Husking of the rice was carried out using the impeller
usker shown in Fig. 3 with a hard urethane liner, a soft
olystyrene liner and without a liner. The husker had
ight blades of surface length 0)13m, radial length of
of 118m, and a rated impeller speed of 2362 min~1. The
nitial radial position r0
is 0.037m and the maximum
adial displacement r1
is 0.155m. Clearance between the
ner and the blades is about 0.015m. The soft liner was
overed with a soft plastic tape for easy identification of
mpact marks. Impeller speed was varied between 1400
nd 3300 min~1 by an electrical inverter and calibrated
using a digital contact tachometer. The grain properties
determined were moisture content, radius of curvature,
length, width, thickness, and weight. About 50 g of uni-
formly selected rough rice at 15% w.b moisture content
was husked at the rate of 0)027 kg s~1 and the weight of
the husked, unhusked, broken and cracked grain deter-
mined. Cracks in the rice were detected using a grain
scope and a digital power meter was used to measure
husking power. A high-speed camera was used to observe
time and radial displacement of the grain (Delta) on the
lade. Grain motion was simulated by Eqn (13) using a coefficient of friction of 0.5. The equation was solved
using Runge Kutta method (Thomas & Finney, 1988).