Stress condition of sliding bulk solids on silo walls

Abstract

Janssen, Jenike and many other researchers proposed the stress condition of bulk solids stored in silo. Owing to those works, for static stress condition, namely when bulk solids are stored in a silo, there is a good agreement between the theories and the practice. The traditional treatment in the discharging process is that the static active state turns into the dynamic passive state at the same time as the discharge starts under constant friction angles. The wall pressures predicted in the traditional theories sometimes cannot explain the practical wall pressures. In this chapter, measuring instantaneous stress states enables more accurate prediction of the resulting wall pressures. The stress states on a silo wall in static and dynamic conditions are analyzed experimentally using direct measuring instruments. As a result of the analysis, the facts relating to an important phenomenon have been established. Although the physical characteristics of bulk solids have been treated as constants in the silo design, the characteristics are not constant, but the phenomena are very accurate cyclic motion. The particle-flows in a deformation area that adjacent to the silo wall are described on experimental ground.