Abstract
From the analysis of the separator of indent cylinder type, the separating factors were clearly defined and their effects were discussed. In addition, the separating mechanisms were modelled, the fractional recovery curve was calculated and compared with the experimental values. The obtained results were as follows:
1) Besides the factor of grain length, the separating factors included the shape and coefficient of friction of grain. The distribution form of the values of physical properties of these factors also had strong effects on the separating performance.
2) The factors which had effects on the separating performance are: size, shape and arrangement density of indent parts; size, number of revolution and material of cylinder; separating time, hopper angle and supplied quantity. It is possible to improve the separating performance if these factors are suitably selected.
3) The boundary value of width of broken and whole grain, and half of this value can be used to determine the width and depth of indent parts respectively.
4) The separating performance was good when the coefficient of friction of grain-cylinder was high, and the improvement of this performance was assured if the grain of which thickness is small was removed by a thickness grader before separating.
5) The separating accuracy was good when the separating time was long, and the hopper angle could be properly selected by regulating this angle in such a way to get the value PB which should be high and small in terms of broken and whole grain respectively. PB was the probability of grain entering the hopper being carried by indent parts.
6) The fractional recovery curve was calculated as in Equations (2-6), these results agreed with the experimental values, and were expressed in Figure 9.
