The excellent separation performance of columns with structured packings strongly depends on the distributor＇s quality and this may be utilized only if it is possible to generate a constant drop size and a uniform drop distribution over the cross-section for all loadings. The size of the drops, which are formed at single distributor orifices, may be controlled by an external flow, thus studies of drop formation with a single two-phase nozzle were made. Paper A presents the results of experiments with the liquid system toluene (dispersed)/water and two-phase nozzle.