Development and Performance Evaluation of Pneumatic Plucking System for Knapsack Type Cotton Plucker

India today is the second largest producer of cotton in the world. In India almost entire cotton is handpicked by human labour. Manual picking of cotton is labour intensive, requiring 1560 man-hours per hectare. In view of this a knapsack type cotton plucker was developed to suit for farmers cultivating cotton on small scale. The major components of the cotton plucker were prime mover, blower, filter, pick-up pipe and collection drum. A polypropylene container of 50 liter capacity was fixed on the frame to collect cotton. Filter was used inside collection drum to restrict the entry of cotton inside the aspirator. Two lightweight aluminum pipe of 50 mm diameter were used as the pick-up pipe. Total length of suction pipe and pick-up pipe was kept as 1580 mm. The performance of developed knapsack type cotton plucker was tested in a laboratory in terms of fuel consumption, picking efficiency, trash content and output capacity for three different type of drum (A, B and C model) and four different speed of blower (4200, 4700, 5200 and 5700 rpm). Results indicate that the fuel consumption ranged from 0.270 to 0.702 l/h, picking efficiency from 91 to 96 per cent; trash content from 2.07 to 8.03 per cent and output capacity from 4.75 to 9.78 kg/h. On the basis of laboratory results B type drum was selected for field evaluation at 5200 rpm speed of blower. The average fuel consumption (l/h), picking efficiency (per cent), trash content (per cent) and output capacity (kg/h) was observed as 0.603, 94.79, 5.77 and 8.84 respectively.