In a process for the catalytic treatment of hydrocarbon charges in the presence of hydrogen in a vertical reactor where the catalyst is introduced at the top and withdrawn at the bottom, countercurrently with the charge which is introduced at the bottom and discharged from the top. There is provided a flared funnel for the catalyst discharge having small perforations for the upward flow of the charge with the perforations of a size sufficiently small to prevent passage of the catalyst therethrough. These perforations are in association with injection tubes having orifices opening in the vicinity of the funnel wall, wherethrough at least a portion of the fluid charge is injected.