Abstract: The present invention discloses membrane modules utilizing innovative geometries of net-type feed spacers for improved performance in separations and spacer-fabrication methods therein. Membrane modules include: a central tube having perforations along its length for collecting a permeate; at least two filtration envelopes, each filtration envelope having two membrane sheets and a porous, fabric-type insert in between the two membrane sheets for facilitating the permeate to flow, wherein each envelope is closed along three edges of the two membrane sheets, and wherein each envelope is configured to allow the permeate to exit from a fourth, open edge attached to the central tube; and a respective feed-spacer sheet in planar contact with an outer membrane surface of a respective filtration envelope; wherein the respective feed-spacer sheet is in the form of net having nodes connected by flexible segments such that the net forms a regular planar net.

Abstract: The present invention discloses membrane modules utilizing innovative geometries of net-type feed spacers for improved performance in separations and spacer-fabrication methods therein. Membrane modules include: a central tube having perforations along its length for collecting a permeate; at least two filtration envelopes, each filtration envelope having two membrane sheets and a porous, fabric-type insert in between the two membrane sheets for facilitating the permeate to flow, wherein each envelope is closed along three edges of the two membrane sheets, and wherein each envelope is configured to allow the permeate to exit from a fourth, open edge attached to the central tube; and a respective feed-spacer sheet in planar contact with an outer membrane surface of a respective filtration envelope; wherein the respective feed-spacer sheet is in the form of net having nodes connected by flexible segments such that the net forms a regular planar net.