Title

OXYGEN SUPERSONIC BLOWING LANCES IN BOF: A COMPARISON OF SKULLS3® TECHNOLOGY AND OUTER STRAIGHT AND CONICAL TUBES OF STEEL AND COPPER

Authorship

Sardinha, Ismar Antônio

Sardinha, Ismar Antônio

I am this author

DOI

10.5151/1982-9345-27644

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Abstract

Usually outer straight steel tubes are used to blow supersonic oxygen into LD converters (BOF) to make liquid steel, although conical tubes are used too. Inner tube for oxygen blow and intermediary tube for water IN and water OUT are normally straight steel tubes. Present paper shows the influence of outer tube shape and metal used to in lance cooling and, consequently, a skull retention on lance surface. There are two parameters more important related to lance cooling: velocity of water out and the total lance cooling by addition of thermal conductivity of outer tube metal to it. For this comparison outer tubes are made of carbon steel or copper, and can be straight or conical. As related to velocity of water OUT, outer straight tubes have bigger efficiency than conical tubes. As related to total lance cooling, outer tube metal made of copper has much bigger efficiency than steel because of its thermal conductivity 7 to 12 times more depending on work temperature. The lance cooling has much bigger efficiency for the patented SKULLS3® technology with no skulls on the lance and no skulls into the mouth of LD converters (BOF).

Keywords

Skull, SKULLS3®, PC module, Conical lance.

Conical lance.