Abstract:
A process is described, for treating liquids with radiation. One process involves passing the liquid over an ultraviolet lamp and ballast assembly which is submerged in the liquid. Apparatus for the process has an elongate frame member which is immersed in the liquid. Attached to the frame member and immersed in the liquid is a plurality of ultraviolet lamps and associated ballasts.

Description:
The present application claims the benefit of U.S. provisional application serial No. 60/107,915 filed Nov. 10, 1998. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an apparatus for ultraviolet treatment of fluids such as water. More particularly, the present invention relates to an apparatus that employs a particular arrangement of ballasts and ultraviolet lamps. 
     BACKGROUND TO THE INVENTION 
     It is known to treat water with ultraviolet light in order to destroy undesirable bacteria and other microorganisms. For example, U.S. Pat. No. 5,660,719 which issued Aug. 26, 1997 to Kurtz et al. discloses an ultraviolet lamp rack assembly comprising an array of vertically disposed ultraviolet lamps for the treatment of fluids. The assembly has a separate enclosure for the housing at least one ballast and electronic components to power the lamps. Kurtz et al. indicate that substantial amounts of heat are generated during functioning of the ballast and that cooling is required. Cooling is provided by blowing air through the enclosure, or by means of air conditioning or the use of a heat exchanger. 
     Another arrangement is disclosed in U.S. Pat. No. 5,019,256 which issued May 28, 1991 to Ifill et al. This patent discloses an ultraviolet lamp rack assembly comprising a vertical array of horizontally disposed ultraviolet lamps for the treatment of waste water. A power control panel is provided at a location remote from the rack assembly for the inclusion of ballasts and various electronic components. Alternatively, the ballasts for the lamps may be located in a submerged vertical conduit which forms a part of the rack. One of the problems associated with such an arrangement is that the ballasts are difficult to remove from the rack, and if one ballast needs to be replaced then all of the ballasts must be removed. This is inefficient, as the ultraviolet treatment unit is out of service for a long period of time. Variations of the device of U.S. Pat. No. 5,019,256 to Ifill et al. are disclosed in U.S. Pat. Nos. 4,482,809, 4,872,980 and 5,006,244 to J. M. Maarschalkerweerd which issued Nov. 13, 1984, Oct. 10, 1989 and Apr. 9, 1991 respectively. The ballasts and power supply to the lamps are separate from the lamps and lamp racks. 
     Most commercial treatment systems for water, in which the water is treated with ultraviolet radiation, use ultraviolet lamps which have electrodes therein and are associated with ballasts. The present invention is also suitable for lamps which are electrodeless and are associated with high frequency excitation couplers. A description of a typical electrodeless lamp and coupler may be found in U.S. Pat. No. 5,070,277 to W. P. Lapatovich which issued Dec. 3, 1991. 
     The present invention attempts to overcome the deficiencies of the previous systems and provide a system which is easily maintained. 
     The term “wire”, as used herein in relation to the present invention, includes a plurality of wires, e.g. as in a cable. 
     The terms “comprising/comprises” when used in this specification are taken to specify the presence of the stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 
     SUMMARY OF THE INVENTION 
     Accordingly, one aspect of the present invention provides a radiation source assembly for use with a fluid, comprising: 
     at least one radiation source adapted to be immersed in said fluid when the assembly is in use, the source producing radiation by excitation of a gas; 
     at least one excitation controlling means for controlling excitation of gas within the radiation source, said excitation controlling means being adapted to be immersed in said fluid when the assembly is in use; 
     a first elongate frame member having a portion adapted to be immersed in the fluid when the assembly is in use, the frame member being connected to at least one of a) the radiation source and b) the excitation controlling means; and 
     electrical conducting means for providing electrical energy to the excitation controlling means. 
     In one embodiment, the radiation source is a lamp for emitting ultraviolet radiation. 
     In another embodiment, the lamp has electrodes and the excitation controlling means is a ballast electrically connected to the lamp. 
     In a further embodiment, the lamp is an electrodeless lamp and the excitation controlling means is a high frequency coupler. 
     In another aspect of the present invention provides a radiation source assembly for use with a material selected from the group consisting of a liquid and a flowing fluid, comprising: 
     a) when the material is a liquid, 
     at least one radiation source adapted to be immersed in said liquid when the assembly is in use; 
     at least one excitation controlling means for controlling excitation of gas within the radiation source, said excitation controlling means being adapted to be immersed in said liquid when the assembly is in use; 
     and electrical conducting means for providing electrical energy to the excitation controlling means; or 
     b) when the material is a flowing fluid, 
     at least one radiation source adapted to be immersed in said flowing fluid when the assembly is in use; 
     at least one excitation controlling means for controlling excitation of gas within the radiation source, said excitation controlling means being adapted to be immersed in said flowing fluid when the assembly is in use; 
     and electrical conducting means for providing electrical energy to the excitation controlling means. 
     In yet another embodiment, the radiation source assembly has a first elongate frame member having a portion adapted to be immersed in the liquid or flowing fluid when the assembly is in use, and the frame member is connected to at least one of the radiation source, a radiation-transparent sleeve for the radiation source and the excitation controlling means. 
     In a further embodiment, the radiation source is adjacent to the excitation controlling means. 
     In one embodiment, the radiation source is a lamp for emitting ultraviolet radiation. 
     In another embodiment, the lamp has electrodes and the excitation controlling means is a ballast electrically connected to the lamp. 
     In a further embodiment, the lamp is an electrodeless lamp and the excitation controlling means is a high frequency coupler. 
     In another embodiment, the ballast is supported by the first elongate frame member. 
     In a further embodiment, the ballast is elongate and has first and second opposed ends, the first end of which is mounted on said portion, the lamp is elongate and has first and second opposed ends, the first end of which is connected to the second end of the ballast. 
     In another embodiment, the lamp is elongate and has first and second ends, the first end of which is connected to the ballast and the second end of the lamp is supported by the first elongate frame member. 
     In a further embodiment, the assembly has a plurality of excitation controlling means, each with a radiation source associated therewith. 
     In yet another embodiment, the assembly has a plurality of radiation sources connected to each excitation controlling means. 
     In another embodiment, the electrical conducting means includes, for each excitation controlling means, an electrical wire which extends from the excitation controlling means to a location which is not immersed in the liquid or flowing fluid. 
     In a further embodiment, all of the electrical wires have a coating which is in contact with the liquid or flowing fluid. 
     In another embodiment, the assembly has a second elongate frame member, and when each ballast is supported by the first elongate frame member, the second end of each associated lamp is supported by said second elongate frame member. 
     In another embodiment, the ballast and lamp are encased in a transparent sleeve which is fluid-tight. 
     In a further embodiment, the transparent sleeve is mounted at a first end with a fluid-tight connection to the portion of the first elongate frame member. 
     In another embodiment, the transparent sleeve is mounted at the first end with a fluid-tight connection to the portion of the first elongate frame member, and mounted at a second end to the second elongate frame member. 
     In yet another embodiment, the first elongate frame member is tubular with an outer wall and, for each excitation controlling means, a support with an externally threaded tubular stub surrounding an access aperture through the outer wall, the excitation controlling means has an external retaining ring fixed adjacent the first end thereof, the assembly further comprising an internally threaded coupling for engaging the stub and the retaining ring, so as to move the stub and the ring toward each other, and a resilient sealing member between the stub and the coupling such that the retaining ring is pressed against the exterior of the excitation controlling means when the coupling is tightened. 
     In a further embodiment, the assembly has a sleeve surrounding each radiation source, said sleeve having one open end and one closed end and being made of a material transparent to radiation emitted by the radiation source, and a further coupling which sealingly supports the open end of said sleeve from the second end of the excitation controlling means. 
     In a further embodiment, the excitation controlling means is a ballast and the radiation source is a lamp with electrodes. 
     Another aspect of the invention provides an assembly for use in a photochemical treatment of a fluid, comprising: 
     at least one radiation source for producing radiation by excitation of a gas; 
     at least one excitation controlling means adapted to be immersed in said fluid when the assembly is in use, for controlling excitation of the gas within the radiation source; 
     a submersible frame member having a portion adapted to be immersed in the fluid when the assembly is in use and having a plurality of supports, each support providing support for at least one of a) a radiation source, b) a radiation-transparent sleeve for the radiation source and b) an excitation controlling means; and 
     electrical conducting means for providing electrical energy to the excitation controlling means. 
     In one embodiment for treatment of a liquid, the assembly is selected from the group consisting of 
     A) an assembly in which the excitation controlling means is a ballast, said ballast having a second end opposed to a first end, and said ballast having an outer sleeve which encloses components of the ballast, the sleeve being sealed to prevent ingress of liquid into the ballast, said ballast and support having connection means for mechanically connecting the first end of the ballast to the support; 
     the radiation source is an elongate ultraviolet lamp having first and second opposed ends, said lamp and ballast having connection means for mechanically and electrically connecting the first end of the lamp to the second end of the ballast; and 
     and the assembly has means for sealing the lamp against direct contact with the liquid; 
     B) an assembly in which the radiation source is an elongate ultraviolet lamp having connection means for mechanically connecting the lamp to the support; 
     the excitation controlling means is a ballast, said lamp and ballast having means for electrically connecting them together; and 
     the assembly has sealing means for sealing the lamp and ballast against direct contact with the liquid; 
     C) an assembly in which the radiation source is an elongate ultraviolet lamp; 
     the excitation controlling means is a ballast, said lamp and ballast having means for electrically connecting them together; 
     and the assembly has a sleeve covering and sealing the lamp and ballast against direct contact with the liquid, and the assembly has connection means for mechanically connecting the sleeve means to the support; and 
     D) an assembly in which the excitation controlling means is a ballast, having an outer sleeve which encloses components of the ballast, the sleeve being sealed to prevent ingress of liquid into the ballast, said ballast having connection means for mechanically connecting the ballast to the support; 
     the radiation source is an elongate ultraviolet lamp having connection means for mechanically connecting the lamp to the support separately from the ballast, and means for sealing the lamp against direct contact with the liquid, said lamp and ballast having means for electrically connecting them together. 
     In another embodiment, the means for sealing the lamp in embodiments A), B) or D) is a sleeve which is transparent to ultraviolet radiation. 
     In a further embodiment, submersible frame member is tubular, and the support surrounds an aperture in a side wall of the frame member, and the assembly further includes 1) a first electrical connection between the ballast and electrically conductive means within the tubular frame member, said first electrical connection having the form of pins entering suitable sockets, and 2) a second electrical connection between the ballast and the ultraviolet lamp, said second electrical connection also having the form of pins entering suitable sockets. 
     In yet another embodiment, the assembly includes electrical power transmission means for transmitting electrical power from a power source to each ballast, said power transmission means being outside the submersible frame member. 
     Preferably, all connections are substantially water tight. 
     The present invention also provides an ultraviolet lamp assembly for submersion in a liquid, comprising a rack with a submersible conduit, and at least one submersible ultraviolet lamp with associated submersible ballast wherein the ultraviolet lamp is removably coupled, physically and electrically, to an associated ballast and the ballast is removably coupled, physically, to the conduit such that when submerged, liquid cannot enter the conduit through the lamp and ballast couplings. 
     In one embodiment, the conduit contains electrical power transmission means and the ballast is removably coupled, electrically, to the power transmission means. 
     In a further embodiment the power transmission means is selected from the group consisting of wire and electrically conductive strips. 
     In another embodiment, the ultraviolet lamp is encased in a sleeve which is transparent to ultraviolet light. 
     In a further embodiment, the conduit has a tubular stub attached thereto such that there is electrical communication between the ballast and the power transmission means. 
     In another embodiment, there is a screw coupling with a liquid tight seal between the lamp, sleeve and ballast. 
     In yet another embodiment, there is a screw coupling and a liquid tight seal between the ballast and the conduit. 
     In another embodiment, the liquid is water. 
     The invention also provides a process for treating liquids with ultraviolet light comprising passing the liquid over an ultraviolet lamp and ballast assembly which is submerged in the liquid. 
     Another aspect of the invention provides means for transmission of electrical power and electrical signals, in the form of a laminate which comprises: 
     a plurality of elongated electrically conducting members, each with a plurality of connectors at spaced apart intervals along the member, said electrically conducting members having an electrically insulating material between the members. 
     In one embodiment, each electrically conducting member is sandwiched between two electrically insulating strips, and at least one of the strips has notches at spaced apart intervals along the strip, wherein the connectors are housed in the notches. 
     In another embodiment, the laminate has first and second elongated electrically conducting members, said first electrically conducting member being sandwiched between first and second electrically insulating members and said second electrically conducting member being sandwiched between second and third electrically insulating members. 
     In a further embodiment, the connectors are spring clip connectors for connecting with electrically conducting pins. 
     In yet another embodiment, each outer electrically insulating member is clad with a further electrically insulating member. 
     In another embodiment, the electrically conducting members are metal strips. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial side view of a single modular UV lamp rack assembly in accordance with the invention. 
     FIG. 2 is a cross-sectional view of a ballast and associated connections in accordance with the invention. 
     FIG. 3, which is located between FIGS. 1 and 2, is an end view of a ballast used in FIG.  2 . 
     FIG. 4 is a perspective view of a portion of a vertical conduit in a UV lamp rack assembly, useful in the present invention. 
     FIG. 5 is a cross sectional view of a ballast and lamp which has an outer sleeve attached to a submersible conduit. 
     FIG. 6 is a cross-sectional view of a ballast and an associated lamp which are separately attached to a submersible conduit. 
     FIG. 7 is an exploded view of a laminate useful as an electrical conduit for use in the present invention. 
     FIG. 8 is a front view of the laminate of FIG. 7, with connecting apertures therein. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIG. 1, there is an ultraviolet lamp rack  10  which has a vertical conduit  11 , a vertical support member  12  and a bar  13 . Located between vertical conduit  11  and vertical member  12  are a plurality of ultraviolet lamps  14  encased in transparent sleeves  15  (partially seen in FIG.  2 ), with associated ballasts  16  and caps  18 . The sleeves  1 S are made from a material which permits passage of ultraviolet light. A preferred material is quartz glass. The ultraviolet lamps  14  and ballasts  16  are submerged in liquid  66 , e.g waste water. The surface of the liquid is shown at  17  and in FIG. 1 is beneath bar  13 . 
     FIG. 2 shows the arrangement of one of the ballasts  16 . Ballast  16  has internal components  22  encased in sleeve  21 . At one end of ballast  16  there are female electrical connectors  20  for cooperation with electrical pins  19  on ultraviolet lamp  14 . At the other end of ballast  16  there is an electrical line pin  23  and an electrical neutral pin  24 . Between line pin  23  and neutral pin  24  there is an electrical insulation barrier  25 . Attached to sleeve  21  is a retaining ring  26 , the purpose of which will be explained hereinafter. 
     FIG. 2 also shows vertical conduit  11  in which there are female electrical connectors  34  and  35 , which are electrically connected to electrical conduits, e.g wires, strips. There is an aperture  36  adjacent to connectors  34  and  35 , through which pins  23  and  24  may be connected to connectors  34  and  35  respectively. Attached, e.g. welded, to vertical conduit  11  is a tubular stub  29 , which has an exterior screw thread, as shown in FIGS. 2 and 4. Ballast  16  is held in place by means of an internally screw threaded coupling  27 . The joint between ballast  16  and tubular stub  29  is made watertight by means of an O-ring  28  which is trapped between retaining ring  26  and tubular stub  29 . 
     As indicated above, the ultraviolet light lamp  14  is electrically connected to ballast  16  by means of pins  19  and female connectors  20 . At the end of ballast  16  adjacent to the connectors  20 , there is a tubular stub  31  which has an external screw thread  31 a. Tubular stub  31  is connected to sleeve  21  by a weld or similar. It will be understood that tubular stub  31  may be an integral part of sleeve  21 . Quartz sleeve  15  surrounds ultraviolet lamp  14 . The connection between the quartz sleeve  15  and tubular stub  31 , and thus between ultraviolet lamp  14  and ballast  16 , is kept waterproof by means of an O-ring  33  which is trapped between tubular stub  31  and internally threaded retaining nut  32 . 
     It will be understood that other arrangements for securing the ballast and lamps in place are possible without departing from the essence of the invention. For example, sleeve  16  and tubular stub  29  may have the same diameter, and abutting ends may be externally threaded and held together with an internally threaded coupling which screws onto both the sleeve and the stub. 
     FIG. 3 shows an end of ballast  16 , which has line and neutral pins  23  and  24  separated by an electrical insulation barrier  25 . The ballast end may have auxiliary pins  38  for alarms and other features. 
     FIGS. 5 and 6 illustrate different arrangements of a ballast and an ultraviolet lamp. In FIG. 5, ballast  70  is electrically and mechanically connected to ultraviolet lamp  71 . Ballast  70  and lamp  71  are enveloped in sleeve  72 . Sleeve  72  has a closed end  73  and an open end  74 . open end  74  fits over and is supported by tubular stub  75  which is welded to a vertically arranged tubular conduit  76 . There is an aperture in conduit  76  so that there may be electrical communication through conduit  76  to the ballast  70  inside sleeve  72 . Electrical communication is accomplished through wires  77  which are appropriately connected to ballast  70 . Sleeve  72  is sealed against ingress of fluid, e.g. liquid, outside the sleeve, by means of O-ring  78  or similar. FIG. 5 also shows closed end  73  of sleeve  72  being supported in a cavity  79  in vertically arranged support member  80 . 
     In FIG. 6, ballast  90  is physically separated from ultraviolet lamp  91 , although ballast  90  and lamp  91  are electrically connected by wires  92 . Lamp  91  is enveloped in sleeve  93 . Sleeve  93  has a closed end  94  and an open end  95 . Open end  95  fits over and is supported by tubular stub  96  which is welded to vertically arranged tubular conduit  97 . There is an aperture in conduit  97  so that there may be electrical communication through conduit  97  to the ballast  90 . Ballast  90 , which has a threaded end, is mechanically supported by externally threaded stub  98  and internally threaded coupling  99 . There is an O-ring  100  trapped between ballast  90  and stub  98  to provided a seal to prevent ingress of fluid into the electrical connections for the ballast and lamp. Ballast  90  has power supply wires  101  connected thereto. Sleeve  93  is sealed against ingress of fluid, e.g. liquid, outside the sleeve, by means of O-ring  102  or similar. Closed end  94  of sleeve  93  has a boot  103  surrounding closed end  94 , and boot  103  is supported in a cavity  104  in vertically arranged support member  105 . 
     FIGS. 7 and 8 illustrate a power and signal laminate  39  which comprises a plurality of strips  40  to  46 . The center strip  43  has a notch  53  therein for receiving electrical insulation barrier  25 . If there are a plurality of ballasts to be connected to the power and signal laminate, it will be understood that there will be a notch for every ballast. FIG. 7 shows three such notches. Center strip  43  is sandwiched between strips  42  and  44 . Strip  42  is sandwiched between strips  43  and  41  and strip  44  is sandwiched between strips  43  and  45 . Attached to strip  42 , between strips  41  and  42  is an electrically conducting power strip  50  (see FIG. 7) with a plurality of spring clips  49  attached thereto. Attached to strip  44 , between strips  44  and  45  is a power strip  47  with a plurality of spring clips  48  attached thereto. Strips  41  and  45  have a plurality of notches  52  and  51  respectively, for reception of electrical pins  23  and  24  respectively. Spring clips  49  nest within notches  52  and spring clips  48  nest within notches  51 . Spring clips  48  are for providing secure electrical connection between power strip  47  and electrical pins  24 . Spring clips  49  are for providing secure electrical connection between power strip  50  and electrical pins  23 . The laminate  39  has outer strips  40  and  46 . 
     The laminate shown in FIG. 8 also has notches  54  and  56  in outer strips  46  and  40  respectively. In notches  54  and  56  there are power strips with spring connectors  55  and  57  respectively therein. 
     Although not shown, microprocessor chips may be embedded between strips so that the microprocessor chips are protected from the environment, e.g. are protected from water damage. The chips can be used for a variety of purposes, e.g. to monitor the lamps, ballasts, excitation couplers and other electrical or electronic components, and trigger alarms at alarm remote panels. 
     It will be understood that electrical pins  23  and  24  form an electrical connection with power strips  47  and  50  when pushed into spring clips  48  and  49  respectively. Connectors  55  and  57  are preferably for auxiliary connections, e.g for detection of burnt-out lamps, defective ballasts, leaking joints and the like. 
     Although the drawings show electrical power being fed to ballasts  16  by means of wires or laminates through conduit  11 , electrical power may be fed to ballast  16  through means external to conduit  11 . In such an instance, waterproof wires may be used, which enter a waterproof coupling to the ballast. As will be understood, in such an instance, conduit  11  could be replaced by a submersible tube or bar which merely supports ballast  16 . Such support may be provided by a flexible or rigid boot attached to the submersible bar. Alternatively, the ballast may be physically separated from the lamp as shown in FIG.  6 . 
     The present invention is useful for the treatment of a wide range of fluids, e.g. gases and liquids. It is preferable that the fluid is flowing around the radiation source and the excitation controlling means. For example, a rack with attached ballasts and ultraviolet lamps is immersed in a flowing gas so that a stream of gas flows over the ultraviolet lamps. 
     The present invention is particularly useful for the treatment of water, e.g. for waste water disinfection, drinking water disinfection, advanced oxidation treatment and other water treatment processes. The rack with attached ballasts and ultraviolet lamps preferably is immersed in the water so that a stream of water flows over the ultraviolet lamps. Electric power is fed to the lamps via the ballasts, preferably by means of wires or laminates of the present invention through a tubular member of the rack. One of the advantages of this aspect of the present invention is that the water that is being treated can be used to cool the ballasts. This removes the necessity for external forced air cooling or for air conditioning equipment. Furthermore, the ballasts can easily be serviced in situ, removed from service or replaced in the same way that ultraviolet lamps may be serviced or replaced. Any downtime for operation is thus kept to a minimum. In the Ifill et al. apparatus, if a ballast, which is present in vertical conduit  15  becomes defective, all of the ballasts and associated wiring must be removed from the conduit, repaired and then reinserted. The present invention is a great improvement over Ifill&#39;s invention and other known systems. 
     Another advantage of the present invention is that the life of ballasts or excitation couplers should be greater because they are kept cooler. 
     It will be understood that the present invention is applicable to low pressure standard output lamps, low pressure high output lamps, low pressure triple output (amalgam) lamps, medium pressure lamps, electrodeless lamps and excimer lamps. 
     Although the drawings have been limited to showing installation of a system with ballasts and ultraviolet lamps, the present invention is equally applicable to other radiation sources and other excitation controlling means. For example, electrodeless ultraviolet lamps or video projection lamps or street lamps may be used with high frequency, e.g. radio frequency, excitation couplers. 
     While several embodiments of this invention have been illustrated in the accompanying drawings and described hereinabove, it will be evident to those skilled in the art that changes and modifications may be made therein without departing from the essence of this invention, as set forth in the appended claims.