- By Alexis T. Belonio, Melvin B. Boquiren, Severo A. Sotocinal, and Celsa B. Tumonog
ABSTRACT
The Appropriate Technology Center, Department of Agricultural Engineering, College of Agriculture, Central Philippine University in collaboration with the SUNLIT International, Inc., has designed and evaluated a vertical-type cassava chipper for chipping cassava roots. This study was conducted from February 1, 2002 to April 25, 2002. The machine basically consists of the following components, namely: (a) loading cylinder, where cassava roots are placed before chipping; (b) chipping plate, which slices cassava into thin strips for ease of drying and milling; (c) discharge hopper, which serves as the outlet of chipped cassava; (d) transmission drive, which delivers the power from the electric motor to the chipping plate via pulley and belt drive; and (3) support frame, which serves as a framework for the machine. The loading cylinder has an inside diameter of 0.6 m and a height of 0.8 m. It is made of BI sheet gauge no. 18. The chipping plate has a diameter of 0.60 m and is made of 1/8 in thick MS plate. It has 23 laterals with nine series of 12 mm diameter holes. One side of the hole is slightly lifted to create chipping action on the product during operation. The plate is driven by a 1.5-hp electric motor through a v-belt and a pulley at a speed of 382 rpm. Beneath the plate is a discharge hopper made of no. 18 BI sheet that collects the product. Performance evaluation shows that the machine has an average throughput capacity of 716.8 kg per hour. The average specific chipping rates were 2560 kg/hr-m2 of the chipping plate and 3.46 kg/hr. per unit hole. The chipping efficiency of the machine ranges from 97.8 to 99.1 percent during testing. Power input averages at 747.8 watts. Two persons are required to operate the machine One person to load while the other person is to unload the product and consequently sundry them. Efficient operation can be achieved by gradually feeding cassava into the machine. Cost-return analysis shows that the machine can chip cassava at P0.08 per kilogram. Compared with manual chipping, the computed return on investment of the machine is 173.8%. The computed benefit-cost ratio is 2.28. The investment for the machine can be recovered after 34.5 days of 1.78 months of operation. The machine can be locally fabricated and performs satisfactorily as per design. It can be further improved to make the unit acceptable for commercial operation.