FLOW PATTERN FOR MULTI-SIZE SILOS

Silo container is a very important storage structure for coal, sand and other granular materials. Nonhomogeneous granular flow is sometimes found in ore discharging in mining engineering, but so far there are only limited studies to this topic, particularly for double opening silo. In views of that, it is necessary to figure out the details about the flow pattern behavior. In the present paper, four physical models are designed to investigate the flow patterns for silos discharge behavior with double openings. The opening spacing, height ratio, sand properties and automatic separated manners are considered in these laboratory tests. Meanwhile, two-dimensional discrete element method is used to reproduce the flow behavior as well as to evaluate the dynamic wall stresses distribution on the silo hopper from bottom to top. It is found that the flow pattern is very sensitive to the spacing between openings under close opening silos. For the wide opening silos, the discharge efficiency would change nearly 30%. The arch effect in the dead zone and ore recovery are significantly influenced by the height /spacing ratio. The results from discrete element analysis can match well with the experimental study if suitable micro-parameters are used in the analysis.