Flow Patterns and Pressure Drop of Ionic Liquid-Water Two-Phase Flows

2 Flow Patterns and Pressure Drop of Ionic Liquid-Water Two-Phase Flows 

An ionic liquid, [C4mim][NTf2], and de-ionised water were used as test fluids, with their properties summarised in Table 4.1. The experimental setup (Fig. 3.2) and details about the system were discussed in Sect. 3.4. Both inlets (T- and Y-junction) were used and the test sections were made of two types of Teflon, FEP and Tefzel, with internal diameter (ID) of 220 and 270 pm respectively, and of borosilicate glass with an internal diameter of 200 pm. Flow patterns and pressure drop measurements were carried out for different flow rates that varied from 0.07 to 11. 5 cm h for the ionic liquid and of from 0.017 to 215 cm h for water. The ionic liquid volume fraction (eil) varied from 0.05 to 0.8. In all cases, the flow rate of 

4 Liquid-Liquid LLows in Micro and Small Channels 

In the case of the Teflon microchaimels, the flow patterns were independent of the first injected fluid. Nevertheless, for consistency, the same procedure as with the glass microchannel was followed. Water, however, could not remain as the continuous phase, because (as it can be seen from Table 4.2) the ionic liquid seems to wet more the Teflon microchannels (contact angles less than 90°), and becomes the continuous phase. Flow pattern and pressure drop measurements were recorded for both Teflon microchannels when steady state was reached. 

When a set of experiments was completed, the microchannel was cleaned by injecting dichloromethane (CH2CI2) to remove any residual ionic liquid. Air was then injected to dry the channel. This procedure was performed to ensure repro-ducibihty of the experimental conditions. 

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TSAOULIDIS, D., DORE, V., ANGELI, P., PLECHKOVA, N. V. SEDDON, K. R. 2013c. Flow patterns and pressure drop of ionic liquid-water two-phase flows in microchannels. International Journal of Multiphase Flow, 54, 1-10. 

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