Horizontal pressures in cylindrical metal silos and comparison with different international standards

José W B Do Nascimento,José P Lopes Neto,Michael D Montross

doi:10.1590/s0100-69162013000400002

José W B Do Nascimento, José P Lopes Neto + Show 1 more

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https://doi.org/10.1590/s0100-69162013000400002

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Abstract

The focus of this research was to evaluate the horizontal pressures on a cylindrical metal silo of corrugated walls and flat bottom with 1.82m diameter and 5.4m high, and to compare the values with those obtained theoretically by the ISO 11697, EP 433 and AS 3774 standards. The silo was symmetrically filled and constant speed with wheat cv. soft red for two different height/diameter ratios (H/D) and was unloaded through three orifices with a diameter of 71.6mm, one concentric and two eccentrics. Horizontal pressures were measured on the walls of the silo at three positions using hydraulic type pressure cells. The results showed that shortly after the start of the unloading, there was a mass flow above the quota of H/D = 1.2, whereas below this quota funnel flow occurred. It can be said that the EP 433 standard was more appropriate to predict horizontal pressures in silos in H/D ratio = 1.0, with eccentric unloading. For the H/D ratio = 1.5, AS 3774 standard was the one that produced values closer to the experimental.

Highlights

With the increasing global industrialization, the use of silos has become important, because it represents the possibility of storage of products originating in the industries of spinning, mining, construction, food, pharmaceutical, among other
The objective of this study was to determine experimentally the horizontal pressures on a vertical metal silo of corrugated wall with two height/diameter ratios (H/D) combined with one symmetric unloading and two asymmetric unloading using grains of wheat, and comparing the results with the pressures obtained by ISO 11697 (1995), EP 433 (2000) and AS 3774 (1996)
Horizontal pressures in cylindrical metal silos and comparison with different international standards and 5.9m high, and the pitch and depth of the corrugated walls were of 67.5mm and 13mm, respectively

Summary

Introduction

With the increasing global industrialization, the use of silos has become important, because it represents the possibility of storage of products originating in the industries of spinning, mining, construction, food, pharmaceutical, among other. In this aspect, functionality problems, such as obstructions in the flow, tube effect and incomplete unloading became more frequent, while structural problems became responsible for many accidents resulting in loss of life and enormous economic damage. Recebido pelo Conselho Editorial em: 9-10-2012 Aprovado pelo Conselho Editorial em: 13-12-2013. Eng. Agríc., Jaboticabal, v.33, n.4, p.601-611, jul./ago.

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