Mixing channel

In addihon to the CFD results, estimates of the mixing length based on the Fourier number  

This observation is supported by experiments carried out with a phosphate buffer and a fluorescein solution for visualization of the mixing process. However, in the experiments there are indications that the critical Reynolds number where the mass transfer enhancement sets in is lower (-7) than predicted by the simulations, a fact which is not well understood. 

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Figure 2.44 Section of a mixing channel with a map P connecting the points of two cross-sectional planes.

Mixing channel width depth 148-469 pm 200 pm Reaction plate thickness 300 pm... 

Reactor type Chip system with triangular interdigital micro mixer-reaction channel Mixing channel width 50 pm... 

Number of parallel mixing channels to which the inlet flow is distributed 9 Tube diameter Not reported... 

Number of mixing stages within one mixing channel 6 3 in top plate, 3 in bottom plate Tube length Not reported... 

WUes and Watts [48,53] have reported the use of a rather successful heterogenic catalytic system to carry out these reactions. They have tested a borosilicate glass microreactor (dimensions 3.0 x 3.0 x 0.6 cm) consisting of two etched layers with two inlets, mixing channels, a larger etched region and the outlet. A solid-supported catalyst was dry-packed in this structure (Fig. 4). 

Mixing channel width, depth, length 250 pm, 250 pm, 30 mm Electrode material Titanium... 

The microstructure consists of a cross-shaped feed structure with one longer mixing channel, connecting to the waste [92], Two of the other three channels serve for feed of the two solutions to be mixed, the third connects to waste. The long channel is placed over nine buried electrodes, having a rectangular shape. 

Mixer material Glass Mixing channel width, length 150 pm, 34 mm... 

Distance electrodes-mixing channel 130 pm Top channel length of the cross 4.4 mm... 

A design of a T-type micro mixer was proposed with the same cross-sections in the feed branches and the mixing channel attached [57]. The T-shape was exactly matched, i.e. the branches are at a 90° angle to the mixing channel. 

Mixer material Artificial design Angle between branch and mixing channel 90°... 

Mixer type Y-type micro mixer Mixing channel 500 pm, 300 pm,... 

A design of a Y-type micro mixer with a Venturi-type throttle (a tiny orifice which opens like a diffuser to the mixing channel) at the connection of feed branches and... 

As base case, the following scenario was considered [57]. The velocities of both fluids were set to 0.3 m s-1, corresponding to a Peclet number of 8.08 in the mixing channel (see Figure 1.51). The mixing length of the base case amounts to 2.83 mm and the pressure drop is 14.6 Pa. 

P 24] Computer simulations were carried out using the software Fluent 6 [68], A 3-D solid model of the T-channel micro mixer was built and named in Gambit The simulations were made solely for the zone of the T-junction, since for all other zones, including the downstream section of the mixing channel, laminar flow was assumed. Thus, a fine mesh of 173 000 brick elements could be used for the solid model. 

Figure 1.52 Mixing length as a function of the aspect ratio for a T-type micro mixer with a mixing channel width of 500 pm [57] (by courtesy of IOP Publishing Ltd.).

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