Definitions

• the present invention relates to a method and apparatus for the purification of water
• This (now acidic) solution is then passed through a bed of anion
• the cation and anion resins are intimately mixed, and the
• exhausted resin remains the principal means of removing dissolved salts from water to
• the system comprises four alternating cation (c)
• a bank of such cells can be used to calculate the cations and anions from the feed solution.
• a bank of such cells can be used to calculate the cations and anions from the feed solution.
• the intermediate concentrating chambers have anions and cations entering through the membranes on
• modules involve a
• the current invention has significant
• the resin to be purified is placed in the ion-depletion chambers of the "Elix" type
• This patent discloses a method for the regeneration of ion exchange resins within the
• each of the dilution compartments (comprising a compartment defined by an anion and a cation exchange membrane), is further divided by a bipolar
• This patent discloses a process for the electrochemical regeneration of a cation
• H + is generated, and displaces ions associated with the cation exchange
• the anion resin is one mixed bed and the cation resin is the other mixed bed, are being
• This patent discloses a method for partial regeneration of ion exchange resin in an
• pair of electrodes one each being associated with a respective material bed such that at least
• the present invention provides apparatus for purifying a
• liquid stream comprising at least two ion exchange material beds, each bed containing a
• the invention also provides a method of purifying a liquid stream comprising the
• the beds being connected at at least one point such that a junction which is permeable to
• electrodes being arranged such that at least some ion exchange material is sandwiched
• the cathode When using separate anion and cation exchange material beds, the cathode is placed
• a liquid stream to be purified is fed into one of the beds, preferably to the base of one
• hydroxide and hydrogen ions at the cathode are anode respectively.
• the electric field causes the contaminant ions that had been absorbed by the ion exchange material to collect
• a small flow of liquid is caused in the vicinity of the bed junction, from one or
• the ion exchange material in the beds is
• These products may be flushed away by a liquid stream passing over the electrodes.
• the cathode may be separated from the ion exchange beds by a cation exchange
• material beds should be such that, at least in part, it is different to the direction of flow of
• beds is formed such that it is permeable to anions or cations or both anions and cations but
• connection path can exist between the ion exchange material beds without allowing the
• a cation exchange membrane is used.
• Another method for forming the junction is to pack ion exchange resin beads into a
• a grid with a larger mesh size could be used as
• the electrode structure could be used as it is
• filaments of ion exchange material or a macroporous monolith of the material are filaments of ion exchange material or a macroporous monolith of the material.
• structures can be made by any suitable method.
• a macroporous monolith could be fabricated by adding foaming agents
• Filaments of ion exchange material can be formed, for example, by melt blowing filaments of polymer which could subsequently be spun bonded
• the polymer which forms the filaments could contain ion exchange
• polyacrylates examples include sulfonate, carboxylic acid,
• the filaments contain cation exchange groups and some contain anion exchange groups.
• Another method is to use filaments, beads or a monolith of suitable polymer material
• the final ion exchange materials contain mixed cation and anion exchange groups.
• polystyrene beads could be chemically treated such that each bead contained both
• the electrical potential is applied across the beds junction such that the
• protons and hydroxide ions thus formed will then travel through the beds of ion exchange
• junction such that cations and anions present in the bed are attracted towards the junction
• a gutter may be provided at the base
• each bed of ion exchange material has at least
• one junction functions as a source of protons
• the junctions can be any suitable type of this aspect of the invention. According to one preferred form of this aspect of the invention, the junctions can be any suitable form of this aspect of the invention.
• the semipermeable membrane may be either a bipolar membrane or a cation or
• the membrane may be either a cation or anion or a cation and anion permselective
• membranes examples include NafionTM (DuPont), TosflexTM (TOSH) or
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the anode is selected from any material that is inert under the conditions used.
• the cathode is fabricated from
• titanium coated with gold, platinum, palladium or iridium titanium coated with gold, platinum, palladium or iridium.
• a shared manifold for the feed liquid to all the beds may
• first ion exchange material beds to assist in pressure equalisation between the pairs of beds.
• the present invention provides a method for forming a junction
• said structure having a packing density sufficient to substantially restrict the flow
• Figure 1 shows a schematic of a one preferred embodiment of a first aspect of the
• Figure 2 shows a schematic of a second prefe ⁇ ed embodiment of the first aspect of
• Figure 3 shows a schematic of a third preferred embodiment of the first aspect of the
• Figure 4 shows a schematic of a one preferred embodiment of the fifth aspect of the
• Figure 5 shows a schematic of a second preferred embodiment of the fifth aspect of
• Figure 6 shows a schematic of a third preferred embodiment of the fifth aspect of the
• two vessels 17 and 18 contain anion exchange material 10
• the liquid to be purified is fed to the base of the anion bed 10 at 5 via a suitable
• a collector could be positioned near the top of the bed
• Purified water exits the bed 11 at 9, again optionally through a suitable
• chloride ions are absorbed by the ion exchange material and replaced with hydroxide ions.
• vents could be incorporated into the tops of vessels 17 and 18 through which any build up
• chloride ions 16 are being continuously deposited, mostly near the base of the ion
• hydroxide or hydrogen ions This is desirable as pairs of hydroxide 14 and hydrogen
• the beds may be such that the liquid flow through each beds
• the liquid may enter the base of the bed at
• purified is directed such that it does not disturb the liquid near the membrane/exchange
• the anode 23 is placed at one end of the stack of ion
• the other end of the stack of ion exchange material beds may be separated from the
• a flow of liquid would be caused to flow past the electrodes to assist in carrying
• This liquid may go directly to waste or be recirculated
• FIG. 3 A third embodiment of the present invention is depicted in Figure 3. This figure
• vessels 21 are filled with mixed anion and cation exchange material 30. Each vessel is
• a piece of anion exchange membrane 28 can be used to prevent the hydroxide
• liquid is directed over them to provide water for the electrode reactions and to assist in
• the liquid to be purified 49 enters the bank of ion exchange material beds 41 via a common manifold 54.
• the liquid travels up through either a cation, 44 or an anion, 45 exchange
• the product liquid 50 then exits the beds via the common
• electrodes being separated from the beds of ion exchange material by a cation exchange
• the gutters 48 have a drain point open to the
• the base of the junctions 46 are optional and may be required when treating feed streams
• the manifolding of the liquid flow through the beds may be changed such that the liquid to be purified first travels through one ion exchange material
• junctions 46 or 47 or both substantially restrict the flow of liquid through
• a separate pair of electrodes may be
• each bank of beds may have one common pair of electrodes.
• exchange material in the first bank has a bed of the opposite type of ion exchange material
• a cathode 42 is placed at the one end of this double bank of ion
• anode and cathode supply current to both banks of beds simultaneously. If desired, the
• Electrodes can be separated from the end beds of ion exchange material either by a cation exchange membrane 51 or an anion exchange membrane 52.
• the two banks of beds can be arranged in any order.
• a separate pair of electrodes is used for each bank of beds. Preferably these
• bank of beds is long enough and of small enough cross-section such that the resistance to
• connection between the beds but restricts or substantially prevents the flow of liquid
• junction means could be an ion exchange membrane.
• the anode is placed at the other end.
• the banks of beds could be joined
• This ion exchange material is formed to make the junction.
• This ion exchange material may be in
• the density of packing of the material is
• resistance may be such that, by itself it restricts the liquid flow to the desired level or, such
• junction resistance is used in combination with a valve or capillary to give the
• the densely packed material has two regions abutting one another, one
• cation exchange material faces the cation exchange bed.
• macroporous material or mesh can be placed between the regions to give a relatively low
• the junction structure may be self
• the mesh is preferably fine enough to substantially retain the powder
• this extruded material can be sprayed with a binder to increase the robustness of the structure.
• Fine powdered material may also be mixed with a binder and
• the thinner portion of the wedge is less than through the thicker portion of the wedge so

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• Separation Using Semi-Permeable Membranes (AREA)
• Treatment Of Water By Ion Exchange (AREA)
• Water Treatment By Electricity Or Magnetism (AREA)

Applications Claiming Priority (5)

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• 1998
  • 1998-05-08 EP EP98920385A patent/EP1027289A1/de not_active Withdrawn
  • 1998-05-08 JP JP2000601891A patent/JP2002538944A/ja active Pending

Non-Patent Citations (1)

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