EFFECT OF MILLING RICE STRAW ON HAMMER MILL MACHINE EFFICIENCY AND MILLING QUALITY
Radwan M. E. I.
Central Laboratory for Aquaculture Research, Agriculture Research Center, Ministry of Agriculture, Egypt
Received 7/ 10/ 2012 Accepted 12/ 11/ 2012
Abstract
In many countries, massive amounts of post-harvest rice residues are eliminated through open air field burning, which presents a threat to public health and poses an environmental pollution problem. So, the overall goal of the present study is to study the effect of grinding rice straw on machine efficiency and bio- product quality using a hammer mill machine to produce a high quality of rice straw and high machine efficiency with optimum cost. The hammer mill machine was evaluated under three levels of different drum speeds of 2400, 3200 and 4000 rpm, four different sieves of holes diameter 3, 6, 12 and 18 mm and three different knives number of 16, 24 and 32 with constant pyramidal knives shape.
The evaluation included machine productivity, machine efficiency, specific energy consumption, fineness degree of rice straw and economical costs of rice straw mass. The obtained data showed that, the highest values of machine productivity of 158.6 kg/h, lowest specific energy consumption of 43.72 kW.h/Mg and the lowest cost per mass unit of 71.29 L.E/Mg were recorded in the case of sieves hole diameter 18 mm, knives number of 24 and drum speeds of 4000 rpm, the highest values of fineness degree of rice straw 83.74 % was recorded in the case of sieves holes diameter 3 mm, knives number of 24 and drum speed of 4000 rpm and a hammer mill machine efficiency of 91.9 % was recorded in the case of sieves hole diameter 6 mm, knives number of 24 and drum speeds of 3200 rpm.
Keywords: Hammer mill machine, rice straw, holes diameter of sieves, drum speeds, knives number, specific energy, economical costs.