The invention is a fluid distribution device for coupling with a fluid distribution conduit or chimney for improving the distribution of downwardly flowing poly-phase mixture including at least one gas phase and at least one liquid phase, above at least one catalyst bed of granular solid catalytic material. The fluid distribution device for receiving the liquid and gas phases has one or more openings in the top and/or upper portion of its height through which a gas phase can enter and has a gas conduit that opens to a mixing cavity within the device. The fluid distribution device further comprises one or more lateral openings for liquid ingress. The lateral opening or openings allow the liquid to enter a liquid conduit that opens to the internal mixing cavity. The mixing cavity allows intimate contact between the liquid and gas phases. Therefore the flow distribution device of the invention provides improved tolerance for tray out of levelness.