Comparison of the Various Cavity Depth or Jet Penetration Index Formulae for Blowing in a Bof With Bottom Stirring

Abstract

Several equations are developed over the years to calculate the penetration depth L of the Oxygen jet generated by the blowing lance for BOF/LD converters and similar processes. The penetration depth L for a given lance tip is primarily impacted by the lance height (gap), the oxygen flow rate and the resulting Oxygen jet momentum. Considering a dimensionless parameter L/Lo, where Lo is the liquid steel bath height, this paper will critically review both the theoretical and practical aspects of these depths of penetration equations, and recommend the most feasible equation(s) to determine the lance gap to use during the oxygen blow. This paper reviews how to translate the L/L0 in comparison with authors and yours considerations about nozzles parameters with respect to lance stirring, bottom stirring and slag layer patterns.

Post Combustion Tip Face - The Solution to Increase Scrap and Reduce Carbon Emissions

“…and the slag layer (14) , the projection of the jets on the metallic bath was determined, as shown in Figure 3. The premises for development were:…”

“…It is a condition observed in industrial processes only when the blow is interrupted for a few minutes and the emulsion of the two predominant phases is segregated. However, this static layer, in particular, monophasic, is the condition of most mathematical models (14) . Only recently was proposed by Willian (1) an equation that considers other phases such as slag layer and bubbling, but still considered static.…”

Blow Ignition - Cause of Premature Failure in Lance Tip

“…Oxygen steel works have through the lance tips the main means to obtain steels primary refining. After loading hot metal and scrap the lance generally perform 04 main operations during the blow: ignition, slag formation, decarburization and temperature hit [1] . In all these steps, variations in process parameters can lead to premature failure of lance tip.…”