Caterpillar mini mixer

Reactor 21 [R 21] Caterpillar Mini Mixer-Tube Reactor... 

Figure 4.22 Second-generation caterpillar mini mixer with splitting plate and improved microstructure geometry [50].

Figure 4.23 Near-ideal multi-lamination flow patterns in the second-generation caterpillar mini mixer as a result of introducing a splitting plate and improving micro structure geometry [50],...

This plate cuts the flow into pieces which are better defined than the poorly defined ones obtained by the first-generation caterpillar mini mixer. In addition, the micro structure geometry was improved by means of simulation. As a result, near-ideal multi-lamination flow patterns were yielded (Figure 4.23), which showed excellent correspondence with simulation [50]. 

Reactor type Caterpillar mini mixer-tube reactor, 1st generation Micro structure in one plate initial depth maximum depth 600 pm 850 pm... 

Mini mixer channel inihal width maximum width 1200 pm 2400 pm Total length of caterpillar mini mixer 19.2 mm... 

P 29] A set-up comprising a steel caterpillar mini mixer and four steel tubes attached was used, being dipped into a cylinder completely filled with a cooling medium (scale-up set-up) [48,108]. By means of a 5/2-way valve, it was possible to switch the reactants to either of the tubes acting as delay loops, differing in inner diameter and hence residence time. 

OS 40] [R 21] [P 29] Using a caterpillar mini mixer inserted in the scale-up setup, a maximum yield of 89% was determined [48]. This is even slightly higher than for the laboratory-scale setup (83%, see above). 

GL 22] [R 3] [R 9] [R 10] [P 23] The mass transfer efficiency of different gas/liquid contactors as a function of residence time was compared qualitatively (Figure 5.29), including an interdigital micro mixer, a caterpillar mini mixer, a mixing tee and three micro bubble columns using micro channels of varying diameter [5]. 

All other devices showed only the increasing part of such a dependence, i.e. the highest performance measured was obtained at the longest residence time [5], The best conversions with the interdigital micro and caterpillar mini mixers (-78 and -70%, respectively) still exceed considerably the performance of a conventional mixing tee (1 mm inner diameter). 

Figure 4.61 Yield of product and side/consecutive products as a function of temperature for the scale-up set-up with a caterpillar steel mini mixer [48],...

A caterpillar steel mini mixer can be connected to conventional tubing, either stainless steel or polymeric, to prolong the residence time. The caterpillar mixer as all types of split-recombine mixers, profits from high volume flows (e.g. 100 1 h and more at moderate pressure drops) at favorable pressure drop (not exceeding 5 bar) as its internal microstructures can be held large [25-28]. 

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