DESIGN AND EVALUATION OF CRUSHING HAMMER MILL

Abstract

A grain size reduction hammer mill for crushing corn (Zea mays L.) was designed depending on variety characteristics and by using computer aided design “ANSYS” software. Suitability of fabricated hammer was tested at three levels of hammer rotor speeds (RS) (600, 1000 and 1440 rpm), three levels of screen holes diameter (Sd) (2, 4 and 6 mm) and three levels of feeding rates (FR) (60, 90 and 120 kg h-1). Geometric mean diameter of crushed corn (dgw), machine productivity (Pm), consumed energy (CE) and cost (CO) were evaluation criteria. Results indicated that the highest (Pm) (113 kg h-1) and lowest (CE and CO) were at 1440 rpm (RS), 6 mm (Sd) and 120 kg h-1 (FR). The empirical results obtained from experiments were used to introduce a derived mathematical equation to predict the value of "dgw, Pm, CE and CO" as a function of "RS, FR and Sd".