Installation of perforated sieve plates into a bubble column has the effect of introducing structure into an otherwise chaotic hydrodynamic behaviour. In this study, we focus on the reduction of backmixing of the liquid phase in compartmentalised bubble columns. Liquid-phase residence time distribution (RTD) measurements were carried out in bubble columns with diameters D-T = 0.10, 0.15 and 0.38 m with air-water system operating at superficial gas velocities of U-G = 0.05-0.4 m/s. Partition sieve plates with open areas of 18.6 and 30.7% were used in the studies. The measured data on RTD were interpreted in terms of an axial dispersion model extended to allow for liquid interchange between compartments. The interchange velocity was found to be strongly dependent on the free area of the plates but practically independent of the column diameter.