Development and evaluation of a low cost power operated paddy thresher-cum-winnower

Abstract

Since threshing is labour intensive and involves considerable human drudgery and as the threshers now available are not suitable for small and marginal farmers, a Low Cost Power Operated Paddy Thresher Cum Winnower has been developed and tested. The machine consists of a threshing unit of wire loop cylinder and cover, a winnowing unit, a grain collecting tray, prime mover, power transmission system and the main frame. The power required to operate the machine is taken from a 2 hp electric motor and is transmitted to the cylinder and blower shafts by V- belt and pulley arrangement. Two labourers can hold the crop against the threshing cylinder. The optimum cylinder speed is 400 rpm. The capacity of the thresher at 16.0 per cent moisture content of the crop is 300 hg per hour. Threshing and cleaning efficiencies are 99.25 and 91.82 per cent respectively. Mechanical damage to the grain is negligible. The labour requirement of the thresher cum winnower is two. The cost of the thresher cum winnower was found out to be around Rs 8000.00 and the cost of operation for threshing and winnowing was Rs 8.50 per quintal. An empirical relation between the energy requirement of the thresher and various crop and thresher parameters is P = 931.035 + 4.683 (MC) – 0.462 (PV) – 1.169 (FR) + 8.251 (G/S ratio) The moisture content of the crop and the Feed Rate have statistically significant effect on power Requirement whereas the cylinder speed and Grain/Straw ratio do not have any statistically significant effect.