Optimisation of the Bottom Tuyeres Configuration for the BOF Vessel Using Physical and Mathematical Modelling

Abstract

An experimental perspex model of the BOF vessel was made to the scale of 1 : 6 on which mixing time measurements were done by injecting potassium chloride (KCl) at a certain point and measuring the conductivity of the solution with time. It was found that the mixing time in the vessel attained a minimum when the bottom nozzles (eight in number) were kept at a pitch circle diameter (PCD) ratio of 0.4 with combined blowing (top blowing as well as bottom blowing) but the mixing time became a minimum at a PCD of 0.5 when only bottom blowing was done. In order to get a finer position of the bottom nozzles so that the mixing time could still be minimized, a mathematical model was used (because experiment could not be done with so close placement of the nozzles in one setup) to simulate the flow in the vessel with the help of the two equation k-e turbulence model along with a discrete phase model to simulate the air bubbles being injected in to the vessel. The mathematical model could predict the mixing time in the vessel to a very good degree of accuracy when compared with the experimental observations for the PCD of 0.5. From the mathematical model it was predicted that the mixing time in the vessel could still be lowered if the bottom nozzles were placed at a PCD of 0.56 instead of 0.5.

Physical and Mathematical Modeling of Multiphase Flows in a Converter

“…The high mixing efficiency in the converter is largely attributed to stirring effects of the bottom injected gas. Therefore, the effects of various bottom nozzles conditions, [16][17][18][19]24,80,83) gas flow rates and gas supply schemes, 21,22,25,48,140) and combination schemed of top gas and bottom gas 20,26,27,30,78,79,119,141) are studied to optimize the mixing effects in the converter. The velocity distribution inside a 335-ton converter bath as well as the velocity and bubble size distribution in a six plugs 190-ton bottom blown converter with standard bottom stirring are presented in Fig.…”

“…K. Nakanishi et al 9) investigated the mixing rate of molten steel and mass transfer rate between slag and metal in Q-BOP through water model experiments. Extensive studies were also carried out on the stirring behavior andbehavior mixing characteristics in top blown, [10][11][12][13][14][15] bottom blown, [16][17][18][19][20][21][22] as well as combined blown [23][24][25][26][27][28][29] converter at different stages 30) during a heat using water models. However, the transport phenomena in steel bath are so complex that many phenomena cannot be presented by water model experiments such as the compressibility of high speed oxygen, the interaction behavior between different phases, high temperature performance, etc.…”

Review on CFD Simulation and Modeling of Decarburization Processes

“…Tilliander [41] 2002 AOD 2D Steady k-e Heat transfer and fluid flow, AOD nozzle Tago [19] 2003 BOF 2D/ 3D transient k-e/RSM Jet pattern and coalescense Tilliander [39] 2004 AOD 3D Transient k-e Side blowing, nozzle submodel Odenthal [26] 2005 BOF 3D Transient k-e Combined blowing Singh [58] 2007 BOF 3D n/a k-e Bottom blowing, optimization of tuyere position…”

Investigation of the carbon monoxide post-combustion flame in the working space of a steelmaking unit

“…The process of blowing the bath of a steelmaking unit using a cold model simulation was studied in [11]. The authors, however, did not specify the effect of changing blowing intensity on the temperature fields in the unit.…”