Experimental pressures exerted by maize in slender cylindrical silo: comparison with ISO 11697

Abstract

Pilot-scale test stations make it possible to obtain reliable and comparable results applicable to full–scale systems by conforming to specified proportional limits. Therefore, in this study, normal and frictional pressures were evaluated in a pilot-scale test station composed of a slender cylinder silo using maize, a free-flowing product, as the stored product. Temporal effects were analyzed and verified during filling, static, and discharge conditions. The maximum normal and frictional pressures were also evaluated. The results were compared with ISO 11697: 1995. During filling, accommodation peaks occurred only in the α: 30° hopper. In general, normal pressures were higher for the flat bottom whereas higher frictional pressures occurred for the 30° hopper. The maximum experimental pressures (normal and frictional) were lower than those provided by ISO 11697. Therefore, it is concluded that the coefficients used in the ISO standard are sufficient to promote safety in silo projects.