Evaluating the Performance of a Threshing Machine for Purslane in Laboratory Scale

Purslane is an important vegetable and medicinal plant that is produced and consumed in the southern regions of Iran. Recently, special attention for processing and pharmaceutical industries of purslane has been paid. Seed separation procedure, is one of the most important and difficult steps in purslane processing. In this Research, a seed threshing unit for mechanization of purslane seed harvesting, was built, evaluated and tested. The most important components of this thresher are the shaft, the rubber thresher and the rubber concave. This machine was designed and manufactured and then the losses were determined. The losses evaluation was carried out under randomized factorial analysis. Experiments were conducted at three levels of drum speed (35, 80 and 120 rpm), feed rate (2, 3 and 5 kgmin-1) and sieve swing speed (180, 200, 220 rpm). The results showed that the impact of drum rotational speed, oscillation of sieve and feed rate on seed separation percentage and unopened sheath is significant at 1% level. The lowest amounts of losses (9.39%) were obtained at 80 rpm drum rotational speed and 2 kgmin-1 feed rate and also 200 rpm sieves swing speed, respectively. Highest percentage of losses (27.83%) was obtained at 120 rpm drum rotational speed, 5 kgmin-1 feed rate and 220 sieves swing speed, respectively. Threshing efficiency at lowest level of machine losses, was 92%. Maximum output capacity (at lowest level of losses) and energy consumption were obtained 2.7kgh-1 and 14084 KJ, respectively.