Design, construction and evaluation of a three-layered sifter and motor-powered mungbean sheller

Abstract

The primary objective of this study was to design, fabricate, and evaluate the performance of a three-layered sifter and motor-powered mungbean sheller, providing local farmers with an alternative to the traditional manual deseeding of mungbeans. Furthermore, the aim was to introduce a mungbean sheller equipped with three separators to effectively filter mungbeans and residues, producing clean beans suitable for the market. The machine's overall dimensions measure 730 mm L by 550 mm W by 880 mm H, and its components include a feeding hopper, shelling unit, tray separators, blower, shell and shelled beans outlets, transmission mechanism, and frame. Fabrication was done at Flame of Hope Metal Craft in Molo, Iloilo City, spanning from June to November 2023. Both pre-testing and final testing were conducted at the fabricator’s workshop facility. Performance testing results indicate that the machine has a shelling capacity of 50 kg/hr, shelling recovery of 92%, shelling efficiency of 96%, blower loss of 2.3%, unshelled loss of 2.08%, scattered loss of 3.82%, purity of 97.5%, and mechanically damaged bean of 2.2%. The operating speeds of the cylinder and blower were 724 and 958 rpm, respectively. The machine met the standards for shelling recovery, efficiency, and unshelled loss according to PNS/BAFS PABES 268:2019. However, losses due to the blower and scattering, as well as mechanical damage to the beans, exceeded the acceptable limits. Additionally, the purity of the cleaned beans fell short of the requirement by 0.5%.