Modification and Performance Evaluation of Cleaning System for IAR Sorghum Thresher

Sorghum is a major source of food for most families and as raw material to many industries in Nigeria. Cleaning is among the most important post-harvest operation after threshing. However, manual cleaning of crop is quite tedious, time and labour intensive. A prototype thresher has already been developed at Institute of Agricultural Research (IAR) but yet it has been associated with many difficulties during operation. Among the problems of IAR prototype sorghum thresher are low operating performance such as higher scatter loss and low cleaning efficiency thus the need for modification to improve the above mentioned parameters. This study was undertaken to modify the cleaning system of the IAR sorghum thresher with the aim of minimizing the drudgery involved in its operation and to improve its performance. The major modifications were on shaking mechanism and sieves. The number of sieves was increased from one to three while the connecting rode for shaking mechanism was changed from horizontal to vertical orientation. The sizes of the pulleys were also changed. Randomized Complete Block Design (RCBD) experimental design was used for determining the effect of moisture content, speed and feed rate on the cleaning performance of the machine. The maximum performance achieved were 99.95 %, 5.45 %, and 250 kg/h for cleaning efficiency, scatter loss and throughput capacity respectively.