Spray-Aufprallvorgänge auf Wandflächen

Spray absorbers are widely used to remove SO2 from flue gases of large coal-fired power plants or garbage incinerators. In such scrubbers the SO2 is absorbed by a suspension of water and lime, which is dispersed by nozzles to obtain a large interfacial area. One scope of the research project is to simulate gas phase flow fields and local liquid phase hold-up in flue gas scrubbers by two-phase flow calculation using CFD methods. A more detailed presentation of this research work is given in „Numerical simulation of two-phase flows in spray scrubbers" in this data-base. Since 30 to 50% of the dispersed slurry are deposited at the walls of the scrubber, a mathematical model that describes the formation of the wall film and the characteristics of the secondary spray generated by spray-wall interaction, is a necessary precondition for the CFD simulations. According to this two scopes of the investigations, two experimental series have been established: 1.) determination of the amount of water deposited at the wall as a function of nozzle pressure, impingement angle, surface structure and wall film, 2.) measurement of the size and the velocity distribution of the secondary spray The characteristics of the secondary spray were determined by means of a DANTECH 2D-LDA, 1-D PDPA system and a COHERENT 10 W argon laser.