WO2014190411A1 - Point of use water treatment system - Google Patents

Point of use water treatment system Download PDF

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Publication number
WO2014190411A1
WO2014190411A1 PCT/CA2014/000418 CA2014000418W WO2014190411A1 WO 2014190411 A1 WO2014190411 A1 WO 2014190411A1 CA 2014000418 W CA2014000418 W CA 2014000418W WO 2014190411 A1 WO2014190411 A1 WO 2014190411A1
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WO
WIPO (PCT)
Prior art keywords
water
water treatment
point
treatment system
fluid
Prior art date
Application number
PCT/CA2014/000418
Other languages
French (fr)
Inventor
Brian G. COOK
Original Assignee
Esil Water Treatment Limited
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 Esil Water Treatment Limited filed Critical Esil Water Treatment Limited
Publication of WO2014190411A1 publication Critical patent/WO2014190411A1/en

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Classifications

    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/467Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
    • C02F1/4672Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electrooxydation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104Devices therefor; Their operating or servicing
    • C02F1/46109Electrodes
    • C02F2001/46133Electrodes characterised by the material
    • C02F2001/46138Electrodes comprising a substrate and a coating
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104Devices therefor; Their operating or servicing
    • C02F1/46109Electrodes
    • C02F2001/46152Electrodes characterised by the shape or form
    • C02F2001/46171Cylindrical or tubular shaped
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2201/00Apparatus for treatment of water, waste water or sewage
    • C02F2201/46Apparatus for electrochemical processes
    • C02F2201/461Electrolysis apparatus
    • C02F2201/46105Details relating to the electrolytic devices
    • C02F2201/4618Supplying or removing reactants or electrolyte
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00Specific treatment goals
    • C02F2303/18Removal of treatment agents after treatment
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2307/00Location of water treatment or water treatment device
    • C02F2307/10Location of water treatment or water treatment device as part of a potable water dispenser, e.g. for use in homes or offices
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2307/00Location of water treatment or water treatment device
    • C02F2307/14Treatment of water in water supply networks, e.g. to prevent bacterial growth

Definitions

  • the present invention relates to water treatment for effecting a reduction in the concentration of pollutants. More particularly the invention relates to a self-contained water treatment system which can be installed at the intended point of use of the water, so as to substantially remove pollutants from the water source available to a user at the point of use.
  • Non-limiting examples of suitable electrolytes were provided, and examples of apparatus to introduce electrolytes into the electrolytic cell were provided.
  • the patent further taught that the electrolysis was preferably carried out in the presence of elemental carbon.
  • the carbon could be a component of one or both electrodes or could be added to the electrolytic cell as elemental carbon, in the form of graphite powder orl a graphite rod.
  • the process and apparatus disclosed in the '563 patent attained a degree of success.
  • the invention also provided a fluid treatment apparatus comprising a housing including a fluid inlet, a fluid outlet and at least one fluid permeable electrolytic cell disposed therebetween such that the flow of fluid from the fluid inlet to the fluid outlet was substantially transverse to the at least one electrolytic cell, the at least one electrolytic cell comprising a channel defined by an outer, perforated first electrode and an inner, coaxially disposed second electrode.
  • a fluid treatment apparatus comprising a housing including a fluid inlet, a fluid outlet and at least one fluid permeable electrolytic cell disposed therebetween such that the flow of fluid from the fluid inlet to the fluid outlet was substantially transverse to the at least one electrolytic cell, the at least one electrolytic cell comprising a channel defined by an outer, perforated first electrode and an inner, coaxially disposed second electrode.
  • Electrolysis using sacrificial steel electrodes captured impurities in the water using positive ferrous and/or ferric ions.
  • Organo-chloride compounds were de- synthesized by electrolysis and that residue was captured by the ferric/ferrous ions.
  • Coagulants were used to aid in removing impurities from the water being treated.
  • H2 hydrogen gas
  • Hydrogen can react explosively in the presence of oxygen at concentrations greater than about 4%. Handling and disposal of hydrogen and other off gasses can be readily facilitated in large commercial scale water treatment installations. In the context of small scale domestic water treatment systems, the product ion of hydrogen gas poses a safety concern. There is the potential for hydrogen gas to accumulate in the area of the electrolytic cells, particularly if the water treatment system is located in an enclosed area. If hydrogen were to accumulate in excess of 4% in the presence of oxygen, such accumulations would pose an explosive hazard.
  • a point of use water treatment system comprises a water treatment chamber having a fluid inlet, and a fluid outlet, and at least one permeable electrolytic cell disposed therebetween substantially completely filling the only path of water from the fluid inlet to the fluid outlet and oriented such that the path of water from the fluid inlet to the fluid outlet is
  • the at least one electrolytic cell comprises a non-sacrificial anode and a cathode coaxially disposed with respect to one another and having a gap therebetween.
  • a water holding tank in is fluid connection with the water treatment chamber for holding water activated by passage through the at least one electrolytic cell.
  • a post settling filtration means is in fluid connection with the water holding tank for removal of flocculent residue not settled from the water while in the water holding tank.
  • An outer surface of the non-sacrificial anode comprises a noble metal selected from the group consisting of ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. More particularly, the non-sacrificial anode comprises a core plated with platinum. The core of the non-sacrificial anode is copper, plated with niobium, and further plated with platinum.
  • the point of use water treatment system has a hydrogen handling means in fluid connection with the fluid treatment chamber.
  • the hydrogen handling means is a catalytic hydrogen trap that comprises a main body defining a multiplicity of openings, all exposed surfaces of the main body comprising a catalyst for the oxidation of hydrogen. More particularly, all exposed surfaces of the main body comprise platinum.
  • FIG. 17 is a schematic diagram of the point of use water treatment apparatus according to the present invention.
  • Figure 2 is a front view of a first embodiment of the point of use water treatment apparatus.
  • Figure 3 is a side view of the point of use water treatment apparatus of Figure 2. .
  • Figure 4A is a side view of a fluid treatment chamber according to the present invention.
  • Figure 4B is a sectional view of the fluid treatment chamber of Figure 4A taken along line B-B.
  • Figure 4C is an enlarged view of a portion of the end wall of the fluid treatment chamber of Figure 4A.
  • Figure 5A is a sectional view of a first embodiment of an anode according to the present invention.
  • Figure 5B is a sectional view of a second embodiment of an anode according to the present invention.
  • Figure 6 is a perspective view of a catalytic hydrogen trap according to the present invention.
  • Figure7 is a sectional view of the catalytic hydrogen trap of Figure 6 taken along line A-A.
  • Figure 8 is a perspective view of an alternate embodiment of the point of use water treatment apparatus.
  • Figure 9 is a schematic diagram of the alternate embodiment of Figure 8.
  • Figure 10 is a front view of another alternate embodiment of the point of use water treatment system scaled for home use.
  • Figure 1 1 is a side view photograph of the point of use water treatment system of Figure 10.
  • the present invention relates to a process and apparatus for electrolytic treatment of water in need of treatment.
  • water in need of treatment is intended to encompass water containing one or more substances or pollutants the concentration of which it is desirable to reduce or eliminate.
  • the term 'electrolysis' is meant to encompass passage of electricity through a water in need of treatment to provide sufficient energy to cause an otherwise non-spontaneous reduction reaction.
  • the term 'electrolyte' is meant to encompass substances which dissociate in solution to produce ions thereby enabling the solution to conduct electricity.
  • the present process and apparatus may be advantageously utilized for treating water on a small scale at the point of use of the water.
  • the term 'treating water' is meant to encompass treatments such as deposition of metals, microbiological load reductions and the like.
  • the process according to the present invention can be used to decompose, without pre-extraction, organo-chlorine and -chloride compounds such as polychlorinated biphenyl's (PCB's), dioxins , furans, perchlorates, and organo-bromine and -bromide compounds such as polybrominated biphenyls (PBB's), known to be detrimental to the environment.
  • PCB's polychlorinated biphenyl's
  • PBB's polybrominated biphenyls
  • a first embodiment of a point of use water treatment system is shown generally by reference numeral 1 0.
  • a support frame13 is provided and all of the components of the water treatment system are mounted directly or indirectly to the support frame 13.
  • the support frame 13 can be constructed from any material suitable to support the weight of the other components (typically about 300 pounds in total, not including the weight of water held in the system).
  • the support frame 13 may be constructed from steel rods, angle steel, cast aluminum, etc.
  • the support frame 13 comprises a base 80 and uprights 82 which in turn support one or more rails 84for mounting the components of the water treatment system 10.
  • the rails 84 define a plurality of holes 86 for receiving fastening means such as anchor screw, bolts etc.
  • the holes 86 are used in the mounting of components of the water treatment system, and also for wall mounting of the support frame 13.
  • a single freestanding support frame 13 to which all components are directly or indirectly mounted would typically have a footprint of 70 inches by 80 inches (177.8 by 203.2 cm). The particular size is not material to the functionality of the present invention, though it is
  • the support frame 13 be of a size that, when all components of the point of use water treatment system 10 are fixed to the support frame 13 and connected in operational condition, the entire water treatment system 10 is comparable in size to a residential furnace. This target size will permit the components of the system to be moved into residence or other point of use location and installed in a modest space in a basement, large closet or utility room.
  • Connecting lines used in conjunction with appropriate connectors are the means by which fluid connection between the elements of the water treatment system is achieved.
  • the general term 'connecting line' is used in the specification to include all suitable fluid connection means.
  • the connecting lines are identified by reference numeral 12throughout this specification; portions of connection line at differing points in the system are consistently labeled 12. The text does not distinguish between portions of connecting line used at different stages in the water treatment system.
  • the point of use water treatment system of the present invention operates at ambient temperatures and at pressures not typically exceeding 50 psi.
  • the water in need of treatment is not typically particularly corrosive in a small scale point of use treatment system.
  • the water treatment system has a connecting line 12 with an inlet designed for fluid connection to a supply 11 of water in need of treatment provided in a line at standard municipal water pressure.
  • a strainer 14 may optionally be provided in fluid connection therewith to remove any particulates which may be present in the flow of water from the municipal source or introduced into the flow from scale in piping6external to the water treatment apparatus 10.
  • a wire strainer having a mesh size on the order of 150 pm would be suitable, however the particular mesh size is not intended to be limiting. The wire strainer can be easily removed by an operator or user for cleaning and then reattached.
  • a one way check valve 16 is provided in fluid connection with the water supply 1 1 in order to isolate the water treatment apparatus 10 and prevent any backflow into the water source. Downstream of the check valve 16, an adjustable pressure regulator 18 is provided in fluid connection to maintain a steady predetermined through flow of water into the treatment apparatus. Typically the flow will be stabilized in a range of 15-20psi.
  • a variable water shutoff 20 such as a solenoid shutoff, is provided to enable water to be drawn into downstream filtration and electrolysis means as needed. In the event of a power failure the shutoff will be closed, stopping the flow of water.
  • a bypass of the electrolytic water treatment system can also be provided, which will enable users to access water which has at least been treated by the pre-treatment filter and post treatment filters and absorbers in instances of prolonged power outage.
  • a bypass of the electrically operated electrolytic cell can be easily installed, to enable water to pass through the pre-filter and post treatment filters and absorber. This would permit a user to have access to water flow that has at least undergone some filtration even if there is an extended power outage which takes the electrolytic cells offline.
  • an operating pressure gauge is preferably provided downstream of the water shutoff 20 in order to check the operating pressure of the water flowing into the filtration and electrolysis means.
  • a pre-filter 24 is provided in fluid connection in the line downstream of the check valve 16.
  • Preferably the pre-filter 24 will have a moderate mesh size, on the order of 5pm.
  • Standard water filters which are suitable for use as pre-filter 24 are available worldwide from Siemens AG and many other manufacturers and distributors. Common filter materials would include polypropylene mesh. Replacement mesh inserts can be readily sourced and periodically replaced as a consumable article. It would be apparent to one skilled in the art that alternative filters could be substituted.
  • a flow indicator 26 installed in fluid connection within the line 2 downstream of the pre-filter 24.
  • An operator can check the flow indicator to confirm that the pre- filter 24 is functioning correctly and has not become clogged.
  • the flow of water at this point is typically within the range of 0.5 gal to 2.0 gal per minute.
  • a flow control valve 28 provided downstream of the flow indicator 26 allows the flow of water to be adjusted.
  • a manually adjustable needle flow control valve would be suitable for this purpose, but is not meant to be limiting.
  • the flow rate of water in need of treatment can be adjusted in order to modify the quality and characteristics of the treated water output from the water treatment apparatus 10, as will be discussed in greater detail below.
  • a fluid inlet 30 is provided in fluid connection downstream of the flow control7valve 28 to introduce the water into a fluid treatment chamber 32.
  • a drain/sampling valve is optionally provided in the inlet to facilitate inspection of the water quality, as well as draining and servicing of the fluid treatment chamber 32.
  • the fluid treatment chamber 32 contains a plurality of fluid permeable electrolytic cells 34, each of which comprises a cathode 36 and an anode 38 which are spaced apart from and coaxially disposed with respect to one another.
  • a gap 37 exists between the coaxially disposed cathode 36 and the anode 38.
  • one of the cathode or the anode is the electrode which is the outer of the two, the construction and materials of the electrodes can be adapted to facilitate either arrangement.
  • the cathode 36 is the outer one of the electrodes and coaxially surrounds the anode 38. This arrangement is not meant to be limiting.
  • the shape of the cross-section of the cathode 36 and anode 38 is not particularly restricted. It is within the scope of the invention to utilize electrolytic cells comprising various cross-sectional shapes. Thus, is possible for cross-sectional shape of the first electrode and/or the second electrode to be circular, triangular, square, rectangular, hexagonal, and the like. Preferably, the cross-sections of the cathode 36 and anode 38are substantially circular. It is preferred that the ratio of the diameter of the cathode 36to the diameter of the anode 38 would be in the range of about 1.10 to about 3.50, more preferably from about 1.10 to about 1.75, most preferably from about 1.10 to about 1.30.
  • a gap 37 exists between the coaxially disposed cathode 36 and anode 38.
  • the gap 37 is preferably quite small; being on the order of approximately 0.1 to 0.2cm. It is critical to maintain substantially perfect coaxial alignment between the cathode 36 and anode 38. A consistent concentric distance at all points along their length in necessary in order to ensure even distribution of electrical charge at all points in the gap 37 between the anode 36 and cathode 38.
  • a major factor in the effectiveness of the present invention is the DC current field that is established between the cathode 36 and the anode 38.
  • a voltage of 5.0 to 8.0 volts is applied across the gap 37 between each of the first 36 and second 38 electrodes in the cells 34.
  • the level of current applied to the electrolytic cells 34 is not particularly restricted.
  • the current through the electrolytic cells 34 is in the range of about 100 to about 5000 milliampere per elec-8trolytic cell.
  • the gap 37 is quite small (0.1 to 0.2 cm), the strength of the electrical field in the gap 37 between the anode and cathode in each cell 34 is extremely high.
  • the application of 6.5 volts across a 1.5 mm gap is equivalent to 6,500 volts across a 1 .5 meter gap or 4000 volts across a 1 m gap in water (i.e. 4.33 kV/meter).
  • Electrochemical activation is a combination of electrochemical and electro physical actions (performed in conditions of minimal heat evolution) on liquid (mostly on water) containing ions and molecules of substances dissolved in it, in the area of spatial charge near the
  • electrochemical system electrode (either anode, or cathode)surface during non-equilibrium transfer of charge by electrons through the border 'electrode - electrolyte'. Positively charged hydrogen ions are created. Exposure to the electric field induces dipole formation in nonpolar particles in the water. Dipole formation allows the formation of micro-aggregates of insoluble substances to be formed. Charge neutralization of ions or charged materials also takes place creating insoluble suspended substances in the water. Unlike prior art systems which introduced ferrous or ferric ions from a sacrificial anode, the present system results in the formation of insoluble suspended substances in smaller overall quantities than previously obtained. The resulting flocculent is inert and ion-bonded.
  • Electrochemical activation makes it possible to purposefully change dissolved gases, composition, acid-base and oxidative-reductive properties of water in wider limits than under equivalent chemical regulation. It thus becomes possible to synthesize metastable chemical reagents (oxidants or reductants) from water and substances dissolved in it. As a result of electrochemical activation, water becomes metastable (activated) demonstrating for a several hours an increased reactivity in various physical and chemical processes. Water activated by cathode (catholyte) acquires such characteristic as superactivity of electrons and a well- pronounced reductant quality. Correspondingly, water activated by anode (anolyte) is characterized by inhibited electron activity and manifests qualities as an oxidant.
  • the present invention takes advantage of the anode 36 for activation of the water so as to produce a9strong oxidant.
  • the electron density in the gaps 37 between the first 36 and second 38 electrodes in each electrolytic cell 34 is sufficient in operation to generate nascent oxygen and ozone at the anode.
  • Ozone is one of the strongest oxidation agents available for use to oxidize solutes.
  • the point of use water treatment apparatus l Oaccording to the present invention has been optimized to produce minimal amounts of flocculent in a form which will readily settle to the bottom of the settling tank 42 by operation of gravity. Since the present invention avoids the use of sacrificial electrodes, the amount of flocculent is greatly reduced when compared to the amount of ferrous or ferric flocculent produced by prior art methods and apparatus which used steel electrodes. Even after long term operation of the electrolytic cells of the present invention there is no build up of contaminants either on the inside of the cathode 36 or on the outside of the anode 38. This lack of buildup is an indication that the anode 38is not being sacrificed during operation of the electrolytic cells 34.
  • the 38anode is selected to deliver maximum current through the gap 37 and to avoid being consumed having regard to the extremely high electron density which exists in the gap37. It will be understood by persons skilled in the art that the anode in an electrolytic cell is the electrode which is at risk of consumption; the cathode is not normally consumed. Accordingly, the material from which the cathode is constructed does not impact the successful operation of the electrolytic cell.
  • the present invention may function with either electrode acting as the anode. If it was desired that the first electrode (being the outer perforated electrode) were to function as the anode, it would be necessary to construct it from a material which is not consumed during electrolysis.
  • Various non-sacrificial anodes may be selected for use in the electrolytic cells 34of the water treatment system according to the present invention.
  • One such anode is constructed from an elongate tube formed from titanium suboxide by molding, extrusion or the like.
  • a current feeder comprises a length of titanium spring wire which extends along the inner bore of the tube. One end of the wire is connected to the power source and the other end may be scaled by an end cap.
  • the coils of the springhare mechanically urged into contact with the inner wall of the tube at longitudinallyl Ospaced apart locations to facilitate substantially uniform distribution of power along the entire length of the electrode. Electrodes of this type are known and have been patented. For example, reference may be had to US Pat. No. 6,998,031 now expired.
  • the anode 38 is a non-sacrificial anode having a noble metal outer surface 101 .
  • Nobel metals typically consist of the group: ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.
  • the outer surface of the non-sacrificial anode comprises platinum.
  • the platinum outer surface 101 is highly conductive and is very efficient at delivering the DC current into the gap 37.
  • Platinum is a non-reactive metal, and thus the anode having a platinum surface resists consumption even in the ozone rich environment at or near the anode during concentric electrolysis.
  • platinum functions as an extremely good catalyst, which likewise facilitates oxidation and ion bonding reactions.
  • FIG. 5A A first embodiment of the non-sacrificial anode 38 having a platinum outer surface101 is illustrated in Figure 5A.
  • the anode is identified by the general reference numeral 38.
  • the anode 38 comprises a first end cap 102.
  • the end cap 102 is constructed of an electrically non- conductive insulating material. Suitable insulating materials may include ABS plastic, acrylic, PVC, etc., amongst others.
  • the end cap102 is preferably slightly chamfered at its distal end to ease of mounting within a socket in the fluid treatment chamber 32.
  • the end cap 102 defines a cavity 106.
  • the cavity 106 extends longitudinally within the end cap 102 and is coaxial therewith.
  • the anode 38 has a core 10 with a distal end 112 and a proximal end 114.
  • the distal end 1 12 of the core 10 is sized and positioned to be received in force fitting relation into the cavity 106 of the insulating end cap 102.
  • the proximal end 114 is sized and positioned to extend through an insulating neck 1 16.
  • the outer shape of the insulating neck 1 16 is not critical, though the insulating neck 116 defines a channel through its centre to longitudinally receive the proximal end 114 of the core 1 10.
  • the proximal end 114 is preferably adapted; such as by screw threading 1 15, for engagement with a bus bar (not shown).
  • the core 1 10 is constructed from an electrically conductive metal.
  • the core 110 is most preferred to construct the core 110 from copper. Although less preferred, it is also possible to construct the core 110 in two portions comprising an copper cylinder and an steel rod frictionally force fit within the copper cylinder and extending beyond the copper cylinder to form the distal and proximal ends of the core.
  • the non-sacrificial anode 38 has a platinum outer surface
  • the core 110 is comprised of copper, as1 1 discussed above. Those skilled in the art will know that platinum will not adhere well directly to copper. Accordingly, the core 1 10 of the present invention is coated with a thin layer of Niobium 118. Niobium can be applied to the core either by dipping or spraying or in any other suitable method in order to form the niobium layer 118. The thickness of the niobium layer is not critical, so long as it will serve as a substrate upon which to base a platinum coat.
  • a niobium layer having a thickness of approximately 0.0002 inches (4-6 pm) has been found to satisfactory.
  • the niobium layer 118 is coated with platinum layer of approximately 0.0001 inches (2-3 ⁇ ) thickness thus forming the platinum outer surface 101.
  • the anode 38 can be constructed without a first end cap 102.
  • the anode 38 is the same in other respects as the anode of Figure 5A, but the core 110 is not sized for insertion to the cavity of an end cap.
  • the core 110 may be slightly rounded or chamfered at its distal end.
  • the niobium plate layer 18 and the platinum outer surface 101 are present on the distal end of the core 110.
  • This second embodiment of the anode 38 is intended to be inserted directly into a socket formed in the wall 16 of the fluid treatment chamber 32, as will be discussed further below, instead of being mounted within the fluid treatment chamber in an indirect manner.
  • the second end wall 316 must be contoured to receive the both electrodes directly and to hold them in coaxial alignment. As shown in Figure 4C, the second end wall 316 defines an annular socket 318 to receive the cathode 36 and a circular socket320 for the cathode 38. It should be noted that Figure 4C is an exploded view of only one portion of the second wall 316 sufficient to show the sockets 318 and 320 in a pair which would accommodate one electrolytic cell 34.
  • Each of the annular sockets 318 is coaxial with a respective one of the circular sockets 320 in order to support the respective anode 38 and cathode 36 of the electrolytic cell 34 in a horizontal position so as to be in transverse alignment to the flow of water into and out of the fluid treatment chamber 32.
  • the coaxial positioning of the annular sockets 318 and the circular sockets 320 also serve as spacers to maintain the coaxial alignment of the cathode 36and anode 38 in each electrolytic cell.
  • a consistent concentric distance must be maintained between the cathodes 36 and anodes 38 at all points along their length is necessary in order to ensure even distribution of electrical charge at all points in the gap 37 therebetween.
  • a plurality of electrolytic cells 34 are arranged within the fluid treatment chamber 32.
  • a particularly preferred aspect of invention relates to forcing the fluid in need of treatment in a direction substantially transverse to the disposition of the electrolytic cells. Most preferably, this is done by disposing the electrolytic cells substantially transverse to the flow of fluid.
  • the electrolytic cells 34 are arranged within12the fluid treatment chamber 32 in a compact manner which permits water to flow through multiple electrolytic cells 34 in order to expose the water to pulsed DC electric fields.
  • the electrolytic cells are in physical contact with one another.
  • seven (7) electrolytic cells 34 are shown in Figures 4A and 4B in a circular array in an arrangement which is analogous in shape to a revolver chamber.
  • the specific length of the electrolytic cells 34 and their particular array is not critical so long as the anode 38 and cathode 36 which make up each electrolytic cell 34 can be maintained in substantially perfect coaxial alignment with one another.
  • the fluid treatment chamber 32 is preferably constructed from an electrically insulative material, such as plastic or acrylic. It can be thought of as a block of insulative material.
  • the chamber 32 has a continuous side wall 310.
  • the side wall 310 of the fluid treatment chamber 32 is scalloped along its inner surfaces in order to minimize the width of a gap 312 between each electrolytic cell 34 and the side wall 310 of the chamber 32.
  • the chamber 32 has a first end wall 314 through which the proximal end 114 of the anode will protrude for mounting and electrical connection to a bus bar.
  • the chamber has a second end wall316 to which the first 36 and second 38 electrodes may be attached.
  • a water inlet 322 is provided in the side wall 310 for fluid connection with the connecting line 12 to bring water into the fluid treatment chamber.
  • a water outlet 324 is provided in the sidewall 310 to permit the flow of water out of the chamber 32. The water enters the fluid chamber through fluid inlet 322 and is forced upward, flowing through a plurality of electrolytic cells 34, as it travels toward the fluid outlet 324.
  • the fluid outlet 324 is in fluid connection with the connecting line to carry the water downstream for further processing.
  • the water treatment apparatus functions sufficiently with a DC current of 1.5 amps (1500 milliampere), and 6.5 volts being applied to water flowing through the fluid treatment chamber 32 at a rate of approximately 0.5 to 2.0gallons per minute.
  • these parameters would be sufficient to purify municipal water.
  • lake water, river water, or water from other raw sources then these parameters can be adjusted accordingly. Either increasing the amperage (current) and/or reducing the flow rate of the water will be effective in purifying water having a higher contaminant load.
  • H2 is a by-product of the electrolysis.
  • the fluid treatment chamber 32 is fitted with an outlet 40 to exhaust the H2 as it is produced. It is desirable to ensure that the H2 concentration does not exceed 4% in the vicinity of the water treatment apparatus to avoid the risk of a hydrogen explosion.
  • the present invention provides two different embodiments of a hydrogen handling means 41. Either embodiment can be integrated into the point of use water treatment system 10 to handle hydrogen gas generated in the by electrolysis occurring in the fluid treatment chamber32.
  • the hydrogen handling means 41 comprises an explosion proof hydrogen exhaust fan connected to the hydrogen outlet40 for forcibly venting hydrogen to the atmosphere.
  • the use of an exhaust fan presupposes that there is a ventilation line to the outdoors. Suitable fans and ventilation lines are commonly available, and a person skilled in the art would be able to select a fan and a ventilation line for use in this system.
  • the hydrogen handling means 41 is a catalytic hydrogen trap, shown generally by reference numeral 200.
  • the catalytic hydrogen trap 200 comprises a main body 202.
  • the main body 202 is constructed sized and shaped for sealed mounting to the outlet40, such that hydrogen cannot escape the fluid treatment chamber 32 without contacting the catalytic hydrogen trap 200.
  • the main body 202 would preferably be shaped as a disc having approximately .25 inches (0.63 cm) thick and approximately 3 inches (7.62 cm) in diameter, to enable a tight friction fit.
  • the main body 202 defines a multiplicity of openings 204 therethrough to facilitate the through-passage of gas.
  • the main body portion 202 could be formed as a plate having an array of small channels therethrough which channels define the multiplicity of small openings 204 in the main14body 202, as shown in Figures 6 and 7.
  • Suitable sizing for the channels might be 0.125inches (3.175mm) in diameter and 0.125 inches (3.175 mm) apart.
  • the size and spacing suggested herein is by way of example and is not meant to be limiting.
  • the main body 202 could be inset with a portion of screen or mesh having a multiplicity of small openings 204 (such screen or mesh also considered to be part of the main body 202).
  • the main body 202 is constructed such that all exposed surfaces 210 thereof comprise a catalyst suitable for catalyzing the oxidation of hydrogen to water. It is preferred that all exposed surfaces of the main body 202comprise platinum. Although the use of a solid platinum main body would be within the scope of the invention, it would likely be economically infeasible.
  • the main body 202 is constructed of a core206 which is preferably comprised of copper.
  • the core 206 has been plated with a layer of niobium 208, approximately 0.0002 inches (4-6 ⁇ ) thick.
  • the niobium Iayer208 is present to facilitate the plating of platinum onto the copper core 206.
  • the particular thicknesses of the plating layers provided are by way of example, and are not meant to be limiting. Other substrates could be used for core 206of the main body so long as all exposed surfaces of main body 202 are platinum coated.
  • the inner surfaces of the openings 204 are platinum plated. If the main body 202 is constructed as a plate having channels therethrough forming the openings, the walls of the channels are platinum plated. In the case of a screen or mesh, the entire surface thereof which defines the openings 204 would also be platinum plated. Image resolution limitations prevent illustration of the plating layers on the inner walls of the openings 204 in Figure 7, though reference numeral 210 has been used to indicate the exposed platinum surfaces. In operation, as oxygen and hydrogen gases generated in the fluid treatment chamber 32 during electrolysis of water rise through the outlet 40 they are drawn toward the openings 204 in the catalytic hydrogen trap 200.
  • the use of the catalytic hydrogen trap 200 as the hydrogen handling means 41 eliminates the need for ventilation to the outdoors, since the potentially harmful hydrogen gas is converted to water, and any remaining oxygen
  • the fluid treatment chamber 32 is optionally fluidly connected by a connecting line to a settling tank 42 and the electrolyzed water is removed from the fluid treatment chamber 32 to the settling tank 42.
  • the positively charged ions continue to combine with negatively charged contaminants in the water to form increasingly large flocculent particles which will settle under gravity in the settling tank 42, leaving pure water containing only naturally occurring trace minerals existing as positive ions.
  • the settling tank 42 is equipped with a drain44 through which accumulated settled flocculent can be gravity drained.
  • a pump 54 is fluidly connected to the settling tank 42 to pump the electrolyzed water, to a post settling filtration means 48.
  • the post settling filtration means is a standard water filter having a moderate mesh size, on the order of 5 pm.
  • Common filter materials would include polypropylene mesh. Replacement mesh inserts can be readily sourced and periodically replaced as a consumable article. It would be apparent to one skilled in the art that alternative filters could be substituted.
  • FIG. 1 and 3 both provide for a settling tank 42(also known as a 'floe tank') where treated water is held and accumulated flocculent particles can settle under gravity. It is not necessary to for the treatment system to have a settling tank 42 in all instances, though it is useful in small commercial or industrial installations where the input water is particularly contaminated and high volumes of water are treated. In smaller scale embodiments, such as that shown in Figures 8 and10, the settling tank has been removed from the system. Treated water would flow directly from the fluid treatment chamber 32 to a water holding tank 52.
  • a sampling valve 50 is provided in the connecting line downstream of the post settling filtration means 66.
  • the water can be sampled at this point to determine whether there has been adequate treatment of the water so as to sufficiently decrease concentrations of pollutants which were in the water supply.
  • the connecting line is the fluidly connected to the inlet of a treated water storage tank 52.
  • the treated water storage tank holding tank 52 has air tight seals to enable the treated water to be stored in the holding tank 52 until there is user demand.
  • a 100 gallon holding tank 52 would be suitable for household or small scale use. The particular size of the holding tank should not be considered to be a limiting factor in the present invention.
  • the treated water storage tank 52 has an outlet equipped with a sampling valve 56 and a shutoff valve 58.
  • a main pump 54 is provided in fluid connection with the outlet of the treated water storage tank 52 to pump treated water to the user.
  • An internal pressure switch in the pump will maintain the water pressure at a level between about 15 psi and 40 psi. Typical household water pressure is usually about 30 psi.
  • a check valve 60 and pressure gauge 62 are advantageously fluidly connected in the connecting line to facilitate monitoring of water pressure to the end user and to enable shutoff of waterl 6flow in the case of malfunction.
  • a surge tank 64 is optionally provided in fluid connection along the connecting line between the check valve 60 and the end user.
  • a series of post treatment filtration means 66 are provided in fluid connection in the connecting line upstream of the end user. The post treatment filtration means
  • 66 preferably includes two 5pm flow filters 48, an activated carbon (charcoal) absorber49, and a final 1 pm absolute polishing filter 51. Downstream of the final filtration means 66 a final pressure regulator 68 and a system outlet check valve 70 are connected into the connecting line. The system outlet check valve 70 provides the final check on flow of treated water into the user's water system.
  • the efficacy of the electrolysis of water can be varied by varying the flow rate of water through the fluid treatment chamber 32, which changes the amount of time the water experiences each DC pulse as it travels through the chamber 32.
  • the flow rate of the water can be adjusted using the flow control valve 28.
  • Efficacy can also be varied by varying the voltage applied across the gap between the first 36 and second 38electrodes. By adjusting these two variables it is possible to selectively vary the strength of the electrolysis to neutralize greater or lesser concentrations of pollutants. In this way, the system can be adjusted to treat water having different concentrations of contaminants.
  • FIGS 8 and 9 of the drawings illustrate an alternate embodiment of the point of use water treatment system 10.
  • the support frame 13 comprises a plurality of support elements, but the support frame 13 is constructed as a split frame comprising two or more support modules.
  • the preferred arrangement of two support modules is shown. It would be understood by a person skilled in the art that additional support modules could be constructed and that particular elements of the water treatment system 10 could be mounted to any of the support modules.
  • the two or more support modules can be either wall mounted or free standing.
  • FIG. 8 The perspective view of Figure 8 provides a visual understanding of the preferred two support modules and their respective size and shape, while the schematics of Figure 9 provide specific illustration of how the various functional elements of the water treatment system 10 are arranged and mounted to one or other of the respective support modules.
  • the dashed line 810 notionally identifies the first module
  • the dashed line 812 notionally identifies the second module.
  • the arrangement and grouping of the elements of the point of use water treatment system are optimized to maximize functional efficiency by keeping functionally related elements physically near one another while placing the elements of the system which a user would need to access most frequently on a single compact support module.
  • a first support module 810 has means for mounting a control panel 820 and the entire filter elements, namely the pre-filter 24, post settling filtration 48, 48, and the17final filtration 66 mounted thereon.
  • the first support module 810 can be quite compact in size, and could have a footprint on the order of 16' by 42" (40.6 cm x 106.7 cm).
  • the first support module 810 could readily be positioned against one wall of a room and either used free standing, or it could be wall mounted.
  • the filtration units are mounted at the front of the support frame, so that filtration units are easily accessible to change out filters as needed.
  • the support frame has mounting means for the control panel at the front of the support frame in order to ensure that the control panel is readily accessible to a user.
  • a second support module 812 has mounted thereon the water treatment chamber32 containing the electrolytic cells 34, the hydrogen vent 40 with the hydrogen handling means 41 , the water holding tank 52 and the system drain 824, the pump 54, and the connecting line 12 to the surge tank 64.
  • the second support module 812 is typically larger than the first support module 810 in order to support the water holding tank 52. As such, it is likely to be free standing rather than wall mounted, though it may be secured to a wall for safety reasons.
  • the second support module 812 may also be provided with collar 82 to support the water holding tank 52.
  • the split frame embodiment is designed to permit a first support module 810 of the point of use water treatment system 10 to be installed in one location and a second support module 812 of the point of use water system to be installed in a different location.
  • the two modules of the system may be placed in different areas of a room (such as on different walls) or in different areas, such as different rooms in the basement of a house. Alternatively, the modules may be placed in more distantly separated locations, such as the first module 810 in the basement of a house and the second module 812 in a garage or shed. So long as the two modules can be conducted by modular connection lines 814, the selection of locations for the installation of the two modules 810, 812 is at the discretion of the user or installer.
  • the first module 81 Oand the second module 812 are operatively connected to one another using modular connecting lines 814 shown schematically in Figure 9 as a dashed line.
  • the modular connection lines 814 have the same functional requirements and can be constructed from the same materials as the fluid connecting lines 12 discussed above.
  • the modular connection lines 814 carry water between the elements mounted to the first support module 810 and the second support module 812.
  • the length of the modular connection lines 814 will be determined in each instance by the distance separating the first support module 810 from the second support module 812. It should be understood that there will also be sensor feedback and control communications between elements of the water treatment system 10 which are mounted to the first support module 810 and the elements which are mounted to the second support module 812.
  • the water holding tank52 has a tapered portion 822 toward the bottom thereof to facilitate settling of the flocculent of coagulated impurities toward a system drain 224 for periodic removal.
  • the treated water from which the coagulated impurities have been removed is taken out of the water holding tank 52 and is then pumped by pump 54 through a connecting line 12 to the post treatment filtration means 66.
  • the connecting line 12 between the pump and the filtration means can be of variable length in accordance with the installed distance between the first support module 810 and the second support module812.
  • the modular connection lines 814 are shown schematically in dotted lines to indicate that they may be of variable length. Dotted and dashed borders notionally define the first support module 810 and the second support module 812 in order to visualize where the various functional elements of the point of use water treatment system 10 are mounted.
  • FIGS 10 and 1 1 show yet another alternate embodiment of the point of use water treatment system 10 which has been scaled for home use, having a single stand alone support frame 13 having all other components attached thereto within one compact footprint.
  • the frame support 13 is provided with mounting means for the filtration units and the fluid lines connecting them.
  • the support frame 13 has been constructed as a support cage 90 comprising a front wall 92, a first side and a second side wall 94, 94 and a back wall 98. All necessary components of the point of use water treatment system 10 are mounted directly or indirectly the walls of the support cage 90. After treatment in the electrolytic cells 34

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Abstract

A point of use water treatment system comprises a water treatment chamber having a fluid inlet, and a fluid outlet, and at least one permeable electrolytic cell disposed therebetween. The electrolytic cell comprises a non-sacrificial anode and a perforated cathode coaxially disposed with respect to one another and having a gap therebetween. A water holding tank in is fluid connection with the water treatment chamber for holding water activated by passage through the electrolytic cell. A post settling filtration means is provided for removal of flocculent residue not settled from the water while in the water holding tank. The non-sacrificial anode comprises a core plated with platinum. The point of use water treatment system has, in fluid connection with the water treatment chamber, a catalytic hydrogen trap comprising a main body defining a multiplicity of openings therethrough, and all exposed surfaces thereof comprising platinum.

Description

POINT OF USE WATER TREATMENT SYSTEM
FIELD OF THE INVENTION
[1] The present invention relates to water treatment for effecting a reduction in the concentration of pollutants. More particularly the invention relates to a self-contained water treatment system which can be installed at the intended point of use of the water, so as to substantially remove pollutants from the water source available to a user at the point of use.
BACKGROUND OF THE INVENTION
[2] Even if water has been treated at a municipal water treatment plant, recontamination can be caused en route from the plant to the user due to aging water transportation infrastructure. Tap water has been known to contain HPC (heterotrophic plate count) bacteria, and heavy metals (including lead, mercury, cyanide and arsenic) regardless of how much chlorine is added at source. Chlorine combines with organics, and although for the most part it kills bacteria, it mutates and forms THM (trihalomethane) and derivatives of this known cancer causing carcinogen such as chloroforms, bromoforms, carbon tetrachloride, bischloroethane and others.
[3] The treatment of fluids generally, and water in particular, to remove pollutants therefrom is a continually developing art. Development is motivated, at least in part, by the recognition that the increasing world population necessitates an increased access to water which is pollutant- reduced or substantially pollutant-free. Generally, water pollutants can be grouped in seven classes as follows: sewage and other oxygen demanding wastes; infectious agents; plant nutrients; hazardous man-made organic compounds such as organo-chorides; inorganic chemicals and heavy metals; sediments; and, radioactive substances.
l [4] While the prior art is replete with processes and apparatus for treatment of water to remove one or more of these classes of water pollutants , a particularly advantageous process and apparatus for treating water containing pollutants was disclosed in U.S.Pat. No. 5,108,563. This patent described electrolytic treatment of water using an electrode comprising a particular arrangement of electrodes. The electrolytic cell comprised a first electrode and a second electrode, wherein the first electrode at least partially encompasses the second electrode. The water to be treated was subjected to electrolysis in the presence of an electrolyte. The '563 patent taught the introduction of an electrolyte, preferably one which ionized completely, into the treatment apparatus. Non-limiting examples of suitable electrolytes were provided, and examples of apparatus to introduce electrolytes into the electrolytic cell were provided. The patent further taught that the electrolysis was preferably carried out in the presence of elemental carbon. The carbon could be a component of one or both electrodes or could be added to the electrolytic cell as elemental carbon, in the form of graphite powder orl a graphite rod. The process and apparatus disclosed in the '563 patent attained a degree of success.
[5] The design of the apparatus and method described in the '563 patent was further optimized to improve the efficiency of water throughput without substantially compromising reduction of the pollutants contained in the water. U.S. Pat. No. 5,439, 567taught those design improvements. The method can be summarized in following steps:(i) feeding the fluid in need of treatment to a fluid treatment chamber having a fluid inlet and a fluid outlet; (ii) passing the fluid in need of treatment though the fluid inlet into the treatment chamber; (iii) forcing the fluid in need of treatment through at least one fluid permeable electrolytic cell disposed substantially transverse to flow of the fluid, the electrolytic cell comprising a channel defined by an outer, perforated first electrode and an inner, coaxially disposed second electrode; (iv) subjecting the fluid in need of treatment to electrolysis as it passes through the channel; (v) forcing the fluid to the fluid outlet; and (vi) allowing the fluid to exit the fluid outlet. The invention also provided a fluid treatment apparatus comprising a housing including a fluid inlet, a fluid outlet and at least one fluid permeable electrolytic cell disposed therebetween such that the flow of fluid from the fluid inlet to the fluid outlet was substantially transverse to the at least one electrolytic cell, the at least one electrolytic cell comprising a channel defined by an outer, perforated first electrode and an inner, coaxially disposed second electrode. The process and apparatus disclosed in the '567patent also attained a certain degree of success.
[6] The implementation of both of the foregoing versions of the apparatus and process for treating water were subject to certain design inefficiencies, which could be accommodated in a large scale facility such as a municipal water treatment plant or commercial water purification and bottling plant. Unfortunately, the design inefficiencies made the development of smaller scale treatment apparatus according to the foregoing inventions impracticable.
[7] Although not particularly restricted, steel electrodes of various compositions, such as AISI Types and L304 stainless steel were utilized. It was believed that the anode should comprise, at least partially, iron. Unfortunately, electrodes constructed from such compositions were rapidly consumed when electrolysis of water was conducted in accordance with the inventions. Consumption of the electrodes required the frequent replacement of electrodes, thus increasing operating costs. It would be desirable if the design could be optimized to minimize or eliminate electrode consumption.
[8] Consumption of the electrodes resulted in the creation of large quantities of flocculent; though not necessarily of a consistent form. Varying the material from which the electrode was constructed resulted in variation of the flocculent produced. For example soft steel produced ferrous (Fe++) flocculent; whereas harder types of steel produced very sticky ferric (Fe+++) flocculent which were difficult to remove from both the treated water and the water treatment equipment. The variability in the nature of flocculent produced necessitated the use of downstream equipment at both the top and bottom of settling tanks capable of removing either floating or settled material. Additionally, it was recommended to introduce a coagulant into the water after electrolysis in order to ensure settling of the flocculent.
[9] Electrolysis using sacrificial steel electrodes captured impurities in the water using positive ferrous and/or ferric ions. In view of the fact that the steel electrodes were consumed over time, quite large volumes of flocculent were created. Organo-chloride compounds were de- synthesized by electrolysis and that residue was captured by the ferric/ferrous ions. Coagulants were used to aid in removing impurities from the water being treated.
[10] It would be desirable if the design could be optimized to minimize the overall quantity of flocculent produced during electrolysis and also improve the consistency of the form of flocculent produced. Improved consistency would permit the use of less complex downstream equipment to complete water treatment. The consistent production of a flocculent that readily settles out of water would permit the use of settling tanks having a simple bottom drain for periodic removal of flocculent.
[1 1] It will be readily understood by a person skilled in the art that a certain amount of hydrogen gas (H2) is a by-product of the electrolysis of water. Hydrogen can react explosively in the presence of oxygen at concentrations greater than about 4%. Handling and disposal of hydrogen and other off gasses can be readily facilitated in large commercial scale water treatment installations. In the context of small scale domestic water treatment systems, the product ion of hydrogen gas poses a safety concern. There is the potential for hydrogen gas to accumulate in the area of the electrolytic cells, particularly if the water treatment system is located in an enclosed area. If hydrogen were to accumulate in excess of 4% in the presence of oxygen, such accumulations would pose an explosive hazard. Users of small scale domestic water treatment systems might be unaware of the presence of hydrogen gas in elevated concentrations since it is colorless and odorless. This hazard is of particular concern in the context of point of use systems since they will typically be installed in homes or other areas which are in close proximity to the end users of the treated water. Thus, it would be desirable to incorporate means for totally venting H2 as it is produced, or reacting H2 to produce pure water.
[12] It would be further desirable to optimize the apparatus and process for treatment of water at the point of use, such as in a home or other small scale location.
SUMMARY OF THE INVENTION
[13] A point of use water treatment system is provided comprises a water treatment chamber having a fluid inlet, and a fluid outlet, and at least one permeable electrolytic cell disposed therebetween substantially completely filling the only path of water from the fluid inlet to the fluid outlet and oriented such that the path of water from the fluid inlet to the fluid outlet is
substantially transverse to the at least one electrolytic cell.3The at least one electrolytic cell comprises a non-sacrificial anode and a cathode coaxially disposed with respect to one another and having a gap therebetween. A water holding tank in is fluid connection with the water treatment chamber for holding water activated by passage through the at least one electrolytic cell. A post settling filtration means is in fluid connection with the water holding tank for removal of flocculent residue not settled from the water while in the water holding tank.
[14] An outer surface of the non-sacrificial anode comprises a noble metal selected from the group consisting of ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. More particularly, the non-sacrificial anode comprises a core plated with platinum. The core of the non-sacrificial anode is copper, plated with niobium, and further plated with platinum.
[15] The point of use water treatment system has a hydrogen handling means in fluid connection with the fluid treatment chamber. The hydrogen handling means is a catalytic hydrogen trap that comprises a main body defining a multiplicity of openings, all exposed surfaces of the main body comprising a catalyst for the oxidation of hydrogen. More particularly, all exposed surfaces of the main body comprise platinum.
BRIEF DESCRIPTION OF THE DRAWINGS
[16] Embodiments of the present invention will be described with reference to the
accompanying drawings in which:
[17] Figure 1 is a schematic diagram of the point of use water treatment apparatus according to the present invention.
[18] Figure 2 is a front view of a first embodiment of the point of use water treatment apparatus.
[19] Figure 3 is a side view of the point of use water treatment apparatus of Figure 2. .
[20] Figure 4A is a side view of a fluid treatment chamber according to the present invention.
[21] Figure 4B is a sectional view of the fluid treatment chamber of Figure 4A taken along line B-B.
[22] Figure 4C is an enlarged view of a portion of the end wall of the fluid treatment chamber of Figure 4A.
[23] Figure 5A is a sectional view of a first embodiment of an anode according to the present invention.
[24] Figure 5B is a sectional view of a second embodiment of an anode according to the present invention.
[25] Figure 6 is a perspective view of a catalytic hydrogen trap according to the present invention. [26] Figure7 is a sectional view of the catalytic hydrogen trap of Figure 6 taken along line A-A.
[27] Figure 8 is a perspective view of an alternate embodiment of the point of use water treatment apparatus.
[28] Figure 9 is a schematic diagram of the alternate embodiment of Figure 8.
[29] Figure 10 is a front view of another alternate embodiment of the point of use water treatment system scaled for home use.
[30] Figure 1 1 is a side view photograph of the point of use water treatment system of Figure 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[31] In general, the present invention relates to a process and apparatus for electrolytic treatment of water in need of treatment. As used throughout this specification, the term water in need of treatment is intended to encompass water containing one or more substances or pollutants the concentration of which it is desirable to reduce or eliminate.
[32] As used throughout this specification, the term 'electrolysis' is meant to encompass passage of electricity through a water in need of treatment to provide sufficient energy to cause an otherwise non-spontaneous reduction reaction. Moreover, as used throughout this specification, the term 'electrolyte' is meant to encompass substances which dissociate in solution to produce ions thereby enabling the solution to conduct electricity.
[33] The present process and apparatus may be advantageously utilized for treating water on a small scale at the point of use of the water. The term 'treating water' is meant to encompass treatments such as deposition of metals, microbiological load reductions and the like. The process according to the present invention can be used to decompose, without pre-extraction, organo-chlorine and -chloride compounds such as polychlorinated biphenyl's (PCB's), dioxins , furans, perchlorates, and organo-bromine and -bromide compounds such as polybrominated biphenyls (PBB's), known to be detrimental to the environment. To the applicant's knowledge, the only manner by which, for example, PCB's can be decomposed effectively and on a commercial scale is by extraction from the effluent (if necessary) followed by thermal treatment at extremely high temperatures (e.g. 1500 degrees C and higher). Unfortunately, the furnace (rotary kiln) required to operate such a process is very expensive to construct and to operate. Further, decomposition of PCB's in this manner often leads to another pollution problem, namely that of air by the products of decomposition. Still further, the operation of a rotary kiln must be monitored very carefully to ensure that temperature drops do not occur and result in emission of the toxic by-products (i.e. incomplete destruction) of the PCB's.
[34] With reference to Figures 1-4 of the drawings, a first embodiment of a point of use water treatment system is shown generally by reference numeral 1 0. A support frame13 is provided and all of the components of the water treatment system are mounted directly or indirectly to the support frame 13. The support frame 13 can be constructed from any material suitable to support the weight of the other components (typically about 300 pounds in total, not including the weight of water held in the system). By5way of example, the support frame 13 may be constructed from steel rods, angle steel, cast aluminum, etc. The support frame 13 comprises a base 80 and uprights 82 which in turn support one or more rails 84for mounting the components of the water treatment system 10. The rails 84 define a plurality of holes 86 for receiving fastening means such as anchor screw, bolts etc. The holes 86 are used in the mounting of components of the water treatment system, and also for wall mounting of the support frame 13. A single freestanding support frame 13 to which all components are directly or indirectly mounted would typically have a footprint of 70 inches by 80 inches (177.8 by 203.2 cm). The particular size is not material to the functionality of the present invention, though it is
advantageous to create a system having the smallest footprint practicable, in order to permit installation of the water treatment system 10 in a variety of small scale, domestic and residential locations. It is preferred that the support frame 13 be of a size that, when all components of the point of use water treatment system 10 are fixed to the support frame 13 and connected in operational condition, the entire water treatment system 10 is comparable in size to a residential furnace. This target size will permit the components of the system to be moved into residence or other point of use location and installed in a modest space in a basement, large closet or utility room.
[35] It will of course be understood that there must be fluid connection between all components of the water treatment system for functional operation. Connecting lines used in conjunction with appropriate connectors are the means by which fluid connection between the elements of the water treatment system is achieved. The general term 'connecting line' is used in the specification to include all suitable fluid connection means. The connecting lines are identified by reference numeral 12throughout this specification; portions of connection line at differing points in the system are consistently labeled 12. The text does not distinguish between portions of connecting line used at different stages in the water treatment system. The point of use water treatment system of the present invention operates at ambient temperatures and at pressures not typically exceeding 50 psi. The water in need of treatment is not typically particularly corrosive in a small scale point of use treatment system. Thus it would be understood by a person skilled in the art that the operating specifications do not dictate the use of particularly specialized or robust for connecting lines 12. It should be understood that any suitable pipe, tubing or flexible line which is approved for use with potable water systems could be used to fluidly connect the components of the point of use water treatment system. [36] The water treatment system has a connecting line 12 with an inlet designed for fluid connection to a supply 11 of water in need of treatment provided in a line at standard municipal water pressure. A strainer 14 may optionally be provided in fluid connection therewith to remove any particulates which may be present in the flow of water from the municipal source or introduced into the flow from scale in piping6external to the water treatment apparatus 10. By way of example, a wire strainer having a mesh size on the order of 150 pm would be suitable, however the particular mesh size is not intended to be limiting. The wire strainer can be easily removed by an operator or user for cleaning and then reattached.
[37] A one way check valve 16 is provided in fluid connection with the water supply 1 1 in order to isolate the water treatment apparatus 10 and prevent any backflow into the water source. Downstream of the check valve 16, an adjustable pressure regulator 18 is provided in fluid connection to maintain a steady predetermined through flow of water into the treatment apparatus. Typically the flow will be stabilized in a range of 15-20psi.
[38] A variable water shutoff 20, such as a solenoid shutoff, is provided to enable water to be drawn into downstream filtration and electrolysis means as needed. In the event of a power failure the shutoff will be closed, stopping the flow of water. A bypass of the electrolytic water treatment system can also be provided, which will enable users to access water which has at least been treated by the pre-treatment filter and post treatment filters and absorbers in instances of prolonged power outage. A bypass of the electrically operated electrolytic cell can be easily installed, to enable water to pass through the pre-filter and post treatment filters and absorber. This would permit a user to have access to water flow that has at least undergone some filtration even if there is an extended power outage which takes the electrolytic cells offline. Downstream of the water shutoff 20 an operating pressure gauge is preferably provided in order to check the operating pressure of the water flowing into the filtration and electrolysis means. [39] A pre-filter 24 is provided in fluid connection in the line downstream of the check valve 16. Preferably the pre-filter 24 will have a moderate mesh size, on the order of 5pm. Standard water filters which are suitable for use as pre-filter 24 are available worldwide from Siemens AG and many other manufacturers and distributors. Common filter materials would include polypropylene mesh. Replacement mesh inserts can be readily sourced and periodically replaced as a consumable article. It would be apparent to one skilled in the art that alternative filters could be substituted.
[40] It is desirable to have a flow indicator 26 installed in fluid connection within the line 2 downstream of the pre-filter 24. An operator can check the flow indicator to confirm that the pre- filter 24 is functioning correctly and has not become clogged. The flow of water at this point is typically within the range of 0.5 gal to 2.0 gal per minute. A flow control valve 28 provided downstream of the flow indicator 26 allows the flow of water to be adjusted. A manually adjustable needle flow control valve would be suitable for this purpose, but is not meant to be limiting. The flow rate of water in need of treatment can be adjusted in order to modify the quality and characteristics of the treated water output from the water treatment apparatus 10, as will be discussed in greater detail below.
[41] A fluid inlet 30 is provided in fluid connection downstream of the flow control7valve 28 to introduce the water into a fluid treatment chamber 32. A drain/sampling valve is optionally provided in the inlet to facilitate inspection of the water quality, as well as draining and servicing of the fluid treatment chamber 32.
[42] With specific reference to Figures 4A and 4B, the fluid treatment chamber 32contains a plurality of fluid permeable electrolytic cells 34, each of which comprises a cathode 36 and an anode 38 which are spaced apart from and coaxially disposed with respect to one another. A gap 37 exists between the coaxially disposed cathode 36 and the anode 38. It is not particularly important which one of the cathode or the anode is the electrode which is the outer of the two, the construction and materials of the electrodes can be adapted to facilitate either arrangement. As a practical matter and for ease of manufacturing, it is preferred that the cathode 36 is the outer one of the electrodes and coaxially surrounds the anode 38. This arrangement is not meant to be limiting.
[43] The shape of the cross-section of the cathode 36 and anode 38 is not particularly restricted. It is within the scope of the invention to utilize electrolytic cells comprising various cross-sectional shapes. Thus, is possible for cross-sectional shape of the first electrode and/or the second electrode to be circular, triangular, square, rectangular, hexagonal, and the like. Preferably, the cross-sections of the cathode 36 and anode 38are substantially circular. It is preferred that the ratio of the diameter of the cathode 36to the diameter of the anode 38 would be in the range of about 1.10 to about 3.50, more preferably from about 1.10 to about 1.75, most preferably from about 1.10 to about 1.30. A gap 37 exists between the coaxially disposed cathode 36 and anode 38. The gap 37 is preferably quite small; being on the order of approximately 0.1 to 0.2cm. It is critical to maintain substantially perfect coaxial alignment between the cathode 36 and anode 38. A consistent concentric distance at all points along their length in necessary in order to ensure even distribution of electrical charge at all points in the gap 37 between the anode 36 and cathode 38.
[44] COAXIAL ELECTROLYSIS OF WATER AND NON- SACRIFICIAL ANODES
[45] A major factor in the effectiveness of the present invention is the DC current field that is established between the cathode 36 and the anode 38. As water flows through the fluid treatment chamber 32 it flows through the gap 37 between the two electrodes by passing through perforations 39 spaced along the entire length of the cathode 36. It has been found that perforations 39 of about 5/16 inches (7.94 mm) in diameter and arranged approximately ½ inch (12.7 mm) apart along the cathode 36 allow an adequate flow of water to pass transversely into the gap 37 between the cathode 36 and anode 38. In the point of use water treatment system 10 according to the present invention, a voltage of 5.0 to 8.0 volts is applied across the gap 37 between each of the first 36 and second 38 electrodes in the cells 34. The level of current applied to the electrolytic cells 34 is not particularly restricted. Preferably, the current through the electrolytic cells 34 is in the range of about 100 to about 5000 milliampere per elec-8trolytic cell. Keeping in mind that the gap 37 is quite small (0.1 to 0.2 cm), the strength of the electrical field in the gap 37 between the anode and cathode in each cell 34 is extremely high. By way of illustration, the application of 6.5 volts across a 1.5 mm gap is equivalent to 6,500 volts across a 1 .5 meter gap or 4000 volts across a 1 m gap in water (i.e. 4.33 kV/meter).
[46] Unlike previous previously patented versions of electrolytic water treatment apparatus, it is not necessary to add an electrolyte to the water in need of treatment. Most naturally occurring water contains between 150 and 600 parts per million total dissolved solids, which include calcium, magnesium, sodium, potassium, chlorine, aluminum phosphorus, manganese, zinc, iron, fluorine. The presence of these dissolved solids in ion form provides sufficient quantities of electrolytes to permit an electrical current to pass through the water. So long as a highly conductive anode is used, electrolysis will successfully occur without the need for the addition of an electrolyte. If the total dissolved solids are 150 ppm or less in a particular source of water to be treated, an electrolyte could be added.
[47] As water flows through each electrolytic cell 34 it undergoes electrochemical activation. Electrochemical activation is a combination of electrochemical and electro physical actions (performed in conditions of minimal heat evolution) on liquid (mostly on water) containing ions and molecules of substances dissolved in it, in the area of spatial charge near the
electrochemical system electrode (either anode, or cathode)surface during non-equilibrium transfer of charge by electrons through the border 'electrode - electrolyte'. Positively charged hydrogen ions are created. Exposure to the electric field induces dipole formation in nonpolar particles in the water. Dipole formation allows the formation of micro-aggregates of insoluble substances to be formed. Charge neutralization of ions or charged materials also takes place creating insoluble suspended substances in the water. Unlike prior art systems which introduced ferrous or ferric ions from a sacrificial anode, the present system results in the formation of insoluble suspended substances in smaller overall quantities than previously obtained. The resulting flocculent is inert and ion-bonded.
[48] Electrochemical activation makes it possible to purposefully change dissolved gases, composition, acid-base and oxidative-reductive properties of water in wider limits than under equivalent chemical regulation. It thus becomes possible to synthesize metastable chemical reagents (oxidants or reductants) from water and substances dissolved in it. As a result of electrochemical activation, water becomes metastable (activated) demonstrating for a several hours an increased reactivity in various physical and chemical processes. Water activated by cathode (catholyte) acquires such characteristic as superactivity of electrons and a well- pronounced reductant quality. Correspondingly, water activated by anode (anolyte) is characterized by inhibited electron activity and manifests qualities as an oxidant. The present invention takes advantage of the anode 36 for activation of the water so as to produce a9strong oxidant.
[49] The electron density in the gaps 37 between the first 36 and second 38 electrodes in each electrolytic cell 34 is sufficient in operation to generate nascent oxygen and ozone at the anode. Ozone is one of the strongest oxidation agents available for use to oxidize solutes.
When the static loaded ozone molecule (03) contacts with something capable of being oxidized, the charge of the ozone molecule will directly flow over, enabling the reversion back to the original form (02). The extra-added oxygen atom will bind (=oxidation) in a split second to every contaminant in the water in need of treatment which has a negative charge. The collision and binding of the extra-added oxygen atoms to negatively charged species continues, resulting in the formation of a flocculent. Even organo-chloride compounds are de-synthesized and oxidized to produce harmless ion bonded residues. The point of use water treatment apparatus l Oaccording to the present invention has been optimized to produce minimal amounts of flocculent in a form which will readily settle to the bottom of the settling tank 42 by operation of gravity. Since the present invention avoids the use of sacrificial electrodes, the amount of flocculent is greatly reduced when compared to the amount of ferrous or ferric flocculent produced by prior art methods and apparatus which used steel electrodes. Even after long term operation of the electrolytic cells of the present invention there is no build up of contaminants either on the inside of the cathode 36 or on the outside of the anode 38. This lack of buildup is an indication that the anode 38is not being sacrificed during operation of the electrolytic cells 34.
[50] In order to maintain the electrical field between the anode and cathode, the 38anode is selected to deliver maximum current through the gap 37 and to avoid being consumed having regard to the extremely high electron density which exists in the gap37. It will be understood by persons skilled in the art that the anode in an electrolytic cell is the electrode which is at risk of consumption; the cathode is not normally consumed. Accordingly, the material from which the cathode is constructed does not impact the successful operation of the electrolytic cell.
Reversing the polarity of the current applied will have the effect of switching the anode and cathode. As mentioned above, the present invention may function with either electrode acting as the anode. If it was desired that the first electrode (being the outer perforated electrode) were to function as the anode, it would be necessary to construct it from a material which is not consumed during electrolysis.
[51] Various non-sacrificial anodes may be selected for use in the electrolytic cells 34of the water treatment system according to the present invention. One such anode is constructed from an elongate tube formed from titanium suboxide by molding, extrusion or the like. A current feeder comprises a length of titanium spring wire which extends along the inner bore of the tube. One end of the wire is connected to the power source and the other end may be scaled by an end cap. The coils of the springhare mechanically urged into contact with the inner wall of the tube at longitudinallyl Ospaced apart locations to facilitate substantially uniform distribution of power along the entire length of the electrode. Electrodes of this type are known and have been patented. For example, reference may be had to US Pat. No. 6,998,031 now expired.
[52] NON-SACRIFICIAL ANODE HAVING A NOBLE METAL OUTER SURFACE
53] Reference is now made to Figures 5A and 5B. In accordance with the preferred embodiment of the present invention the anode 38 is a non-sacrificial anode having a noble metal outer surface 101 . Nobel metals typically consist of the group: ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. In the preferred embodiment of the present invention the outer surface of the non-sacrificial anode comprises platinum. The platinum outer surface 101 is highly conductive and is very efficient at delivering the DC current into the gap 37. Platinum is a non-reactive metal, and thus the anode having a platinum surface resists consumption even in the ozone rich environment at or near the anode during concentric electrolysis. Moreover, platinum functions as an extremely good catalyst, which likewise facilitates oxidation and ion bonding reactions.
[54] A first embodiment of the non-sacrificial anode 38 having a platinum outer surface101 is illustrated in Figure 5A. The anode is identified by the general reference numeral 38. The anode 38 comprises a first end cap 102. The end cap 102 is constructed of an electrically non- conductive insulating material. Suitable insulating materials may include ABS plastic, acrylic, PVC, etc., amongst others. The end cap102 is preferably slightly chamfered at its distal end to ease of mounting within a socket in the fluid treatment chamber 32. The end cap 102 defines a cavity 106. The cavity 106 extends longitudinally within the end cap 102 and is coaxial therewith.
[55] The anode 38 has a core 10 with a distal end 112 and a proximal end 114. The distal end 1 12 of the core 10 is sized and positioned to be received in force fitting relation into the cavity 106 of the insulating end cap 102. The proximal end 114 is sized and positioned to extend through an insulating neck 1 16. The outer shape of the insulating neck 1 16 is not critical, though the insulating neck 116 defines a channel through its centre to longitudinally receive the proximal end 114 of the core 1 10. The proximal end 114 is preferably adapted; such as by screw threading 1 15, for engagement with a bus bar (not shown). The core 1 10 is constructed from an electrically conductive metal. It is most preferred to construct the core 110 from copper. Although less preferred, it is also possible to construct the core 110 in two portions comprising an copper cylinder and an steel rod frictionally force fit within the copper cylinder and extending beyond the copper cylinder to form the distal and proximal ends of the core.
[56] As mentioned above, the non-sacrificial anode 38 has a platinum outer surface
101. While is understood that a solid platinum core would function well, the use of a solid platinum core would be cost prohibitive. The platinum outer surface 101 of the anode38 may be achieved using electroplating techniques. In accordance with the preferred embodiment of the present invention, the core 110 is comprised of copper, as1 1 discussed above. Those skilled in the art will know that platinum will not adhere well directly to copper. Accordingly, the core 1 10 of the present invention is coated with a thin layer of Niobium 118. Niobium can be applied to the core either by dipping or spraying or in any other suitable method in order to form the niobium layer 118. The thickness of the niobium layer is not critical, so long as it will serve as a substrate upon which to base a platinum coat. By way of example, a niobium layer having a thickness of approximately 0.0002 inches (4-6 pm) has been found to satisfactory. The niobium layer 118 is coated with platinum layer of approximately 0.0001 inches (2-3 μηι) thickness thus forming the platinum outer surface 101.
[57] Alternatively, as shown in Figure 5B, in a second embodiment, the anode 38 can be constructed without a first end cap 102. The anode 38 is the same in other respects as the anode of Figure 5A, but the core 110 is not sized for insertion to the cavity of an end cap. The core 110 may be slightly rounded or chamfered at its distal end. The niobium plate layer 18 and the platinum outer surface 101 are present on the distal end of the core 110. This second embodiment of the anode 38 is intended to be inserted directly into a socket formed in the wall 16 of the fluid treatment chamber 32, as will be discussed further below, instead of being mounted within the fluid treatment chamber in an indirect manner.
[58] If the non-sacrificial anode 38 having a platinum surface 101 but no end cap will be used, then the second end wall 316 must be contoured to receive the both electrodes directly and to hold them in coaxial alignment. As shown in Figure 4C, the second end wall 316 defines an annular socket 318 to receive the cathode 36 and a circular socket320 for the cathode 38. It should be noted that Figure 4C is an exploded view of only one portion of the second wall 316 sufficient to show the sockets 318 and 320 in a pair which would accommodate one electrolytic cell 34. Each of the annular sockets 318 is coaxial with a respective one of the circular sockets 320 in order to support the respective anode 38 and cathode 36 of the electrolytic cell 34 in a horizontal position so as to be in transverse alignment to the flow of water into and out of the fluid treatment chamber 32. The coaxial positioning of the annular sockets 318 and the circular sockets 320 also serve as spacers to maintain the coaxial alignment of the cathode 36and anode 38 in each electrolytic cell. A consistent concentric distance must be maintained between the cathodes 36 and anodes 38 at all points along their length is necessary in order to ensure even distribution of electrical charge at all points in the gap 37 therebetween. [59] In the present invention a plurality of electrolytic cells 34 are arranged within the fluid treatment chamber 32. A particularly preferred aspect of invention relates to forcing the fluid in need of treatment in a direction substantially transverse to the disposition of the electrolytic cells. Most preferably, this is done by disposing the electrolytic cells substantially transverse to the flow of fluid.
[60] With reference to Figures 4A and 4B, the electrolytic cells 34 are arranged within12the fluid treatment chamber 32 in a compact manner which permits water to flow through multiple electrolytic cells 34 in order to expose the water to pulsed DC electric fields. Preferably, the electrolytic cells are in physical contact with one another. By way of example, seven (7) electrolytic cells 34 are shown in Figures 4A and 4B in a circular array in an arrangement which is analogous in shape to a revolver chamber. The specific length of the electrolytic cells 34 and their particular array is not critical so long as the anode 38 and cathode 36 which make up each electrolytic cell 34 can be maintained in substantially perfect coaxial alignment with one another. Various means may be provided for maintaining the coaxial alignment with a consistent concentric distance between the first 36 and second 38 electrodes at all points along their length. As discussed elsewhere in this specification the maximum anode length to resist warping is approximately 12 inches (30.6 cm). The fluid treatment chamber 32 is preferably constructed from an electrically insulative material, such as plastic or acrylic. It can be thought of as a block of insulative material. The chamber 32 has a continuous side wall 310. The side wall 310 of the fluid treatment chamber 32 is scalloped along its inner surfaces in order to minimize the width of a gap 312 between each electrolytic cell 34 and the side wall 310 of the chamber 32. The chamber 32 has a first end wall 314 through which the proximal end 114 of the anode will protrude for mounting and electrical connection to a bus bar. The chamber has a second end wall316 to which the first 36 and second 38 electrodes may be attached. A water inlet 322is provided in the side wall 310 for fluid connection with the connecting line 12 to bring water into the fluid treatment chamber. A water outlet 324 is provided in the sidewall 310 to permit the flow of water out of the chamber 32. The water enters the fluid chamber through fluid inlet 322 and is forced upward, flowing through a plurality of electrolytic cells 34, as it travels toward the fluid outlet 324. The fluid outlet 324 is in fluid connection with the connecting line to carry the water downstream for further processing.
[61] After the water has passed out of one electrolytic cell 34, it experiences no electric field until it is compelled to pass through the next electrolytic cell 34. The passage of water through consecutive electrolytic cells 34 exposes any substance or organism in the water to pulsed DC electric fields. By way of example, assuming that the walls of the hollow cathode 36 are approximately 1/16 inch (0.2 cm) thick and the gap 37between the anode 38 and the cathode 36is1/16 inch (0.2 cm), then as water passes between two electrolytic cells 34 it travels a distance of 2/32 inch (0.4 cm) where during which time it experiences no electric field. Passing between the anode 38 and the cathode 36 the water experiences an electric field for a distance of1/ 6 inch (0.2cm). Thus as the water passes on a path through multiple electrolytic cells it effectively experiences a pulsating DC current at a ratio of 2:1 , where 2 is the duration of non- exposure and 1 is the duration of exposure to the electrical current.
[62] It has been found that with appropriate calibration of the flow rate of water into thel 3fluid treatment chamber 32, and the voltage applied to the gap 37 between the electrodes in each electrolytic cell 34, the contaminants and pollutants occurring in the water in need of treatment provide sufficient electrolytic material, to make the addition of an electrolyte unnecessary.
[63] By way of example, it has been determined that the water treatment apparatus according to the first embodiment of the present invention functions sufficiently with a DC current of 1.5 amps (1500 milliampere), and 6.5 volts being applied to water flowing through the fluid treatment chamber 32 at a rate of approximately 0.5 to 2.0gallons per minute. Typically, these parameters would be sufficient to purify municipal water. However, if lake water, river water, or water from other raw sources is used, then these parameters can be adjusted accordingly. Either increasing the amperage (current) and/or reducing the flow rate of the water will be effective in purifying water having a higher contaminant load.
[64] HYDROGEN HANDLING MEANS
[65] As previously mentioned, H2 is a by-product of the electrolysis. The fluid treatment chamber 32 is fitted with an outlet 40 to exhaust the H2 as it is produced. It is desirable to ensure that the H2 concentration does not exceed 4% in the vicinity of the water treatment apparatus to avoid the risk of a hydrogen explosion. The present invention provides two different embodiments of a hydrogen handling means 41. Either embodiment can be integrated into the point of use water treatment system 10 to handle hydrogen gas generated in the by electrolysis occurring in the fluid treatment chamber32.
[66] In a first embodiment shown in Figure 1 , the hydrogen handling means 41 comprises an explosion proof hydrogen exhaust fan connected to the hydrogen outlet40 for forcibly venting hydrogen to the atmosphere. The use of an exhaust fan presupposes that there is a ventilation line to the outdoors. Suitable fans and ventilation lines are commonly available, and a person skilled in the art would be able to select a fan and a ventilation line for use in this system.
[67] In an alternate and preferred embodiment of the invention, shown in Figures 6 and7, the hydrogen handling means 41 is a catalytic hydrogen trap, shown generally by reference numeral 200. The catalytic hydrogen trap 200 comprises a main body 202. The main body 202 is constructed sized and shaped for sealed mounting to the outlet40, such that hydrogen cannot escape the fluid treatment chamber 32 without contacting the catalytic hydrogen trap 200. By way of example, for a standard 3 inch (7.62 cm) internal diameter vent pipe, the main body 202 would preferably be shaped as a disc having approximately .25 inches (0.63 cm) thick and approximately 3 inches (7.62 cm) in diameter, to enable a tight friction fit. The main body 202 defines a multiplicity of openings 204 therethrough to facilitate the through-passage of gas. The main body portion 202 could be formed as a plate having an array of small channels therethrough which channels define the multiplicity of small openings 204 in the main14body 202, as shown in Figures 6 and 7. Suitable sizing for the channels might be 0.125inches (3.175mm) in diameter and 0.125 inches (3.175 mm) apart. The size and spacing suggested herein is by way of example and is not meant to be limiting. Alternatively, the main body 202 could be inset with a portion of screen or mesh having a multiplicity of small openings 204 (such screen or mesh also considered to be part of the main body 202). In all cases, the main body 202 is constructed such that all exposed surfaces 210 thereof comprise a catalyst suitable for catalyzing the oxidation of hydrogen to water. It is preferred that all exposed surfaces of the main body 202comprise platinum. Although the use of a solid platinum main body would be within the scope of the invention, it would likely be economically infeasible. In the preferred embodiment illustrated in Figures 6 and 7, the main body 202 is constructed of a core206 which is preferably comprised of copper. The core 206 has been plated with a layer of niobium 208, approximately 0.0002 inches (4-6 μητι) thick. The niobium Iayer208 is present to facilitate the plating of platinum onto the copper core 206. A thin platinum layer approximately 0.0001 inches (2-3 Mm) thick coats the main body 202 on top of the niobium layer 208 so as to provide ensure that all exposed surfaces comprise platinum. The particular thicknesses of the plating layers provided are by way of example, and are not meant to be limiting. Other substrates could be used for core 206of the main body so long as all exposed surfaces of main body 202 are platinum coated.
[68] For clarity, it should be understood that the inner surfaces of the openings 204 are platinum plated. If the main body 202 is constructed as a plate having channels therethrough forming the openings, the walls of the channels are platinum plated. In the case of a screen or mesh, the entire surface thereof which defines the openings 204 would also be platinum plated. Image resolution limitations prevent illustration of the plating layers on the inner walls of the openings 204 in Figure 7, though reference numeral 210 has been used to indicate the exposed platinum surfaces. In operation, as oxygen and hydrogen gases generated in the fluid treatment chamber 32 during electrolysis of water rise through the outlet 40 they are drawn toward the openings 204 in the catalytic hydrogen trap 200. Any hydrogen molecules which hit the platinum surface 210 of the main body 202 of the hydrogen trap 200 undergo an immediate catalyzed reaction with the free oxygen (also produced during electrolysis) to form water which, depending upon temperature either falls as liquid water back through the outlet 40 into the fluid treatment chamber 32 or continues through the openings 204 as water vapor. Any hydrogen molecules which enter the openings 204 will be brought into very close proximity with the platinum surface 210 present on the walls of the openings 204, and will likewise undergo a catalyzed reaction with the free oxygen to form water molecules. The use of the catalytic hydrogen trap 200 as the hydrogen handling means 41 eliminates the need for ventilation to the outdoors, since the potentially harmful hydrogen gas is converted to water, and any remaining oxygen
and/or15water vapor which pass through the openings 204 are safe to be released into the surrounding environment whether indoors or outdoors.
[69] Returning now to the water treatment system 10, the fluid treatment chamber 32 is optionally fluidly connected by a connecting line to a settling tank 42 and the electrolyzed water is removed from the fluid treatment chamber 32 to the settling tank 42. The positively charged ions continue to combine with negatively charged contaminants in the water to form increasingly large flocculent particles which will settle under gravity in the settling tank 42, leaving pure water containing only naturally occurring trace minerals existing as positive ions. The settling tank 42 is equipped with a drain44 through which accumulated settled flocculent can be gravity drained. A pump 54 is fluidly connected to the settling tank 42 to pump the electrolyzed water, to a post settling filtration means 48. Preferably the post settling filtration means is a standard water filter having a moderate mesh size, on the order of 5 pm. Common filter materials would include polypropylene mesh. Replacement mesh inserts can be readily sourced and periodically replaced as a consumable article. It would be apparent to one skilled in the art that alternative filters could be substituted.
[70] The embodiments shown in Figures 1 and 3 both provide for a settling tank 42(also known as a 'floe tank') where treated water is held and accumulated flocculent particles can settle under gravity. It is not necessary to for the treatment system to have a settling tank 42 in all instances, though it is useful in small commercial or industrial installations where the input water is particularly contaminated and high volumes of water are treated. In smaller scale embodiments, such as that shown in Figures 8 and10, the settling tank has been removed from the system. Treated water would flow directly from the fluid treatment chamber 32 to a water holding tank 52.
[71] A sampling valve 50 is provided in the connecting line downstream of the post settling filtration means 66. The water can be sampled at this point to determine whether there has been adequate treatment of the water so as to sufficiently decrease concentrations of pollutants which were in the water supply. The connecting line is the fluidly connected to the inlet of a treated water storage tank 52. The treated water storage tank holding tank 52 has air tight seals to enable the treated water to be stored in the holding tank 52 until there is user demand. A 100 gallon holding tank 52 would be suitable for household or small scale use. The particular size of the holding tank should not be considered to be a limiting factor in the present invention. The treated water storage tank 52 has an outlet equipped with a sampling valve 56 and a shutoff valve 58. A main pump 54 is provided in fluid connection with the outlet of the treated water storage tank 52 to pump treated water to the user. An internal pressure switch in the pump will maintain the water pressure at a level between about 15 psi and 40 psi. Typical household water pressure is usually about 30 psi. A check valve 60 and pressure gauge 62 are advantageously fluidly connected in the connecting line to facilitate monitoring of water pressure to the end user and to enable shutoff of waterl 6flow in the case of malfunction. A surge tank 64 is optionally provided in fluid connection along the connecting line between the check valve 60 and the end user. A series of post treatment filtration means 66 are provided in fluid connection in the connecting line upstream of the end user. The post treatment filtration means
66preferably includes two 5pm flow filters 48, an activated carbon (charcoal) absorber49, and a final 1 pm absolute polishing filter 51. Downstream of the final filtration means 66 a final pressure regulator 68 and a system outlet check valve 70 are connected into the connecting line. The system outlet check valve 70 provides the final check on flow of treated water into the user's water system.
[72] The efficacy of the electrolysis of water can be varied by varying the flow rate of water through the fluid treatment chamber 32, which changes the amount of time the water experiences each DC pulse as it travels through the chamber 32. The flow rate of the water can be adjusted using the flow control valve 28. Efficacy can also be varied by varying the voltage applied across the gap between the first 36 and second 38electrodes. By adjusting these two variables it is possible to selectively vary the strength of the electrolysis to neutralize greater or lesser concentrations of pollutants. In this way, the system can be adjusted to treat water having different concentrations of contaminants.
[73] Figures 8 and 9 of the drawings illustrate an alternate embodiment of the point of use water treatment system 10. In this alternate embodiment the support frame 13comprises a plurality of support elements, but the support frame 13 is constructed as a split frame comprising two or more support modules. For the purposes of illustration, the preferred arrangement of two support modules is shown. It would be understood by a person skilled in the art that additional support modules could be constructed and that particular elements of the water treatment system 10 could be mounted to any of the support modules. In the same manner as discussed generally above with reference to the support frame 13, the two or more support modules can be either wall mounted or free standing.
[74] The perspective view of Figure 8 provides a visual understanding of the preferred two support modules and their respective size and shape, while the schematics of Figure 9 provide specific illustration of how the various functional elements of the water treatment system 10 are arranged and mounted to one or other of the respective support modules. In Figure 9, the dashed line 810 notionally identifies the first module and the dashed line 812 notionally identifies the second module. The arrangement and grouping of the elements of the point of use water treatment system are optimized to maximize functional efficiency by keeping functionally related elements physically near one another while placing the elements of the system which a user would need to access most frequently on a single compact support module.
[75] A first support module 810 has means for mounting a control panel 820 and the entire filter elements, namely the pre-filter 24, post settling filtration 48, 48, and the17final filtration 66 mounted thereon. The first support module 810 can be quite compact in size, and could have a footprint on the order of 16' by 42" (40.6 cm x 106.7 cm). The first support module 810 could readily be positioned against one wall of a room and either used free standing, or it could be wall mounted. The filtration units are mounted at the front of the support frame, so that filtration units are easily accessible to change out filters as needed. Similarly, the support frame has mounting means for the control panel at the front of the support frame in order to ensure that the control panel is readily accessible to a user.
[76] A second support module 812 has mounted thereon the water treatment chamber32 containing the electrolytic cells 34, the hydrogen vent 40 with the hydrogen handling means 41 , the water holding tank 52 and the system drain 824, the pump 54, and the connecting line 12 to the surge tank 64. The second support module 812 is typically larger than the first support module 810 in order to support the water holding tank 52. As such, it is likely to be free standing rather than wall mounted, though it may be secured to a wall for safety reasons. The second support module 812 may also be provided with collar 82 to support the water holding tank 52.
[77] The split frame embodiment is designed to permit a first support module 810 of the point of use water treatment system 10 to be installed in one location and a second support module 812 of the point of use water system to be installed in a different location. The two modules of the system may be placed in different areas of a room (such as on different walls) or in different areas, such as different rooms in the basement of a house. Alternatively, the modules may be placed in more distantly separated locations, such as the first module 810 in the basement of a house and the second module 812 in a garage or shed. So long as the two modules can be conducted by modular connection lines 814, the selection of locations for the installation of the two modules 810, 812 is at the discretion of the user or installer. The first module 81 Oand the second module 812 are operatively connected to one another using modular connecting lines 814 shown schematically in Figure 9 as a dashed line. The modular connection lines 814 have the same functional requirements and can be constructed from the same materials as the fluid connecting lines 12 discussed above. The modular connection lines 814 carry water between the elements mounted to the first support module 810 and the second support module 812. The length of the modular connection lines 814 will be determined in each instance by the distance separating the first support module 810 from the second support module 812. It should be understood that there will also be sensor feedback and control communications between elements of the water treatment system 10 which are mounted to the first support module 810 and the elements which are mounted to the second support module 812. Sensor feedback and control means for a water treatment system are well known and the selection and assembly feedback and control means are within the understanding of a person skilled in the art. [78] The functionality of the point of use water treatment system 10 shown in Figures 8and 9 is substantially the same as that discussed in detail above; however the settling tank 42 has been eliminated, as will be discussed in greater detail below. Aftertreatment in the electrolytic cells 34 of the fluid treatment chamber 32, the water is held in a water holding tank 52. The water in the water holding tank 52 remains active for a time after treatment. The settling function now occurs in a water holding tank indicated by reference numeral 100. As best seen in Figure 8, the water holding tank52 has a tapered portion 822 toward the bottom thereof to facilitate settling of the flocculent of coagulated impurities toward a system drain 224 for periodic removal. The treated water from which the coagulated impurities have been removed is taken out of the water holding tank 52 and is then pumped by pump 54 through a connecting line 12 to the post treatment filtration means 66. The connecting line 12 between the pump and the filtration means can be of variable length in accordance with the installed distance between the first support module 810 and the second support module812. In Figure 9 the modular connection lines 814 are shown schematically in dotted lines to indicate that they may be of variable length. Dotted and dashed borders notionally define the first support module 810 and the second support module 812 in order to visualize where the various functional elements of the point of use water treatment system 10 are mounted.
[79] Figures 10 and 1 1 show yet another alternate embodiment of the point of use water treatment system 10 which has been scaled for home use, having a single stand alone support frame 13 having all other components attached thereto within one compact footprint. The frame support 13 is provided with mounting means for the filtration units and the fluid lines connecting them. In this embodiment of the invention the support frame 13 has been constructed as a support cage 90 comprising a front wall 92, a first side and a second side wall 94, 94 and a back wall 98. All necessary components of the point of use water treatment system 10 are mounted directly or indirectly the walls of the support cage 90. After treatment in the electrolytic cells 34

Claims

We Claim:
1. A point of use water treatment system comprising:
(a) a water treatment chamber having a fluid inlet, and a fluid outlet, and at least one permeable electrolytic cell disposed therebetween substantially completely filling the only path of water from the fluid inlet to the fluid outlet and oriented such that the path of water from the fluid inlet to the fluid outlet is substantially transverse to the at least one electrolytic cell, wherein said at least one electrolytic cell comprises an non-sacrificial anode and a cathode coaxially disposed with respect to one another and having a gap therebetween;
(b) a water holding tank in fluid connection with the water treatment chamber for holding water activated by passage through the at least one electrolytic cell; and,
(c) a post settling filtration means in fluid connection with the water holding tank for removal of flocculent residue not settled from the water while in the water holding tank.
2. The point of use water treatment system of claim 1 , wherein the outer surface of the non- sacrificial anode comprises a noble metal selected from the group consisting of ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.
3. The point of use water treatment system of claim 2, wherein the non-sacrificial anode comprises a core plated with platinum.
4. The point of use water treatment system of claim 3, wherein the core of the non- sacrificial anode is copper, plated with a niobium, and further plated with platinum.
5. The point of use water treatment system of claim 2, further comprising a hydrogen handling means in fluid connection with an outlet from the fluid treatment chamber.
6. The point of use water treatment system of claim 5, wherein the hydrogen handling means is an explosion proof fan vented to the outdoors.
7. The point of use water treatment system of claim 5, wherein the hydrogen handling means is a catalytic hydrogen trap.
8. The point of use water treatment system of claim 7, wherein the catalytic hydrogen trap is sized and shaped for sealed mounting to the outlet from the fluid treatment chamber, such that hydrogen cannot escape the fluid treatment chamber without contacting the catalytic hydrogen trap; and all exposed surfaces of the catalytic hydrogen trap comprise a catalyst for the oxidation of hydrogen.
9. The point of use water treatment system of claim 8, wherein the catalytic hydrogen trap comprises a main body defining a multiplicity of openings therethrough to facilitate the through- passage of hydrogen, all exposed surfaces21 of the main body comprising platinum.
10. The point of use water treatment system of claim 9, wherein the main body of the catalytic hydrogen trap is platinum plated.
11. The point of use water treatment system of claim 9, wherein the main body is formed as a plate having an array of channels therethrough which channels define the multiplicity of openings.
12. The point of use water treatment system of claim 9, wherein the main body is inset with a screen or a mesh defining the multiplicity of openings.
13. The point of use water treatment system of claim 12 further comprising a support frame for direct or indirect supporting attachment of the fluid treatment chamber, the water holding tank and the post settling filtration means.
14. The point of use water treatment system of claim 13 wherein the support frame comprises two or more support modules.
15. The use of a non-sacrificial anode having a noble metal outer surface in a point of use electrolytic water treatment system.
16. A non-sacrificial anode for use in a point of use electrolytic water treatment system, said non-sacrificial anode having an outer surface comprising a noble metal selected from the group consisting of ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.
17. A catalytic hydrogen trap comprising a main body defining a multiplicity of openings therethrough, and all exposed surfaces thereof comprising a catalyst for the oxidation of hydrogen.
18. The catalytic hydrogen trap of claim 17, wherein the main body is platinum plated.
19. The catalytic hydrogen trap of claim 18, wherein the main body is formed as a plate having an array of channels therethrough which channels define the multiplicity of openings.
20. The catalytic hydrogen trap of claim 18, wherein the main body is inset with a screen or a mesh defining the multiplicity of openings.
PCT/CA2014/000418 2013-05-31 2014-05-15 Point of use water treatment system WO2014190411A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267029A (en) * 1980-01-07 1981-05-12 Pennwalt Corporation Anode for high resistivity cathodic protection systems
CA2649873A1 (en) * 2008-06-24 2009-04-08 Saltworks Technologies Inc. Method, apparatus and plant for desalinating saltwater using concentration difference energy
JP4469369B2 (en) * 2004-05-20 2010-05-26 株式会社エルム Water purification equipment
CA2835727A1 (en) * 2011-06-06 2012-12-13 Axine Water Technologies Inc. Efficient treatment of wastewater using electrochemical cell
GB2500663A (en) * 2012-03-29 2013-10-02 Hydro Ind Ltd Method and apparatus for treatment of fluids by media assisted electro-based treatment

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267029A (en) * 1980-01-07 1981-05-12 Pennwalt Corporation Anode for high resistivity cathodic protection systems
JP4469369B2 (en) * 2004-05-20 2010-05-26 株式会社エルム Water purification equipment
CA2649873A1 (en) * 2008-06-24 2009-04-08 Saltworks Technologies Inc. Method, apparatus and plant for desalinating saltwater using concentration difference energy
CA2835727A1 (en) * 2011-06-06 2012-12-13 Axine Water Technologies Inc. Efficient treatment of wastewater using electrochemical cell
GB2500663A (en) * 2012-03-29 2013-10-02 Hydro Ind Ltd Method and apparatus for treatment of fluids by media assisted electro-based treatment

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"A Fast Electrocatalyst for Oxidation of Hydrogen", CENTER FOR MOLECULAR ELECTROCATALYSIS, November 2010 (2010-11-01), Retrieved from the Internet <URL:http://efrc.pnnl.gov/research/electrocatalyst.asp> [retrieved on 20140729] *
A. Q. ZADE ET AL.: "Homogeneous oxidation of hydrogen in catalytic mini/microchannels", ASME 2011 9TH INTERNATIONAL CONFERENCE ON NANOCHANNELS, MICROCHANNELS, AND MINICHANNELS, vol. 1, 2011, pages 35 - 43 *

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