The use of downcomer (DC) in a turbulent bed contactor (TBC) is novel and instrumental in enhancing its gas-treating capacity and extending its range of operation when compared to the conventional TBC operation (without DC). However, the hydrodynamic behaviour for the novel operation of a TBC with DC is very much similar to that of the conventional TBC operation. Experimental data are collected on liquid and gas holdups, bed expansion and pressure drop in TBC with DC over a wide range of variables and correlations are developed for the above hydrodynamic aspects for single-stage operation employing light and dense particles.