Measurements of slug frequency and length in gas-liquid flow in a microreactor channel
Special Symposium - EPIC-1: European Process Intensification Conference - 1
EPIC-1: Poster Session (EPIC - Poster) - P1
Keywords: Microreactor, Interfacial area, Gas absorption
According to earlier experiments carried out to determine the character of the gas/liquid flow in microchannels (“regime maps”) [1], the most common regime is the slug regime. In this regime slugs of one phase flow through the microchannel alternately with slugs of the other phase (gas bubbles and liquid slugs in the case of a gas-liquid system). In the case of a liquid wetting the microreactor wall material, the microreactor wall is covered by a thin liquid layer, and the gas bubbles are sliding over this “lubricating” layer [2]. The “lateral” part of the interfacial area may be many times greater than the “perpendicular” part. To be able to apply the criterion for the activity for mass transfer of the lateral part of the interfacial area [1], one has to know the frequency and bubble length involved.
The slug frequency and length in gas-liquid flow in a microreactor channel have been measured, using three different liquids and two microreactors using nitrogen as an inert gas. The microreactors were Y shaped, with the following main channel dimensions:
Microreactor 1:
material PETg (polyethylene terephthalate midified by glycol)
width - 0.2 mm
height - 0.55 mm
length - 55 mm
Microreactor 2:
material PDMS (polydimethyloxosilane)
width - 0.15 mm
height - 0.15 mm
length - 25 mm
The slug and bubble lengths and frequencies were measured using high speed camera CCD (PCI 8000S). The results of the measurements have been compared with numerical simulations, and correlated with the flow parameters.
This work has been supported by 6th Framework EU under Grant IMPULSE No: NMP2-CT-2005-011816
[1] R. Pohorecki, P. Sobieszuk, K. Kula, W. Moniuk, M. Zieliński, 17th International Congress of Chemical and Process Engineering, 27-31.08.2006, Prague, Czech Republic, CHISA 2006, CD, org no.: J2.1.
[2] S. Waelchli, P. von Rohr, International Journal of Multiphase Flow, 32 (2006), 791-806.
Presented Wednesday 19, 13:30 to 14:40, in session EPIC-1 Poster Session (EPIC - Poster) - P1.
