References of "Marchot, Pierre"
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See detailLocal measurements of void fraction and liquid holdup in packed columns using X-ray computed tomography
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Chemical Engineering & Processing (1998), 37(6), 511-520

A 'tailor made' computed X-ray tomographic scanner has been developed as a tool for the analysis of the distribution of gas, liquid and solid phases in packed columns. The very good spatial resolution of ... [more ▼]

A 'tailor made' computed X-ray tomographic scanner has been developed as a tool for the analysis of the distribution of gas, liquid and solid phases in packed columns. The very good spatial resolution of the scanner has first been assessed by the imaging of objects of known shape and size, called 'physical' phantoms. Images have then been realized on a 0.6 m diameter and 2 m height column packed with Cascade Mini-Ring 1A packing elements, which is a random polypropylene packing designed to be used in absorption columns. The solid phase distribution, leading to the void fraction distribution, has been analyzed on cross-section images of the dry packed column (without any liquid flowrate). The measured value of the bed void fraction is equal to the value provided by the manufacturer. The analysis of the axial profile of void fraction shows that the 'end effect' may be neglected, whereas the analysis of the radial profile evidences the existence of a non negligible 'wall effect'. Images have then been carried out on the packed column irrigated by a liquid flowrate ranging between 0 and 6000 1 h(-1) (0-6.10(-3) m s(-1)). Hold-up values have been measured in different cross-sections of the column and averaged in order to obtain the total hold-up value in the bed. The computed values are in very good agreement with those reported in the literature for similar packing. The dependence of the liquid hold-up on the liquid superficial velocity can be expressed in terms of a power law. The fitted value of the exponent, equal to 0.65, is in the range of exponent values found in correlations of the literature. (C) 1998 Elsevier Science S.A. All rights reserved. [less ▲]

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See detailInvestigating trickle flow in packed columns by X-ray tomography
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

Conference (1997, October)

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See detailX-ray tomography in random packings
Toye, Dominique ULg; Crine, Michel ULg; Marchot, Pierre ULg

Scientific conference (1997, September 30)

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See detailComputer-assisted tomography for liquid imaging in trickle-flow columns
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Non-invasive Monitoring of Multiphase Flows (1996)

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See detailModelling of multiphase flow in packed beds by computer-assisted x-ray tomography
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Measurement Science & Technology (1996), 7(3), 436-443

The high resolution which can be obtained by computer-assisted x-ray tomography is used to investigate Various scale heterogeneities of the flow texture characterizing multiphase flow in packed beds. The ... [more ▼]

The high resolution which can be obtained by computer-assisted x-ray tomography is used to investigate Various scale heterogeneities of the flow texture characterizing multiphase flow in packed beds. The direct counting of 'irrigated' pixels allows the determination of the number of individual liquid rivulets as well as their size. The evolution of the liquid flow texture versus the liquid velocity agrees quite well with the predictions of a percolation-based model. This agreement is further confirmed by the comparison of the experimental hold-up values averaged over the column cross-section with the theoretical model. [less ▲]

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See detailSYNTHESIS OF SIO2-TIO2 XEROGELS BY SOL-GEL PROCESS
Pirson, Anne-Marie ULg; MOHSINE, Abdel; Marchot, Pierre ULg et al

in Journal of Sol-Gel Science and Technology (1995), 4(3), 179-185

A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O'Pr)(4)] and tetraethylorthosilicate [TEOS]: they are mixed in the ... [more ▼]

A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O'Pr)(4)] and tetraethylorthosilicate [TEOS]: they are mixed in the same solvent and then directly hydrolysed. This one-step reaction is possible because of the use of 2-methoxyethanol, a protic polar solvent. This alcohol plays two different specific roles: it acts as a solvent as well as a stabilizer of titanium alkoxide towards the hydrolysis-precipitation reaction. So, by an accurate adjustment of the quantity of methoxyethanol in the mixture, we can control the reactivity of the titanium precursor. Monolithic and transparent xerogels were obtained whatever the composition. Three monolithic SiO2-TiO2 gels containing 20, 50 and 75 mol% of TiO2 were prepared and studied in details. By using the TG-DSC analysis, we can follow the evolution of the loss of water and organic residues. The structural evolution of gels during calcination is characterized by IR spectroscopy and X-Ray diffraction. [less ▲]

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See detailAnalysis of liquid flow distribution in trickle bed reactor using computer assisted tomography
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Beck, M. S.; Hoyle, B. S.; Morris, M. A. (Eds.) et al Process tomography - 1995 - Implementation for industrial processes (1995)

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See detailAnalysis of liquid flow distribution in a trickle bed reactor
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Frontiers in Industrial Process Tomography (1995)

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See detailAnalysis of Liquid Flow Distribution in Trickling Flow Reactor Using Computer-Assisted X-Ray Tomography
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Chemical Engineering Research & Design : Transactions of the Institution of Chemical Engineers Part A (1995), 73(A3), 258-262

In this paper, we propose a new experimental technique, based on X-ray tomography, allowing the analysis of the gas-liquid-solid phase distribution in trickling flow reactors. Tomography refers to the ... [more ▼]

In this paper, we propose a new experimental technique, based on X-ray tomography, allowing the analysis of the gas-liquid-solid phase distribution in trickling flow reactors. Tomography refers to the cross-sectional imaging of an object from data collected by illuminating this object from many directions. The experimental set-up allows the scanning of transverse sections of rather large columns: up to 0.8 m diameter and 2 m height can be irradiated. Experiments were carried out both without and with liquid flow. In the absence of liquid, the reconstructed images give a view of the non-uniformity of the solid phase distribution. The images obtained are very complex because they result from the superposition of several distributions with different Spatial scales. We show the existence of a first spatial scale which allows us to separate properties belonging to the individual packing elements from those belonging to the bed scale. When liquid is flowing through the packed bed X-ray scans give a clear picture of the distribution of the liquid phase saturation, despite the very low liquid film thickness. Average values of this liquid phase saturation are determined and confronted with a partial wetting model. [less ▲]

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See detailTrickle flow in packed columns : new experimental and theoretical investigations
Crine, Michel ULg; Marchot, Pierre ULg; Toye, Dominique ULg et al

in Trends in Chemical Engineering (1994), 2

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See detailInteractions between the biofilm growth and the hydrodynamics in an aerobic trickling filter
Lekhlif, B.; Toye, Dominique ULg; Marchot, Pierre ULg et al

in Water Science & Technology (1994), 29

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See detailThe use of large scale computer assisted tomography for the study of hydrodynamics in trickling filters
Toye, Dominique ULg; Marchot, Pierre ULg; Crine, Michel ULg et al

in Chemical Engineering Science (1994), 49(24B), 5271-5280

In this paper, a new experimental technique is proposed, based on X-ray tomography, allowing the analysis of the gas-liquid-solid phase distribution in trickling filters. Tomography refers to the cross ... [more ▼]

In this paper, a new experimental technique is proposed, based on X-ray tomography, allowing the analysis of the gas-liquid-solid phase distribution in trickling filters. Tomography refers to the cross-sectional imaging of an object from data collected by illuminating this object from many directions. The experimental set-up allows the scanning of transverse sections of rather large filters: up to 0.8 m diameter and 2 m height can be irradiated. Experiments were carried out both without and with liquid flow. In the absence of liquid, the reconstructed images give a view of the non-uniformity of the solid phase distribution. The images obtained are very complex because they result from the superposition of several distributions with different spatial scales. The existence of a first spatial scale is shown which allows separation of the properties belonging to the individual packing elements from those belonging to the bed scale. When liquid is flowing through the packed bed, the distribution of the liquid hold-up is clearly evidenced, despite the very low liquid film thickness. [less ▲]

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