Determination the Effect of a Vacuum Cleaning System on the Quality of Wheat Harvesting in Combines

Conventional combines have a set of straw walkers for separation of the grain fromthe straw because the crop passes the concave very quickly and a lot of threshed grains aretherefore still contained in the straw. All combines contain a cleaner in which chaff, immaturegrains and small straw particles are separated from the grains. After cleaning system, seeds areconveyed to tank and then the chaff and straw are thrown a way from the combines. In easterncountries, straw is very valuable material and for this reason farmers would like to gather themalong with the seeds during wheat harvesting. In order to collect the straw, a major modificationshould be made on conventional combines and this is a costly operation. The objective of thisresarch was to design a vacuum type cleaning system for both separation of the grain from thestraw and for collecting the straw. For this reason, a traditional combine was modified with vacuumcleaning system and was compared with conventional combines for wheat harvesting in Azerbeijan.The experiment was conducted with three combines; two different conventional combines and onemodified combine at two different revolutions of thresher, 650 and 750 rpm. According to theresults; vacuum type cleaning system was found statistically successful for both separation of thegrain from the straw and for collecting the straw. Although this new cleaning system allowscollecting the straw, the field capacity was found to be low as compared to the traditionalcombines. The field capacites were found to be 0.90, 0.96 and 0.30 ha h-1 for traditional combinesand the modified combine, respectively. It should be stated here that the modified combine is theprefferred one by the farmer since obtaining the straw costs less eventhough the field capacity isone third on the conventional ones.