ABSTRACT

 A machine for processing cassava into strands (African salad) is highly and greatly needed for consistency in the usage of cassava in the local and international level. With regards to these indispensable needs, this cassava shredding machine was designed to shred the half cooked cassava tubers into strands. In attainment to this, a reciprocating cassava shredding machine was designed, fabricated and evaluated. The machine consists essentially of a hopper where peeled cassava tubers will be put. Directly below the hopper is the perforated shredder plate coupled to a horizontal shaft which when in operation will undergo reciprocating motion. The shredding plate was enclosed within the collector chamber. The horizontal shaft derived its motion through a slider and crank mechanism which was coupled to an electric motor using belt drives with a pulley for primary speed reduction and regulation. The capacity ofthe machine is 220kg/hr. The efficiency ranges from 71.30% to 79.04% while the throughput ranges from 15.12 to 30.60kg/hr when operating at 90 rpm while at 60 rpm, the efficiency ofthe machine range from 65% to 80.2% and throughput ranged from 15.70 to 25.41kg/hr. Generally, the steaming time affected the efficiency, throughput and the length of shreds. The optimum performance was shredding at a speed of 60 rpm and steaming time of lOminutes, which gave a longer shred length of 79mm with a width of 4.23mm and efficiency of 70% but with a throughput of24kg/hr. For optimum performance at 90 rpm, throughput of38.23kg/hr and efficiency of 79.04% was obtained at a boiling time of lOmins, with average shred length of 65mm and width of 3.23mm.