An annular gas feed element for use in gasification plants with a dry fuel supply. A gas feed ring element for tensioning and fluidizing gas/solid suspensions, in which gas feed ring element there is a housing ring which has a circumferential recess on its inner side, a support ring with a multiplicity of openings, filter material fitted between the support ring and the internal diameter of the housing ring, where the recess and the filter material delimit a distributor chamber, and a gas feed arranged from outside into the distributor chamber. The flangeless gas feed ring element makes rapid tensioning possible and secondly improves the fluidizing behavior and therefore the flow behavior.

A method and apparatus for separation of radioactive particulates from liquids by filtration to remove or recover the particulates, that reduces the surfaces forces associated with electrostatic attraction between the particles and the filter medium by modifying or coating the surface of the filter medium with a material that exhibits a surface charge closer to or the same as that of the particulates in a given aqueous liquid. The method and apparatus can be used to filter radioactive particulates and contaminants from aqueous liquid or liquid process streams with a radiation resistant filter medium. The filters can exhibit a surface charge different from that of the particulates targeted for separation by mechanical filtration. The filtration medium can be modified to increase its resistance to erosion to permit use of more powerful backwashing regeneration methods and prevent attachment of the particulates to the filtration medium by coating the medium with a hydrophobic layer.