A MODEL FOR THE REMOVAL OF WATER DROPLET AEROSOLS FROM A FLASHING JET IMPINGING ONTO A PLATE

In this paper, we present an approach to modelling the removal of water aerosol droplets from a flashing jet that is impinging onto a flat surface. The entire process, from the break to the impingement surface, is dealt with in several sequential regions: flashing, jet expansion, jet deflection and jet impingement. In the flashing region, the single-phase liquid jet is discharged from the break and rapidly expands to form a water-steam two-phase jet. After the flashing region, the jet expands much more slowly and linearly, mainly because of the entrainment of the surrounding atmosphere. In the jet deflection and impingement region, classical impaction theory is used to calculate the cut-off diameter of aerosols after they impinge onto structural surfaces. The model underpredicts the removal fraction when compared with limited experimental data. Possible reasons for the discrepancy are given, which point out what the direction of future work should be.