A commonly used method to remove the sulphur dioxide (SO2) originating from the combustion of sulphur is the wet absorption process with limestone slurry in a spray scrubber. In order to understand the manifold of mechanisms which happen during this flue gas cleaning, these facilities are analysed with computational fluid dynamics. Together with Austrian Energy & Environment AG & Co KG there has been a research cooperation with the Institute for Process Technology and Industrial Environmental Protection in this field of operations since the mid nineties. In this presented work the development status of those simulations is summed up and highlighted with several applications and studies. Besides a presentation of the models being used, which enhance the commercial simulation tools, also the new ionic species look-up table for the computation of the chemisorption is introduced. As a result - besides realistic development of the pH value in single droplet experiments and simulations of industrial scale scrubbers - also a comparison of measured and simulated SO2 concentration profiles for different sized spray towers can being shown. From these comparisons it can be deducted, that the used methodology is very well suited for the identification of problem areas inside spray scrubbers. Although many effects must be simplified in the simulations, the quantitative results still give a good resemblance of the reality.