Multi-probe system for measuring bubble characteristics gas hold-up,

Abstract

Method and apparatus are disclosed for determining one or more physical characteristics of individual bubbles in a gas-liquid system and a gas-liquid-solid system at high temperatures and pressures. An in situ probe device is inserted into the system over which individual bubbles flow. The probe device has a plurality of independent probes. Each has a rounded fibre optic end portion projecting into the system. A source of incident light is directed onto each of the probes. The rounded end portion of each probe is formed with a radius of curvature sufficiently large whereby the angle of incidence of the source light at the rounded portion is greater than the angle of total reflection for the fibre optic when in contact with the gas. The angle of incidence is less than the angle of total reflection for the fibre optic when in contact with the liquid. The plurality of probes are spatially arranged to detect one or more of the bubble physical characteristics as a bubble flows over the probe device. The change in light intensity of reflected light emerging from the probe is measured. The change in light intensities of each of the probes over time is evaluated to determine the one or more bubble characteristics. Each probe is formed of sufficiently thin fibre optic and spaced from the other probes of the device to enable detection of the bubble characteristics for individual bubbles flowing over the probe device. This probe system enables the monitoring of physical characteristics of bubbles in two and three phase systems in an efficient, reliable, economical manner. The system also provides for a measure of solid, gas and liquid hold-ups in a three-phase system.