US20050127000A1 - Inverted air box aerator and aeration method for immersed membranes - Google Patents
Inverted air box aerator and aeration method for immersed membranes Download PDFInfo
- Publication number
- US20050127000A1 US20050127000A1 US11/052,092 US5209205A US2005127000A1 US 20050127000 A1 US20050127000 A1 US 20050127000A1 US 5209205 A US5209205 A US 5209205A US 2005127000 A1 US2005127000 A1 US 2005127000A1
- Authority
- US
- United States
- Prior art keywords
- air
- aerator
- flow
- rate
- flow rate
- Prior art date
- Legal status (The legal status 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 status listed.)
- Abandoned
Links
Images
Classifications
-
- 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
- B01D65/08—Prevention of membrane fouling or of concentration polarisation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/14—Ultrafiltration; Microfiltration
- B01D61/18—Apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/14—Ultrafiltration; Microfiltration
- B01D61/20—Accessories; Auxiliary operations
-
- 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
- B01D65/02—Membrane cleaning or sterilisation ; Membrane regeneration
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
- C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/12—Activated sludge processes
- C02F3/20—Activated sludge processes using diffusers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2315/00—Details relating to the membrane module operation
- B01D2315/06—Submerged-type; Immersion type
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2321/00—Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
- B01D2321/02—Forward flushing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2321/00—Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
- B01D2321/18—Use of gases
- B01D2321/185—Aeration
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2303/00—Specific treatment goals
- C02F2303/16—Regeneration of sorbents, filters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S261/00—Gas and liquid contact apparatus
- Y10S261/70—Sewage aerators; diffusers
Definitions
- This invention relates to an aerator, aerating method and filtration system for immersed membranes.
- Aeration is used with immersed membranes to scour the membranes and to disperse areas of tank water having increased concentrations of rejected solids from near the membranes.
- An ideal aeration system for immersed membranes would scour the entire assembly of membranes with minimum energy use, cost and maintenance required to keep the aerators from plugging.
- a casing surrounds the air diffuser and the membrane cartridges, extending vertically from the bottom of the diffuser to the top of the membrane cartridges.
- the diffuser is locater about 1 m below the membrane cartridges and the diffusers provide a small number of holes per square metre of horizontal cross-sectional area of the assembly of membrane cartridges. Air is supplied such that the air velocity and pressure in the holes of the diffusers is sufficient to prevent water or sludge from creeping into the holes of the diffuser.
- the casing and location of the diffuser below the membrane cartridges encourages the bubbles to become evenly dispersed by the time that they reach the membrane cartridges.
- the shroud and deep aerators increase both the equipment cost and the energy required to produce bubbles.
- the method also relies on the membrane cartridges being arranged in parallel vertical plates for full effectiveness.
- aerator having an aerator shell with openings for discharging bubbles from its upper surface and a shape capable of at least temporarily containing a variable volume of air in fluid communication with the openings for discharging bubbles.
- the shell is open to tank water such that the tank water can act on the volume of contained air and so that substrate can be displaced from or enter into the aerator as the volume of trapped air changes.
- the aerator shell is located so that discharged bubbles will rise through an assembly of filtering membranes.
- the shell may be a separate structure, such as an inverted box, or may be wholly or partially made of parts, for example headers, of modules of the filtering membranes.
- the aerator shell is fed with air varying between a higher rate of air flow and a lower rate of air flow, which is one half or less of the higher flow rate, in short repeated cycles of between about 10 seconds and 100 seconds in duration, or between about 10 seconds and 60 seconds in duration.
- the lower rate of air flow may be an air off condition or be about 10% or less than the higher rate of air flow. Apparatus for providing such cycles are described in PCT Application PCT/CA99/00940, published as WO 00/21890. All of PCT/CA99/00490 is incorporated herein by this reference to it.
- Air may be provided to the aerator shell at the higher flow rate during about 1 ⁇ 8 to 1 ⁇ 2 of each cycle.
- the aerator traps a pocket of air which grows in volume and releases bubbles from its upper surface.
- the aerator may continue to release bubbles from its upper surface and the volume of the air pocket decreases. Bubbles may be released during about 1 ⁇ 3 to 2 ⁇ 3 of the cycle duration.
- the aerator may become partially or completely flooded during a later part of the lower air flow period to help remove accumulated solids. Alternately, bubbles may be produced throughout each cycle.
- a filtration system which may be used to extract drinking water from a water to be filtered, has one or more immersed membranes assemblies, or modules, located in a tank open to the atmosphere with the membranes immersed in the substrate.
- An inlet for adding substrate and an outlet for retentate are located so as to create a horizontal flow of substrate through the tank. Some or all of the retentate may be, but preferably is not, circulated to the inlet and a second outlet or other means for removing settled solids may be provided.
- the membrane assemblies are located within the horizontal flow of substrate and may be spaced or oriented to encourage the horizontal flow to carry solids in the substrate to the outlet.
- Aerators as described above are provided and operated as described above. The aerators may be comprised of parts of the membrane assemblies or located closely below the membrane assemblies since the horizontal flow of substrate reduces or eliminates the need for the tank water to circulate around the membrane assemblies.
- FIG. 1 is a schematic view of the side of a membrane assembly, and a first embodiment of an aerator.
- FIG. 2 is schematic top and side views of the aerator of FIG. 1 .
- FIG. 3 is a schematic view of side and plan views of other embodiments of aerators partially or wholly made up of parts of membrane assemblies.
- FIG. 4 is a schematic view of parts of a filtration system.
- FIGS. 1 and 2 show a first aerator 10 having an aerator shell 12 in the shape of an inverted box which will be called an air box 2 .
- the air box 2 is located below at least one membrane assembly 1 .
- the first aerator 10 may also service a plurality of membrane assemblies 1 , for example four to sixteen, or more, membrane assemblies 1 .
- a space between the membrane assembly 1 and the air box 2 optionally promotes liquid recirculation through and about the membrane assembly 1 . Alternately, the space may be reduced or eliminated to preserve space when the air box 2 is used with the filtration system described further below.
- the air box 2 may be rectangular or other shapes capable of supporting holes 5 in desired locations in an upper surface, at least temporarily containing a variable volume of air in communication with the holes 5 and open to tank water so that tank water can be displaced from or enter into the air box 2 as the volume of contained air changes.
- the air box 2 may have horizontal dimensions to generally match the footprint of the membrane assembly 1 above it.
- the height of the side walls of the air box 2 are such that the air box 2 can contain a volume of air corresponding to the amount of air which is provided from an air distribution pipe 3 less the volume of air produced as bubbles through the holes 5 , and nipples 4 if used, as will be described further below.
- the air distribution pipe 3 is located as close as possible to the air box 2 to limit the height of the water column (or pressure) which must be overcome to eject air and thereby minimize energy required.
- the air distribution pipe may be located such that it discharges air directly inside the air box 2 .
- the air box 2 may be attached to the membrane assembly 1 which facilitates inspection when the membrane assembly is pulled out.
- the air box 2 may be attached to the air distribution pipe 3 or attached to its own mounting apparatus.
- the air distribution pipe 3 has at least one large aeration hole located under each air box 2 .
- the size of the aeration holes in the air distribution pipe 3 may be chosen to minimize fouling, for example, very large holes may foul less rapidly.
- the air distribution pipe 3 may simultaneously supply air to several air boxes 2 .
- the air box 2 upper surface has a series of air holes 5 arranged in a regular pattern.
- the hole size is such that the holes 5 do not plug from debris in water and produce bubbles of an appropriate diameter for scouring the membrane assembly 1 , typically 5-15 mm.
- the density of holes 5 depends on design of the membrane assembly 1 and aeration requirements and may be 25 to 160 holes per square metre.
- the holes may be fitted with nipples 4 pointing downward to provide a residual air cushion in the air box 2 which promotes the rapid horizontal dispersion of air.
- the rate of air flow in the air distribution pipe 3 varies in a repeated cycle having a total cycle length or duration of between about 10 and 100 seconds. In general, there is a period at a higher flow rate and a period at a lower flow rate. The lower flow rate is one half or less of the higher flow rate.
- the lower flow rate may be 10% or less than the higher flow rate or the lower flow rate may an air off condition or have substantially no air flow.
- the period of higher flow may be between about 1 ⁇ 8 and 1 ⁇ 2 of the total cycle duration. Most often, the period of higher flow and period of lower flow are each about 1 ⁇ 2 of the cycle duration.
- the change between the higher flow rate and the lower flow rate is performed rapidly, i.e. in less than about 6 seconds or in less than about 3 seconds.
- the air box 2 fills with air because the air flow from the air distribution pipe 3 is larger than the air flow from the air box 2 as bubbles which flow upwards to the membrane assembly 1 .
- the air box continues to discharge air bubbles through the holes 5 to scour the membrane assembly 1 during the lower flow period.
- the air box 2 may be sized in relation to the number and size of holes 5 and the flow rate and duration of air flow from the air distribution pipe 3 such that air flows through the holes 5 throughout each cycle. Alternately, the air box 2 may be sized to become empty of air during a part of the lower flow period which allows tank water to flow thorough the holes 5 or nipples 4 to wash away deposits left around the holes 5 or nipples 4 .
- Air cycling meaning a flow of air that varies in rate as described above, may be provided to multiple, distinct groups of membrane assemblies 1 connected to 2 or more air distribution pipes 3 from a single air blower operated at a single rate. This is done by providing a plurality of air distribution pipes 3 which form or communicate with a plurality of distinct branches of an air distribution system.
- a valve set communicates between an air supply and the distinct branches. The valve set is operated to split an initial air flow from the air supply such that at any time at least one distinct branch receives air at a higher flow rate and at least one other of the branches receives air at a lower rate.
- the valve set switches which distinct branch or branches receives air at the higher flow rate and the lower flow rate in repeated cycles. This is described more fully in WO 00/21890 which is incorporated herein in its entirety by this reference.
- bubbles are produced for a greater portion of the cycle than the higher flow period.
- the higher flow period in each will be about 1 ⁇ 2 of the cycle duration but bubbles may be produced for between about 1 ⁇ 2 and 3 ⁇ 4 of the cycle duration.
- 4 distinct branches might be fitted to a single blower and each receive air at the higher flow rate for about 1 ⁇ 4 of the cycle duration.
- bubbles can be produced for about 1 ⁇ 3 to 1 ⁇ 2 of the cycle duration.
- FIG. 3 Three further embodiments, A, B and C, are shown in FIG. 3 . These embodiments are like the first embodiment in many ways and the description of the first embodiment generally applies to them except for the differences noted below.
- FIG. 3 shows second aerators 110 A, 110 B and 110 C.
- Each has a second aerator shell 112 A,B,C with openings 114 for discharging bubbles from their upper surfaces.
- the shape of the second aerator shells 112 A,B,C allows them to at least temporarily contain a variable volume of air in fluid communication with the openings 114 .
- the second aerator shells 112 A,B,C are also downwardly open to allow tank water or substrate to act against any contained air.
- the openings 114 are located so that discharged bubbles will rise through a membrane assembly 1 .
- Parts of the membrane assemblies 1 for example headers 116 , form part of the second aerator shells 112 A,B,C.
- the second aerator shells 112 A,B,C may be used with more membrane assemblies, ie. between four and sixteen, or more, membrane assemblies 1 .
- Side walls 118 of the second aerator shells 112 A,B,C may also be made as parts of the membrane assemblies 1 .
- Flanges 120 on the headers 116 are also part of the second aerator shell 112 B.
- Hole forming strips 122 between the headers 116 are part of the third aerator shell 112 C. The hole forming strips may be made as part of the membrane assemblies 122 .
- Air distribution pipes 3 are provided below the second aerators 110 as described above.
- FIG. 4 shows a filtration system 130 having membrane assemblies 1 located in a tank 132 which is open to the atmosphere to immerse membranes 134 in a substrate 136 .
- An inlet 138 for adding substrate 136 and an outlet 140 for retentate are located so as to create a horizontal flow of substrate 142 through the tank 132 .
- Some or all of the retentate may be, but preferably is not, circulated to the inlet 138 and a second outlet 144 or other means for removing settled solids may be provided.
- the membrane assemblies 1 are located within the horizontal flow of substrate 142 and may be spaced or oriented to encourage the horizontal flow of substrate 142 to carry solids in the substrate to the outlet 140 .
- elongated membrane assemblies 1 may be oriented generally parallel with the horizontal flow of substrate 142 .
- Second aerators 110 A are shown although first aerators 10 or second aerators 110 B,C may also be used.
- the aerators 10 , 110 are operated as described above. If first aerators 10 are used, they may be located closely below the membrane assemblies 1 since the horizontal flow of substrate 142 reduces or eliminates the need for substrate 136 to circulate around the membrane assemblies 1 .
- Air is supplied to the aerators 10 , 110 through air distribution pipes 3 connected to branches 146 of a cyclic aeration system 148 .
Abstract
An aerator for immersed filtering membranes has an aerator shell with openings for discharging bubbles from its upper surface and a shape capable of temporarily containing a volume of air in fluid communication with the openings. The shell is open to tank water below it and located so that discharged bubbles will rise through an assembly of the filtering membranes. The shell may be wholly or partially made of parts of the assemblies of filtering membranes. A supply of air is provided to the air space in the aerators alternating between a high flow rate and a low flow rate in short cycles of between about 10 seconds and 100 seconds. A filtration system has an inlet for adding substrate and an outlet for retentate are located so as to create a horizontal flow of substrate through the tank. Membrane assemblies are located within the horizontal flow of substrate. Aerators as described above are provided and operated as described above.
Description
- This is a continuation of U.S. patent application Ser. No. 10/171,997 filed Jun. 17, 2002, which is a continuation-in-part of U.S. patent application Ser. No. 10/061,108, filed Feb. 1, 2002, which is an application claiming the benefit under 35 USC 119(e) of U.S. Provisional Application Ser. No. 60/278,007 filed Mar. 23, 2001. U.S. application Ser. Nos. 10/171,997, 10/061,108 and U.S. 60/278,007 are incorporated herein, in their entirety, by this reference to them.
- This invention relates to an aerator, aerating method and filtration system for immersed membranes.
- Aeration is used with immersed membranes to scour the membranes and to disperse areas of tank water having increased concentrations of rejected solids from near the membranes. An ideal aeration system for immersed membranes would scour the entire assembly of membranes with minimum energy use, cost and maintenance required to keep the aerators from plugging.
- U.S. Pat. Nos. 5,192,456 and 5,482,625, issued on Mar. 9, 1993 and Jan. 9, 1996 to Kubota Corporation, describe an air diffuser disposed below a set of membrane cartridges. A casing surrounds the air diffuser and the membrane cartridges, extending vertically from the bottom of the diffuser to the top of the membrane cartridges. In commercial embodiments, the diffuser is locater about 1 m below the membrane cartridges and the diffusers provide a small number of holes per square metre of horizontal cross-sectional area of the assembly of membrane cartridges. Air is supplied such that the air velocity and pressure in the holes of the diffusers is sufficient to prevent water or sludge from creeping into the holes of the diffuser. The casing and location of the diffuser below the membrane cartridges encourages the bubbles to become evenly dispersed by the time that they reach the membrane cartridges. The shroud and deep aerators increase both the equipment cost and the energy required to produce bubbles. The method also relies on the membrane cartridges being arranged in parallel vertical plates for full effectiveness.
- Another approach is described in U.S. Pat. No. 5,944,997, issued on Aug. 31, 1999 to Zenon Environmental Inc. In this patent, aerators are located directly below a set of membrane modules and no shroud is used but there are many more holes—about 130-160 holes per square metre of horizontal cross-sectional of the assembly of membrane modules. Although the large number of holes provides well distributed bubbles, the air flow per hole is not sufficient to prevent tank water or sludge from creeping into the aerators around the perimeter of the holes. To prevent this tank water from leaving deposits in the aerator, the aerators are periodically flushed. Although effective, this method involves an extensive grid of aerators to provide the large number of holes and additional equipment for flushing the aerators.
- It is an object of the invention to improve on the prior art. Other objects of the invention include providing an aerator and aeration process for immersed filtering membranes and providing a membrane filtration system. The objects of the invention are met by the combination of features, steps or both described in the claims. The following summary may not describe all necessary features of the invention which may reside in a sub-combination of the following features or in a combination of some or all of the following features and features described in other parts of this document.
- Various aspects of the invention are directed at an aerator having an aerator shell with openings for discharging bubbles from its upper surface and a shape capable of at least temporarily containing a variable volume of air in fluid communication with the openings for discharging bubbles. The shell is open to tank water such that the tank water can act on the volume of contained air and so that substrate can be displaced from or enter into the aerator as the volume of trapped air changes. The aerator shell is located so that discharged bubbles will rise through an assembly of filtering membranes. The shell may be a separate structure, such as an inverted box, or may be wholly or partially made of parts, for example headers, of modules of the filtering membranes. The aerator shell is fed with air varying between a higher rate of air flow and a lower rate of air flow, which is one half or less of the higher flow rate, in short repeated cycles of between about 10 seconds and 100 seconds in duration, or between about 10 seconds and 60 seconds in duration. The lower rate of air flow may be an air off condition or be about 10% or less than the higher rate of air flow. Apparatus for providing such cycles are described in PCT Application PCT/CA99/00940, published as WO 00/21890. All of PCT/CA99/00490 is incorporated herein by this reference to it.
- Air may be provided to the aerator shell at the higher flow rate during about ⅛ to ½ of each cycle. When air is provided at a higher rate of air flow, the aerator traps a pocket of air which grows in volume and releases bubbles from its upper surface. When air is provided at the lower rate of air flow, the aerator may continue to release bubbles from its upper surface and the volume of the air pocket decreases. Bubbles may be released during about ⅓ to ⅔ of the cycle duration. The aerator may become partially or completely flooded during a later part of the lower air flow period to help remove accumulated solids. Alternately, bubbles may be produced throughout each cycle.
- In other aspects of the invention, a filtration system, which may be used to extract drinking water from a water to be filtered, has one or more immersed membranes assemblies, or modules, located in a tank open to the atmosphere with the membranes immersed in the substrate. An inlet for adding substrate and an outlet for retentate are located so as to create a horizontal flow of substrate through the tank. Some or all of the retentate may be, but preferably is not, circulated to the inlet and a second outlet or other means for removing settled solids may be provided. The membrane assemblies are located within the horizontal flow of substrate and may be spaced or oriented to encourage the horizontal flow to carry solids in the substrate to the outlet. Aerators as described above are provided and operated as described above. The aerators may be comprised of parts of the membrane assemblies or located closely below the membrane assemblies since the horizontal flow of substrate reduces or eliminates the need for the tank water to circulate around the membrane assemblies.
- For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example to one or more embodiments illustrated in the following drawings in which:
-
FIG. 1 is a schematic view of the side of a membrane assembly, and a first embodiment of an aerator. -
FIG. 2 is schematic top and side views of the aerator ofFIG. 1 . -
FIG. 3 is a schematic view of side and plan views of other embodiments of aerators partially or wholly made up of parts of membrane assemblies. -
FIG. 4 is a schematic view of parts of a filtration system. -
FIGS. 1 and 2 show afirst aerator 10 having anaerator shell 12 in the shape of an inverted box which will be called anair box 2. Referring toFIG. 1 , theair box 2 is located below at least onemembrane assembly 1. Thefirst aerator 10 may also service a plurality ofmembrane assemblies 1, for example four to sixteen, or more,membrane assemblies 1. A space between themembrane assembly 1 and theair box 2 optionally promotes liquid recirculation through and about themembrane assembly 1. Alternately, the space may be reduced or eliminated to preserve space when theair box 2 is used with the filtration system described further below. - The
air box 2 may be rectangular or other shapes capable of supportingholes 5 in desired locations in an upper surface, at least temporarily containing a variable volume of air in communication with theholes 5 and open to tank water so that tank water can be displaced from or enter into theair box 2 as the volume of contained air changes. Theair box 2 may have horizontal dimensions to generally match the footprint of themembrane assembly 1 above it. The height of the side walls of theair box 2 are such that theair box 2 can contain a volume of air corresponding to the amount of air which is provided from anair distribution pipe 3 less the volume of air produced as bubbles through theholes 5, andnipples 4 if used, as will be described further below. - The
air distribution pipe 3 is located as close as possible to theair box 2 to limit the height of the water column (or pressure) which must be overcome to eject air and thereby minimize energy required. The air distribution pipe may be located such that it discharges air directly inside theair box 2. - The
air box 2 may be attached to themembrane assembly 1 which facilitates inspection when the membrane assembly is pulled out. Alternately, theair box 2 may be attached to theair distribution pipe 3 or attached to its own mounting apparatus. - The
air distribution pipe 3 has at least one large aeration hole located under eachair box 2. The size of the aeration holes in theair distribution pipe 3 may be chosen to minimize fouling, for example, very large holes may foul less rapidly. Theair distribution pipe 3 may simultaneously supply air toseveral air boxes 2. - Referring to
FIG. 2 , theair box 2 upper surface has a series ofair holes 5 arranged in a regular pattern. The hole size is such that theholes 5 do not plug from debris in water and produce bubbles of an appropriate diameter for scouring themembrane assembly 1, typically 5-15 mm. The density ofholes 5 depends on design of themembrane assembly 1 and aeration requirements and may be 25 to 160 holes per square metre. The holes may be fitted withnipples 4 pointing downward to provide a residual air cushion in theair box 2 which promotes the rapid horizontal dispersion of air. - In operation, the rate of air flow in the
air distribution pipe 3 varies in a repeated cycle having a total cycle length or duration of between about 10 and 100 seconds. In general, there is a period at a higher flow rate and a period at a lower flow rate. The lower flow rate is one half or less of the higher flow rate. - The lower flow rate may be 10% or less than the higher flow rate or the lower flow rate may an air off condition or have substantially no air flow. The period of higher flow may be between about ⅛ and ½ of the total cycle duration. Most often, the period of higher flow and period of lower flow are each about ½ of the cycle duration. The change between the higher flow rate and the lower flow rate is performed rapidly, i.e. in less than about 6 seconds or in less than about 3 seconds.
- During the higher flow period, the
air box 2 fills with air because the air flow from theair distribution pipe 3 is larger than the air flow from theair box 2 as bubbles which flow upwards to themembrane assembly 1. - The air box continues to discharge air bubbles through the
holes 5 to scour themembrane assembly 1 during the lower flow period. Theair box 2 may be sized in relation to the number and size ofholes 5 and the flow rate and duration of air flow from theair distribution pipe 3 such that air flows through theholes 5 throughout each cycle. Alternately, theair box 2 may be sized to become empty of air during a part of the lower flow period which allows tank water to flow thorough theholes 5 ornipples 4 to wash away deposits left around theholes 5 ornipples 4. - Air cycling, meaning a flow of air that varies in rate as described above, may be provided to multiple, distinct groups of
membrane assemblies 1 connected to 2 or moreair distribution pipes 3 from a single air blower operated at a single rate. This is done by providing a plurality ofair distribution pipes 3 which form or communicate with a plurality of distinct branches of an air distribution system. A valve set communicates between an air supply and the distinct branches. The valve set is operated to split an initial air flow from the air supply such that at any time at least one distinct branch receives air at a higher flow rate and at least one other of the branches receives air at a lower rate. The valve set switches which distinct branch or branches receives air at the higher flow rate and the lower flow rate in repeated cycles. This is described more fully in WO 00/21890 which is incorporated herein in its entirety by this reference. - Because of the volume of air temporarily contained in the
air box 2 during the high flow period, bubbles are produced for a greater portion of the cycle than the higher flow period. For example, if two distinct branches are provided, the higher flow period in each will be about ½ of the cycle duration but bubbles may be produced for between about ½ and ¾ of the cycle duration. Alternately, 4 distinct branches might be fitted to a single blower and each receive air at the higher flow rate for about ¼ of the cycle duration. Yet, because of the volume of air temporarily trapped in theair box 2, bubbles can be produced for about ⅓ to ½ of the cycle duration. - Benefits of the first embodiment include:
- 1. Avoid an aerator grid which requires a larger network of pipes.
- 2. Reduce the need to flush aerators with permeate to wash away deposits left by tank water entering the aerator as described in U.S. Pat. No. 5,944,997 issued on Aug. 31, 1999 to Pedersen et al.
- 3. Facilitates scale-up to aeration of a large set of
membrane assemblies 1. - 4. Decreases maintenance requirements since the
air box 2 is easily cleaned and is generally self cleaning when permitted to flood periodically. - Three further embodiments, A, B and C, are shown in
FIG. 3 . These embodiments are like the first embodiment in many ways and the description of the first embodiment generally applies to them except for the differences noted below. -
FIG. 3 showssecond aerators second aerator shell 112A,B,C withopenings 114 for discharging bubbles from their upper surfaces. The shape of thesecond aerator shells 112A,B,C allows them to at least temporarily contain a variable volume of air in fluid communication with theopenings 114. Thesecond aerator shells 112A,B,C are also downwardly open to allow tank water or substrate to act against any contained air. Theopenings 114 are located so that discharged bubbles will rise through amembrane assembly 1. Parts of themembrane assemblies 1, forexample headers 116, form part of thesecond aerator shells 112A,B,C.Four membrane assemblies 1 are shown, but thesecond aerator shells 112A,B,C may be used with more membrane assemblies, ie. between four and sixteen, or more,membrane assemblies 1.Side walls 118 of thesecond aerator shells 112A,B,C may also be made as parts of themembrane assemblies 1.Flanges 120 on theheaders 116 are also part of thesecond aerator shell 112B. Hole formingstrips 122 between theheaders 116 are part of thethird aerator shell 112C. The hole forming strips may be made as part of themembrane assemblies 122.Air distribution pipes 3 are provided below the second aerators 110 as described above. -
FIG. 4 shows afiltration system 130 havingmembrane assemblies 1 located in atank 132 which is open to the atmosphere to immersemembranes 134 in asubstrate 136. Aninlet 138 for addingsubstrate 136 and anoutlet 140 for retentate are located so as to create a horizontal flow ofsubstrate 142 through thetank 132. Some or all of the retentate may be, but preferably is not, circulated to theinlet 138 and asecond outlet 144 or other means for removing settled solids may be provided. Themembrane assemblies 1 are located within the horizontal flow ofsubstrate 142 and may be spaced or oriented to encourage the horizontal flow ofsubstrate 142 to carry solids in the substrate to theoutlet 140. For example,elongated membrane assemblies 1 may be oriented generally parallel with the horizontal flow ofsubstrate 142.Second aerators 110A are shown althoughfirst aerators 10 orsecond aerators 110B,C may also be used. Theaerators 10,110 are operated as described above. Iffirst aerators 10 are used, they may be located closely below themembrane assemblies 1 since the horizontal flow ofsubstrate 142 reduces or eliminates the need forsubstrate 136 to circulate around themembrane assemblies 1. Air is supplied to theaerators 10, 110 throughair distribution pipes 3 connected tobranches 146 of acyclic aeration system 148. - Other embodiments of the invention may be made in alternate configurations and operated according to alternate methods within the scope of the invention which is defined by the following claims:
Claims (10)
1. A process for aerating a membrane assembly comprising the steps of
a. providing
i. a membrane assembly having hollow fiber membranes held at their lower ends in a mass of potting material,
ii. side walls extending downwards from the mass of potting material; and,
iii. an aerator shell comprising the mass of potting material and the side walls and further comprising openings for discharging bubbles, the openings oriented vertically and adapted to transmit a gas through the aerator shell from below the mass of potting material to above the mass of potting material, the aerator shell adapted to contain a variable volume of the gas in fluid communication with the openings; and,
b. flowing a gas into the aerator shell at a rate that varies cyclically from a higher flow rate to a lower flow rate, the lower flow rate being in the range from no flow to one half of the higher flow rate, the cycles having a duration of 120 seconds or less.
2. The process of claim 1 wherein the rate of air flow during the period of low flow is 10% or less of the rate of air flow during the period of high flow.
3. The process of claim 2 wherein there is substantially no air flow during the period of low air flow.
4. The process of any of claim 1 wherein the period of high flow is between about ⅛ and ½ of the total cycle duration.
5. The process of any of claim 1 wherein the change between the high flow rate and low flow rate is performed in less than about 6 seconds.
6. The process of claim 5 wherein the change between the high flow rate and low flow rate is performed in less than about 3 seconds.
7. The process of any of claim 1 wherein the aerator is sized in relation to the duration and rate of air flow provided during a cycle such that air flows through the holes throughout each cycle.
8. The process of any of claim 1 wherein the aerator is sized in relation to the duration and rate of air flow provided during a cycle such that no air flows through the holes during at least part of the cycle such that liquid in the tank may flow into the holes.
9. The process of claim 8 wherein air flows through the holes of the aerator for between about ⅓ and ¾ of the cycle duration.
10. The process of claim 9 wherein air flows through the holes for about ½ of the cycle duration.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/052,092 US20050127000A1 (en) | 2001-03-23 | 2005-02-08 | Inverted air box aerator and aeration method for immersed membranes |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US27800701P | 2001-03-23 | 2001-03-23 | |
US10/061,108 US20020134740A1 (en) | 2001-03-23 | 2002-02-01 | Inverted air box aerator and aeration method for immersed membrane |
US10/171,997 US6863823B2 (en) | 2001-03-23 | 2002-06-17 | Inverted air box aerator and aeration method for immersed membrane |
US11/052,092 US20050127000A1 (en) | 2001-03-23 | 2005-02-08 | Inverted air box aerator and aeration method for immersed membranes |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/171,997 Continuation US6863823B2 (en) | 1995-08-11 | 2002-06-17 | Inverted air box aerator and aeration method for immersed membrane |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050127000A1 true US20050127000A1 (en) | 2005-06-16 |
Family
ID=34657820
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/171,997 Expired - Fee Related US6863823B2 (en) | 1995-08-11 | 2002-06-17 | Inverted air box aerator and aeration method for immersed membrane |
US11/052,092 Abandoned US20050127000A1 (en) | 2001-03-23 | 2005-02-08 | Inverted air box aerator and aeration method for immersed membranes |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/171,997 Expired - Fee Related US6863823B2 (en) | 1995-08-11 | 2002-06-17 | Inverted air box aerator and aeration method for immersed membrane |
Country Status (1)
Country | Link |
---|---|
US (2) | US6863823B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090071901A1 (en) * | 2007-09-19 | 2009-03-19 | Rabie Hamid R | System and method for filtering liquids |
WO2012148990A1 (en) * | 2011-04-25 | 2012-11-01 | Hydranautics | Diffuser for gas scouring filtration membranes |
Families Citing this family (52)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6863823B2 (en) * | 2001-03-23 | 2005-03-08 | Zenon Environmental Inc. | Inverted air box aerator and aeration method for immersed membrane |
DE69633806T2 (en) * | 1995-08-11 | 2005-05-12 | Zenon Environmental Inc., Oakville | Device for removing permeate from a liquid substrate with several components |
CA2639642C (en) | 1996-12-20 | 2013-01-15 | Siemens Water Technologies Corp. | Scouring method |
US6641733B2 (en) * | 1998-09-25 | 2003-11-04 | U. S. Filter Wastewater Group, Inc. | Apparatus and method for cleaning membrane filtration modules |
US6706189B2 (en) * | 1998-10-09 | 2004-03-16 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US7014173B2 (en) * | 1998-10-09 | 2006-03-21 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
CA2290053C (en) * | 1999-11-18 | 2009-10-20 | Zenon Environmental Inc. | Immersed membrane module and process |
AUPR421501A0 (en) | 2001-04-04 | 2001-05-03 | U.S. Filter Wastewater Group, Inc. | Potting method |
AUPR692401A0 (en) | 2001-08-09 | 2001-08-30 | U.S. Filter Wastewater Group, Inc. | Method of cleaning membrane modules |
AUPS300602A0 (en) | 2002-06-18 | 2002-07-11 | U.S. Filter Wastewater Group, Inc. | Methods of minimising the effect of integrity loss in hollow fibre membrane modules |
AU2002950934A0 (en) * | 2002-08-21 | 2002-09-12 | U. S. Filter Wastewater Group, Inc. | Aeration method |
CA2501628C (en) | 2002-10-10 | 2012-12-04 | U.S. Filter Wastewater Group, Inc. | A filtration and backwashing arrangement for membrane modules |
AU2002953111A0 (en) * | 2002-12-05 | 2002-12-19 | U. S. Filter Wastewater Group, Inc. | Mixing chamber |
AU2003297476A1 (en) * | 2002-12-19 | 2004-07-14 | Hydranautics | Methods for cleaning and maintaining membrane surface during filtration |
EP1599276B1 (en) * | 2003-03-05 | 2008-05-14 | Hydranautics | Submergible membrane modular filtration device having replaceable membrane elements |
EP1466658A1 (en) * | 2003-04-11 | 2004-10-13 | UTISOL Technologies AG | Device and method for aeration of membrane filters |
WO2005021140A1 (en) | 2003-08-29 | 2005-03-10 | U.S. Filter Wastewater Group, Inc. | Backwash |
CN100421772C (en) | 2003-11-14 | 2008-10-01 | 西门子水技术公司 | Improved module cleaning method |
WO2005092799A1 (en) | 2004-03-26 | 2005-10-06 | U.S. Filter Wastewater Group, Inc. | Process and apparatus for purifying impure water using microfiltration or ultrafiltration in combination with reverse osmosis |
AU2005240524C1 (en) | 2004-04-22 | 2009-12-24 | Evoqua Water Technologies Llc | Filtration apparatus comprising a membrane bioreactor and a treatment vessel for digesting organic materials |
EP1789164B1 (en) * | 2004-08-20 | 2013-07-03 | Siemens Industry, Inc. | Square mbr manifolding system |
JP4838248B2 (en) | 2004-09-07 | 2011-12-14 | シーメンス・ウォーター・テクノロジーズ・コーポレーション | Reduction of backwash liquid waste |
CA2579857A1 (en) | 2004-09-14 | 2006-03-23 | Siemens Water Technologies Corp. | Membrane filtration module and cleaning process |
CA2579894A1 (en) * | 2004-09-15 | 2006-03-23 | Siemens Water Technologies Corp. | Continuously variable aeration |
US8496828B2 (en) | 2004-12-24 | 2013-07-30 | Siemens Industry, Inc. | Cleaning in membrane filtration systems |
JP2008525167A (en) | 2004-12-24 | 2008-07-17 | シーメンス・ウォーター・テクノロジーズ・コーポレーション | Simple gas cleaning method and apparatus in the technical field |
JP2008526497A (en) * | 2005-01-14 | 2008-07-24 | シーメンス・ウォーター・テクノロジーズ・コーポレーション | Filtration system |
CA2605757A1 (en) | 2005-04-29 | 2006-11-09 | Siemens Water Technologies Corp. | Chemical clean for membrane filter |
WO2007022576A1 (en) | 2005-08-22 | 2007-03-01 | Siemens Water Technologies Corp. | An assembly for water filtration using a tube manifold to minimise backwash |
US20070138090A1 (en) | 2005-10-05 | 2007-06-21 | Jordan Edward J | Method and apparatus for treating wastewater |
WO2008051546A2 (en) | 2006-10-24 | 2008-05-02 | Siemens Water Technologies Corp. | Infiltration/inflow control for membrane bioreactor |
EP2129629A1 (en) | 2007-04-02 | 2009-12-09 | Siemens Water Technologies Corp. | Improved infiltration/inflow control for membrane bioreactor |
US9764288B2 (en) | 2007-04-04 | 2017-09-19 | Evoqua Water Technologies Llc | Membrane module protection |
CA3058737C (en) | 2007-05-29 | 2022-04-26 | Fufang Zha | Membrane cleaning with pulsed airlift pump |
KR101614520B1 (en) | 2008-07-24 | 2016-04-21 | 에보쿠아 워터 테크놀로지스 엘엘씨 | Frame system for membrane filtration modules |
NZ591259A (en) | 2008-08-20 | 2013-02-22 | Siemens Industry Inc | A hollow membrane filter backwash system using gas pressurised at at least two pressures feed from the down stream side to push water through the filter to clean it |
AU2010257526A1 (en) | 2009-06-11 | 2012-01-12 | Siemens Industry, Inc | Methods for cleaning a porous polymeric membrane and a kit for cleaning a porous polymeric membrane |
US9914097B2 (en) | 2010-04-30 | 2018-03-13 | Evoqua Water Technologies Llc | Fluid flow distribution device |
DE102010019505B4 (en) * | 2010-05-06 | 2016-09-29 | Microdyn - Nadir Gmbh | Filtration device with internal recirculation |
WO2012040412A1 (en) | 2010-09-24 | 2012-03-29 | Siemens Industry, Inc. | Fluid control manifold for membrane filtration system |
US8910799B2 (en) | 2011-08-01 | 2014-12-16 | Enveera, Inc. | Integrated membrane system for distributed water treatment |
US8876089B2 (en) | 2011-09-15 | 2014-11-04 | Zenon Technology Partnership | Method and apparatus to keep an aerator full of air |
HUE058060T2 (en) | 2011-09-30 | 2022-07-28 | Rohm & Haas Electronic Mat | Isolation valve |
KR101964484B1 (en) | 2011-09-30 | 2019-04-01 | 에보쿠아 워터 테크놀로지스 엘엘씨 | Improved manifold arrangement |
US9533261B2 (en) | 2012-06-28 | 2017-01-03 | Evoqua Water Technologies Llc | Potting method |
GB2520871B (en) | 2012-09-26 | 2020-08-19 | Evoqua Water Tech Llc | Membrane securement device |
AU2013231145B2 (en) | 2012-09-26 | 2017-08-17 | Evoqua Water Technologies Llc | Membrane potting methods |
WO2014052139A1 (en) | 2012-09-27 | 2014-04-03 | Evoqua Water Technologies Llc | Gas scouring apparatus for immersed membranes |
EP3052221B1 (en) | 2013-10-02 | 2022-12-14 | Rohm & Haas Electronic Materials Singapore Pte. Ltd | Device for repairing a membrane filtration module |
WO2017011068A1 (en) | 2015-07-14 | 2017-01-19 | Evoqua Water Technologies Llc | Aeration device for filtration system |
US10894731B2 (en) * | 2016-10-25 | 2021-01-19 | Ds Services Of America, Inc. | Ozone generator for water purification system |
CN112774444B (en) * | 2020-12-18 | 2022-06-14 | 武汉艾科滤膜技术有限公司 | Free floating ball type gas-liquid separation ultrafiltration membrane component |
Citations (29)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2995497A (en) * | 1957-01-26 | 1961-08-08 | Biochemical Processes Inc | Method and means for treatment of a liquid with a gaseous medium, or viceversa |
US4923614A (en) * | 1986-06-12 | 1990-05-08 | Wilke Engelbart | Process and device for large surface-area fine-bubble gasification of liquids |
US5133862A (en) * | 1991-01-31 | 1992-07-28 | Fmc Corporation | Flexible membrane diffuser |
US5151191A (en) * | 1990-09-26 | 1992-09-29 | Japan Organo Co., Ltd. | Filtration process using hollow fiber membrane module |
US5192456A (en) * | 1991-03-07 | 1993-03-09 | Kubota Corporation | Apparatus for treating activated sludge and method of cleaning it |
US5248424A (en) * | 1990-08-17 | 1993-09-28 | Zenon Environmental Inc. | Frameless array of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate |
US5480553A (en) * | 1992-02-12 | 1996-01-02 | Mitsubishi Rayon Co., Ltd. | Hollow fiber membrane module |
US5482625A (en) * | 1994-01-07 | 1996-01-09 | Kubota Corporation | Filtration membrane module |
US5639373A (en) * | 1995-08-11 | 1997-06-17 | Zenon Environmental Inc. | Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate |
US5716519A (en) * | 1996-04-05 | 1998-02-10 | Chicago Bridge & Iron Technical Services Company | Apparatus for discharging fluid additives into a water treatment vessel |
US5910250A (en) * | 1995-08-11 | 1999-06-08 | Zenon Environmental Inc. | Baffle for conversion of fine bubbles to coarse while filtering with a vertical skein of hollow fibers |
US5922201A (en) * | 1992-02-12 | 1999-07-13 | Mitsubishi Rayon Co., Ltd. | Hollow fiber membrane module |
US5944997A (en) * | 1995-08-11 | 1999-08-31 | Zenon Environmental Inc. | System for maintaining a clean skein of hollow fibers while filtering suspended solids |
US5989428A (en) * | 1996-06-21 | 1999-11-23 | Goronszy; Mervyn Charles | Controlling wastewater treatment by monitoring oxygen utilization rates |
US6156200A (en) * | 1998-12-08 | 2000-12-05 | Usf Filtration & Separations Group, Inc. | Gas-scrubbed hollow fiber membrane module |
US6193890B1 (en) * | 1995-08-11 | 2001-02-27 | Zenon Environmental Inc. | System for maintaining a clean skein of hollow fibers while filtering suspended solids |
US6199835B1 (en) * | 1997-10-21 | 2001-03-13 | Exxon Research And Engineering Company | Throat and cone gas injector and gas distribution grid for slurry reactor (LAW646) |
US6245239B1 (en) * | 1998-10-09 | 2001-06-12 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6280626B1 (en) * | 1998-08-12 | 2001-08-28 | Mitsubishi Rayon Co., Ltd. | Membrane separator assembly and method of cleaning the assembly utilizing gas diffuser underneath the assembly |
US6284135B1 (en) * | 1997-12-16 | 2001-09-04 | Sumitomo Heavy Industries, Ltd. | Membrane filter apparatus with gas discharge cleaning means |
US20010027951A1 (en) * | 1998-10-09 | 2001-10-11 | Christian Gungerich | Aerated immersed membrane system |
US6319411B1 (en) * | 1998-10-09 | 2001-11-20 | Zenon Environmental Inc. | Method of maintaining clean vertical skeins of hollow fiber membranes and system therefor |
US6478964B1 (en) * | 2001-05-18 | 2002-11-12 | Midwest Water Management, Llp | Floating fine-bubble aeration system |
US6524481B2 (en) * | 1998-09-25 | 2003-02-25 | U.S. Filter Wastewater Group, Inc. | Apparatus and method for cleaning membrane filtration modules |
US6550747B2 (en) * | 1998-10-09 | 2003-04-22 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6641733B2 (en) * | 1998-09-25 | 2003-11-04 | U. S. Filter Wastewater Group, Inc. | Apparatus and method for cleaning membrane filtration modules |
US6658358B2 (en) * | 2002-05-02 | 2003-12-02 | Hewlett-Packard Development Company, L.P. | Method and system for computing forces on data objects for physics-based visualization |
US6706189B2 (en) * | 1998-10-09 | 2004-03-16 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6863823B2 (en) * | 2001-03-23 | 2005-03-08 | Zenon Environmental Inc. | Inverted air box aerator and aeration method for immersed membrane |
-
2002
- 2002-06-17 US US10/171,997 patent/US6863823B2/en not_active Expired - Fee Related
-
2005
- 2005-02-08 US US11/052,092 patent/US20050127000A1/en not_active Abandoned
Patent Citations (34)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2995497A (en) * | 1957-01-26 | 1961-08-08 | Biochemical Processes Inc | Method and means for treatment of a liquid with a gaseous medium, or viceversa |
US4923614A (en) * | 1986-06-12 | 1990-05-08 | Wilke Engelbart | Process and device for large surface-area fine-bubble gasification of liquids |
US5248424A (en) * | 1990-08-17 | 1993-09-28 | Zenon Environmental Inc. | Frameless array of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate |
US5151191A (en) * | 1990-09-26 | 1992-09-29 | Japan Organo Co., Ltd. | Filtration process using hollow fiber membrane module |
US5133862A (en) * | 1991-01-31 | 1992-07-28 | Fmc Corporation | Flexible membrane diffuser |
US5192456A (en) * | 1991-03-07 | 1993-03-09 | Kubota Corporation | Apparatus for treating activated sludge and method of cleaning it |
US5922201A (en) * | 1992-02-12 | 1999-07-13 | Mitsubishi Rayon Co., Ltd. | Hollow fiber membrane module |
US5480553A (en) * | 1992-02-12 | 1996-01-02 | Mitsubishi Rayon Co., Ltd. | Hollow fiber membrane module |
US5482625A (en) * | 1994-01-07 | 1996-01-09 | Kubota Corporation | Filtration membrane module |
USRE37549E1 (en) * | 1995-08-11 | 2002-02-19 | Zenon Environmental Inc. | Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate |
US6620319B2 (en) * | 1995-08-11 | 2003-09-16 | Zenon Enviromental Inc. | Apparatus for withdrawing permeate using an immersed vertical skein of hollow fibre membranes |
US5910250A (en) * | 1995-08-11 | 1999-06-08 | Zenon Environmental Inc. | Baffle for conversion of fine bubbles to coarse while filtering with a vertical skein of hollow fibers |
US5639373A (en) * | 1995-08-11 | 1997-06-17 | Zenon Environmental Inc. | Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate |
US5944997A (en) * | 1995-08-11 | 1999-08-31 | Zenon Environmental Inc. | System for maintaining a clean skein of hollow fibers while filtering suspended solids |
US5783083A (en) * | 1995-08-11 | 1998-07-21 | Zenon Environmental Inc. | Vertical cylindrical skein of hollow fiber membranes and method of maintaining clean fiber surfaces |
US6042677A (en) * | 1995-08-11 | 2000-03-28 | Zenon Environmental, Inc. | Potted header for hollow fiber membranes and method for making it |
US6193890B1 (en) * | 1995-08-11 | 2001-02-27 | Zenon Environmental Inc. | System for maintaining a clean skein of hollow fibers while filtering suspended solids |
US5716519A (en) * | 1996-04-05 | 1998-02-10 | Chicago Bridge & Iron Technical Services Company | Apparatus for discharging fluid additives into a water treatment vessel |
US5989428A (en) * | 1996-06-21 | 1999-11-23 | Goronszy; Mervyn Charles | Controlling wastewater treatment by monitoring oxygen utilization rates |
US6199835B1 (en) * | 1997-10-21 | 2001-03-13 | Exxon Research And Engineering Company | Throat and cone gas injector and gas distribution grid for slurry reactor (LAW646) |
US6402955B2 (en) * | 1997-12-16 | 2002-06-11 | Sumitomo Heavy Industries, Ltd. | Method for operating a membrane filter having a gas discharge cleaning means |
US6284135B1 (en) * | 1997-12-16 | 2001-09-04 | Sumitomo Heavy Industries, Ltd. | Membrane filter apparatus with gas discharge cleaning means |
US6280626B1 (en) * | 1998-08-12 | 2001-08-28 | Mitsubishi Rayon Co., Ltd. | Membrane separator assembly and method of cleaning the assembly utilizing gas diffuser underneath the assembly |
US6641733B2 (en) * | 1998-09-25 | 2003-11-04 | U. S. Filter Wastewater Group, Inc. | Apparatus and method for cleaning membrane filtration modules |
US6524481B2 (en) * | 1998-09-25 | 2003-02-25 | U.S. Filter Wastewater Group, Inc. | Apparatus and method for cleaning membrane filtration modules |
US6550747B2 (en) * | 1998-10-09 | 2003-04-22 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6319411B1 (en) * | 1998-10-09 | 2001-11-20 | Zenon Environmental Inc. | Method of maintaining clean vertical skeins of hollow fiber membranes and system therefor |
US20010027951A1 (en) * | 1998-10-09 | 2001-10-11 | Christian Gungerich | Aerated immersed membrane system |
US6245239B1 (en) * | 1998-10-09 | 2001-06-12 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6706189B2 (en) * | 1998-10-09 | 2004-03-16 | Zenon Environmental Inc. | Cyclic aeration system for submerged membrane modules |
US6156200A (en) * | 1998-12-08 | 2000-12-05 | Usf Filtration & Separations Group, Inc. | Gas-scrubbed hollow fiber membrane module |
US6863823B2 (en) * | 2001-03-23 | 2005-03-08 | Zenon Environmental Inc. | Inverted air box aerator and aeration method for immersed membrane |
US6478964B1 (en) * | 2001-05-18 | 2002-11-12 | Midwest Water Management, Llp | Floating fine-bubble aeration system |
US6658358B2 (en) * | 2002-05-02 | 2003-12-02 | Hewlett-Packard Development Company, L.P. | Method and system for computing forces on data objects for physics-based visualization |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090071901A1 (en) * | 2007-09-19 | 2009-03-19 | Rabie Hamid R | System and method for filtering liquids |
WO2012148990A1 (en) * | 2011-04-25 | 2012-11-01 | Hydranautics | Diffuser for gas scouring filtration membranes |
Also Published As
Publication number | Publication date |
---|---|
US6863823B2 (en) | 2005-03-08 |
US20020153313A1 (en) | 2002-10-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6863823B2 (en) | Inverted air box aerator and aeration method for immersed membrane | |
US7087173B2 (en) | Inverted cavity aerator for membrane module | |
AU776211B2 (en) | Immersed membrane filtration system and overflow process | |
US6893568B1 (en) | Immersed membrane filtration system and overflow process | |
KR101625172B1 (en) | Water treatment system | |
US6708957B2 (en) | Moving aerator for immersed membranes | |
AU2008255640B2 (en) | Membrane cleaning using an airlift pump | |
US20100237014A1 (en) | Membrane module with multiple bottom headers and filtration process | |
US10828607B2 (en) | Aerator device, filter system including an aerator device, and method of aerating a filter using an aerator device | |
US9815027B2 (en) | Gas scouring apparatus for immersed membranes | |
PL214717B1 (en) | Cyclic aeration system for submerged membrane modules | |
US20020134740A1 (en) | Inverted air box aerator and aeration method for immersed membrane | |
AU2013206181A1 (en) | Membrane module with multiple bottom headers and filtration process |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ZENON ENVIRONMENTAL INC., CANADA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:COTE, PIERRE LUCIEN;REEL/FRAME:016788/0185 Effective date: 20050406 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |