Some physical properties of lentil seeds

Several physical properties of lentil seed were evaluated as a function of moisture content. The average diameter, thickness, unit mass and volume of seed were 6.64 mm, 2.65 mm, 0.070 g and 49.08 mm(3) respectively at 6.5% m.c.d.b. Studies on rewetted seed showed that as moisture content increased from 6.5 to 32.6% d.b., bulk density decreased from 1190 to 935 kg/m(3), porosity increased from 27.4 to 32.0%, projected area increased from 56 to 82 mm(2) and terminal velocity increased from 10.95 to 12.06 m/s. The static and dynamic coefficients of friction of lentil seed against galvanized sheet metal, plywood and rubber surfaces increased with moisture content in the range from 6.5 to 32.6% d.b. The largest coefficient of friction was against a rubber surface, ranging from 0.374 to 0.532. The effect of moisture content was as great as or greater than the difference between the surfaces. (C) 1996 Silsoe Research Institute