Contact

Dr. Markus Schubert

m.schubertAthzdr.de
Phone: +49 351 260 2627

Prof. Dr.-Ing. Dr. h. c. Uwe Hampel

Head
Experimental Thermal Fluid Dynamics
u.hampel@hzdr.de
Phone: +49 351 260 2772

Monolithic reactors

Two-phase flow in narrow channels with hydraulic diameters of a few millimeters are relevant for micro reactors and structured reactors, compact heat exchangers, micro condensation units or fuel cells due to the low heat and mass transfer resistance between the fluidic layers.

The Taylor flow is a beneficial flow regime due its intensive gas-liquid contact at the interface of the film surrounding the Taylor bubbles and due to the enhanced mixing in the liquid slugs downstream the Taylor bubbles.

Knowledge of the flow topology and precise measurement of liquid film thickness and Taylor bubble shape at microscopic length scales are of primary importance for the development and validation of interface resolving computational flow simulation tools.

These allow developing transport models and proposing process intensification concepts. Further objectives cover the scale-up and design of large-scale applications and related technological aspects such as to ensure homogeneous phase distribution in multi-channel configurations in order to obtain a better overall process understanding.

Current research activities comprise:

Foto: Benchmark Taylorblase in Minikanälen - Referenzbild ©Copyright: Dr. Markus Schubert

Taylor bubbles in small hydraulic channels

Liquid flow with Taylor bubbles are characterized by an intensified gas-liquid contact in the liquid film surrounding the Taylor bubbles and by an enhanced mixing in the liquid slugs downstream the Taylor bubbles. To disclose the three-dimensional shape of Taylor bubbles in small channels, enhanced X-ray radioscopic and X-ray ­tomo­graphic measurement techniques were developed and qualified. These techniques provide benchmark validation data numerical flow models.
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Foto: Zweiphasenströmung in keramischen Monolithen - Referenzbild ©Copyright: Dr. Markus Schubert

Two-phase flow in ceramic monoliths

An intensification of heterogeneous catalytic reaction processes can be achieved by monolithic structures operated in the Taylor flow regime. To benefit from the excellent gas-liquid mass transfer behavior and tunable residence time of the Taylor flow regime in monolithic structures, homogeneous and well defined gas-liquid distribution patterns are required. A new methodology to evaluate the impact of flow maldistribution from the targeted process configuration using the ultrafast electron beam X-ray modality and a pseudo 2D reactor model is proposed.
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