Abstract: In a radial flow catalytic reactor, a gravity supported centerpipe is restrained from vertical upward movement due to thermal cycling of the catalyst and the reactor internals and/or the reactor and/or changes in process fluid flow conditions by forming the centerpipe with a taper, either continuous or stepped to have a generally frustoconical configuration. Gravity effect of the catalyst particles forming the bed act along the tapered sides of the centerpipe. Additionally improved radial flow through the uniformly packed catalyst bed, is achieved by the tapered conical shape of the centerpipe by gradually increasing the volume of the centerpipe along the length of the catalyst bed to accommodate ever increasing fluid flow from top to bottom through the radial bed.

Abstract: In an apparatus for contacting fluid with subdivided contact material, such as a radial-flow catalytic reactor, means having a substantially horizontal surface is attached to a lower portion of a vertically movable member within the reactor, the member being selected from center pipes and particle-retaining screens. The weight of contact material on the means restrains upward movement of the member during temperature cycling, and thus prevents problems caused by the upward movement.