Abstract: Fluid fractionating membrane apparatus is described in which a jacket is provided with a fluid inlet and a fluid outlet for introducing and extracting a first fluid to and from the jacket, at least one core extending within said jacket. A number of continuous porous tubular membrane support elements, having at least one longitudinal channel connected to the exterior of the jacket, are wound uniformly either spirally or helically around the core and they are each provided with a membrane which covers the exterior surface thereof.

Abstract: A flexible semi-permeable tubular assembly is provided which consists essentially of a cord comprising a textile sheath which carries a semi-permeable membrane, said sheath being composed of yarns, the external surface of the sheath being compressed and flattened, the internal surface of the sheath defining an axial channel which communicates with the exterior. This assembly is particularly suitable for the concentration, separation and purification of fluids by reverse osmosis, ultra-filtration and gas permeation. The assembly combines good tensile strength with good porosity.

Abstract: Fluid fractionating apparatus comprising a jacket, two side plates forming with said jacket a closed chamber, at least one aperture formed in each side plate, a cap located at least partly in each aperture, each cap having a cavity communicating with the interior of the chamber and an orifice communicating via its aperture with the exterior of the chamber, a plurality of cylindrical elements extending substantially axially in said chamber and each comprising a textile sheath forming at least one channel, and a membrane covering the textile sheath and being joined thereto at each of its ends in a leakproof manner, the cylindrical elements having an external diameter of between 1 and 10 mm, the two ends of the cylindrical elements each being located in a fluidtight manner in the cavity of one of said caps, and means for feeding a fluid to and from the chamber. The cylindrical elements are grouped in bundles, the ends of the elements of a bundle being located in the cavity of a single cap.

Abstract: A selectively-permeable tubular element is provided which comprises an essentially tubular sheath of uniform textile material, the whole of which has been heated to a uniform temperature such that the sheath can subsequently be bent in an arc of radius of curvature not exceeding about 10 cm while retaining substantially circular cross-section, with a selectively permeable membrane applied to the sheath.