Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A physical modeling study of top blowing with focus on the penetration region
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
2005 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

This thesis work aimed at increasing the knowledge regarding phenomena occurring when gas is injected using a top-blown lance on to a bath. All results are based on physical modeling studies carried out both using low and high gas flow rates and nozzle diameters ranging from 0.8 mm to 3.0 mm. At the low gas flow rates, the penetration depth in the bath was studied. The experiments focused on studying the effect of nozzle diameter, lance height and gas flow rate on the penetration depth. It was found that the penetration depth increases with decreasing nozzle diameter, decreasing lance height and with increasing gas flow rate. The results were also compared with previous work. More specifically, it was studied how the previous published empirical relationships fitted the current experimental data. It was found that the relationships of Banks [1], Davenport [2], Chatterjee [3] and Qian [4] agreed well with the experimental data of this investigation for nozzle diameters of 2.0 mm and 3.0 mm. However, for smaller nozzle diameters there were considerable deviations. Therefore, a new correlation heuristically derived from energy conservation consideration was suggested and showed better agreement for small nozzle diameters.

The experiments carried out at higher gas flow rates focused on the study of swirl motion. The effects of nozzle diameter, lance height, gas flow rate and aspect ratio on the swirl motion were investigated. The amplitude and period of the swirl as well as the starting time and the damping time of the swirl were determined. The amplitude was found to increase with an increased nozzle diameter and gas flow rate, while the period had a constant value of about 0.5 s for all nozzle diameters, gas flow rates and lance heights. The starting time for the swirl motion was found to decrease with an increased gas flow, while the damping time was found to be independent of gas flow rate, nozzle diameter, lance height and ratio of depth to diameter.

Place, publisher, year, edition, pages
Stockholm: KTH , 2005. , viii, 16 p.
Keyword [en]
Materials science, physical modelling, top blown converters, lances, blowing, penetration, swirl
Keyword [sv]
Materialvetenskap
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:kth:diva-284ISBN: 91-7283-970-8 (print)OAI: oai:DiVA.org:kth-284DiVA: diva2:8564
Presentation
2005-03-18, B2, Brinellvägen 23, Stockholm, 10:00
Supervisors
Note
QC 20101217Available from: 2005-07-06 Created: 2005-07-06 Last updated: 2010-12-17Bibliographically approved
List of papers
1. The effect of nozzle diameter, lance height and flow rate on penetration depth in a top-blown water model
Open this publication in new window or tab >>The effect of nozzle diameter, lance height and flow rate on penetration depth in a top-blown water model
2006 (English)In: Steel Research International, ISSN 1611-3683, Vol. 77, 82-90 p.Article in journal (Refereed) Published
Abstract [en]

This work aimed at investigating the penetration depth in a water model during lance blowing. A study of accessible literature was carried out to summarise previous work that had studied penetration depth. Based on the literature study an experimental plan was devised consisting of experiments focused on studying the effect of nozzle diameter, lance height and flow rate on the penetration depth. However, the primary focus was on studying the effect of small nozzle diameters on the penetration depth, which has not previously been reported in the literature. It was found that the results of the experiments in general agreed well with previous work, namely: the penetration depth increases with decreasing nozzle diameter, decreasing lance height and increasing gas flow rate. All equations known previously were used to calculate the penetration depth based on current experimental data. Thereafter, it was deduced which of the empirical relationships best fitted the experimental data. The jet momentum number was also determined from the experimental data and it was found that the penetration depth increased with an increased jet momentum number. However, for smaller nozzle diameters there was a considerable deviation. Therefore, a new correlation was suggested, heuristically derived from a macroscopic energy conservation consideration, and it was shown to result in better agreement between experiments and predictions for small nozzle diameters.

Keyword
Data acquisition, Energy conservation, Heuristic methods, Jets, Mathematical models, Nozzles, Lance, Penetration, Physical modelling, Blow molding
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-24669 (URN)000236143600002 ()2-s2.0-33644638045 (Scopus ID)
Note
QC 20100921Available from: 2010-09-21 Created: 2010-09-21 Last updated: 2012-02-24Bibliographically approved
2. A physical model study of swirl phenomena in a top blown bath
Open this publication in new window or tab >>A physical model study of swirl phenomena in a top blown bath
Show others...
2006 (English)In: Steel Research International, ISSN 1611-3683, Vol. 77, 234-241 p.Article in journal (Refereed) Published
Abstract [en]

The present study is focused on swirl motion in a top blown water model, where a deep water swirl motion is observed. During the experiments, the top lance, with cylindrical nozzles, was placed above the water surface and thereby produced an external force on the bath. The effect on how different parameters, such as nozzle diameter and the distance between the bath surface and nozzle exit, i.e. the lance height, affect the swirl motion were studied. More specifically, the amplitude and period of the swirl as well as the starting and damping time of the swirl were determined. The amplitude was found to increase with an increased nozzle diameter and gas flow, while the period had a constant value of about 0.5 s for all nozzle diameters, gas flows and lance heights. The starting time for the swirl motion was found to decrease with an increased gas flow, while the damping time was found to be independent of gas flow rate, nozzle diameter, lance height and ratio of depth to diameter.

Keyword
Nozzles, Physical properties, Steel, Surface properties, Water, Bath, Lance, Physical modeling, Swirl, Swirling flow
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-24670 (URN)000237794000002 ()2-s2.0-33646267693 (Scopus ID)
Note

QC 20100921

Available from: 2010-09-21 Created: 2010-09-21 Last updated: 2016-04-27Bibliographically approved

Open Access in DiVA

fulltext(459 kB)883 downloads
File information
File name FULLTEXT01.pdfFile size 459 kBChecksum MD5
c1490e238ba862128917d801dda8b3cf100a5438309c20e92fcceb180b0fe0445cd67c65
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Nordquist, Annie
By organisation
Applied Process Metallurgy
Materials Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 883 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 522 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf