STUDY ON THRESHING AND WINNOWING MACHINE FOR GRAIN CROPS AND VEGETABLES A SIMPLIFIED DESIGN AND PERFORMANCE STUDY OF THRESHING AND WINNOWING MACHINE SUITABLE FOR SMALL HOLDINGS

Abstract

The aim of the present study was to design and to study the performance of threshing and winnowing machine suitable for small holdings. The source of required power for operation of this machine is as follows: Machine operated by using its own engine 3.75 kW. (5 hp) at 3600 r.p.m., max. torque 1.1 kg-m at 3200 r.p.m and fuel consumption of about 0.45 L/h.

The effects offourcylinderspeeds, 12.14, 15.18,18.21 and21.25 m/s (800, 1000, 1200 and 1400 r.p.m.) four feed rates of 15, 20, 25 and 30 kg/min., and three levels of moisture contents of 14.8, 18.2 and 21.5% (db) for grain and 12, 16.1 and 19% (db) for straw, respectively, on threshing machine capacity (kg/min.), total grain losses(%), total grain damage (%), grain quality (%),husking grain(%), power consumption (kW), useful power (kW) and unit energy kW. h/Mg. and threshing' efficiency (%) were studied.

The results of the present study led to the following conclusion:

1. The machine capacity increased as the cylinder speed, and feed rate increased. The capacity input decreased as crop moisture contents in grain and straw were increased. The grain out put increased as the cylinder speed increased, the maximum amount of grain out put was 9.891 kg/min. at cylinder speed 21.25 m/s (1400 r.p.m.), feed rate of

30 kg/min. and moisture content of 14.8% (db) in grain and 12% (db) in straw. 2. Unthreshed grain losses was decreased as the cylinder speed was

increased when other variables were kept constant. The unthreshed grain losses were directly proportional to feed rate and crop moisture contents in grain and straw. The minimum unthreshed grain losses were 0.239% at cylinder speed of21.25 m/s (1400 r.p.m.), feed rate of 15 kg/min. and moisture contents of 14.8% in grain and 12% in straw.