کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6465341 1422950 2017 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Bed expansion and multi-bubble behavior of gas-liquid-solid micro-fluidized beds in sub-millimeter capillary
ترجمه فارسی عنوان
انبساط بستر و رفتار چندبازی در تختهای میکروسیلیس گازی مایع جامد در مویرگی چند میلیمتری
کلمات کلیدی
تختهای میکروسیلیس گاز مایع جامد، رژیم جریان، نسبت بشقاب اندازه حباب، سرعت ترمینال حباب،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


- The coalesced bubble flow was identified from the multi-bubble flow.
- The bubble size follows a specific step-type distribution.
- The wall effect has impact on the coalescence of bubbles.
- The larger coalesced bubbles dominate the rise velocity of the multi-bubble flow.

Hydrodynamic study was performed on the gas-liquid-solid micro-fluidized beds with 0.8 mm bed diameter and multi-bubbles through high speed camera recording system. Flow regimes including dispersed bubble flow, coalesced bubble flow and slug flow were identified from the multi-bubble flow. Wall effect at the small bed-to-particle diameter ratio led to the occurrence of bubble coalescence and flow regime transition at lower solid holdups. Obvious bed contraction appeared only at lower liquid velocities or higher gas velocities. The diameter range of the spherical micro-bubbles in the micro-fluidized beds was 200-500 μm. The bubble size in dispersed bubble flow was normally distributed and slightly increased with the solid holdup. And in coalesced bubble flow, the bubble size was decided by the overall coalescence probability and presented a special step distribution. The larger coalesced bubbles concentrated the distribution of bubble terminal velocity. And the bubble terminal velocity decreased with the solid holdup and inversely with the bubble size. In dispersed bubble flow regime, there was positive linear relationship between the apparent viscosity and the solid holdup. Three-phase micro-fluidized beds meet the further development of micro-reactors, and this study on the hydrodynamic characteristics contributes to their wider application.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Journal - Volume 328, 15 November 2017, Pages 1122-1138
نویسندگان
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