Performance Evaluation of Pneumatic Machines for Hazelnut Harvesting

It has been considered an hazelnut harvest technique by hazelnuts aspiration from the soil, and a comparison with the characteristics of the crop and of the soil, with which the considered machines have to interact, has been performed. This technique has broadly spread in Campania Region and for it, it is not required a meadow around the trees. After having performed some tests for the considered harvest technique, the characteristic parameters of working capacity, working quality and energy costs have been evaluated. Further, it has been faced the problems due to the soil dusts. to identify a filtering system capable of reducing the great amounts of dusts introduced in the environment during the process of hazelnuts picking up by means turbo-aspirating machines. The main types of dust removers for medium-thin dusts have been studied and examined; a comparative exam proved the mechanical removal by cyclone (centrifugal dust separator) to be the most effective. Therefore, two prototype filters were examined, each consisting of four cyclones with a turning diameter of mm 350 and mm 250 respectively. Field tests showed the effectiveness of the system; the 350 mm multi-cyclone proved to have a dust removing capacity of 90%, with no reduction in performance caused by the dust that goes through it, while the 250 mm removes 93.75%, with a reduction in performance of approximatevely 30%. However, it would be a mistake to give preference to the former over the latter, as its better performance does not compensate, in terms of environment hygiene, the 3.75% difference which, though seemingly slight, represents a further reduction of 50% of the thinner dust contained in the atmosphere