Development and Performance Evaluation of a Double-Rotor Self-Action Cassava Grater
ABSTRACT
The modification of a single-rotor cassava grater was undertaken. The single-rotor grater was modified into a double-rotor self-action grater and its performances evaluated by determining its throughput capacity and efficiency. The throughput capacity was determined by grating known quantities of cassava roots in three respective runs and the time taken to grate them measured from a stop watch. The efficiency of the machine was calculated frog m the quantity of roots grated and quantity of roots not recovered as dough. The percentage improvement of the measured parameters of the improved machine over the single-rotor was also determined. t-test was used to determine if there was any significant difference in the performance of the single-rotor and double-rotor machine at P ≤ 0.05. Performance test-run of the machines showed that of the 10kg mean value of cassava root used for the test, 8.88kg was recovered as dough and 1.12kg not recovered for the single-rotor machine while 9.95kg was recovered and 0.55kg not recovered for the double-rotor type. The result obtained showed that the throughput capacity of the double-rotor and single-rotor were 1152kg/h and 684kg/h respectively. The corresponding efficiencies were 89% and 95% respectively. This showed an improvement of 72% and 7% of the double-rotor over the single-rotor. The t-test analysis showed that the throughput capacity of the improved machine was significantly different from that of the single-rotor grater at P ≤ 0.05. However, the machines efficiencies were not significantly different. The modification of the single-rotor grater into a double-rotor self-action machine showed great improvement in the throughput capacity of the machine. Thus, it was established that power rating of prime-mover of existing motorized grater can also be used to run the modified grater to result in much greater throughput capacity without any significant difference in their efficiencies.