Abstract
Void fraction is very important parameter for gas-liquid two-phase flow for performance evaluation of industrial equipments quantitatively. Therefore it is required to measure void fraction with high time and spatial resolution in real-time. Impedance method which utilizes difference of electric conductivities or electric permittivities between liquid and gas can realize real-time measurements of void fraction. However, the effect of bubble diameter on impedance methods is not evaluated yet, the electric measurements for bubbly flow with tiny bubbles which is applied in various industrial fields are not established. In order to establish real-time measurement of void fraction in bubbly flow with tiny bubbles (microbubbles), the void fraction measurement of this flow with ring electrodes by Constant Electric Current Method is conducted in this study. Microbubbles were generated with a Venturi tube. The void fraction was estimated by Maxwell's theory from measured voltage. And the estimated void fraction is compared to the result measured with quick valve method.
