کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
235673 465644 2015 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of fluidization velocity on solid stack volume in a bubbling fluidized-bed with nozzle-type distributor
ترجمه فارسی عنوان
اثرات سرعت سیال شدن در حجم پشته جامد در یک تخت مایع ذوب شده با توزیع کننده نوع نازل
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


• Bubbling fluidized-bed hydrodynamics with ideal and real distributors are examined.
• Pressure drops obtained from CFD agree well with experimental measurements.
• Uniformity index (UI) of solid hold-up is higher in ideal distributor than real one.
• A compromise between UI and solid stack volume (SSV) is found at u/umf = 2.9.

Hydrodynamic characteristics in a wind-box and bubbling fluidized-bed (BFB) gasifier zone of a dual fluidized-bed (DFB) were investigated by a two-phase three-dimensional computational fluid dynamics (CFD) model. The gas and solid phases were treated by an Eulerian–Eulerian two-fluid model, coupled with the realizable k–epsilon turbulence model and the kinetic theory of granular flow (KTGF) describing the random motion of solid particles. Pressure drops obtained from the cold-rig CFD simulation were validated with experimental data which were measured in a pilot-scale BFB using air as a fluidization agent and sand as heat carrier particles at an operating temperature of 800 °C. Hydrodynamics of the fluidized-bed with a uniform gas distributor (Ideal case) and a nozzle-type gas distributor (Real case) were evaluated in terms of the pressure drop, solid volume fraction (SVF), uniformity index (UI), and solid stack volume (SSV) for three inlet air flow rates (low, medium and high). Similar behaviors were shown for both the two cases in pressure drop along the gasifier height. However, significant differences were observed in SVF, UI, and SSV. A threshold changing the slope of SSV to the air flow rate was found at a fluidization index (u/umf) of 2.9.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 275, May 2015, Pages 188–198
نویسندگان
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