This paper presents a new simulation model for the AOD process that takes the local variations into account but is still computationally efficient. The new idea here was to model AOD reactor as a combination of a plug flow reactor for the plume zone and a continuously stirred tank reactor (CSTR) for the bath and surface slag. This approach adopted has many advantages compared with the previous models. At first, it offers an effective method for considering the locally varying conditions as the gas bubbles rise in the plume. The model can be built computationally very effective compared to CFD due to significantly smaller amount of variables. The validation of the model is also easier as it has features that can be experimentally determined. The model is based on the simultaneous solution of conservation equations of mass, species and energy in all the vertical cells of the plug flow reactor, and a single volume in bath and surface slag. A novel method was developed and used for solving the rates in a mass transfer controlled multi-component reaction system. In this Part I of this paper, the model is presented and its features discussed by few illustrative examples. In the following Part II, the model is broadly validated with new full scale industrial AOD process measurements for carbon release rate, melt composition, slag composition and bath temperature rise during final stages of carbon removal.

A CFD model based on water model experiments has been created to simulate slag entrainment and droplet formation. Multiphase Volume of Fluid (VOF) method is used to track the interface between slag and steel and User Defined File (UDF) code is applied to track separate droplets. Four oil-water systems and three slag-metal systems were simulated. The main objective of this research was to obtain droplet diameter distributions and the average droplet diameter in several different cases. With slag-metal cases the main interest was the effect of interfacial tension to droplet formation. With oil-water systems we studied the effect oil layer width and oil viscosity. The obtained droplet diameter distributions show that the dominant droplet size is 2-3 mm in every oil-water systems. In slag-metal systems the dominant size varies between 1-2 mm and 2-3 mm. The simulations show also that the average droplet size in all cases is 2.78-3.63 mm. The results were compared to the studies available in the literature.

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A fundamental mathematical model for AOD process has been developed and proposed in ''Fundamental Mathematical Model for AOD Process. Part I: Derivation of the Model'' [1]. Validation of the model with process data, measured from full scale AOD process, is presented in this paper.A broad selection of input data for the model was exported from various types of full scale industrial AOD heats. In this study 6 different types of heats were studied and simulated. Process data was measured from two AOD converters (95 t, 150 t). Validation of the model was then done by comparing simulated and measured values for carbon and chromium content, carbon release rate, melt composition, slag composition and bath temperature during final stages of carbon removal.The validation results showed that the model was in good agreement with the measured process data, and same model parameters were valid in all of the simulated heats.

Computational fluid dynamics (CFD) simulations have been carried out to study interfacial velocity and its effect on slag emulsification at the steel–slag interface. The multiphase volume of fluid (VOF) method was used to track the interface between slag and steel and a user defined function (UDF) was applied to calculate the interfacial velocity and to track separate droplets. Slag entrainment based on composition adjustment by sealed argon bubbling‐oxygen blowing (CAS‐OB) process was simulated using different inlet velocities of steel. The main objective of the present work was to study how steel flow velocity effects droplet distributions. Continuous Rosin–Rammler–Sperling (RRS) distribution function was fitted to computational results in order to provide a quantitative description of the droplet size distribution. The generation rates of the interfacial area between slag and steel were estimated based on obtained RRS‐distributions. The Sauter diameter was found to vary between 4 and 6 mm and the generation rate of the interfacial area between 0.2 and 0.6 m2 s−1. The results agree well with previous studies presented in the literature.