Development and performance evaluation of a motorized rotary sifter for cassava cake in Gari production
In this study, a motorized rotary sifter was designed and constructed to pulverize pressed cassava cake and sift out fibre free cassava meal for gari and cassava flour production. The effects (in terms of percentage contribution) of sifter screen speed, pulverizing drum speed, pressing time and sifter screen aperture size on material recovery efficiency of the machine were 12.45% 4.79% 41.30% and 24.66% respectively. Only the pulverizing drum speed (F 4) did not have significant effect on the recovery efficiency of the machine. Bulk density and moisture content of cassava cake decreased with increase in pressing time and the optimum throughput capacity and material recovery efficiency of the machine were231.79 kg/h and 92.98%respectively compared to 56.29 kg/h and 100% for the manual method. The problems associated with the manual method were eliminated and the motorized rotary sifter was readily adopted by cassava processors. The results show that the motorized rotary sifter performs better than the popular manual method in terms of throughput even though there was a slight decrease in material recovery efficiency. The new technology has great potential in helping to industrialize cassava processing in the cassava producing countries of Sub Sahara Africa.