DESIGN AND DEVELOPMENT OF A SMALL POTATO-GRADING MACHINE USING CAPRON NET
Grading potatoes by size is an important operation for preparing tubers for seed and for commercial purposes. Farmers in Iran and in developing countries grade potatoes by hand, which is very slow and costly. This work concerns the development of a potato-grading machine for small-scale farmers. The design is characterized by a spiral structure covered with a capron net to form a cribriform rotating drum as the grading surface. Potato tubers are fed into the drum, moved forward by the spiral structure, and dropped through holes of the net according to their dimensions. The design parameters included net stiffness (T), rotating drum speed (n) and feeding rate (q). The grading accuracy of the machine was evaluated to determine optimum condition of machine performance. An acceptable grading accuracy of about 70% with a low tuber damage of 5.5% were obtained at T = 0.14 N/mm, n = 27 rpm and q = 2,500 kg/h as optimum condition. PRACTICAL APPLICATIONS
Commercial potato-grading machines are designed for medium- to large-scale farms, and are not suitable for the majority of farmers in developing countries. In these countries, grading of potato tubers, especially for seed purpose, is performed by hand, which is very time-consuming and labor-intensive. A small grading machine has been developed that can sort five times more tubers per person per unit time than the rate achieved by hand grading. The machine is very simply constructed and costs approximately US$800, which is considerably cheaper than current commercial grading machinery.
Document Type: Research Article
Affiliations: 1: Russian Research Institute of Agricultural Machinery (VISKHOM) 127247, Russia 2: Department of Agricultural Technical EngineeringAbureyhan Campus, Tehran University Iran 3: Department of Agricultural MachineryFaculty of Agriculture, Shahrekord University, PO Box 115 Iran
Publication date: 2010-12-01