Abstract:
The postharvest processing of cassava tubers into useful products rests on properly peeled and cleaned cassava tubers. The studies of past researches revealed that the problems faced by effective mechanical peeling of cassava tubers are yet to be eradicated. To further reduce the problems, this research devised a unique and highly effective peeling mechanism for an automated system which was used for cleaning, peeling and washing cassava tubers. The peeling mechanism adopted utilizes a rotating peeling drum inscribed with cutting blades of 10 mm in height with 2740 mm long and auger of 2 mm thick with 2700 mm in length. This resulted into careful removal of the tuber peels across a maximum of two peeling throughput. The automated system was designed and evaluated using newly harvested tubers of length, 𝐿𝑇, and diameter, ∅𝑇, grouped into small; medium and big sizes of: 100<𝐿𝑇<250, 31.35<∅𝑇<45.55; 150<𝐿𝑇<280, 40.75<∅𝑇<70.29 and 175<𝐿𝑇<310, 68.27<∅𝑇<91.67 respectively. The peeling machine has an optimum capacity of 3.96 tons/hr at an average feed rate of 2 tons/hr. The design of the peeling drum and its evaluation revealed that the machine efficiency of peeling was highest when operated at 50 rpm. The operational parameters used for the evaluation of the peeling system were rotational speed of the peeling drum- with values ranging from 40 rpm to 60 rpm at 5 rpm interval-; tuber loadings- from 1 to 5 tubers- and peeling days- from day 1 to day 3. These resulted into value ranges of 69 % - 83 %; 55 % - 75 % and 86 % - 95 % for the average peeling efficiencies at first peeling, second peeling and overall peeling throughput respectively, across all the operational parameters. The machine has an average peeling efficiency of 95 % which occurred when the machine was operated at 50 rpm with single tuber loading on day 1. The average result of the peeling efficiency indicated that the peeling mechanism adopted by this project was very effective for peeling cassava tubers
