Design, fabrication and Investigation of a vacuum combine for harvest rangeland seeds

A vacuum system was designed for harvesting rangeland and grass seeds from the soil surface or the plant canopy including vacuum harvester head, thresher and cleaner units. System design was based on physical characteristics, mechanical and aerodynamic properties of Annual medics. This combine is designed as a full or half –mechanized seed harvester suitable for even and uneven ground levels. To work on uneven ground, the head is easily detached and seeds can be harvested using hoods operated by one or two workers. Combine design is so that with suitable adjustment is able to harvest many kinds of rangeland seeds. Suction capacity was 312 kg/ha for seeds having 40 % purity and 750 kg/ha at 60 % purity. Efficiency of the cleaning sieves and the air separator were 67 5 and 80 % respectively. Threshing efficiency on various thresher speeds was 75 % up to 90 %. System power requirement is 1.07 KW provided by tractor PTO shaft through a belt-drive system.