The effects of inclination on the hydrodynamic behavior of a packed bed operating under gas-liquid cocurrent upflow were experimentally investigated in terms of liquid saturation, bed overall pressure drop and gas-liquid segregation. The non-invasive electrical capacitance tomography (ECT) imaging technique was applied to scrutinize local and axial phase distribution pattern and cross-sectionally averaged liquid saturation. The results indicate that bed inclination creates short circuits for the gas phase along the upper wall where it can flow in a segregated manner. Inception of transition from bubble to segregated flow regime was identified through monitoring a defined uniformity factor for ECT images. Phase segregation developed along the bed with minimum impact in the region close to the entrance. The removed bubbles were replaced by liquid phase resulting in higher liquid saturation values as complete segregation state was approached. The effect of operating conditions on axial profile of liquid saturation was examined. (C) 2013 Elsevier Ltd. All rights reserved