Capacitance CT Measurement of Natural Formation of Plug in a Horizontal Pipe

Abstract

Particle concentration distribution images of a dense solid-air two-phase flow have been obtained at 10 milli-second in a horizontal pipeline by means of a capacitance computed tomography. The volume fractions based on the CT measurements were measured as parameters of air flow velocity and particle height of an initial accumulation layer. As a result, a plug is naturally formed at a specific velocity and height condition. Moreover, the factor of the plug natural formation is theoretically discussed with a two-flow model. The parameters, which are the initial height accumulation layer and the air flow velocity, do not make a big difference of the solid-phase volume fraction in the dispersion layer; however, make a difference of the accumulation layer height. Therefore, it seems that accumulation layer height contributes to the plug nature formation rather than a solid-phase volume fraction in a dispersion layer.