DESIGN, FABRICATION AND EVALUATION OF MOTORIZED CASSAVA MESH SIEVING MACHINE

Abstract

The sieving operation occupies an important position in the effective transformation of cassava into fine ‘garri’ flakes however, the traditional sieving operation consumes time and energy which necessitated the design of an appropriate mechanical device. The method of operating any existing ‘garri’ sieving machine was realized to be inefficient and laborious like the traditional manual method. In order to solve this problem, the need thus arises to develop a better sieve that would not only remove the drudgery associated with it but also increase the output per hour to meet the high demand of ‘garri’. The aim of this study is to design, fabricate carry out the performance evaluation of the machine. Some design criteria considered include durability, portability, and safety of operations. The components designed include; the sieve bed, screening material, shaft, pulley belt, hopper and power source. Cassava tubers were peeled, washed, grated, and fermented pulverized and frying. The machine was evaluated by varying the speed of operation (350, 400,450rpm). The electric motor-powered sieve was tested at speeds of 350, 400 and 450 rpm. After sieving, sample of sieved ‘garri’ was used to determine its fines modulus using Tyler series analysis method. The throughput capacity and sieving efficiency were also calculated. At a speed of 350 rpm the sieve has the highest output capacity of 80.16 kg/hr with sieve efficiency of 92.01%. As the speed of the machine increases, the output capacity decreases.