WO1999011361A1 - Ensemble de filtration par osmose inverse et procede de fabrication - Google Patents

Ensemble de filtration par osmose inverse et procede de fabrication Download PDF

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Publication number
WO1999011361A1
WO1999011361A1 PCT/US1998/017193 US9817193W WO9911361A1 WO 1999011361 A1 WO1999011361 A1 WO 1999011361A1 US 9817193 W US9817193 W US 9817193W WO 9911361 A1 WO9911361 A1 WO 9911361A1
Authority
WO
WIPO (PCT)
Prior art keywords
membrane
filter
assembly
filter assembly
filter membrane
Prior art date
Application number
PCT/US1998/017193
Other languages
English (en)
Inventor
Robert P. Hallmark
Original Assignee
Hydranautics
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hydranautics filed Critical Hydranautics
Publication of WO1999011361A1 publication Critical patent/WO1999011361A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
    • B01D63/10—Spiral-wound membrane modules
    • B01D63/101—Spiral winding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
    • B01D63/10—Spiral-wound membrane modules

Definitions

  • the present invention relates to filtration systems and, in particular, a reverse osmosis (RO) filter assembly having no pressure vessel that provides higher flux and operates at half the pressure.
  • RO reverse osmosis
  • Reverse osmosis is a well known process for the removal of dissolved particulates from a fluid stream such as water.
  • Osmotic filters involve a process whereby fluid flows across a semipermeable membrane barrier thereby forming a salt concentration gradient across the solid/liquid interface so as to allow for the preferential transport of solvent over solute, for example, water over salt ions.
  • Feed water typically is purified by reverse osmosis systems for applications that include agricultural, by-product reclamation, sewage and industrial wastewater treatment, and highly purified water for medical use or electronics manufacturing.
  • Conventional RO filter devices include a pressure vessel or housing containing a semipermeable membrane which permits water to pass through but is substantially impermeable to certain impurities.
  • a pressure vessel is necessary in conventional RO filter designs because high pressure is applied within the housing to the membrane so as to force unpurified water through the membrane, while impurities are prevented from passing therethrough. While pressure vessels are suitable for numerous RO filtration applications, it is desirable to eliminate the cost and performance limitations of pressure vessels.
  • the present invention overcomes the problems associated with conventional RO filter systems utilizing pressure vessels to provide a reverse osmosis filter apparatus that requires no pressure vessel and achieves increased performance.
  • the present invention provides a filtration assembly that features a filter membrane having improved flux at lower pressures in an FRP enclosure to eliminate costs and a myriad of problems associated with pressure vessels.
  • the present invention provides a reverse osmosis filter assembly that includes a hollow, perforated core tube comprising an unobstructed bore and a tapped, spirally wound filter membrane disposed thereon.
  • the filter membrane includes an elongated envelope formed from a pair of semipermeable membrane sheets that surround a permeate carrier sheet.
  • the filter membrane is spirally wound around the core tube with separator means to maintain spacial relationship between convoluted layers of the elongated envelope.
  • the filter assembly comprises end caps disposed adjacent each end of the filter membrane assembly.
  • the end caps include a plurality of ports to form a feed inlet, a concentrate outlet and permeate outlets, whereby the permeate outlets are disposed adjacent to the core tube.
  • the filter assembly includes an enclosure or shell that encompasses and surrounds the end caps and filter membrane to form a cylindrical chamber.
  • the core tube is disposed in coaxial relationship with and within the chamber. The enclosure operates at high pressures without a pressure vessel.
  • the present invention provides a process of manufacturing a filter assembly, the process comprising the steps of forming a spirally wound filter membrane assembly on a hollow, perforated core tube having an unobstructed bore.
  • the forming step includes forming an elongated envelope from a pair of semipermeable membrane sheets of a polyamide structure and a permeate carrier sheet, whereby the semipermeable membrane sheets surround the permeate carrier sheet and each of the membrane and carrier sheets are spirally wound around the core tube with a separator sheet thereby maintaining spacial relationship between convoluted layers of the elongated envelope.
  • the filter membrane assembly is taped around an outer circumference thereof and each end of the filter membrane assembly is cut to a predetermined length.
  • End caps having a bonding area are added adjacent each end of the filter membrane assembly.
  • a shell e.g. made of fiber reinforced plastic (FRP) is formed around the bonding area and filter membrane assembly.
  • FRP fiber reinforced plastic
  • FIG. 1 is a schematic cross-section illustrating the RO filtration module according to an embodiment of the present invention
  • FIG. 2 is a schematic view illustrating the interior of an end-cap of the present invention
  • FIG. 3 is a schematic cross-sectional view, taken along lines 3-3 of FIG. 2, illustrating the end-cap filter of the present invention
  • FIG. 4 is a schematic end view illustrating the end cap of the present invention
  • FIG. 5 is a schematic cross-sectional view, taken along lines 5-5 of FIG. 3, illustrating the annular lands of the end caps
  • FIG. 6 is a schematic view illustrating an additional embodiment of a filter module of the present invention.
  • the filtration module 10 generally includes a shell 12 and end caps 14 and 16 for enclosing a filter element or membrane 18 surrounding a permeable core tube 20.
  • the end caps 14 and 16 have permeate ports 22 and 24, respectively, for transporting filtered fluid out of the filtration module 10.
  • the permeate ports 22 and 24 are located at the center of the end caps 14 and 16, and are adapted to connect to the core tube 20.
  • a feed port 26 and a concentrate port 28 are located offset from the center of the end caps 14 and 16, respectively.
  • the feed port 26 is adapted to connect to piping that supplies feed fluid to the filtration module 10.
  • the concentrate port 28 is adapted to connect to piping that carries concentrate fluid out of the filtration module 10.
  • Each of the feed and concentrate ports 26 and 28 are further adapted to interface with the filter element 18.
  • the feed and concentrate ports 26 and 28 can be smaller and disposed around the perimeter of the permeate ports 22 and 24 in the end caps 14 and 16 as is illustrated in FIG. 6.
  • a plug 30 may close off a permeate port 24 when it is necessary to terminate it such as at the end of a series of filtration modules.
  • the shell 12 of the filtration module 10 can formed of fiber reinforced plastic
  • the shell such as an FRP shell
  • the shell 12 can be fabricated from any combination of composite materials including fiberglass, carbon fiber and other natural or manmade fibers and combined with polyester, epoxy and other resins.
  • the shell 12 consists essentially of wrapped fiberglass threads reinforced by polyurethane and dried to form a hard outer shell.
  • the shell 12 can also be made from extruded stock material, of a cylindrical shape, made from polymers, metals or composite materials. Elimination of the pressure vessel has many advantages including the elimination of numerous manufacturing tolerances required for typical filter designs for filtration systems requiring pressure vessels. Such reduced manufacturing tolerances can reduce the cost of manufacturing relative to conventional element designs.
  • the filter module of the present invention is designed to operate normally at pressures up to 400 psi but under failure testing has operated at operating pressures of 1,200 psi of more.
  • the filter module 10 of the present invention also can have applications in high-pressure filtration systems, whereby such module 10 featuring the elimination of a separate pressure vessel is considered an advancement over conventional filter designs.
  • the end caps 14 and 16 are configured to have the feed, concentrate and permeate ports located on the ends of the end cap so as to facilitate connections to conventional piping.
  • the end caps 14 and 16 can be designed to have side entry ports.
  • the end caps 14 and 16 have threaded feed, concentrate and permeate ports so as to allow connection to any form of coupling such as hydraulic couplings, quick disconnecting fittings, plain and flange fittings, and the like.
  • the module 10 can use a 1/2" threaded opening for the permeate ports 22 and 24, as well as for the feed and concentrate ports 26 and 28, respectively.
  • the end caps 14 and 16 are adapted to have an inner diameter configured to receive the end filtration membrane, thereby disposing the end of the filtration membrane adjacent the end caps 14 and 16.
  • End caps 14 and 16 also are configured to connect permeate ports 22 and 24 directly to the core tube 20 such as by adhesives, bonding or the like, thereby eliminating the need for o-rings.
  • the filtration module 10 of the present invention advantageously eliminates multiple o-ring seals as are used in conventional pressure vessels, such o-ring seals also are known to be a source of cross contamination such as, for example, leakage during operation which reduces the quality of permeate output (or product) obtained from the separation process.
  • the filtration module 10 of the present invention is designed for a filter element or membrane 18 of a spirally wound configuration.
  • the filter element can utilize advantageously a membrane providing high salt rejection elements or high performance RO membrane elements.
  • An Energy-Saving Polyamide (ESP A) element manufactured by Hydranautics of Oceanside CA, has the qualities of permeate flow rate in the range of approximately 2,600 to 12,000 gallons per day ("GPD") or a flux rate in the range of approximately 9 to 50 meters cubed/meters squared/per day (m 3 /m 2 /d), thereby providing superior salt rejection while reducing water usage, energy consumption and plant downtime.
  • GPD Hydranautics of Oceanside CA
  • An Energy-Saving Nanofiltration (ESNA) element also manufactured by Hydranautics of Oceanside CA, has qualities of permeate flow rate in the range of approximately 2,600 to 12,000 GPD or a flux rate in the range of approximately 9 to 50 m 3 /m 2 /d, thereby providing an ideal membrane for applications requiring the removal of organic particulates, bacteria or viruses and provides a nominal 90% salt rejection.
  • the filtration module 10 can advantageously be used in multiple or single element systems including applications that operate systems using micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) and reverse osmosis (RO) membranes such as, for example, filtration systems used in car washes and vending machines. Ultra-low-pressure operation provides increased energy savings with significantly lower installation and operating costs.
  • the filtration module 10 also can be referred to as an ESPA-FREE or ESNA-FREE module having low-pressure high flux membrane which is free of pressure vessels, thereby reducing system complexity and cost.
  • Conventional modules utilize a u-packing seal for sealing the void between the filter element and the inner wall of the pressure vessel.
  • the u-packing of conventional filters can be a potential area of by- pass leakage during the operation of the filtration module whereby any leakage reduces the separation efficiency of the filtration module.
  • the filtration module 10 of the present invention has the additional advantage of not needing the u-packing so as to eliminate the u-packing seal as a source of by-pass leakage.
  • the performance of membrane elements operating in a reverse osmosis system is affected by the feed water composition, feed temperature, feed pressure, and permeate recovery ratio. Performance at a given set of system operating parameters can be calculated from nominal membrane performance at reference test conditions.
  • RO filtration systems equipped with spiral wound membrane elements are designed to operate at a constant flux rate, i.e., to produce a constant permeate flow.
  • the feed pressure is adjusted to compensate for fluctuation of feed water temperature, salinity and permeate flux decline due to fouling or compaction of the membrane.
  • the ESPA and ESNA polyamide series of membranes have improved performance characteristics at low pressures when compared to conventional composite membranes.
  • the membrane structure of these two membranes has been enhanced to allow greater water permeability without sacrificing salt rejection, for example, the ESPA and ESNA polyamide series of membranes use about half the feed pressure to produce the same amount of permeate as conventional membranes thereby lowering feed pressures by 50 to 250 psi.
  • the core tube 20 can be made from stock material having the permeate holes machined therein.
  • the core tube can be extruded from polymers, metals or composite materials, such as polyvinylchloride (PVC).
  • PVC polyvinylchloride
  • the membrane 18 and spacer material are wound around the core tube 20, which can be wrapped on the outside by taping and the like.
  • the core tube 20 engages the permeate ports 22 and 24 in such as manner as to create a seal.
  • each of the end caps 14 and 16 include a bonding area 32 having a plurality of raised lands 34 formed circumferentially around the end caps 14 and 16. For ease of illustration, end cap 14 only is shown.
  • the bonding area 32 and raised lands 34 assist in forming the shell 12.
  • Lands 34 can be formed circumferentially on the outer surface of the end caps 14 and 16.
  • the end cap 14 includes an inner diameter 36 configured to accept the filter membrane 18.
  • the annular lands 34 connect and mate with the shell 12 to retain the end caps 14 and 16 adjacent the end of the filter membrane 18.
  • the end caps 14 and 16 further include segments 38 disposed on portions 40 arranged to form quadrant areas 42. Segments 38 are configured to engage and hold an end of the cylindrical filtration membrane 18, thereby resisting conning or telescoping of a spirally formed filtration membrane 18.
  • the quadrant areas 42, in connection with the segments 38 on portions 40 form voids so as to allow for fluid flow and the efficient forming of a gradient at the ends of the filtration membrane 18.
  • end caps 14 and 16 of the present invention advantageously are designed to include the features of forming (1) a gradient or distribution of the salts of the liquid between the feed and concentrate ports; (2) a system to resist conning on the telescoping effect of the filter element 18 under pressure because of the holding action of the end caps; (3) an exit port for the permeate integral to the end cap; and (4) a structural housing of the membrane integral to the FRP shell.
  • a filter module 50 includes end caps 14 and 16 having permeate ports 22 and 24, feed port 52 and concentrate port 54.
  • Feed and concentrate ports 52 and 54 respectively, comprise a plurality of small diameter holes arranged adjacent the permeate ports 22 and 24 respectively.
  • the construction of feed port 52 is adapted to engage a source of fluid so as to supply the filter module 10.
  • the concentrate port 54 is adapted to engage an output so as to supply concentrate thereto.
  • the filtration module 10 of the present invention also can have applications in filtration systems having and is an advancement over conventional filter designs.
  • feed water or liquid is supplied through the feed port 26 which passes through the membrane 18 and is thereby collected in the core tube 20 and exits through the permeate ports 22 and 24.
  • the filtration module 10 separates, e.g. water from salt ions, using a spirally wound ESPA or ESNA membrane.
  • the spirally wound membrane assembly is comprised of semipermeable membrane sheets or leaves, that are affixed at the edges to form an envelope and a spacing material sheet for the passage of permeated solutions.
  • On top of the semipermeable membrane sheet is another spacer material sheet that allows the feed and nonpermeated solution to flow over the surface of the membrane leaves.
  • the membrane envelope, the spacing material sheets for the feed and permeate are spirally wound around the hollow core tube 20 having numerous holes along the length thereof.
  • a feed solution is supplied to the feed port 20 and such feed solution flows from the spiral edges of the membrane envelope parallel to the core tube 20.
  • As a result of this separation process a reduced solids solution is collected on the permeate side of the membrane (inside) and a concentrated solution forms on the outer surface of the membrane envelope.
  • the permeated solution flows spirally through the permeate spacing material sheet and is discharged into the center of the core tube 20 where the solution can flow out of the central permeate ports 22 and 24 located on either end of the module.
  • the concentrated feed solution flows over the surface of the membrane through the feed spacing material and exits the module via concentrate port 28 on the end of the module opposite feed port 26.
  • the RO filter module 10 of the present invention can advantageously operate at low pressures to filter a feed solution.
  • the filtration module of the present invention can be manufactured according to a process of forming the shell 12 around an assembly formed of the filtration element 18 and end caps 14 and 16.
  • the spirally wound filter membrane assembly 18 can be formed on a hollow, perforated core tube 20 having an unobstructed bore.
  • An elongated envelope is formed from a pair of semipermeable membrane sheets of a polyamide structure and a permeate carrier sheet.
  • the semipermeable membrane sheets are configured to surround the permeate carrier sheet.
  • each of the membrane and carrier sheets are spirally wound around the core tube 20 along with a separator sheet or web so as to maintain a spacial relationship between convoluted layers of the elongated envelope.
  • the filter membrane assembly can be held together by winding tape or other web around an outer circumference thereof.
  • Each end of the filter membrane assembly is cut or trimmed to a predetermined length, for example, 40 inches, so as to be received by each end cap.
  • the fiber reinforced plastic (FRP) shell is formed by winding the fibers and reinforced material around the bonding area of each end cap and filter membrane assembly. The assembly can be dried by heating or the like.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

L'invention porte sur un ensemble de filtration et sur son procédé de fabrication consistant à séparer des matières particulaires d'un courant fluidique. Cet ensemble de filtration est formé dans un tube creux doté d'une membrane (18) de filtration enroulée en spirale sur laquelle est placé un polyamide composé. L'ensemble de filtration comporte à ses extrémités des bouchons (14, 16) pourvus d'une pluralité de trous formant un orifice d'admission (26) de la charge, un orifice d'évacuation (28) du concentrat et des orifices d'évacuation (22, 24) du perméat. Cet ensemble comporte également une enveloppe ou coquille (12) qui entoure les bouchons (14, 16) et la membrane de filtration (18) de façon à former une chambre cylindrique. Le tube creux (20) est disposé de manière coaxiale dans la chambre.
PCT/US1998/017193 1997-08-29 1998-08-20 Ensemble de filtration par osmose inverse et procede de fabrication WO1999011361A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US92089797A 1997-08-29 1997-08-29
US08/920,897 1997-08-29

Publications (1)

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WO1999011361A1 true WO1999011361A1 (fr) 1999-03-11

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WO (1) WO1999011361A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1016793C2 (nl) * 2000-12-04 2002-06-05 Simon Roelof Vasse Filterbehuizing.
US7842769B1 (en) 2003-06-13 2010-11-30 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US8128853B2 (en) 2003-06-13 2012-03-06 Underground Solutions Technologies Group, Inc. Fusion process for conduit
US8167338B2 (en) 2007-09-24 2012-05-01 Cantex, Inc. Non-metallic raceway for wiring and fiber optic cable and method of forming raceway
CN103755056A (zh) * 2014-02-12 2014-04-30 浙江沁园水处理科技有限公司 一种反渗透净水一体机
CN111617637A (zh) * 2020-06-10 2020-09-04 湖南澳维环保科技有限公司 一种卷式膜元件的卷制方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3852198A (en) * 1972-02-12 1974-12-03 Plastic Kogaku Kenkyusho Kk Dialyzing apparatus for artifical kidney
US4855058A (en) * 1986-06-24 1989-08-08 Hydranautics High recovery spiral wound membrane element
US5108604A (en) * 1991-08-23 1992-04-28 Desalination Systems, Inc. Semipermeable membrane cartridge and method of making
US5128037A (en) * 1990-12-27 1992-07-07 Millipore Corporation Spiral wound filtration membrane cartridge
US5755964A (en) * 1996-02-02 1998-05-26 The Dow Chemical Company Method of treating polyamide membranes to increase flux

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3852198A (en) * 1972-02-12 1974-12-03 Plastic Kogaku Kenkyusho Kk Dialyzing apparatus for artifical kidney
US4855058A (en) * 1986-06-24 1989-08-08 Hydranautics High recovery spiral wound membrane element
US5128037A (en) * 1990-12-27 1992-07-07 Millipore Corporation Spiral wound filtration membrane cartridge
US5108604A (en) * 1991-08-23 1992-04-28 Desalination Systems, Inc. Semipermeable membrane cartridge and method of making
US5755964A (en) * 1996-02-02 1998-05-26 The Dow Chemical Company Method of treating polyamide membranes to increase flux

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1016793C2 (nl) * 2000-12-04 2002-06-05 Simon Roelof Vasse Filterbehuizing.
WO2002045817A1 (fr) * 2000-12-04 2002-06-13 Simon Roelof Vasse Boitier de filtre
US8569436B2 (en) 2003-06-13 2013-10-29 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US8906188B2 (en) 2003-06-13 2014-12-09 Underground Solutions Technologies Group, Inc. Fusion process for conduit
US8058378B1 (en) 2003-06-13 2011-11-15 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US8128853B2 (en) 2003-06-13 2012-03-06 Underground Solutions Technologies Group, Inc. Fusion process for conduit
US7915366B1 (en) 2003-06-13 2011-03-29 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US8178640B2 (en) 2003-06-13 2012-05-15 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US7842769B1 (en) 2003-06-13 2010-11-30 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US9023263B2 (en) 2003-06-13 2015-05-05 Underground Solutions Technologies Group, Inc. Fusion process for conduit
US8796407B2 (en) 2003-06-13 2014-08-05 Underground Solutions Technologies Group, Inc. Polyvinyl chloride formulations
US8167338B2 (en) 2007-09-24 2012-05-01 Cantex, Inc. Non-metallic raceway for wiring and fiber optic cable and method of forming raceway
CN103755056A (zh) * 2014-02-12 2014-04-30 浙江沁园水处理科技有限公司 一种反渗透净水一体机
CN103755056B (zh) * 2014-02-12 2015-10-28 浙江沁园水处理科技有限公司 一种反渗透净水一体机
CN111617637A (zh) * 2020-06-10 2020-09-04 湖南澳维环保科技有限公司 一种卷式膜元件的卷制方法
CN111617637B (zh) * 2020-06-10 2022-07-22 湖南澳维科技股份有限公司 一种卷式膜元件的卷制方法

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