Performance evaluation of ceiling crystallization for suppressing buoyancy-induced convection in mass transfer applications: An interferometric study
DSpace at IIT Bombay
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Title |
Performance evaluation of ceiling crystallization for suppressing buoyancy-induced convection in mass transfer applications: An interferometric study
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Creator |
VARMA, SS
SRIVASTAVA, A |
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Subject |
STRONG MAGNETIC-FIELD
CRYSTAL-GROWTH 3-DIMENSIONAL RECONSTRUCTION LYSOZYME CRYSTAL AQUEOUS-SOLUTION SURFACE-TENSION SOLIDIFICATION TEMPERATURE TOMOGRAPHY Mass transfer Convection Diffusion Crystal growth Aqueous solution Interferometry |
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Description |
The present study is concerned with the investigation of the phenomena of solute transport in aqueous solution-based crystal growth processes when the growing crystal is fixed in the upside-down (ceiling) configuration. The ceiling crystallization method has been employed for suppressing the adverse effects of buoyancy when the crystal growth experiments are conducted under normal gravity conditions. A Mach-Zehnder interferometer has been employed to record the line-of-sight images of the concentration field. In order to assess the feasibility of the ceiling crystallization approach for creating diffusion-dominated conditions, the results have been compared with that of the conventionally employed approach wherein the growing crystal is platform-supported. Experiments have been carried out for two levels of supersaturation i.e. sigma = 2% and 4% and sodium chlorate (NaCIO3) has been chosen as the model material. Results have been presented in the form of interferometric images of the concentration field, two-dimensional concentration contours and spatio-temporal variations of supersaturation around the growing crystal in both the configurations considered. Results of the experiments clearly reveal the suppression of buoyancy-induced convection currents and the formation of an extended horizontally stratified depletion zone around the growing crystal in ceiling configuration. The mass transport phenomenon was seen to be diffusion-dominated, thus eliminating the possibilities of sharp variations in the supersaturation levels in the vicinity of the crystal, which otherwise deteriorate the quality of the growing crystal in convection-dominated conditions. (C) 2014 Elsevier Ltd. All rights reserved.
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Publisher |
PERGAMON-ELSEVIER SCIENCE LTD
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Date |
2016-01-14T13:52:37Z
2016-01-14T13:52:37Z 2015 |
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Type |
Article
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Identifier |
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 84,61-72
0017-9310 1879-2189 http://dx.doi.org/10.1016/j.ijheatmasstransfer.2014.12.050 http://dspace.library.iitb.ac.in/jspui/handle/100/17662 |
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Language |
en
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