Fundamental Studies on the Improvement of Fertilizer Distributors (VIII)

On the Relations between the Critical Void Ratios of Fertilizers and their Fluidities

Abstract

Such fertilizers as granular urea etc. which have respectively smaller amount of bridge spaces in the structure of particle disposition, not only have less differences between their void ratios when ordinally packed in a vessel and their critical void ratios, but also have occasionally the larger former void ratios than the latter. So that, they are potentially easy to collapse and flow, and kineticaly easy to expand and reduce internal friction remarkably when sheared. In addition, they have less coherency which prevents the increase of volumes and void ratios. Consequently, their fluidities is high.
On the other hand, in such fertilizers as fused tricalcium phosphate etc. which have larger amount of bridge spaces in the structure of particle disposition, there are relatively large differences between two kinds of void ratios. In addition, they are kineticaly difficult to expand and reduce internal friction when sheared and have larger coherency. Consequently, they have low fluidities.
As mentioned above, the relation between two kinds of void ratios is the potential dominant factor whicn controls the ease of flow of fertilizers.