Micromixing performances, comparison

Table 7.4 Comparison of mixing performance of three interdigital micromixers (8 L/h)...

There are numerous experimental studies on micromixer characterization and, among the different methods, the well-known Villermaux-Dushman reaction is one of the most used. A few papers have proposed the comparison of the mixers performances thanks to these chemical reactions. As explained previously, mixing quality is a relative concept with regard to chemical reaction and chemical test methods... 

Many authors have adapted their own concentration protocol of the Villermaux-Dushman method so that it is almost impossible to compare the performances of the studied micromixers simply by the confrontation of the segregation indices. The best way to propose a comparative study is to consider mixing times which are independent of the chemical conditions. Below we present a detailed comparison of the mixing times in different mixers. The theoretical developments presented previously are used to propose an interpretation of experimental data versus the Reynolds number and the power dissipation. From the confrontation with theoretical values, the energetic mixing efficiency in micromixers can be estimated. 

Comparison of Micromixers with Regard to Performance in Liquid-Liquid Dispersions... 

As stated above, the focus of recent investigations of microreactor applications in the field of emulsification was on the use of micromixers, and different types of micromixers have been employed. However, it is difficult to compare them with regard to liquid-liquid dispersion performance since the mixers are most often investigated for different specific applications. However, a suitable comparison is the basis for future targeted equipment selection. Furthermore, micrombcers are in competition with conventional and other innovative equipment such as static mixers, membranes and homogenizers. Therefore, benchmarking with such equipment is also required. 

In this context, the work of Lob et al. [3] is considered below since it describes a first comparison of different micromixers based on a common model system. The micromixers investigated cover three different functional principles and also different characteristic internal dimensions. Albeit the work is not final and cannot be regarded as comprehensive, it points out some of the major issues to be considered when comparing micromixers with regard to liquid-liquid dispersion performance. 

Figure22.1 Comparison ofdifFerent micromixer with a volumetric flow ratio of 1 5 (1 10 in the performances with regard to liquid-liquid case of the StarLamlS). The mean droplet...

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