BigPatents India

System for restraining the upward motion of granular material in a vessel containing a bed of the granular material through which a fluid flows in an upward direction. The system comprises flexible porous basket within the vessel in contact with the top of the bed of granular material and in contact with the inner walls of the vessel above the bed of granular material, wherein the porous basket has openings which are smaller than the smallest particles of the granular material such that granular material does not pass through the openings. The system also includes a layer of solid bodies located within the flexible porous basket wherein the solid bodies press the flexible porous basket against the top of the bed of granular material and against the inner walls of the cylindrical vessel above the bed of granular material, wherein the solid bodies in the layer of solid bodies have an average diameter greater than the average particle diameter of the granular material and the material forming the solid bodies has a density greater than the bulk density of the granular material.