کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7052412 1457416 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Generation mechanism of micro-bubbles in a pressurized dissolution method
ترجمه فارسی عنوان
مکانیزم تولید مکانیکی میکرو حباب ها در یک روش انحلال تحت فشار
کلمات کلیدی
میکرو حباب، روش انحلال تحت فشار، کاویتاسیون، قطر حباب، تراکم تعداد حباب، جریان چند مرحلهای،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
Micro-bubbles are in use in many industrial fields such as water treatment, purification of lake water, chemical engineering, washing processes and housing equipment by virtues of their large interfacial area concentration and long residence time in liquid. A pressurized dissolution method based on decompression of liquid with dissolved gas is one of promising methods for generating fine micro-bubbles at high number density. Since the mechanism of micro-bubble generation is not clarified yet, design and improvement of micro-bubble generators are based on trial and error. In this study, effects of liquid volume flux at a decompression nozzle and dissolved gas concentration in the upstream region of the nozzle on diameter and number density of generated micro-bubbles are examined to understand generation mechanism of micro-bubbles in a pressurized dissolution method. The diameter and the number density of micro-bubbles are measured by using phase Doppler anemometry (PDA) in the downstream region of the nozzle, and the flow patterns in the nozzle are visualized by using a high-speed camera. The experimental results show that diameter and number density of generated micro-bubbles depend on cavitation pattern at the nozzle, and that cavitation bubbles containing not only vapor but also non-condensable gas become micro-bubbles due to their shrink caused by condensation of the vapor in the downstream region of the nozzle.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Thermal and Fluid Science - Volume 60, January 2015, Pages 201-207
نویسندگان
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