FACTORS AFFECTING THE MECHANICAL GRADING OF PEACH FRUITS

The main objective of the present study is to study factors affecting the mechanical grading of peach fruits. The studied parameters were: grading-drum speeds of 4, 7, 10 and 13 rpm (0.05, 0.08, 0.12 and 0.15 m/s), fruit batch of 5, 10, 15 and 20 kg and types of grading cylinder (PVC and rubber coated cylinder) using constant grading tilt angle of 7◦ . The main results in this study can be summarized in the following points: The maximum grading- efficiency of 98.9 % were obtained with grading speed of 4 - 7 rpm and feed rate of 5 kg. Meanwhile, the minimum grading-efficiency of 83.6 % were obtained with grading speed of 13 rpm., and feed rate of 20 kg. The maximum fruit damage of 4.14 % was obtained with grading speed of 13 rpm (0.13 m/s) fruit batch of 5 kg and PVC cylinder. Meanwhile, the minimum fruit-damage of zero and 0.07 % was obtained with grading speed of 4 rpm (0.05 m/s), fruit batch of 20 kg and rubber- coated cylinder. The maximum machine productivity of 1075.6 kg/h was obtained with grading speed of 13 rpm (0.13 m/s) fruit batch of 20 kg. Meanwhile, the minimum machine productivity of 295.9 kg/h was obtained with grading speed of 4 rpm (0.05 m/s), fruit batch of 5 kg. The operation and production costs and rubber-coated cylinder) were 12.82 L.E./h and 26.98 L.E./ton at optimum conditions (grading speed of 7 rpm or 0.08 m/s, fruit batch of 10 kg and rubber-coated cylinder.