風力分級機による木材ファイバーの分級特性

抄録

Experiments were made to evaluate the cut size of wood fiber by a centrifugal air classifier. The classifier used was of industrial scale “Micron-separator” sized 1, 100mm in diameter. Experimental wood fibers were of Oak and Basswood.
Results obtained were:
1) Drag force on the fiber was calculated from the data on experimental cut size. The cut size, the size corresponded to 50% recovery, is the size of fiber we assumed to be in dynamic equilibrium in centrifugal field of separating rotor.
Drag coefficient of cut size C was correlated with the Reynolds no. Re based on circular equivalent diameter and radial velocity of the air. The relation, C vs. Re, was the same obtained by elutriating method measured in gravitational field. Cut size of fiber can be evaluated from the relation C vs. Re.
2) Fractional recovery was plotted on logarithmic probability paper as a function of fiber size and the data fall fairly well on straight line. In the experiments, effects of operating parameter of classifer, i.e., inlet velocity of air, rotational speed of separating rotor, consistency of fed fibers and secondary air velocity were found to be neglected on the values of the slopes of these relations.