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Numerical Studies On Hydrodynamics In Various Circulating Fluidization Systems, Zeneng Sun

Electronic Thesis and Dissertation Repository

Various circulating fluidized bed (CFB) systems including gas-solid fluidization, liquid-solid fluidization, and gas-liquid-solid three-phase fluidization are numerically studied. With a comprehensive knowledge from the experiments, improved computational fluid dynamic (CFD) models are developed for detailed investigations on a wide operating range in the gas-solid CFB (GSCFB) system. The CFD model developed is also extended to study two new types of fluidized beds, an inverse liquid-solid circulating fluidized bed (ILSCFB) and a bubble induced fluidized bed (BIFB), as a supplement to the experimental work.

Flow structures and transitions from low-density operations to high-density operations in both GSCFB riser and downer are …

Experimental Investigations On The Instantaneous Flow Structure In Circulating Fluidized Beds, Xiaoyang Wei

Electronic Thesis and Dissertation Repository

Knowing the instantaneous flow structure is of great importance for the understanding of gas-particle interaction and for the prediction of reactor performances. In this thesis, a systematic and comprehensive study has been conducted on the instantaneous flow structure in a narrow rectangular riser (19 mm in thickness, 114 mm in width and 7.6 m in height), in a cylindrical riser (76 mm in diameter, 10.2 m in height) and in a cylindrical downer (50 mm in diameter, 4.9 m in height). A wider range of operating conditions has been achieved in risers and downer with superficial gas velocity from 3.0 …