Study on performance improvement of a head feeding type rice combine for foxtail millet harvesting

摘要

The study was conducted to investigate the mesh size of concave, chaffer angle of oscillating sieve and fan speed of the head feeding type rice combine for foxtail millet harvesting. The study aimed to determine the harvesting condition at 0.5 m/s working speed and at 40° and 55° sieve chaffer angle of the rice combine harvester. The harvesting loss of foxtail millet based on the speed of fan and oscillating speed of sieve of the rice combine harvester was measured at three levels of fan speed andoscillating sieve speed. Threshing rates of foxtail millet varieties were 83.5-86.2% at 7 mm mesh size of the concave. Harvesting loss of foxtail millet was 0.9% at 40° sieve chaffer angle and 4.8 Hz oscillating sieve(cleaning shoe) frequency and foundlower than at 55° sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged 0.2%-0.5% at 7 mm mesh concave, 40° chaffer angle, 4.8 Hz sieve frequency, and 20 m/s fan speed at 2,000 RPM engine speed. Findings showed that foxtail millet could be harvested using the combine harvester.