Mathematical Model for Decarburization Process in RH Refining Process

Abstract

A three-dimensional mathematical model for natural decarburization process of ultra-low carbon Al killed steel during RH refining has been established. The decarburization behavior in RH degasser was discussed on the basis of a comparison between simulation data and the actual plant trials ones. The effects of the different initial carbon content, initial oxygen content, the lift gas rate and inside diameter on decarburization were investigated. The results showed that when the dissolved oxygen concentration was 0.08% in the molten steel, the flow rate of gas injected through the up-leg was 120 Nm 3 /h, the inside diameter of up and down-leg was 650 mm, under these conditions, the initial carbon content was 0.03%, 0.023% and 0.015%, respectively, after about 25 minute, the average carbon content in molten steel was 0.011%, 0.01% and 0.0008%. The final dissolved carbon content is related to the initial dissolved oxygen content in molten steel. The average carbon concentration and the decarburization rate of the molten steel will decrease with the increasing of the initial dissolved oxygen content. The effects of different inside diameter of up and down-leg were also compared, it shows that the increasing of the diameter of up/down-leg will promote decarburization effectively, which can increase the circulation flow rate and promote the reaction rate.

Simulação Numérica Do Fluxo Recirculatório Em Um Reator Rh: Aplicação À Dessulfuração

“…Vários pesquisadores [1][2][3], entre outros ressaltam que a cinética destas reações, são afetadas principalmente pela taxa de circulação do aço entre a câmara de vácuo e a panela. Salientam que a taxa de circulação depende da vazão de argônio, posicionamento e configuração dos bicos de injeção de argônio; número, comprimento, diâmetro interno e formato das pernas; pressão na câmara de vácuo.…”

Fluid Mixing in Ladle of RH Degasser Induced by Down Flow

“…The almost equal values of H/D leg for RH2 and RH3 resulted in the equal t C /t R values from Eqs. (4) and (7). However, the differences in t M /t R values for RH2 and RH 3 as shown in Table 3 suggest that t M is affected by the other factor in addition to t C .…”

“…concentration distribution of the ladle. Zhang et al 7) built a decarburization model by adding the fluid flow in the vacuum vessel and ladle. The flow pattern of steel melt in the ladle was analyzed by the computation fluid dynamics (CFD) [6][7][8][9][10][11][12][13][14][15] and perfect mixing time 14,15) was also calculated by the time-change in a tracer concentration at a given point after a tracer injection.…”

Modeling on the Fluid Flow and Mixing Phenomena in a RH Steel Degasser with Oval Down‐Leg Snorkel

“…It is generally considered that the circulation rate and the mixing time are two significant parameters during the RH process. Thus, many researchers have developed physical or mathematical models to simulate the multiphase fluid flow, mixing phenomena, behaviors of bubbles and inclusions, and decarburization process during the RH treatment. Based on previous works on circulation rate of RH, some empirical formulas are listed in Table , which includes the formulas put forward at the first time and excludes similar equations reported later.…”