Abstract: A device for loading catalyst particles into a reaction zone which distributes said particles, at substantially the same rate, uniformly across the catalyst bed area of said zone. The catalyst particle loading device is employed in combination with a catalytic reaction zone. The catalyst particle loading device comprises a hopper having a conical bottom portion provided with an opening at its lower end. The opening is in communication with a catalytic reaction zone. A vertically movable hollow sleeve is coaxially disposed within the hopper. The sleeve has a lower conical end portion which forms with the conical bottom portion of the hopper a throttle valve for the opening. A rotary shaft is coaxially disposed within the sleeve and extends through the opening at the lower end of the hopper and into the upper portion of the reaction zone. A particle-dispersion wheel is attached to the lower end of the shaft below the opening.