Loads in Model Grain Bins as Affected by Filling Methods

Abstract

Measurements of wall and bottom loads in flat-bottom model bins have shown the influence of filling methods and wall surface on wall loads and the static-to-dynamic load shift. Four spout-filling methods, at center and eccentric locations, sprinkle filling, and uniformly filling through an annular ring near the bin wall, were evaluated. Three types of bin walls were tested for each filling method: smooth galvanized steel, corrugated galvanized steel, and smooth steel covered with abrasive cloth. Soft and hard winter wheats were used in the experiments. The static wall load to total grain load ratio (SWL/TGL) and the dynamic-to-static wall load ratio (DSR) were found to be influenced by the filling method. In general, a higher SWL/TGL resulted in a lower DSR. Sprinkle filling produced lower SWL/TGL values on the smooth wall and higher values on the rough and corrugated walls. The ratio of the wall to total grain load at the start of discharge was highest for the first opening of the discharge gate as compared to two successive gate openings (each after 30 min of rest). The filling method and the type of wheat significantly influenced the negative friction force on the smooth wall bin. Negative friction force values were highest for the top filling methods. A negative friction force was not observed for corrugated and rough wall bins.