Vol. 7, Issue 5, Part D (2025)

Black gram (Urad Dal) is one of the most important pulse crops in India, both nutritionally and economically. As the world's largest producer, India accounts for over 70% of the global black gram production. For efficient processing of black gram in flour mills, it is crucial to understand its physical properties, such as sphericity, bulk density, coefficient of friction, angle of repose, terminal velocity, and moisture content. These properties significantly influence the milling process, machinery design, and overall processing efficiency. In this study, the physical properties of black gram were investigated. Based on these properties, a flour mill was designed using SOLIDWORKS software. The average bulk density of black gram grains was found to be 864 kg/m³. The average sphericity was calculated to be 0.84. The coefficient of friction for black gram grains was recorded as 0.42 on mild steel, 0.60 on galvanized iron, 0.58 on aluminum, and 0.70 on belt material. The mean angle of repose was determined to be 35.54º. The average terminal velocity of the grains was reported as 12.23 m/s. The average moisture content of black gram grains was 16%, and the thousand-grain weight was recorded as 52 g.