Mathematical Comparison of Two VOD Nozzle Jets

Abstract

Studies of physical phenomena in a jet caused by VOD (Vacuum Oxygen Decarburization) nozzles have been carried out. The VOD process is a metallurgical process where the steel-making route is controlled under vacuum environment with oxygen top blowing. In this work, two VOD nozzle models have been employed for an investigation based on two real De Laval geometries used in industry. Numerical modeling was used to study oxygen blowing states of the nozzles at different temperatures and ambient pressures. The nozzle models were numerically computed with two dimensional domains, where vacuum conditions and temperatures were specifically defined. The modeling results showed that one of the nozzles was more applicably proper for lower pressures, displaying a more stable flow pattern. Furthermore, it was found that a change in ambient pressure has a stronger effect on the jet force than a change in ambient temperature. In addition, it was proved that the profiles of the dynamic pressure at a certain blowing distance fit well to Multi-Gaussian curves.

Physical and Mathematical Modeling of Multiphase Flows in a Converter

“…125) The length of the potential core is one of the significant operating parameters, which represents the attenuation rate of the supersonic flow. 64) Long potential core length can be obtained by large Mach number, 94,10) high operating pressure, 126,127) incorrect expansion, 10) high ambient pressure, 128,129) high ambient temperature, 116,130,131) etc. Longer potential core will lead to slower attenuation of the oxygen jet, which results in more intensive stirring of the molten bath in the converter.…”

Review on CFD Simulation and Modeling of Decarburization Processes

“…This is natural due to its lower share of the total world production. The behavior of supersonic jets in the VOD has been reported in a few papers [7,8] and is included in this review due to its similarity towards the BOF process jets. Table 1 is a summary of the models and simplifications used in the different CFD approaches to investigate the decarburization process in steelmaking.…”

“…When the ambient conditions fluctuate less, the deviation from the design point may be tolerated. [7] Song also compared two different de Laval nozzle designs. The first was simple to manufacture, but it included some sharp angles inside the nozzle.…”

“…Song [7] 2011 VOD 2D Steady k-e VOD De-Laval nozzle operation Song [8] 2011 VOD 2D Steady k-e VOD De-Laval nozzle design Wei [48] 2011 AOD 3D Steady Modified k-e Combined blowing, top and side Andersson [13] 2012 AOD 3D Transient Kim-Chen k-e Reactions Ek [9] 2012 BOF 3D Transient k-e Dephosphorization Kundu [59] 2012…”

“…[19] Song et al used CFD to describe the spreading and shape of supersonic jets under the influence of different ambient temperatures and pressures. [7] Songś work was primarily directed toward understanding the effects of the large pressure variations in the VOD process cycle and how they would affect the choice of de Laval nozzle design. The work was very similar to studies of the BOF nozzle design.…”