MANUFACTURING AND PERFORMANCE EVALUATION OF AUTOMATIC ORANGE GRADING PROTOTYPE

Abstract

Manual grading of fruits is a time and labours consuming process and results in inability of proper grading. In addition, the manual grading is not yet economically visible at the processing scale and with large quantities of fruits. Therefore, this research therefore developed and manufactured an automated grading prototype which is able to incorporate flexibility and separate selected orange . However, at the same time move objects automatically to the defined places by the regulation of the integrated load cells sensors, microcontroller and relay switch circuit (RSC) to detect a value range of weight and to drive the grading gates and required movements. The prototype consists of feeding unit and grading unit as two major components. Both components are working together smoothly and in sequence to transfer and sort the received orange fruits by implementing different mechanical and electronic parts through proper frames, transmission and control systems. Feeding unit’ main components were; electric motor, transmission systems, feeding hopper, conveyer chain and spoons. Grading unit consists of frame, connecting belt, weight sensing area, gates’ open-close control units and distribution gates. The automatic grading prototype was tested and evaluated at Rice Mechanization Center (RMC), Agricultural Mechanization Research Institute, Ministry of Agriculture (Meet El Dyba, Kafrelsheikh governorate) during the period from 2014 to 2016. The performance evaluation was conducted at two distances between spoons on conveyer chain (182 and 364 mm), four different surfaces of the belt that connect feeding unit to weight sensing area (wood, cotton, linen and leather), grading with and without infrared control unit and three sensing time (3, 6 and 9 sec) for Valencia orange fruits. Physical and mechanical properties were measured and recorded for processed fruits. The results showed that the grading prototype is quite successful for grading Valencia orange. The optimum operational conditions for maximizing the grading efficiency were 182 mm distance between spoons, 3 sec for sensing the weight and using infrared unit to control the feeding rate. Technical evaluation also showed that the maximum productivity value of the grading prototype was 0.47 Mg/h for Valencia orange with the optimum operational parameters. The cost of materials and fabrications of such prototype was 10,000 LE and total operational cost of the prototype was 26 LE/ h, while, optimum production cost were 55 LE/Mg for Valencia orange with the optimum operational parameters.