PERFORMANCE EVALUATION OF A MOTORIZED COCOYAM CHIPPING MACHINE

Abstract

The performance of a motorized cocoyam chipping machine developed at the National Root Crops Research Institute, Umudike was evaluated. The machine comprises of the following major parts namely, the main frame, housing, chipping plate and the power transmission unit. Two varieties of cocoyam tubers from Colocasia esculenta species, NCe 001 (coco India) with average geometric mean diameter (3.20 cm), sphericity (0.81), weight (98.05 g), moisture content (48.97 %) and NCe 002 (ede ofe green) with the average geometric mean diameter (3.42 cm), sphericity (0.76), weight (87.14 g), moisture content (52.06 %) were used for the evaluation. The machine was evaluated using 5 kg of cocoyam tubers for capacity and efficiency at five varying speeds of 300, 325, 350, 375 and 400 rpm. The results obtained showed that the capacity of the machine increases with the speed, while the efficiency increases with speed up to 375 rpm, but beyond that level, it drops. The highest capacity of 195.04 kg/hr was obtained at speed of 400 rpm, but 92 % efficiency was obtained at 375 rpm. Evaluation of the effect of feed rates and chute clearance on the capacity of the chipper was also carried out using Analysis of Variance (ANOVA) in 3 x 5 factorial with three levels of feeding chute clearance (0.07, 0.09 and 0.12 m) and five levels of feed rate (2.5, 2.8, 3.0, 3.2 and 3.5 kg/min) in a Randomized Complete Block Design (RCBD). The results of the statistical analysis showed that both the feed rate from 2.5 to 3.5 kg/min and the chute clearance from 0.07 to 0.12 m had a highly significant effect at 1% level on the capacity of the chipper