Development and Performance Evaluation of an Integrated Bio-degradable Kitchen Waste Comminution and Drying Machine

Abstract

In this study, a kitchen waste comminution machine for converting biodegradable waste was designed, fabricated, and evaluated, using locally sourced standard materials. The machine consists of two unit operations: the comminution unit for grinding/shredding of the biodegradable domestic waste using grinding discs and the drying unit for moisture removal from the ground material using a heating element. The units were integrated and synchronized for continuous operation using a pulley-belt arrangement and powered by a single phase 2 HP electric motor. The drying unit equipped with an auger-like shaft for material stirring and conveying/evacuation was lagged for the prevention of excessive heat loss. The performance of the machine was evaluated using various kitchen wastes of tuber peels, fruit peels, vegetable stalks, and grain chaffs for shredding efficiency, throughput capacity, and dryness. The approximate values of the designed machine were established, as a force of 150 N and heat of 2 kW were required for respective grinding and drying of an average mass of 5.87 kg of the bio-waste. The machine performance analysis revealed comminution/shredding efficiency of 71.08%, drying efficiency of 32.78%, and throughput of 0.05 kg/s at an average moisture removal rate of 0.018 kg/s for bio-waste conversion. The production cost of the machine stood at N 250,000 (Two hundred and fifty thousand naira) only. Thus, the adoption of this innovation is recommended as a veritable option for the quality management of domestic kitchen waste since it reduces littering and promotes hygiene.