled by saturating the air at 13·8·C for each experiment giving a range of 5-23% relative humidity. A model based on diffusion in a sphere described the thin layer drying data most effectively giving a root mean square error of 0·306% d.b. based on all data points. The diffusivity was related to seed temperature by an Arrhenius relationship. A simpler Newtonian drying model was also fitted to the data. This was less accurate giving a root mean square error of 1·34% d.b. based on all data points. © 1994 Silsoe Research Institute.