Comparative Performance Evaluation of Top Hammer Miller Machine to Crop Residue Crushing for Livestock Feed Purpose

摘要

Crop residues are considered among the most important materials in Ethiopia especially maize stalk, bean stalk, sorghum stalk, and wheat and barley straw. There are many types and models of imported top hammer miller in Ethiopia to assist in milling the grain. Those machines which are imported have many problems such as size of mill and rusting of hammers which not advisable to human food. Therefore the machines adapted and evaluated for livestock feed process purpose in terms of crop residues like maize stalk, bean stalk and wheat straw with predetermined feed rate and hammers’ shaft speed (RPM). The research was conducted at Asella Agricultural Engineering Research Center (AAERC), Maki and Bokoji district to evaluate the machine performance in crushing maize stalk, bean stalk, and wheat straw for animal feed. In this paper, two top feed hammer mills were used. They are collected from market and Bako Agricultural Engineering Research Center (BAERC). The performance of the machine is evaluated in terms of crushing capacity, crushing efficiency and crushing loss. The output of the market top hammer miller was satisfactory. The market top hammer miller produced a highest crushing efficiency and capacity about 99.33 % and 152.54 kg/hr while the BAERC’s was produced 94% and 78.68 kg/hr, respectively. The crushing losses of the market top hammer miller were 2.67, 0.67 and 5 % on maize stalk, bean stalk and wheat straw respectively.