Experimental Capacitance Planar Array Sensor

for Investigating Bed Fluidization and Oil­Water Separation

Bartosz Matusiak1, Marco Jose da Silva2, Sebastian Thiele2, Uwe Hampel2

1Computer Engineering Department, Technical University of Lodz, Stefanowskiego 18/22, 90 924 Lodz, Poland, bmatus@kis.p.lodz.pl

2Institute of Safety Research, Research Center Forschungszentrum Dresden­Rossendorf e.V., POB 51 01 19, 01314 Dresden, Germany

ABSTRACT

In this paper we report on a prospective study concerning the use of a capacitive planar array sensor for the visualization of phase distributions in two common processes in the chemical processing industry, namely bed fluidization and oil­water separation. In the first part of this study we developed a 706 mm long and 86 mm wide capacitance surface sensor consisting of 16 x 64 electrodes, presenting 1024 measurement points. The developed sensor was placed inside an experimental fluidized bed column and applied to monitor flow regimes. The surface array sensor was connected to a newly developed capacitance measuring electronics. We also performed a numerical analysis of the sensor’s sensitivity, which shows the feasibility to observe changes of a relative electric permittivity in the distance up to 3 mm from the sensor surface. In a second part of this study, we used a 32 x 32 planar array sensor connected to the same capacitive electronics to evaluate its applicability to water­ oil separation measurements. Although the relation between relative electric permittivity of these substances is rather large, it was possible to monitor the evolution of their separation and to detect the presence of emulsion.

Keywords capacitance planar array sensor; fluidized bed; oil­water separation, flow visualization