Jet Mixing of Liquids in a Rotating Cylindrical Vessel

抄録

Jet mixing time of liquids t_M in a rotating vessel was observed from the pulse response curve of electric conductivity. The ratio of mixing time to mean residence time, t_M/t_R, was well correlated with the dimensionless angular velocity Ω*, which was equal to the ratio of tangential velocity at the vessel wall to jet velocity at the nozzle hole. For the present experimental conditions, t_M/t_R showed a minimum value of about 0.2 regardless of jet nozzle angle, and the minimum value appeared at Ω* = 0.2–0.3. The observed response curves were classified into five types by shape. The transition of shape to shape depended only on Ω* regardless of jet flow rate, and the transition point agreed well with the Ω* value giving the minimum value of t_M/t_f. The ratio of mixing time to apparent circulation time, t_M/t_AC was 5 to 9 for the non-rotating condition (Ω* = 0), and these values were almost the same, 5 to 6, for the ratio of mixing time to circulation time in an agitated vessel with impeller. t_M/t_AC increases stepwise with increase of Ω* where the position of the step agrees with that of the transition of the shape of response curve.