Fluxo e pressões de minério de ferro em tremonhas piramidais industriais

Abstract

Hoppers for iron ore are structures that present deformations and a high-rate flow stoppage motivated mainly by the lack of knowledge of the material flow behavior, inappropriate designs, and absence of a technical foundation for flow and pressure design. The objective of this work is to present a theoretical and numerical model development of flow and pressure design in pyramidal hoppers for iron ore storage, which in turn has peculiar characteristics, such high bulk density, varied chemical composition and high abrasion capacity, which have significant influences on static and dynamic behaviors inside the hoppers. Proper flow properties characterization of the material is essential for define the right flow pattern and hopper geometry, as well as the pressures acting on the hopper walls. Based on research developed by Jenike and Roberts and on world renowned standards such as AS 3774-1996 and EN 1991-4/2006, the purpose of this work’s methodology is to identify the flow properties of iron ore and make the needed parameterizations for hoppers flow and pressure design. An example design was presented for methodology application, where are two hoppers in line, representing a train load-out system. Results has shown that one of the most one of the most challenges in the bulk solids handling field is reconciling design criteria, design constraints, system operational requirements while ensuring the desired flow. However, it is not possible to meet all design criteria simultaneously, and trade-offs are often necessary to make the final decision. It is possible to conclude that there is a lack of knowledge in this search field, as there are few research and developments related to the subject and this study presented the importance of the appropriate determination of the material flow properties for the correct development of pressure and flow design in these units.