Counter current dual-flow spiral wound dual-pipe membrane separation

A membrane separation device which device comprises:

• (a) a housing adapted to contain a spiral-wound membrane separation module, the housing being essentially sealed to the environment and having an interior surface,
• (b) a spiral-wound membrane module positioned within the housing to define a generally annular clearance space between the exterior surface of the spiral wound module and the interior wall of the housing the spiral-wound membrane module being designed to separate the fluid feed stream into a permeate stream and a concentrate stream,
• (c) means to completely seal the annular clearance space between the exterior surface of the module and the interior surface of the housing creating a first chamber and a second chamber,
• (d) means to introduce a feed stream axially to the spiral-wound membrane module in said first chamber means to withdraw a concentrate stream from said second chamber, and
• (e) means to withdraw a permeate stream,
• wherein said spiral wound membrane module comprises:
• a centrally located feed pipe,
• at least one permselective membrane envelope, having within the fold at least one feed spacer means for controlling the feed flow in the feed passageway,
• a centrally located permeate pipe which is generally parallel to the feed pipe,
• at least one permeate spacer means for controlling the permeate flow in the permeate passageway and optionally for controlling the flow of a countercurrent or cocurrent fluid in the permeate,
• and first and second volume space filling means for obtaining a substantially circular outer surface of the module, wherein
• the generally hollow feed pipe has a wall barrier intermediate in its length dividing the pipe into a first compartment and a second compartment, the feed pipe having means for introducing a fluid feed stream to the first compartment of the pipe and means for removing the more concentrate (feed) effluent fluid from the second compartment of the pipe, the first and second feed pipe compartments each having at least one axial opening through the pipe circumference through which the feed fluid will pass,
• the porous feed spacer means are in fluid communication with the axial openings of the first and second feed pipe compartments,
• the membrane envelope comprises a sheet membrane having a first surface and a second surface which is opposite to the first surface, wherein the membrane is generally folded once around the hollow feed pipe at the fold so that a first half of the first surface of the membrane layer faces the other half of the first surface of the membrane envelope creating a feed passageway and interposed between the first and second surfaces of the membrane is the porous fluid feed spacer means for controlling the flow of fluid in the feed passageway,
• the permeate passageway for the fluid permeate is formed by the adjacent second membrane surfaces which are opposite to the first membrane surface, wherein the permeate passageway has porous permeate spacer means which control the flow of fluid in the permeate passageway and, optionally, the flow of a countercurrent or cocurrent fluid in the permeate passageway between the adjacent second membrane envelope surfaces which are opposite to the first membrane surface,
• the generally hollow permeate pipe is in the permeate passageway adjacent to and generally parallel with the feed pipe, the permeate pipe having a wall barrier intermediate in its length dividing the permeate pipe into a first permeate compartment and a second permeate compartment, the permeate pipe having means for removing the permeate from the first and second permeate compartments, where the first and second permeate pipe compartments each have at least one axial opening through the permeate pipe circumference through which the permeate fluid passes, and the permeate passageway is in fluid communication with the axial fluid openings of the first and second permeate pipe compartments,
• first volume space filling means to obtain a circular shape, adjacent to and in contact with the curved longitudinal outer surface of up to about one wrapping of the porous feed spacer means about the feed pipe and also in contact with the outer surface of about one layer of the porous permeate spacer means about the permeate pipe, second volume space filling means adjacent to and in contact with about one wrapping of the permeate spacer means about the permeate pipe and in contact with the outer surface of about one layer of the porous spacer means about the feed pipe wherein both volume space filling means each have an outer larger generally arcuate convex surface wherein the larger surface arc is slightly larger in diameter than the sum of the diameters of the feed pipe and the permeate pipe, and a smaller first and a smaller second inner concave intersecting arcuate surfaces which intersect each other and the outer edge of the larger arc to define a linear three dimensional volume having three curved surfaces and two generally perpendicular end surfaces, wherein the smaller inner arcuate surfaces are about the same diameter and shape of the feed pipe and permeate pipe and the two inner concave surfaces of the space filling means are in contact with the adjacent convex outer surface of the porous feed spacer means about the feed pipe and the convex outer surface of the porous permeate spacer means surrounding the permeate pipe, wherein the first and second volume space filling means, when placed in contact with the porous spacer means surrounding the feed pipe and the porous spacer means about the permeate pipe, together form a substantially circular outer surface about which the feed membrane and permeate spacer means are spirally wrapped in alternating layers,
• means to seal the edges of the membranes of the module to contain the fluids therein, and
• means for removal of permeate fluid from the fluid permeate passageway to the exterior of the module, and
• means for restraining the unspiraling of the compact module roll under operational conditions.