Wet resuspension of insoluble material from a boiling sump

Experiments have been conducted using the technical scale THAI test facility to investigate the wet resuspension of aerosols from a boiling sump. One test with a water solution of potassium iodide and cesium chloride salts and two tests with different suspensions of calcium carbonate in water (primary mass-median-diameters of 0.065 μm and 0.9 μm) have been performed. Resuspension was derived by injecting steam at the bottom of the sump. The investigated superficial velocities, ranging from 0.025 m/s to 0.13 m/s, extend previous resuspension of soluble material experiments in the THAI facility to turbulent flow regime. The aerosol released from the boiling sump into the gas space has been measured independently by using an SMPS particle counter and gas scrubbers. The droplet entrainment has been quantified, based on the concentrations of salts resuspended into the gas atmospheric flow. The entrainment derived from the gas scrubber measurements is well in accordance to previous experimental findings obtained in the THAI facility and other test facilities. A significant enrichment of insoluble aerosol concentration inside the droplets has been found. The SMPS results revealed that very small aerosols are dominantly released from a boiling sump which might remain airborne for long times. (author)