Effects of operational factors on the efficiency and thoroughput capacity of African locust bean processing Machine

Abstract

De-hulling and cleaning of beans remains a major tedious operation in the processing of locust bean. Using a locust bean de-huller that combine de-hulling and cleaning is one approach to reduce drudgery and improve the quality of the seed. The aim of research is to optimise the operating conditions of a locust bean processing machine for de-hulling and cleaning. To measure de-hulling and cleaning efficiency, dried locust beans were boiled at 2, 4 and 6hr boiling time, loaded onto the machine at various feeing rates (15, 20, and 25kg/hr) and shaft speed (7, 8, 9). The Response Surface Methodology (RSM) was utilised to optimize the operating parameter used in de-hulling process. Quadratic models were developed to establish the interaction between the operational parameters and the response factors. The effect of the investigated operational parameters on the de-hulling and cleaning efficiency were significant (p ≤0.01).  The optimal condition of the process for shaft speed, boiling time and feeding rate were 7m/s, 6hr and 25kg/hr, respectively, resulting in quantitative de-hulling efficiency, qualitative de-hulling efficiency, throughput capacity and cleaning efficiency of 98.67%, 25.85%, 21.66kg/hr and 84.62%, respectively.  This indicate that the locust bean processing machine performed efficiently at optimal conditions thus valid the models developed.