Geometry optimisation of a gravity dust-catcher using computational fluid dynamics simulation

Abstract

A gravity dust-catcher is a high tonnage device that is widely used to separate a mixture of dusts from blast furnace (BF) top gas flow. Dusts include limestone, iron ore and coke/coal. The flow pattern within the dust-catcher is complex due to the turbulent vortices formed within, consequently making it hard to accurately predict dust-catcher performance. Using data from an on-site dust-catcher, CFD simulations are conducted on a range of geometry modifications to produce an optimised dust-catcher design specification.The effect on particle separation efficiency during a typical blast furnace (BF) operational cycle is analysed. An attempt is made to develop and optimise a more efficient gravity dust-catcher using CFD simulation results at distinct stages of the design process. It is concluded that the newly patented dust-catcher design, can control the air flow profile much more effectively than the existing on-site design, being approximately 48% more efficient on average, from a particle separation efficiency perspective. The design may provide an effective low cost alternative to a gas separation cyclone.