Development of a Low-Cost Hammer Mill Machine for Food Processing

Abstract

This hammer mill was fabricated from locally sourced and available materials for grinding of large sized grain particles such as SORGHUM, maize, millet, guinea, etc. into small sizes enough to pass through the holes of the cylindrical sieve positioned beneath the hammer assembly. Hammer mills have enjoyed major use in the pulverization and/or grinding of granular objects or similar solid materials into smaller sizes or particles. Major parts of the Conventional hammer mills are shaft, free swinging hammers, sieve, hopper, electric motor, and discharge chute amongst other component parts. Functional hammer mills operated within the urban settlements in Nigeria are mostly imported and expensive to acquire by rural farmers thus the need to develop one that can be easily acquired by the rural farmers as well as ease of maintenance. The grinding process is achieved using a hammer in beating the material fed into fine particles; the fineness aimed depends on the beating operation that happens when the Hammers hit the grain particles across the inner walls of the grinding or crushing chamber. The final size of the ground sorghum is a product of the aperture size which ranges from 87µm to 2 mm. This particular design has its major focus on the analytical design of an improved compact hammer mill that employs a single-acting operation to pulverize, move and push out pulverized bulk material particles against gravity through a cyclone. This machine consists of some vital components like the loading hopper and tray, low and high-pressure throats, shaft, spacing discs, hammers, axial fan, gate, cyclone, electric motor, bearings and pulley. This fabricated hammer mill is compact, and cost-effective to produce, operate and maintain. Its commercial production and use will be a reprieve to rural farmers as well as promote local content technology in Nigeria. The economic evaluation of the machine revealed that the material worth of US$85.20 was used for its construction. Testing and performance evaluation carried out on the machine showed that the machine had a 98.4% crushing and grinding efficiency.