Cleaning efficiency, paddy, thresher, threshing efficiency, wheat
A multi-crop thresher was designed and fabricated in Farm Machinery and Post harvest Process Engineering Division, Bangladesh Agricultural Research Institute Gazipur. The thresher was fabricated with the locally available materials such as wood, M.S. flat bar, M.S. rod, G.P. sheet, belt-pully, bearing, nut-bolts etc. All efforts were made to keep the cost of the machine low and the operation and maintenance as simple as possible. Thresher's functional units are, namely, 1) frame, 2) threshing cylinder with pegs, 3) threshing concave, 4 ) Hopper, 5) Sieve, 6) outlet chute, etc.
Frame: It is made of pieces angle bar of sizes 65 mm x 65 mm welded together. Its function is to support the machine and to keep it rigid.
Threshing chamber: Threshing chamber consist of cylinder and concave. The threshing cylinder is made of 1.5 mm thick M.S. sheet. The diameter and length of the threshing cylinder are 600 mm and 800 mm, respectively. The size of peg is 60 mm long, 12 mm wide and 12 mm thick. The pegs are fixed on threshing cylinder at an equal distance. Eight rows of pegs are also fitted on the threshing cylinder.
The thresher was tested with paddy and wheat in the year 2002-2003. During the test grain straw ratio, operation time, grain output, threshing capacity, threshing efficiency, cleaning efficiency, separation efficiency, threshing cylinder speed, sieve speed and fan speed were recorded and calculated.
(i) A multi crop thresher was developed for threshing paddy and wheat
(ii) The average threshing capacities were 788 kg/h and 340 kg/h for paddy and wheat, respectively.
(iii) Threshing and cleaning efficiencies were 99 percent and 95 percent for paddy and wheat, respectively.