Effect of Operating Speed and Chipping Disc Blade Number on the Performance of a Motorised Cassava Chipping Machine

Cassava (Manihot esculenta) remains one of the most important and widely grown food crops in tropical region which has persistently contributed food security and economy. Cassava roots deteriorate rapidly within 40-48 hours after harvest, due to physiological factors and microbial infection. Fresh roots storage is a huge challenge, there is thus a pressing need to process tubers into some stable form as soon as they are harvested. Cassava roots can be processed into chips to hasten drying into a staple form while vital qualities of the roots are preserved. This creates a huge export demand for cassava chips making it an agricultural foreign exchange earner. A rotary disc (knife and groove) type chipping machine was also developed at the National Centre for Agricultural Mechanization, Ilorin, Kwara State, Nigeria (NCAM). This study sought to test the effect of the number of knives on the rotary chipping disc on the performance of the chipping machine. This is intended to improve chip efficiencies for boosting capabilities to preserve cassava root and also make Nigeria better active in the international chip export market. Results of this study showed that the chipping disc with two blades at the medium test operating speed of 596 rpm had the best chipping capacity of 375kg/hr., while the two blade disc operating at the least test speed of 422 rpm gave the best chipping efficiency of 88%. The two blade disc operating at the mid test speed of 596 rpm also recorded the best quality performance. On the other hand, the three blade disc at the medium test operating speed had the highest mechanical loss.