Abstract: Moving catalyst bed reactor comprising a normally vertically extending cylindrical vessel having separate inlets for reactant and catalyst at the upper part of the vessel, an intermediate catalyst bed supporting means and a bottom catalyst bed supporting means inside the vessel and separate outlets for reactor effluent and catalyst. At least the intermediate catalyst bed supporting means consists of a plurality of interconnected downwardly converging frustoconical surfaces having their lower ends connected to spaced apart vertical outlet channels having circumferential walls provided with substantially circumferential screen sections for withdrawing reactor effluent from catalyst, the vertical outlet channels 12 having their axes arranged substantially uniformly distributed in a circular pattern.