Experimental Characterisation

The experimental characterisation of micro structuctured mixers made by the IMVT and the mixing processes is done in group LIQ. Mainly the Iodide-Iodate-Method, also known as Villermaux or Villermaux-Dushmann-Method is applied. This Method has originally been designed for the Characterization of stirred tanks [Fournier1996a,b] and has been transferred to static mixers [Panic2004]. It is now the most widely used method using chemical reactions for both cases. The principle is to characterize two competing chemical reactions of different velocity. In this case the Triiodide concentration is used to characterize mixing. High concentrations signify less effective mixing. Using the method parameter studies have been performed [Kölbl 2008a, 2010]. Furthermore the method can be used to discriminate mixing models [Fournier1996a,b]. To do this quantitatively exact kinetic data are necessary [Bourne2008], which are difficult to obtain [Kölbl2008b].

The main types investigated so far are the V-type mixer [Kölbl2008a] and the micro structured cyclone mixer Kölbl2010].

The V-type mixer was investigated especially in reference to scalability in respect to throughput, pressure drop and viscosity. The scalability in respect to these parameters has been experimentally proven for lab scale (in the range of several liters per hour). It is expected to be true far beyond the investigated range, due to the scaling method (internal numbering-up). Analogous investigations on the cyclone-type mixer are in progress. The first results in comparison with fluiddynamic calculations showed encouraging results.