Abstract
In this paper, the powder bulk density distributions near the slide valve of a storage hopper before and after closing it were systematically taken on a X-ray radiograph by using the measurement method developed by us. Then, a porosity analysis method, which was developed by the authors, was applied to the X-ray pictures mentioned above, and the porosity distributions near the slide valve after it closed were qualitatively and quantitatively discussed. As a result, it was pointed out that the porosity near the slide valve after its closing decreases in comparison with that before it closed.
