A filter element comprises a membrane layer; and a feed spacer on the membrane layer, wherein the feed spacer comprises a plurality of unit cells arranged in three dimensions, wherein each of the plurality of unit cells comprises a cavity defined by a triply periodic minimal surface, and wherein the cavities of the plurality of unit cells are interconnected to allow a fluid to pass through the cavities of the plurality of unit cells.

The present disclosure is directed to ion-exchange systems and devices that can monitor key parameters related to the performance of the ion-exchange device. Specifically, the ion-exchange systems and devices disclosed herein can provide real time voltage drop across groups of membrane pairs using diagnostic spacer borders between the pairs. In addition, the ion-exchange systems and devices disclosed herein can monitor the compression force applied by the compression plates holding the ion-exchange systems and devices together.

Provided is a feed spacer having a three-layered structure, and a reverse osmosis membrane filter module including the same, where the feed spacer includes a first set of a plurality of strands that are positioned in parallel; a second set of a plurality of parallel strands provided to cross the first set; and a third set of a plurality of parallel strands positioned in parallel with a raw water flow direction, where at least one of the first set and the second set consists of strands having a smaller thickness than that of the strands constituting the third set.

Embodiments of the present invention provide for the deposition of spacing elements for spiral wound elements which promote mixing within the feed space during element operation thereby improving element performance and reducing concentration polarization and potential for biological fouling.

Embodiments of the invention provide replacements for a continuous layer of feed spacer mesh in spiral-wound reverse osmosis elements and replacing such mesh with discrete regions of feed spacer supporting the inlet and outlet ends of the element and a stiffening bridge feature to bridge between these regions at the tail end of each membrane leaf comprising the element during the element rolling process. The stiffening bridge feature prevents inward deflection of the inner layer of the membrane leaf during rolling, facilitating proper sealing of the adhesive through the permeate carrier to the adjacent membrane film using known membrane rolling techniques.

A CMS membrane module includes plurality of hollow fiber CMS membranes that are enclosed within an open cylindrical shell whose ends are embedded in tubesheets. The shell is concentrically disposed within an open cylindrical pressure vessel whose open ends are covered by and secured by end caps. The shell includes a feed fluid inlet formed therein between the tubesheets and a retentate outlet in between one of the tubesheets and an adjacent end cap. A retentate seal is formed between the shell and the pressure vessel at a position between the tubesheets. A permeate seal is formed between the pressure vessel and the tubesheet that is adjacent a permeate port of the module. A structure made up of the CMS membranes, shell, tubesheets, and seals is slidable within the pressure vessel and not fixed in place in relation to the pressure vessel and end caps.

Embodiments of the present invention provide for the deposition of spacing elements for spiral wound elements which promote mixing within the feed space during element operation thereby improving element performance and reducing concentration polarization and potential for biological fouling.

In embodiments of the present invention, flow dividing strips are used in the construction of the spiral wound element to segregate and direct feed to reject flow of a reverse osmosis element Flow dividing strips isolate the flow of fluid through distinct regions of the spiral-wound element. The flow dividing features can also be used to direct flow within the element in order to create a longer flow path for the fluid through the element, enabling even higher recovery in some applications.

The disclosure of the present invention relates to a method for preparing membrane and associated membrane and filter element. The method comprises providing a porous substrate having a plurality of pores; and applying a pre-filler solution to at least partially occupy the pores in the porous substrate. The membrane comprises a porous substrate and a filter layer formed on the porous substrate. The filter element comprises a core tube; and a membrane as prepared and rolled around the core tube.

A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the permeate spacer has an open space volume of at least 0.0004 m.sup.3/m.sup.2; and (b) the membrane sheet has an aspect ratio of at least 1.5.