Design and Fabrication of a Compact Single Acting Hammer Mill

Abstract

A compact single acting hammer mill was designed and fabricated
using locally sourced materials. Hammer mills are used for the
pulverization and or grinding of grains and similar bulk solid
materials into smaller particles. Conventional hammer mills consist
of shaft, free swinging hammers, sieve, hopper, electric motor and
discharge. Hammer mills found mostly within the urban settlements
in Nigeria are imported and expensive to acquire by rural farmers.
Conventional hammer mills have some setbacks which include sieve
screen wear and blockages, moisture build up in pulverizing
chamber, bulkiness and production of undesired coarse particles.
The present design was focused on 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. It consists of a loading hopper
and tray, low and high pressure throats, shaft, spacing discs,
hammers, axial fan, gate, cyclone, electric motor, bearings and
pulley.Test procedures carried out using the machine showed that
fine particles sizes (between 400µm-600µ) were produced from
pulverization of dried bulk food material such as cassava, maize,
plantain. The fabricated 7.46kw capacity hammer mill is compact,
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.