Design, development, and performance evaluation of carrot washing and grading machine

Abstract

Carrot washing and grading is performed after harvesting and before transporting to the market has been done with traditional methods by farmers in Ethiopia with too tedious, much time, and labor-consuming which leads to health problems, Fertile soil erosion, discouraging for carrot production and river water pollution. The main objective of this study was to design, develop, and perform the evaluation of carrot washing and grading machine after harvesting before transporting to market that was not used for cooking purposes to alleviate the above-stated problems. During design, a power source, initial speed, and discharge capacity of the pump were considered as 50W, 60rpm, and 0.036l/s respectively based on literature reviews. Performance of this machine evaluation was carried out with Nantey variety at two levels of feeding loads 10kg and 15 kg at different drum speeds; 14rpm, 21rpm, and 28rpm. The data was collected in both qualitative and quantitative methods and the collected data were analyzed by using Statistical Package for the Social Sciences software (SPSS) at a 5% level of significance. The overall mean results obtained for performance indicators in terms of time required to complete washing and grading activities, washing efficiency, grading efficiency, percentage of damage tuber, and throughout put capacity were recorded as 2.22minutes, 98.70%, 92.23%, 1.21%, and 242.17 kg/hr respectively. The evaluation results indicated the time required of 2 to 10.88minutes, washing efficiencies of 84.87  to 98.70 %  for the range of the variable of drum speed between 14 to 28 rpm and for the range of the variable of feeding load 10-15kg. The grading efficiency increased 72.89 to 92.23%  as the speed increased (14 to 28 rpm), for the feeding load increased from10 to 15kg. The carrot washing and grading machine is simple to operate and maintain without formal education and the machine was fabricated from locally sourced materials. The unit cost of this machine was birr 16363.52, which is cheap and can be afforded by an average of Ethiopian farmers.