Perfomance of Hammer Bar Type Feed Mill (I)

Particle Distribution Curve of Grains in Batch

Abstract

In order to improve the feed mill, first of all the authers investigated about particle distribution curve of some grains crushed with a hammer bar type mill.
From these experiments we found the following.
1. Particle distribution curve of grains crushed with the mill is approximately indicated by the following formula known as Rosin-Rammlers law,
R=e^-bσn×100
where R=Residue of crushed products
δ=Particle size of crushed products
b, n=Constants
e=base of natural logarithm.
2. The index n of the upper formula varies form 0.7 to 1.8 at the hammers speed of 1, 500 to 3, 600rpm and it increases in proportion to the speed of hammers.
3. Except for the rate of feed at 300 grams, the index n is independent of the rate of feed to be crushed.
4. The Indian corn has the maximum values of the index n, followed by soybean, and the wheat has the minimum values among the grains experimented.