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
Effect of swirling blade on flow pattern in nozzle for up-hill teeming
KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
2006 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

The fluid flow in the mold during up-hill teeming is of great importance for the quality of the cast ingot and therefore the quality of the final steel products. At the early stage of the filling of an up-hill teeming mold, liquid steel enters, with high velocity, from the runner into the mold and the turbulence on the meniscus could lead to entrainment of mold flux. The entrained mold flux might subsequently end up as defects in the final product. It is therefore very important to get a mild and stable inlet flow in the entrance region of the mold. It has been acknowledged recently that swirling motion induced using a helix shaped swirl blade, in the submerged entry nozzle is remarkably effective to control the fluid flow pattern in both the slab and billet type continuous casting molds. This result in increased productivity and quality of the produced steel. Due to the result with continuous casting there is reason to investigate the swirling effect for up-hill teeming, a casting method with similar problem with turbulence.

With this thesis we will study the effect of swirling flow generated through a swirl blade inserted into the entry nozzle, as a new method of reducing the deformation of the rising surface and the unevenness of the flow during filling of the up-hill teeming mold. The swirling blade has two features: (1) to generate a swirling flow in the entrance nozzle and (2) to suppress the uneven flow, generated/developed after flowing through the elbow. The effect of the use of a helix shaped swirl blade was studied using both numerical calculations and physical modelling. Water modelling was used to assert the effect of the swirling blade on rectifying of tangential and axial velocities in the filling tube for the up-hill teeming and also to verify the results from the numerical calculations. The effect of swirl in combination with diverged nozzle was also investigated in a similar way, i. e. with water model trials and numerical calculations.

Place, publisher, year, edition, pages
Stockholm: KTH , 2006. , x, 33 p.
Series
ISRN KTH/MSE--06/68--SE+APRMETU/AVH
Keyword [en]
swirling flow, up-hill teeming, nozzle, casting, fluid flow, modelling, CFD, LDA.
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:kth:diva-4269ISBN: 978-91-7178-521-3 (print)OAI: oai:DiVA.org:kth-4269DiVA: diva2:11542
Presentation
2007-01-19, Sal B2, KTH, Brinellvägen 23, Stockholm, 11:00
Opponent
Supervisors
Note
QC 20101115Available from: 2007-01-18 Created: 2007-01-18 Last updated: 2010-11-15Bibliographically approved
List of papers
1. Effect of nozzle swirl blade on flow pattern in runner during uphill teeming
Open this publication in new window or tab >>Effect of nozzle swirl blade on flow pattern in runner during uphill teeming
Show others...
2006 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 46, no 11, 1645-1651 p.Article in journal (Refereed) Published
Abstract [en]

Recent research has found a swirling flow induced by a twist-tape swirl blade inserted in the submerged entry nozzle of both slab and billet continuous casting molds to be remarkably effective for controlling the fluid-flow pattern in mold filling. The objective of the work reported on in this paper was to investigate usage of the swirl blade in the filling of molds in uphill teeming. Both mathematical and physical modeling were employed. Resulting velocity predictions and measurements corresponding to different positions in the water model were compared. Specific focus was on manipulation of the flow pattern by the swirl blade and its affect on flow unevenness, i.e. tangential and axial velocities. Good agreement was observed between the calculated and experimental results. The study's findings strongly suggest that equipping the entry nozzle of the uphill-teeming mold with a swirl blade would be a highly effective means of reducing flow unevenness during filling.

Keyword
Casting, CFD, Fluid flow, LDA, Modeling, Nozzle, Swirling flow, Uphill teeming
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-6743 (URN)10.2355/isijinternational.46.1645 (DOI)000242258800014 ()2-s2.0-33846391274 (Scopus ID)
Note
QC 20100909Available from: 2007-01-18 Created: 2007-01-18 Last updated: 2017-12-14Bibliographically approved
2. Effect of nozzle type and swirl on flow pattern for initial filling conditions in the mould for up-hill teeming
Open this publication in new window or tab >>Effect of nozzle type and swirl on flow pattern for initial filling conditions in the mould for up-hill teeming
Show others...
2007 (English)In: Steel Research International, ISSN 1611-3683, Vol. 78, no 3, 254-259 p.Article in journal (Refereed) Published
Abstract [en]

With increasingly more stringent requirements on steel quality and productivity in uphill teeming production, it is vital to attain more desirable fluid flow conditions in the filling of the mould. In this investigation, physical and mathematical modelling was carried out to study the effects of nozzle type and utilization of a swirl generator in the inlet nozzle on the flow pattern in the ingot mould during the initial filling period. Specific focus was on the effects on the resultant hump and axial velocities. Three cases were considered: 1) a straight nozzle, 2) a divergent nozzle, and 3) a divergent nozzle combined with a swirl generator. It was found that usage of the divergent nozzle, compared to the straight nozzle, resulted in a smaller hump and lower axial velocities in the bath. For the combination of divergent nozzle and swirl generator, these findings were even more pronounced, with the hump practically eliminated, and the axial velocities, as well as the turbulence at the meniscus, significantly lower. The findings of the study suggest that a divergent nozzle combined with a swirling flow generated in the nozzle could be used in the up-hill teeming process in purpose to get calmer initial filling conditions.

Keyword
Casting, Fluid flow, Modelling, Mould, Nozzle, Swirling flow
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-6744 (URN)000246043900013 ()2-s2.0-34047244029 (Scopus ID)
Note
QC 20101115. Uppdaterad från Accepted till Published (20101115).Available from: 2007-01-18 Created: 2007-01-18 Last updated: 2012-11-20Bibliographically approved

Open Access in DiVA

fulltext(654 kB)1386 downloads
File information
File name FULLTEXT01.pdfFile size 654 kBChecksum MD5
679967a3b25e94579831978998c6b28b836b469d4041c87237ba86901ab12e114f6ac5e1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Hallgren, Line
By organisation
Materials Science and Engineering
Metallurgy and Metallic Materials

Search outside of DiVA

GoogleGoogle Scholar
Total: 1386 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: 545 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