Abstract: New methods and apparatus are described for assessing the integrity of a separation module or filtration system. A principle embodiment concerns use of a transient pulse of challenge species to probe a spiral wound module. The resulting time-dependent concentration of challenge species in the permeate is detected, recorded, and compared to a reference. An apparatus is further claimed for detecting permeate conductivity at multiple points within the permeate collection tube of a spiral wound module. Also disclosed is a process whereby the permeate stream from a filtration system is concentration by a high recovery membrane apparatus prior to measurement of challenge species concentration.

Abstract: A loader for moving a filter element between loaded and unloaded positions with respect to a pressure vessel is provided. The loader includes a connection section associated with a loader section. The connection section is operative to be secured in coaxial alignment with the pressure vessel. The loader section is operative to receive a filter element and move the filter element between the loaded and unloaded positions. The loader section includes a cradle assembly for supporting a filter element and a carriage assembly operative to engage the filter element and move it between the loaded and unloaded positions.

Abstract: New methods and apparatus are described for assessing the integrity of a separation module or filtration system. A principle embodiment concerns use of a transient pulse of challenge species to probe a spiral wound module. The resulting time-dependent concentration of challenge species in the permeate is detected, recorded, and compared to a reference. An apparatus is further claimed for detecting permeate conductivity at multiple points within the permeate collection tube of a spiral wound module. Also disclosed is a process whereby the permeate stream from a filtration system is concentration by a high recovery membrane apparatus prior to measurement of challenge species concentration.

Abstract: A fuel return system for returning fuel from a fuel pump to first and second fuel tanks in an automotive vehicle includes an open T fitting having branches connected through couplings to the first and second fuel tanks. The couplings each have a low return, fuel flow orifice which is continually open and a high return, fuel flow orifice which is normally closed by a valve. The low pass through orifices prevent one tank from receiving extra fuel during idle and allow the first and second fuel tanks to siphon to the same fuel level when the vehicle is parked. The high flow through orifices open to prevent return fuel back pressure to the engine and have a cracking pressure responsive to the engine running at a level higher than idle.

Abstract: The present invention is an improved feed spacer, spiral wound element incorporating said feed spacer, filtration system and a method for making and using the same. In one embodiment the present invention includes an improved spiral wound element having: a central collection tube with a plurality of openings along its length to receive permeate; at least one filtration envelope extending outwardly from and wound about the tube and at least one feed spacer sheet wound about the collection tube wherein the feed spacer sheet being in planar contact with the outer surface of at least one filtration envelope.

Abstract: The present invention is an improved feed spacer, spiral wound element incorporating said feed spacer, filtration system and a method for making and using the same. In one embodiment the present invention includes an improved spiral wound element having: a central collection tube with a plurality of openings along its length to receive permeate; at least one filtration envelope extending outwardly from and wound about the tube and at least one feed spacer sheet wound about the collection tube wherein the feed spacer sheet being in planar contact with the outer surface of at least one filtration envelope.

Abstract: A separation end cap adapted for connecting adjacent separation elements is provided. The end cap may be located at the distal ends of a separation element and is adapted for connection with a permeate tube located within the separation element. In one embodiment the end cap includes an inner hub for receiving an O-ring to seal against an inner hub of an end cap on an adjacent separation element. The inner hub of the end cap may be spin-welded to the outer surface of the permeate tube. A locking structure on an outer hub of the end cap co-acts with a locking structure on an end cap of an adjacent separation element to releaseably lock the end caps and, therefore, adjacent separation elements. The locking structure preferably provides a predetermined axial force on the O-ring to seal the connection between permeate tubes of adjacent separation elements.

Abstract: A separation end cap adapted for connecting adjacent separation elements is provided. The end cap may be located at the distal ends of a separation element and is adapted for connection with a permeate tube located within the separation element. In one embodiment the end cap includes an inner hub for receiving an O-ring to seal against an inner hub of an end cap on an adjacent separation element. The inner hub of the end cap may be spin-welded to the outer surface of the permeate tube. A locking structure on an outer hub of the end cap co-acts with a locking structure on an end cap of an adjacent separation element to releaseably lock the end caps and, therefore, adjacent separation elements. The locking structure preferably provides a predetermined axial force on the O-ring to seal the connection between permeate tubes of adjacent separation elements.

Abstract: An improved air-to-air, heat-and-moisture exchanger is described which facilitates the simultaneous transfer of both heat and water vapor between two streams of air while greatly inhibiting the transfer of pollutant gases. A rigid encasement supports a stack of flat, thin-film composite membranes that are held in parallel, spaced-apart relation, thereby forming a box-shaped exchanger. The membranes are synthesized by interfacial polymerization, a process whereby a thin, non-porous film may be uniformly deposited onto a porous substrate material. The thin film is hydrophilic so as to provide high water vapor flux together with excellent selectivity against the transfer of other gases and vapors. The substrate provides mechanical support.