根据在直径0.186 m、高8 m 和直径0.14 m、高12 m 两台快速流化床装置的实验结果,并综合文献研究报道,研究了操作气速、颗粒循环速率、颗粒物性、床层直径以及进口、出口结构等因素对床层截面平均空隙率轴向分布的影响。表明一般情况下...根据在直径0.186 m、高8 m 和直径0.14 m、高12 m 两台快速流化床装置的实验结果,并综合文献研究报道,研究了操作气速、颗粒循环速率、颗粒物性、床层直径以及进口、出口结构等因素对床层截面平均空隙率轴向分布的影响。表明一般情况下,快速流化床截面平均空隙率轴向分布的基本形式是上部空隙率高、下部空隙率低的单调指数函数。在特定的床结构条件下,快速流化床截面平均空隙率轴向分布曲线可能发生变异,即在出口结构有强约束作用时,可能呈反C,在入口结构有弱约束作用时,可能呈 S 型。展开更多
The axial profile of gas holdups was measured using a γ-ray densitometry in the pressurized bubble column,0.3 m in diameter and 6.6 m in height.The principle of γ-ray measurement and data processing is discussed.The...The axial profile of gas holdups was measured using a γ-ray densitometry in the pressurized bubble column,0.3 m in diameter and 6.6 m in height.The principle of γ-ray measurement and data processing is discussed.The axial profile of gas holdups and its average value in two-phase system were obtained in the churn-turbulent flow regime with a gas velocity up to 0.40 m·s -1 and a system pressure up to 1.0 MPa, which are in agreement with results obtained by differential pressure method.The effects of superficial gas velocity, liquid surface tension, liquid viscosity and system pressure on the axial profile of gas holdups were investigated.It is shown that the gas holdup decreases with the increasing liquid viscosity and liquid surface tension, and increases with the increase of pressure and superficial gas velocity.展开更多
文摘根据在直径0.186 m、高8 m 和直径0.14 m、高12 m 两台快速流化床装置的实验结果,并综合文献研究报道,研究了操作气速、颗粒循环速率、颗粒物性、床层直径以及进口、出口结构等因素对床层截面平均空隙率轴向分布的影响。表明一般情况下,快速流化床截面平均空隙率轴向分布的基本形式是上部空隙率高、下部空隙率低的单调指数函数。在特定的床结构条件下,快速流化床截面平均空隙率轴向分布曲线可能发生变异,即在出口结构有强约束作用时,可能呈反C,在入口结构有弱约束作用时,可能呈 S 型。
文摘The axial profile of gas holdups was measured using a γ-ray densitometry in the pressurized bubble column,0.3 m in diameter and 6.6 m in height.The principle of γ-ray measurement and data processing is discussed.The axial profile of gas holdups and its average value in two-phase system were obtained in the churn-turbulent flow regime with a gas velocity up to 0.40 m·s -1 and a system pressure up to 1.0 MPa, which are in agreement with results obtained by differential pressure method.The effects of superficial gas velocity, liquid surface tension, liquid viscosity and system pressure on the axial profile of gas holdups were investigated.It is shown that the gas holdup decreases with the increasing liquid viscosity and liquid surface tension, and increases with the increase of pressure and superficial gas velocity.
