بررسي مشخصات عملکردي بهينه ماشين اندازهبند پياز به منظور افزايشبازدهي و کاهش صدمات مکانيکي

Onion is one of the most important crops in the world, including Iran. Despite the high quantity produced in Iran, it is sent to the domestic and foreign markets in inappropriate conditions and at a low price due to the lack of a sorting process and appropriate packaging. This study aimed to evaluate an onion sorting machine, study the effect of the performance characteristics of the machine on the sorting quality indexes, and determine the probable mechanical damage to the product during the sorting to achieve the machine's optimum performance characteristics. This machine was designed and constructed with two reciprocating sieves with a length and width of 2×1 m², using a wobble shaft. Onion was sorted at 3 degrees based on their diameter according to the international standards code (D<50 mm, 50mm<D<70 mm, and D>70mm). The sorting performance indexes comprised the degree of pollution and purity, measured and calculated while sorting 200 kg of onion. Also, based on the obtained indexes in all test conditions, the number of optimum performance characteristics of the machine was determined, such as effective capacity, slope (6, 8, and 10 degrees), and frequency of sieves (2.66, 3, 3.33 s^-1) and their effect on the onion mechanical damage during the sorting process. The highest degree of purity, equal to 95.60%, was obtained at a frequency of 3.33 s^-1 and a slope of 10 degrees for the sieves at a capacity of 1 to 1.2 t/h. Also, the overall sorting efficiency of the machine was 92.34%, and no mechanical damage was observed to the onion. [ABSTRACT FROM AUTHOR]