DESIGN, FABRICATION AND PERFORMANCE EVALUATIONOF LABORATORY HAMMER MILL

Abstract

In this project, a laboratory hammer mill has been designed and constructed with output crushing force of 23 kN and average crushing strength 12 kN/mm2. The feed crushing performance varies between 300 and 340 kg/hr of granite rock, depending on the type of rock to be crushed and screen size. All the components of the machine such as the hammers, hammer discs, shaft, pulley drive, belt drive and machine casing were designed and constructed from locally sourced materials. The hammers are normally made from manganese steel which is scarce locally, the hammer in this work has been made based on improvisation of spring steel materials to reduce cost. A mild steel shaft of θ70 mm, 495 mm long made of mild steel were machined using lathe machine down to θ50 mm, 489 mm long. The power rating of the machine was determined to be 4.0 kW (5.3 Hp) electric motor requiring 415 volts and 50 Hz frequency.