SUPPORT STRUCTURES FOR A CATALYST

摘要

An improved catalytic reactor for high temperature reactions having a reaction chamber and an monolithic catalyst structure disposed in the reaction chamber is disclosed wherein the catalyst structure has a multiplicity of longitudinally disposed channels formed by thin metal substrate walls which expand on exposure to the heat generated in high temperature reactions and reactor also includes a monolithic open cellular support structure disposed in the reaction chamber having a multiplicity of longitudinally disposed passageways formed by strips of high temperature resistant metal or ceramic material with the support structure being secured on its outer periphery to the wall of the reaction chamber to limit movement along the longitudinal axis, and being positioned at and abutting against the outlet end of the catalyst structure. In this improved structure, an annular space is formed between the outer periphery of the catalyst structure and the wall of the reaction chamber which is sized to accommodate the thermal expansion of the catalyst structure which occurs during the high temperature reaction without allowing the catalyst structure to be deformed by pressing against the reaction chamber wall. The improved reactor further includes a plurality of flexible flanges which extend from the outer peripheral surface of the catalyst structure to the inner surface of reaction chamber tubular wall to susbstantially block the flow of reaction gas mixture through the annular space. The flanges are sufficiently flexible to allow bending as the catalyst structure undergoes thermal expansion, and to prevent localized deformation of the catalyst structure where the flanges contact the catalyst structure. A radial centering assembly is disclosed for the improved reactor which includes cooperating struts and splines mounted on the chamber wall and the support structure to permit thermal expansion of the support structure. Also disclosed is an optional centering support structure for transferring a portion of the force from the flow of gases onto a second support structure positioned on the inlet side of the catalyst structure. Further disclosed is an outer metal band for the support structure has slots formed therein to provide sufficient flexibility for thermal expansion of the support structure while providing additional support therefor.