Local flow direction measurements using tri-segmented microelectrode in packed beds.

An electrodiffusion measurement system has been developed and used in a packed bed with single phase liquid flow. It is based on a tri-segmented microelectrode flush mounted at the surface of an Altuglass sphere equator area. Four of such probes are placed in lozenge form in the packed bed thus constituting a pore where the measurements were carried out. Each probe is equipped with a rotating system which allows the probe to turn around its vertical axis and consequently allows the microelectrode to cover all azimuthal positions. The tri-segmented microelecrodes are first calibrated in a separate experimental setup where the hydrodynamics is controlled and then placed in the packed bed. The results presented concern mainly the velocity gradient and local flow direction measurements. [ABSTRACT FROM AUTHOR]