Comparative study of design aspects and construction practices of silos

Abstract

Silo is the term applied commonly to a structure in which dry granular materials are stored. Silos are those structures in which the height of the container is large as compared to its diameter so that the plane of rupture cuts the opposite side and does not cut the top horizontal surface. Silos are used in a wide range of industries, such as agriculture, mining, chemical engineering, power plants, cement and food processing, where most bulk solids storage, handling and transportation systems are applied for storing solid materials like grains, coal, cement etc. When bulk solids are allowed to flow out of a bin or hopper under gravity alone, its flow pattern can be basically of two types: mass flow or funnel flow. With mass flow, the hopper is sufficiently steep and smooth to cause flow of all the solids in the bin without ‗dead‘ regions occurring during discharge, funnel flow occurs when the hopper is not sufficiently steep and smooth to force material to slide along the walls or when the outlet of a bin is not fully effective, due to poor feeder or outlet design. From the view point of processing, mass flow is preferred in making the bulk solids processing system efficient, reliable, predictable and more easily controlled. The flow of solid particles from mass flow bins or mass flow hoppers is, therefore, a subject of considerable practical and theoretical interest. In this project, a comparative study has been carried out on the design of silos by Indian Standard (IS) and applying rational method to provide a good hopper. In addition, schedule bar bending and cost estimation has been prepared for various heights of silos for better optimisation and economy.