Chickpea threshing efficiency and energy consumption for different beater-contrbeater combinations

Abstract

Threshing efficiency, specific energy consumption and power requirements of different beater (drum) and contrbeater (concave) types in chickpea threshing were investigated in this experimental research. The purpose was to define the effect of beater and contrbeater types made of different materials on the threshing of various chickpea varieties. The trials used six beater-contrbeater combinations of three types of beaters (spike-tooth, lama (flat)-tooth and peg-tooth) and two types of contrbeaters (PVC and chromium) with a stationary thresher. Rotational speed of threshing drum, contrbeater clearance and feeding rate were 12.5 m/s, 25 mm and 720 kg/h, respectively. ln order to determine the appropriate peripheral speed, contrbeater clearance and feeding rate serial preliminary experiments were conducted. Five rotational drum speeds (19.0, 14.5, 12.5, 10.50 and 8.0 m/s), five contrbeater clearances (150, 200, 250, 300 and 350 mm) and four feeding rates (360 kg/h, 540 kg/h, 720 kg/h, and 900 kg/h) were selected for the preliminary studies. According to the results of these experiments and observations during these trial periods, the appropriate values were chosen. Three chickpea varieties (K Usmen, Koylu and Akcin) were also selected because these chickpea varieties are largely cultivated in all regions of Turkey. The results showed that threshing efficiency significantly changed with chickpea variety while the specific energy consumption and power requirement was slightly affected by the beater- contrbeater combination and chickpea variety. The highest threshing efficiency and appropriate specific energy consumption were achieved with pegtooth beater - chromium contrbeater, spike-tooth beater - PVC contrbeater and lama-tooth beater - PVC contrbeater combinations with values of 67.06%, 0.71 kWh/t, 89.11%, 0.60 kWh/t, 95.29% and 0.68 kWh/t for Kusmen, Koylu and Akcin varieties, respectively.