Abstract: A vertical processing vessel includes an upper feed zone, an intermediate treatment zone and a lower removal zone, with the treatment zone including an improved system for distributing treating fluids uniformly across the cross-section of the vessel. The system provides for mutually perpendicular fluid distributing tubes which, in the preferred embodiment, has one set of tubes that extend completely across the vessel and a second set of perpendicular tubes that merely penetrate the wall of the vessel to deliver treating fluids along the perimeter of the vessel. The degree to which the delivery tubes in the second set penetrate the vessel is determined by the size of the vessel so that optimal conditions are attained for the delivery of the treating fluids.