Mixing solid-liquid

Suspended solids are often the process objective that requires a specific degree of uniformity. Five guides to better liquid/solid mixing are ... 

Hartmann, H., Detailed simulations of liquid and liquid-solid mixing—turbulent agitated flow and mass transfer , Ph.D. Thesis, Delft University of Technology, Delft, Netherlands (2005). 

Gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are widely used in the chemical and petrochemical industries for processes such as methanol synthesis, coal liquefaction, Fischer-Tropsch synthesis and separation methods such as solvent extraction and particle/gas flotation. The hydrodynamic behavior of gas-liquid bubble columns and gas-liquid-solid slurry bubble columns are of great importance for the design and scale-up of reactors. Although the hydrodynamics of the bubble and slurry bubble columns has been a subject of intensive research through experiments and computations, the flow structure quantification of complex multi-phase flows are still not well understood, especially in the three-dimensional region. In bubble and slurry bubble columns, the presence of gas bubbles plays an important role to induce appreciable liquid/solids mixing as well as mass transfer. The flows within these systems are divided into two... 

Multi-phase mixing is often seen in industries. In general, the distribution of not only the dispersed phase but also the continuous phase depends on the local position in the equipment in the case of a multi-phase operation such as gas-liquid mixing system, liquid-liquid mixing system, solid-liquid mixing system, and gas-liquid-solid mixing system. In order to evaluate the mixing state in such systems, both the dispersed phase and continuous phase should be considered. 

Low feed rates are suitable for trickle bed reactors where for gas-liquid-solid mixing, the gas and the liquid are fed into the top of the reactor. This gives long gas residence times but short liquid residence times. Such a configuration is often used in hydrogenation reactions. When the gas-liquid is fed into the bottom of the reactor, it is known as a bubble reactor. Here the gas residence times are short but the liquid residence times are relatively long. This is commonly used in oxidation reactions. Heat transfer can be a major problem with both trickle and bubble reactors and in such cases a slurry bubble column reactor can be employed. 

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