Review of Modeling Methods

Iguchi and O.J. Hegbusi, Modeling Multiphase Materials Processes Gas-Liquid Systems, DOI 10.1007/978-1-4419-7479-2 9, 

A schematic representation of a gas-agitated system is show in Fig. 9.1. The system consists of a water pool with a top layer of dissimilar fluid of smaller density. This arrangement simulates a real steelmaking process with a top slag cover. The system is agitated by gas injected through a nozzle at the bottom. 

This two-phase mixture termed plume rises to the bath surface and subsequently flows down into the bath along the vessel walls, causing gross circulation of the liquid known as recirculatory flow.  

A major problem with the gas-stirring method of fluid mixing and impurity removal is the re-entrainment of the slag into the molten steel. This phenomenon is generally associated with the mixing and flow characteristics at the slag/metal interface and has attracted the interest of many researchers in recent years [3-8]. 

The gas phase distribution and plume shape are important parameters in the quantification of mixing in the system. Tacke et al. [16] performed experiments and observed that gas distribution in the bath was a function of gas and liquid properties as well as gas flow rate. Castillejos and Brimacombe [17] reported time-averaged gas fraction maps for air-water system, demonstrating symmetry about the central axis and a decrease in gas fraction from the nozzle tip to the bath surface. In a subsequent study, Castillejos and Brimacombe [18] experimentally measured the plume shape and consistency in a water pool agitated by an injected air steam. 

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