کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10281055 | 465864 | 2005 | 20 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Fluctuations and waves in fluidized bed systems: The influence of the air-supply system
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Fluctuations and waves in fluidized bed systems: The influence of the air-supply system Fluctuations and waves in fluidized bed systems: The influence of the air-supply system](/preview/png/10281055.png)
چکیده انگلیسی
A general model of the response of a fluidized bed to disturbances is formulated, and the information provided by the model with respect to the dynamics of the bed, the bed plus the air-plenum and the bed plus the entire air-supply system, is investigated. Expressions given in literature on the fundamental frequency of the bed-plenum system are analyzed, and it is shown that they are a special case of the general model. In order to simulate various types of interaction between the bed and the rest of the system, experiments were performed in a cold fluidized bed unit operated under both non-circulating and circulating conditions. At low velocity, three regimes were identified: the multiple bubble regime with almost no interaction between bed and air-plenum, the single bubble regime with the interaction between bed and air-plenum only, and a regime with numerous irregular bubbles, where the bed interacted with the entire air-supply system. At high fluidization velocity, the exploding bubble regime was identified, with the same dominant frequency as that of the single bubble regime (the interaction with the air-supply system remains at that frequency). The models investigated correctly reproduce the dynamics when the bed is independent of the other parts of the system, or when the bed interacts only with the air-plenum. However, the models are only partially applicable when the bed interacts with the entire air-supply system. The reasons for this are investigated. In the case of system interaction, pressure waves, generated in the bed, interact with pressure pulsations from the air-supply system. This results in a coupled system, which is not covered by the models. Pressure waves resulting from events in the bed, are recognized as the coherent part of the cross power spectra of pressure fluctuations measured in the bed and the air-plenum.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 153, Issue 3, 1 June 2005, Pages 176-195
Journal: Powder Technology - Volume 153, Issue 3, 1 June 2005, Pages 176-195
نویسندگان
Srdjan Sasic, Bo Leckner, Filip Johnsson,