Gas dispersion characteristics, i.e. ungassed and gassed power consumption, flow patterns and gas hold-up of the dual hollow blade disk turbines (6HB), which had been recently developed by a manufacturer to obtain a better gas dispersion performance than the traditional 6-bladed Rushton disc turbine (6DT), were investigated experimentally. The effect of impeller spacing in the dual 6HB impeller system on the unaerated and aerated power consumption was examined thoroughly.The gassed power consumption and gas hold up for the dual 6HB were compared with those obtained for the dual 6DT (radial flow impellers) and the dual Lightnin A315 (axial flow characteristics), of which performance has been also advanced recently. An enhancement of the gas handling capacity of the 6HB was achieved.