Fluid Mechanics of Mixing

This volume is a selection of the material presented at the 7th European Mixing Congress. It is concerned exclusively with mixing in circular section vessels, using centrally mounted paddles or similar impellers. The contents are arranged under three classifications: Modelling of Mixing Processes, Mixing Operations and Experimental Techniques. The classifications result in the original material appearing in a different order to that of the Congress. This arrangement is intended to assist the reader in identifying the topic area by function or application, rather than by technology. In this book the section on Modelling contains papers which focus on the representation of the mixing process, whether by equation, scale-up criteria, or fluid dynamic simulation. Similarly, Mixing Operations are concerned with the application or function of the mixing process, such as mass transfer, heat transfer or mixing time. Experimental Techniques addresses the tools the researcher needs to use at the data gathering experimental stage. It collects together advances made in the various methods used by some of the foremost researchers, and indicates those areas still in need of additional instrumentation or methods of data reduction. The book is intended for researchers, designers and users of mixing equipment, and for those planning research and development programmes and who wish to keep up to date with advances in the basic technology and its applications.

Contenu

Effect of macromixing on a competitive/consecutive reaction in a semi-batch stirred reactor: Paul's iodination experiments interpreted by networks-of-zones.- The variation of flow pattern and mixing time with impeller spacing in stirred vessels with two Rushton impellers.- Development of transitional flow mixing impeller.- Distribution of turbulence characteristics in agitated systems with axial high-speed impeller and baffles.- A computational study on dispersing gas in a stirred reactor.- Measurements and modelling of flow in gas sparged, agitated vessels.- Simple performance correlations for agitated vessels.- Gradients in production scale bioreactors.- Solid distribution in slurry reactors stirred with multiple impellers: continuous flow systems.- The mixing of miscible liquids with large differences in density and viscosity.- Power input and gas hold up in gas liquid dispersions agitated by axial flow impellers.- Improving Xanthan fermentation performance by changing agitators.- Determination of the mean specific power input in stirred vessels with suspensions.- A comparison of the efficiency of five agitator designs for solids suspension duties at high solids concentrations.- The design of agitated dissolution tanks.- Modelling and control of multistage mixer extractors.- Local measurements of liquid and solid velocities and of particle sizes in stirred suspensions with a phase doppler particle analyser.- Hydrodynamic characteristics of a gas-inducing impeller.- Heat transfer in mechanically stirred gas-liquid system.- Heat and mass transfer efficiencies of multi-impeller gas-viscous liquids contactors.- Measurement of concentration fluctuations during mixing in a stirred tank and in a channel flow by laser induced fluorescence spectroscopy.- Reynolds stresses and stirring regimes of a Rushton turbine.- Micromixing behaviour in a batch vessel with several impellers using alkali-fluorescent dye system.- An experimental study of micromixing using two parallel reactions.- LDA measurements of flow in stirred gas-liquid reactors.- A study of ventilated gas cavities on disc-turbine blades.- Numerical particle tracking in a turbine agitated vessel.- Residence time distribution of solid and liquid phase in a stirred tank reactor.- Local wall heat transfer coefficients using surface calorimeters.