کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
656901 1458058 2015 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Performance evaluation of ceiling crystallization for suppressing buoyancy-induced convection in mass transfer applications: An interferometric study
ترجمه فارسی عنوان
ارزیابی عملکرد بلورسازی سقف برای سرکوب گرمادهی ناشی از شناوری در برنامه های کاربردی انتقال جرم: یک مطالعه بینفاکتوریم
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
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. σ = 2% and 4% and sodium chlorate (NaClO3) 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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 84, May 2015, Pages 61-72
نویسندگان
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