Fluidizing-bed plate

Claim 1

FOR USE IN FLUIDIZING BEDS, A COMPOSITE PLATE STRUCTURE HAVING AN UPPER SURFACE ON WHICH PARTICULATE MATERIAL TO BE FLUIDIZED IS ADAPTED TO BE LOCATED, AND A LOWER SURFACE EXPOSED TO THE FLUIDIZING MEDIUM, SAID COMPOSITE PLATE STRUCTURE INCLUDING AT LEAST A LOWER, A MIDDLE AND AN UPPER PLATE SUPERIMPOSED UPON EACH OTHER, SAID LOWER OF SAID PLATES HAVING A PLURALITY OF SPACED APERTURES THERETHROUGH; SAID MIDDLE ONE OF SAID PLATES BEING SUPERIMPOSED UPON SAID LOWER PLATE AND HAVING A PLURALITY OF APERTURES OVERLAPPING AT LEAST PARTLY SAID APERTURES IN SAID LOWER ONE OF SAID PLATES AND HAVING A CROSS-SECTIONAL AREA GREATER THAN THE AREA OF THE RESPECTIVE EXPOSED PORTION OF THE CORRESPONDING APERTURE IN SAID LOWER SHEET; AND AN UPPER PLATE SUPERIMPOSED UPON SAID MIDDLE PLATE AND HAVING A PLURALITY OF APERTURES CORRESPONDING TO SAID APERTURES IN SAID MIDDLE PLATE AND EACH OF SAID APERTURES OF SAID UPPER PLATE BEING ALIGNED WITH A PORTION OF AN APERTURE IN SAID MIDDLE PLATE, WHICH PORTION IS NOT IN ALIGNMENT WITH SAID EXPOSED PORTION OF THE CORRESPONDING APERTURE IN SAID LOWER PLATE, WHEREBY SAID APERTURES FORM FOR THE FLUIDIZING MEDIUM COMPOSITE CIRCUITOUS PASSAGES WHICH EXTEND IN A DIRECTION OTHER THAN NORMAL TO THE GENERAL PLANE OF SAID COMPOSITE PLATE STRUCTURE.