Study of moisture dependent physio-engineering properties of green gram

Abstract

Physical and engineering properties of any crop grain, are the function of moisture content play a significant role in designing and development of many types of post-harvest machinery for grading, cleaning, separating, milling and sieving. etc, like material processing and handling. The effect of moisture content of green gram grains on various physical and engineering properties at different levels within the range from 10.31 to 26.17% evaluated. The study shows that length, thickness, width, AMD, GMD, SMD, EQD, surface area, test weight, porosity, sphericity, aspect ratio, angle of repose, co-efficient of friction and terminal velocity increased with increase of moisture content in the said rage of moisture content (length: 4.42 - 4.89 mm, width: 3.13 - 3.63 mm, thickness: 3.03 - 3.47 mm, AMD: 3.41 - 3.89 mm, GMD: 3.47 - 3.96 mm, SMD: 5.66 - 6.42 mm, EQD: 4.22 - 4.79 mm, test weight: 35.51- 43.37 gm, volume: 8.12 mm3 - 11.87 mm3, surface area37.83 - 49.45 mm2,sphericity: 0.786- 0.809, aspect ratio: 0.708- 0.746, angle of repose: 29.83- 31.50, porosity: 43.53- 45.12%, coefficient of friction on - (stainless steel: 0.255-0.353, galvanized iron: 0.295- 0.398, wood: 0.305- 0.465, aluminium: 0.266-0.366) and terminal velocity: 7.24-7.84 ms-1). But the true density, bulk density, and density ratio decreased with increase in the said moisture content range (true density: 1335.38- 1300.08 Kg.m-3 and bulk density: 754.08- 713.55 Kg.m-3 and density ratio: 0.57-0.55).