Design and simulation of a bean flour making machine

Abstract

The large and increasing production of beans in Uganda has posed a challenge of significant postharvest losses of produce during storage, preservation and transportation resulting from attacks from pests, rotting and germination of seeds, as well as difficulty in handling respectively. This necessitated value addition to bean produce through size reduction by milling. This report therefore entails the project objectives of determining the requirements and specifications of the bean milling machine, developing a preliminary and detailed design of the equipment, and developing a simulation of the design of the equipment. The methodologies used to achieve the project objectives included data collection methods, data analysis, design, and simulation through motion simulations, Force analysis/ Finite Element Analysis (FEA), and Photo realistic renders and animations. The machine was designed and simulated using Solid Edge software, version 2020. The designed machine consists of components that include the hopper (top casing) and the housing (bottom casing). The bottom casing consists of a rotor assembly in which rotor plates are fixed to the main shaft enclosed in some form of grinding chamber. The actual working mechanisms are the hammers, which are swinging, and the round screens or grinding plates that are beneath the rotor. These collectively crush the beans on impact. The rotor discs are welded to the shaft and supported by bearings at both ends. This provides a more stable running mill and reduces the tendency for a rotor shaft to wind up. The hammers are flat metal bars with holes at their ends to enable fixation on the rotor. Other parts include; the frame, transmission bearings, drive pulley, driver pulley, V-belt, electric motor, electric motor mounting, bolts, and lock nuts. The pulley on the electric motor is connected to the pulley on the shaft via the v-belt. The shaft is suspended on bearings mounted on their sitting on the two sides of the bottom casing. The bottom casing is bolted strongly on the structural base. Results obtained included the theoretical capacity of the machine, material physical properties, maximum force and stress concentrations, maximum deflections for the different component parts, and the Design Failure Mode and Effect Analysis (DFMEA). In conclusion, the objectives were fully achieved with recommendations such as addition of an air system, a cubbyhole and a magnetic system to separate seeds from unwanted heavy particles fed in along with the beans.