Effect of Mesh Count and Percentage Open Area on Throughput Capacity in Developing Cassava Cake Screening Medium

Abstract

The screen is a medium for breaking cassava cake lump into fine particles before the heating process that turns the fine particles into garri. The objective of this research is ascertain the effect of mesh count and percentage open area on throughput capacity of cassava cake screening medium, with respect to two methods of development. To this end, six screens each of diameters 1.5, 3, 4.5, 6, 7.5 and 9mm were developed using perforated and the traditional woven wire mesh method respectively. Measurement was made of the mesh count and open area of the screens and screening was done with 2kg of cassava cake across each screening medium. Data was obtained from the mesh count and open area of the screens as well as the throughput capacities. The data obtained were analyzed using t test and regression analysis. Result showed that the mesh count for 3mm screen for the woven wire mesh was approximately 3 while the mesh count for a smaller diameter of 1.5mm for the perforated screen was 10.6. This resulted to percentage open area of 11 and 28.3 respectively. Also screening time was 4.1min for 3mm against 3.4 min for 1.5 mm, given throughput capacity of 24kg/hr and 35.6kh/hr, for the woven wire and perforated mesh respectively. The t-test showed that there is a statistical significant difference in the throughput capacity of the two methods. The perforated method has advantage of higher throughput capacity, lower time and energy input and hence is recommended for manual and motorized screening process.