Untersuchungen zur Staubabscheidung in Nassabscheidern durch Wasserdampfkondensation

The off-gas from the incineration of waste and fossil fuels contains numerous gaseous and solid pollutants which must be removed as far as possible from this off-gas by off-gas cleaning. This investigation involved experiments in which very fine dust particles (aerosols) in the particle size range from 0.05 to 6 $\mu$m were separated from the gas in a spray washer. The objective was to examine the extent to which dust separation can be improved or simplified by combining it iwith the condensation of the water vapour present in the exhaust gas. A laboratory facility was constructed for these investigations providing the possibility of comparing various process technologies during condensation in front of and in a wet scrubber while varying the gas parameters of dust content, particle size distribution and water vapour content. The results of the measurements show that not the water content or the condensed water quantity alone is of significance for improving the dust separation by condensation of water vapour. On the contrary, the essential prerequisite is a proper procedure for initiating condensation and the creation of thermodynamic conditions under which a condensation on the aerosols is possible. If these conditions, realizable with existing scrubbers, are achieved then condensation leads to improved dust separation over the entire particle size range. In the experiments improvements of up to 95 % or more of the total degree of separation were achieved by condensation in comparison to separation without condensation