Development and Performance Evaluation of Bone Crushing Machine

Abstract

A bone crushing machine for crushing animal bones to produce animal feeds was designed, fabricated and tested. Material selection was based on how they are readily available at a minimal cost in the country. Crushers of 5 mm thickness was utilized to accomplish the expected size of bones. The machine comprises of two sets of crushers, shaft, P206 bearings, helical gears, hopper, couplings, tray, stainless steel, angle iron and two 5 hp motor with 25 and 1440 rev/min. Performance evaluation was carried out on the machine to determine the crushing efficiency, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\eta$</tex> , for various masses (100, 200, 300, 400 and 500 g) of cow bones and chicken bones. The crushing rate (g/sec) was evaluated. The results show that the average efficiency of the bone crushing machine for the five samples cow and chicken bones crushed using a 5 hp motor with 25 rpm and at 1440 rpm were 90.79% and 88.97%, respectively. Using a motor with 25 and at 1440 rpm, the crushing rate of 45.58 and 96.51 g/sec were obtained, respectively. This shows that hard materials such as cow bones require low speed for the crushing to be more effective. The evaluation done on the developed machine proves its functionality to crush bones before further utilization of the crushed bones.