Helical gear reducers H1 flender H1SV-3-C

Flender/Flender Gear Units/Helical gear reducers H1

- overs. Cleaning of grains from such mixture is either assisted by the oscillating sieving mechanism or by the pneumatic method. The latter utilizes the aerodynamic characteristicsof particle mixtures. Cleaning of grain by winnowing, an ancient method, is not really effective and seldom nds its place in threshing and harvesting machines. In all cleaningmechanisms, however, the assistance of air is mainly utilized () to remove light materials,() to assist in orienting the particles on the perforated sieves, and () to move the particles caught in the opening of perforated sieves during the oscillation process. Further removal of chaff and other debris from grain, and separation of brokens are simultaneously carried out by the cleaning unit, which comprises one or more oscillatingsieves having circular perforations of uniform size, pedal-type conventional fan deliv-ering air at the front and up through the sieves, an extension at the rear of the upper sieve,and augers for conveying the tailings and clean grains to the elevators. For effectiveremoval of light materials, an adjustable air deector is provided between the sieves and the fan. In the process of sieving, the mixture moves rearward over the perforated surface, horizontally across it, and the seeds or brokens that are smaller than the size andshape of the opening fall down to the next sieve by gravity, when the air blast carriesaway most of the light materials. Unthreshed and partially threshed earheads, and othermaterials that pass through the upper sieve and not through the lower sieve (that has 1 Datta smaller openings) are discharged to the tailing auger. The process of cleaning is accelerated by oscillating the sieve() continuously and using fan to deliver an air blast through thesieve(). Besides the pneumatic force created by the fan, the efciency of sieving and, hence, the removal of chaff, is affected by () seed parameterssize, shape, and weight of each seed; () sieve parameterssize, shape, and spac