Abstract
In the design and operation of general industrial particulate processes, the elucidation on the mechanism of the formation of bulk density distribution can be taken to be one of the most urgent problems which should be solved. However, it has not yet been elucidated sufficiently. Then, in this paper, the reflection phenomena of a loose bulk density zone to a solid wall are noticed and fundamentally discussed. As a result, it is pointed out that the sum of the incidence angle and the reflection one to a solid wall should equal to that of the internal friction angle of the particulate material and the wall friction angle. That indicates the fundamental condition of incidence-reflection of a loose bulk density zone to a solid wall. And it is shown that this condition is consistent with the experimental results by X-ray radiographs of the reflected loose bulk density zone to a solid wall, formed in the experiments of plunger penetration. This fact can be taken to be an important information to the fundamental discussions of the bulk density distribution formed in such a vessel of particulate processes.
