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Akbarnejad, S. (2016). Experimental and Mathematical Study of Incompressible Fluid Flow through Ceramic Foam Filters. (Licentiate dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Experimental and Mathematical Study of Incompressible Fluid Flow through Ceramic Foam Filters
2016 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Ceramic Foam Filters (CFFs) are widely used to filter solid particles and inclusions from molten metal in metal production, particularly in the aluminum industry. In general, the molten metal is poured on the top of a ceramic foam filter until it reaches a certain height, also known as metal head or gravity head. This is done to build the required pressure to prime the filter media and to initiate filtration. To predict the required metal head, it is necessary to obtain the Darcy and non-Darcy permeability coefficients of the filter. The coefficients vary upon filter type. Here, it is common to classify CFFs based on grades or pore per inches (PPI). These CFFs range from10 to100 PPI and their properties vary in everything from cell and window size to strut size. The 80-100 PPI CFFs are generally not practical for use by industry, since the priming of the filters by a gravitational force requires an excessive metal head. However, recently a new method has been developed to prime such filters by using electromagnetic Lorentz forces. This allows the filters to be primed at a low metal head.

To continue the research work, it was deemed necessary to measure the pressure gradients of single and stack of commercial alumina ceramic foam filters and to obtain the permeability characteristics. Therefore, efforts have been made to validate the previously obtained results, to improve the permeametry experimental setup, and to obtain Darcy and non-Darcy permeability coefficients of single 30, 50, and 80 PPI filters and stacks of filters. Furthermore, the experimentally obtained pressure gradients were analyzed and compered to the mathematically and analytically estimated pressure gradients.

The studies showed that, in permeametry experiments, the sample sealing procedure plays an important role for an accurate estimation of the permeability constants. An inadequate sealing or an un-sealed sample results in an underestimation of the pressure drop, which causes a considerable error in the obtained Darcy and non-Darcy permeability coefficients. Meanwhile, the results from the single filter experiments showed that the permeability values of the similar PPI filters are not identical. However, the stacks of three identical filters gave substantially the same measured pressure drop values and roughly the same Darcy and non-Darcy coefficients as for the single filters.

The permeability coefficients of the filters are believed to be best defined and calculated by using the Forchheimer equation. The well-known and widely used Ergun and Dietrich equations cannot correctly predict the pressure drop unless a correction factor is introduced. The accuracy of the mathematically estimated pressure drop, using COMSOL Multiphysics® 5.1, found to be dependent on the drag term used in the Brinkman-Forchheimer equation.  Unacceptable error, as high as 84 to 89 percent for the 30, 50 and 80 PPI single filters, compared to the experimentally obtained pressure gradient values were observed when the literature defined Brinkman-Forchheimer drag term was used. However, when the same second order drag term (containing the non-Darcy coefficient) as defined in the Forchheimer equation was used, the predicted pressure gradient profiles satisfactorily agreed with the experiment data with as little as 0.3 to 5.5 percent deviations for the 30, 50 and 80 PPI single filters.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2016. p. xi, 64
National Category
Materials Engineering Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-183031 (URN)978-91-7595-877-4 (ISBN)
External cooperation:
Presentation
2016-03-18, M131, Brinellvagen 23, KTH, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

QC 20160226

Available from: 2016-02-26 Created: 2016-02-25 Last updated: 2016-08-26Bibliographically approved
Akbarnejad, S., Kennedy, M. W., Fritzsch, R. & Aune, R. E. (2015). An investigation on permeability of ceramic foam filters (CFF). In: TMS Light Metals: . Paper presented at Light Metals 2015 - TMS 2015 Annual Meeting and Exhibition, 15 March 2015 through 19 March 2015 (pp. 949-954).
Open this publication in new window or tab >>An investigation on permeability of ceramic foam filters (CFF)
2015 (English)In: TMS Light Metals, 2015, p. 949-954Conference paper, Published paper (Refereed)
Abstract [en]

CFFs are used to filter liquid metal in the aluminum industry. CFFs are classified in grades or pores per inch (PPI), ranging from 10-100 PPI. Their properties vary in everything from pore and strut size to window size. CFFs of 80-100 PPI are generally not practical for use by industry, as priming of the filters by gravitational forces requires an excessive metal head. Recently, co-authors have invented a method to prime such filters using electromagnetic Lorentz forces, thus allowing filters to be primed with a low metal head. In the continuation of this research work, an improved experimental setup was developed in the present study to validate previous results and to measure the permeability of different filters, as well as a stack of filters. The study of permeability facilitates estimation of the required pressure drop to prime the filters and the head required to generate a given casting rate.

Keywords
CFF, Filtration, Forchheimer, Permeability, Light metals, Mechanical permeability, Aluminum industry, Casting rate, Ceramic foam filters, Gravitational forces, Pores per inches, Window Size, Metals
National Category
Signal Processing Control Engineering
Identifiers
urn:nbn:se:kth:diva-181552 (URN)2-s2.0-84942907016 (Scopus ID)9781119082446 (ISBN)
Conference
Light Metals 2015 - TMS 2015 Annual Meeting and Exhibition, 15 March 2015 through 19 March 2015
Note

QC 20160226

Available from: 2016-02-02 Created: 2016-02-02 Last updated: 2016-02-26Bibliographically approved
Fritzsch, R., Kennedy, M. W., Akbarnejad, S. & Aune, R. E. (2015). Effect of electromagnetic fields on the priming of high grade Ceramic Foam Filters (CFF) with liquid aluminum. In: TMS Light Metals: . Paper presented at Light Metals 2015 - TMS 2015 Annual Meeting and Exhibition, 15 March 2015 through 19 March 2015 (pp. 929-935). The Minerals, Metals, and Materials Society
Open this publication in new window or tab >>Effect of electromagnetic fields on the priming of high grade Ceramic Foam Filters (CFF) with liquid aluminum
2015 (English)In: TMS Light Metals, The Minerals, Metals, and Materials Society, 2015, p. 929-935Conference paper, Published paper (Refereed)
Abstract [en]

Electromagnetic fields can influence the behavior of liquid metals in commercial Ceramic Foam Filters (CFF's). In the present study 9 inch industrial CFF's of high grade with 50 and 80 pores per inch (ppi) have been investigated. The main objective was to prime the 9 inch industrial scale CFF's with a standard aluminum casting alloy (3XXX - alloy) by the use of various magnetic field strengths (max. 0.12 T) induced by a coil. The obtained results were compared with reference gravity experiments. The influence of the electromagnetic Lorentz forces on the obtained results was calculated with 2D Finite Element Modeling (FEM) using the COMSOL® software. The fluid flow characteristics inside the CFF were considered and are part of another publication within the group.

Place, publisher, year, edition, pages
The Minerals, Metals, and Materials Society, 2015
Keywords
Aluminum, CFF, Electromagnetism, Filtration, Liquid metal, Priming, Aluminum castings, Ceramic foams, Ceramic materials, Electromagnetic fields, Flow of fluids, Functional electric stimulation, Light metals, Liquid metals, Liquids, Metal casting, Metals, Aluminum casting alloys, Ceramic foam filters, Commercial ceramic foams, Industrial scale, Magnetic field strengths, Pores per inches, Finite element method
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-181520 (URN)2-s2.0-84942891632 (Scopus ID)9781119082446 (ISBN)
Conference
Light Metals 2015 - TMS 2015 Annual Meeting and Exhibition, 15 March 2015 through 19 March 2015
Note

QC 20160216

Available from: 2016-02-16 Created: 2016-02-02 Last updated: 2016-02-16Bibliographically approved
Fritzsch, R., Akbarnejad, S. & Aune, R. E. (2014). A novel method for automated quantification of particles in solidified aluminium. In: TMS 2014 143rd Annual Meeting & Exhibition, Annual Meeting Supplemental Proceedings: . Paper presented at 143rd Annual Meeting and Exhibition, TMS 2014; San Diego, CA; United States; 16 February 2014 through 20 February 2014 (pp. 535-543). The Minerals, Metals, and Materials Society
Open this publication in new window or tab >>A novel method for automated quantification of particles in solidified aluminium
2014 (English)In: TMS 2014 143rd Annual Meeting & Exhibition, Annual Meeting Supplemental Proceedings, The Minerals, Metals, and Materials Society, 2014, p. 535-543Conference paper, Published paper (Refereed)
Abstract [en]

Particle concentration and size distribution in the melt can give important information regarding the filtration efficiency and the quality of the aluminium. LiMCA (Liquid Metal Cleanliness Analyser) system, used in primary and secondary production of aluminium, provides in-situ data for granulometric and total density information on the inclusion content, but has problems quantifying particles < 20 μm in size. To be able to determine the required cleanliness with particle counts down' to 10 μm for modern alloys a novel method for automated quantitative results has been developed. Results are obtained using a user friendly technique based on the ImagePro® Plus 7.0 software. The different image processing steps adopted for automated quantification of the particle count in a size range from 2 to 50 μm is described and discussed together with the obtained results. The automated technique has been benchmarked elsewhere with a manual particle count reviling an error of ∼3% on the overall filtration efficiency.

Place, publisher, year, edition, pages
The Minerals, Metals, and Materials Society, 2014
Series
TMS Annual Meeting
Keywords
Automation, Image processing, ImagePro® Plus 7.0, Melt quality, Particle counting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-145499 (URN)000354941300065 ()2-s2.0-84899768457 (Scopus ID)978-111888972-5 (ISBN)
Conference
143rd Annual Meeting and Exhibition, TMS 2014; San Diego, CA; United States; 16 February 2014 through 20 February 2014
Note

QC 20140521

Available from: 2014-05-21 Created: 2014-05-21 Last updated: 2015-08-18Bibliographically approved
Akbarnejad, S., Jonsson, L., Kennedy, M. W., Aune, R. E. & Jönsson, P. Analysis on Experimental Investigation and Mathematical Modelling of Incompressible Flow through Ceramic Foam Filters.
Open this publication in new window or tab >>Analysis on Experimental Investigation and Mathematical Modelling of Incompressible Flow through Ceramic Foam Filters
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(English)Manuscript (preprint) (Other academic)
Identifiers
urn:nbn:se:kth:diva-183071 (URN)9781119082446 (ISBN)
Note

QS 20160226

Available from: 2016-02-26 Created: 2016-02-26 Last updated: 2016-02-26Bibliographically approved
Akbarnejad, S., Saffari Pour, M., Jonsson, L. & Jönsson, P. Significance of Fluid Bypassing Effect on Darcy and Non-Darcy Permeability Parameters of Ceramic Foam Filters.
Open this publication in new window or tab >>Significance of Fluid Bypassing Effect on Darcy and Non-Darcy Permeability Parameters of Ceramic Foam Filters
(English)Manuscript (preprint) (Other academic)
Identifiers
urn:nbn:se:kth:diva-183073 (URN)9781119082446 (ISBN)
Note

QS 2016

Available from: 2016-02-26 Created: 2016-02-26 Last updated: 2016-02-26Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7957-348X

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