Development and performance evaluation of a manually operated onions grading machine

• Published in: Journal of agriculture and food research 2020-12, Vol.2, p.100070, Article 100070
• Main Authors: Umani, Kingsley Charles, Markson, Idorenyin Etiese
• Format: Article
• Language: English
• Subjects: Crank revolution; Cushioned; Feed gate opening; Grading capacity; Grading efficiency; Grading machine; Manual operation; Non-cushioned; Onions
• ISSN: 2666-1543; 2666-1543
• DOI: 10.1016/j.jafr.2020.100070

Grading of onion bulbs carried out on the basis of size and shape is important for marketing uniform high quality produce for a better economic gain. A manually operated size grading machine for onion bulbs was developed aiming to achieve negligible mechanical impact on the onion in order to maintain its quality by using thin-layer foam of 5 mm as the cushioning material. The machine was designed to grade onions into three distinct size ranges of 0−40mm, 40−60mm and ≥60mm. The grading performance of the machine was based on grading efficiency and grading capacity at non-cushioned and cushioned conditions for different treatment combination of the machine parameters (feed gate opening and crank revolution). The effects of feed gate opening [half (F1) and full (F2)] and crank revolution [20(R1), 40(R2), 60(R3), 80(R4) and 100(R5) rpm) on grading efficiency and grading capacity of the developed grader were studied at α=0.05. The overall grading efficiency and grading capacity for the non-cushioned condition was 80% at F1R3 and F1R4; and 76.17 g/s at F1R3, respectively, while the overall grading efficiency and grading capacity for the cushioned condition was 77% at F1R3 and 82.75 g/s at F1R2, respectively. Statistical analysis of the data showed that feed gate opening and crank revolution at various levels combinations have significant effect on the grading performance at non-cushioned and cushioned conditions. [Display omitted] •Development of a manually operated onion bulbs grading machine.•Evaluation of the performance of the developed machine based on grading efficiency and capacity.•Investigate the effects of feed gate opening and crank revolution on the machine performance.