Design and Development of a Sunflower Thresher for Separating the Seeds

Abstract

The area under sunflower crops is now increasing, especially in the southern region of Bangladesh. Sunflowers are manually threshed by beating the sunflower heads with sticks. Though farm machinery significantly reduces the time required to complete farm tasks, efficient machinery for separating sunflower seeds is not available in farmers' fields in Bangladesh. The aim of the experiment was to design and fabricate a power-operated machine that would separate seeds from sunflower heads. The sunflower thresher was designed and fabricated in the FMPE Divisional workshop of Bangladesh Agricultural Research Institute (BARI) using locally available materials during 2020-22. The threshing was done by beating with the pegs of the rotating cylinder. The thresher was powered by a 2.98 kW diesel engine. The weight of the thresher was 125 kg (without engine). The capacity thresher ranged from 600 to 1000 kg/h, depending on the moisture content of the sunflower heads. Especial criteria for this machine is that it can be used for both fresh-harvested heads and dry heads. No broken seeds were found during the operation. The machine is operated at a 375-400 rpm speed of the threshing cylinder to avoid unshelled seeds. The threshing cost of the sunflower thresher was 494 BDT/ton. The benefit-cost ratio (BCR) for the machine's custom-hire service is 3.45. The sunflower thresher was also evaluated at farmer's field. Farmers expressed their satisfaction with sunflower threshing. The machine could be recommended for threshing of sunflower in Bangladesh.