A novel surface aeration configuration featured with aself-rotating and floating baffle (SRFB) and a Rushton disk turbine(DT) with a perforated disk has been developed. The SRFB, consistedof 12 fan blades twisted By an angle of 30 deg to the horizontalplane, is incorporated onto the impeller shaft to improve gasentrainment, bubble Breakup, mixing in a φ 154 mm agitated vessel.This new configuration is compared to the conventional DT surfaceAeration experimentally. The results suggest that the criticalimpeller speed for onset of gas entrainment is lower for The newconfiguration and it demands greater power consumption. Moreover, theSRFB system produces 30/100-168/100 Higher volumetric mass transfercoefficient per unit power input than that obtained in theconventional DT surface Aerator under the same operation conditions.
Hydroformylation of 1-dodecene was studied in a biphasic systemusing water-soluble rhodium complex [RhCl(CO)(TPPTS)_2] as catalystin the presence of cetyl trimethyl ammonium bromide as surfactant toenhance the reaction rate. Efforts were devoted to improve theperformance of hydroformylation by exploring reactor configurationwhich enhanced the mixing, dispersion and interphase mass transfer.Experiments were carried out in a 0.5 L autoclave at the totalpressure of 1.1 Mpa and temperature from 363 K to 373 K.
For the mass transfer to single drops during the stage of steady buoyancy-driven motion, experimental measurement is complicated with the terminal effect of additional mass transfer during drop formation and coalescence at the drop collector. Analysis reveals that consistent operating conditions and experimental procedure are of critical significance for minimizing the terminal effect of drop coalescence on the accuracy of mass transfer measurements. The novel design of a totally-closed extraction column is proposed for this purpose, which guarantees that the volumetric rate of drop phase injection is exactly equal to that of withdrawal of drops. Tests in two extraction systems demonstrate that the experimental repeatability is improved greatly and the terminal effect of mass transfer during drop coalescence is brought well under control.
In accordance to the anisotropic feature of turbulent flow, ananisotropic algebraic stress model is adopted to predict theturbulent flow field and turbulent characteristics generated by aRushton disc turbine with the improved inner-outer iterativeprocedure. The predicted turbulent flow is compared with experimentaldata and the simulation by the standard k-ε turbulence model. Theanisotropic algebraic stress model is found to give better predictionthan the standard k-ε turbulence model. The predicted turbulent flowfield is in accordance to experimental data and the trend of theturbulence intensity can be effectively reflected in the simulation.
An orthogonal experiment design is adopted for studying the macroscopic reaction kinetics of hydroformylation of 1-dodecene catalyzed by water-soluble rhodium complex. The experimental data of reaction rate and n∶i aldehyde ratio are analysed by margin and variance analyses. The optimal hydroformylation reaction conditions are suggested by compromise of initial reaction rate and normal/isomeric ratio of product aldehyde.
