Engineering and Technology Horizons | 2026
Authors: Kosum K.
DOI: 10.55003/ETH.430202
Journal: Engineering and Technology Horizons
Year: 2026
Publisher: King Mongkut's Institute of Technology Ladkrabang
Document Type: Article
Open Access: All Open Access; Gold Open Access
Cited by: 0
Small-scale rice mills in rural Thailand lack advanced sorting equipment for removing impurities from jasmine rice. This study investigated sorting bin geometry and operational parameter effects on separation efficiency using a rotating drum sorter with three-layer concentric screens (2.51 mm, 1.55 mm, 8.0 mm apertures). Three geometries (cylindrical, octagonal, hexagonal) were evaluated at three inclination angles (2°, 3°, 4°) and rotation speeds (50, 55, 60 rpm) using 3³ factorial design (n = 81). ANOVA revealed bin geometry as the dominant factor (61.2% contribution, F = 287.45, P < 0.001), with cylindrical bins achieving optimal performance at 55 rpm and 3° inclination: 82.0 ± 2.1% separation efficiency, 3.02 ± 0.15 min/kg processing time, 96.3 ± 1.1% purity, and 10.4 ± 1.2% material loss. Cylindrical geometry outperformed hexagonal (64.0%, 28% improvement) and octagonal (58.0%, 41% improvement) configurations through four mechanisms: uniform centrifugal force distribution, laminar material flow, minimal dead zones (<2% versus 8-12%), and consistent grain-screen contact dynamics. Compared to manual methods (72 ± 8% efficiency, 8.5 ± 2.1 min/kg), the cylindrical sorter offers 14% higher efficiency, 2.8× faster processing, and 6-8 month payback period, providing cost-effective mechanization for approximately 15,000 small rice mills in Thailand. © 2026, King Mongkut's Institute of Technology Ladkrabang. All rights reserved.
Grain processing; Jasmine rice; Rotating drum sorter; Separation efficiency