The turbulent flow is effected by baffles, flow devices or other moveable vortex generators that in a pipe reactor are located prior to i. e. upstream of, the elongated ultraviolet lamp assemblies. In an open channel system, the baffles, flow devices or other moveable vortex generators may be located between elongated ultraviolet lamp assemblies. The moveable vortex generators are free to move in the current of water passing through the apparatus, e. g. by freely swinging - on an axis perpendicular to the flow of water, thereby causing turbulence in the water.

As used herein, the expression"moveable vortex generator"is used to include baffles, flow devices and other moveable turbulence generators that are placed in the water to be treated.

BACKGROUND TO THE INVENTION It is known to treat water with ultraviolet light to destroy undesirable bacteria and other micro-organisms. In one form of typical apparatus used in the treatment of water, rack assemblies with a vertical array of elongated ultraviolet lamps are used, usually with several racks in a side-by-side arrangement. In such vertical arrays, the elongated ultraviolet lamps are oriented horizontally in the rack.

The racks are located in an open channel through which water to be treated is passed. The ultraviolet lamps are enclosed in quartz sleeves.

A variety of apparatus with vertical arrays of elongated ultraviolet lamps are known. Examples include the apparatus disclosed in U. S. Patent 5,019,256. This patent discloses an ultraviolet lamp rack assembly comprising a vertical array of horizontally disposed ultraviolet lamps for the treatment of waste water. Variations of this apparatus are disclosed in U. S. Patents 4,482,809,4,872,980 and 5,006,244. Such apparatus have the ballast located above the water level. Apparatus with the ballast located under water and adjacent to the lamp is disclosed in U. S. Patent 6,193,939.

Apparatus is also known in which the elongated ultraviolet lamps are oriented vertically. For example, U. S. Patent 5,660,719 discloses an ultraviolet lamp rack assembly comprising an array of vertically disposed ultraviolet lamps for the treatment of fluids.

Tubular reactors, also known as pipe reactors, are also used in the ultraviolet treatment of water. In a tubular reactor, water is passed through a fluid-flow passageway, typically an annular passageway, in which there are elongated ultraviolet lamp assemblies. The lamp assemblies may be aligned with the direction of flow of water i. e. aligned longitudinally, or extend lateral to the direction of flow i. e. extend across a diameter of the annular passageway.

The ability of an ultraviolet light treatment system to inactivate (kill) micro-organisms is a function of the UV fluence generated in the treatment system. The UV fluence is the product of the fluence rate and the time of treatment. The ability of ultraviolet light to penetrate wastewater, and hence treat the wastewater, is affected by the transmission of ultraviolet light. As the ultraviolet transmission from the lamp decreases, the fluence rate also decreases. Thus, for a particular

ultraviolet lamp, the important factors in the transmission of ultraviolet light include the age of the lamp, the degree of fouling of the lamps i. e. the degree of fouling of the quartz sleeve around the lamp, and the clarity of the wastewater that is being treated. Steps may be taken to clean the lamps and especially the quartz sleeve around the lamp, but the clarity of the water to be treated may be difficult or impossible to control. In addition, the amount of ultraviolet light obtainable from an ultraviolet lamp is limited. Thus, the consequence of the need to provide a UV fluence to efficiently and effectively treat the water is that there is a tendency and desire to place the ultraviolet lamps closer and closer together and/or to use more ultraviolet lamps.

To kill microorganisms in water, it is necessary to subject the microorganisms to a minimum fluence of ultraviolet light. As the microorganisms pass through a water purification apparatus, the microorganisms are subjected to a range of UV fluences, depending on the quality of the water and especially on the location of the microorganisms with respect to the array of lamps. Consequently, a water purification apparatus is designed to produce an average fluence that is sufficient to kill the microorganisms.

Nonetheless, the UV fluence that a particular microorganism is subjected to may vary over a wide range depending on the particular path that the microorganism takes as it passes through the reactor. In a poorly designed apparatus, microorganisms may be able to pass through the apparatus without being subjected to sufficient UV fluence to kill the microorganism.

- Creation of turbulence within the zone of the apparatus in which treatment occurs is intended to prevent microorganisms from passing through without being subjected to at least the minimum UV fluence to kill the microorganisms. Examples of methods to create turbulence include the use of ring-shaped devices e. g. washers, on the exterior

surface of the elongated ultraviolet light assemblies as disclosed in WO 98/29345, the use of distributors as disclosed in U. S. 4 952 376, the use of baffles within a tube as disclosed in U. S. 4 304 996, U. S. 5 696 380 and 5 866 910 and the use of serpentine flow as disclosed in U. S.

5 352 359.

Improvements in the method of creation of turbulence that would more effectively than known methods disinfect fluids, particularly waste water containing a variety of microorganisms, would be useful.

SUMMARY OF THE INVENTION An ultraviolet water treatment apparatus with a moveable vortex generator has now been developed.

Accordingly, one aspect of the present invention provides a water purification apparatus comprising at least one elongated ultraviolet light assembly extending into a flow of water to be treated, at least one moveable vortex generator located upstream of said at least one elongated ultraviolet lamp assembly, said moveable vortex generator being adapted to be continuously moveable with respect to the direction of flow of water during said treatment of water.

In a preferred embodiment of the apparatus of the present invention, there is a housing having a fluid-flow passageway therethrough, said at least one elongated ultraviolet lamp assembly extending into said fluid-flow passageway for the treatment of water passing through said passageway, said moveable vortex generator being at least one baffle located in said passageway upstream of said elongated ultraviolet lamp assembly.

In another preferred embodiment, there are at least two elongated ultraviolet lamp assemblies aligned axially in the fluid-flow passageway.

In a further embodiment, the elongated ultraviolet lamp assemblies are axially located, especially in a fluid-flow passageway that is an annular passage. Alternatively, the elongated ultraviolet lamp assemblies may be staggered.

In another embodiment, there are two moveable baffles on opposed sides of the fluid-flow passageway.

In a further embodiment, the elongated ultraviolet lamp assemblies extend across a substantial portion of the height of the passageway.

In another preferred embodiment, there are a plurality of elongated ultraviolet lamp assemblies adapted to be immersed in water in an open channel having water flowing longitudinally therethrough, said elongated ultraviolet lamp assemblies being supported by a frame, said at least one moveable vortex generator being located upstream of and juxtaposed to said elongated ultraviolet lamp assemblies.

In a further embodiment, the moveable vortex generator causes flow of water in a direction other than the longitudinal direction of flow of water through the channel.

In another embodiment, there are at least two racks of elongated ultraviolet lamp assemblies relationship, said at least one moveable vortex generator being aligned with the space between racks. Preferably, there are at least two racks of elongated ultraviolet lamp assemblies in a parallel spaced apart relationship, said at least one moveable vortex generator being aligned with a rack.

In another embodiment, there are at least two vortex generators, said vortex generators being aligned vertically.

In still another embodiment, there are a plurality of elongated ultraviolet lamp assemblies and a corresponding plurality of moveable vortex generators.

In a still further embodiment, the moveable vortex generator is separable from or separate from the elongated ultraviolet lamp assembly for independent removal from the channel.

Another aspect of the present invention provides an open channel water purification apparatus comprising at least one elongated ultraviolet light assembly extending into a flow of water to be treated, at least one moveable vortex generator, said moveable vortex generator being adapted to be continuously moveable with respect to the direction of flow of water during said treatment of water.

In embodiments of the open channel apparatus of the present invention, there are a plurality of elongated ultraviolet lamp assemblies adapted to be immersed in water in an open channel having water flowing longitudinally therethrough, said elongated ultraviolet lamp assemblies being supported by a frame.

In further embodiments, at least one moveable vortex generator is located upstream of and juxtaposed to said elongated ultraviolet lamp assemblies. Alternatively, at least one moveable vortex generator is located between said elongated ultraviolet lamp assemblies.

In another embodiment, the moveable vortex generator causes flow of water in a direction other than the longitudinal direction of flow of water through the channel.

In a further embodiment, the moveable vortex generator is separable from the elongated ultraviolet lamp assembly for independent removal from the channel.

According to another aspect of the present invention is a method for the photochemical treatment of water in a water purification apparatus comprising at least one ultraviolet lamp assembly extending into a flow of water to be treated, and at least one moveable vortex generator located upstream of said elongated ultraviolet lamp

assembly, said method comprising redirecting longitudinally flowing water in a turbulent pattern towards and about said elongated ultraviolet lamp assemblies and throughout said channel, such that any microorganism present in said water is destroyed, wherein said water is redirected by said moveable vortex generator which is continuously moveable with respect to the direction of flow of water during said treatment of water.

Other features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples while indicating embodiments of the invention are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from said detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS - The present invention is illustrated by the embodiments shown in the drawings, in which: Figure 1 is a schematic representation of an end view of apparatus of the present invention; Figure 2 is a schematic representation of a cross section of the apparatus of Figure 1, through A-A; Figure 3 is a schematic representation of a cross-section of the apparatus of Figure 1, through B-B of Fig. 2; Figure 4 is a schematic representation of detail of"C"of the apparatus of Figure 1; Figure 5 is a schematic representation of an alternate embodiment of the apparatus of Figure 1; and Fig. 6 is a schematic

representation of a cross-section of the apparatus of Fig. 5, through D- D.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water purification apparatus and in preferred embodiments to a water purification apparatus having a housing with a fluid-flow passageway therethrough. In particular, the water purification apparatus is of a type that has a pipe reactor with at least one elongated ultraviolet lamp assembly extending into the fluid- flow passageway. Typically, there would be a plurality of such elongated ultraviolet lamp assemblies extending into the fluid-flow passageway. The lamp assemblies are for the treatment of water that is passed through the passageway. At least one moveable vortex generator is located in the passageway in the stream of the elongated ultraviolet lamp assemblies, with the vortex generator being adapted to be continuously moveable in position during the treatment of water.

This creates turbulence within the fluid-flow passageway.

The present invention will be especially described herein with reference to a moveable vortex generator associated with elongated ultraviolet lamp assemblies in a fluid-flow passageway of a tubular or pipe reactor for the treatment of water. However, the moveable vortex generator may also be used in association with racks of elongated ultraviolet lamp assemblies in a open channel system for the treatment of water.

Apparatus 10 has flange 12 with a plurality of bolt holes 14, which are used to attach the flange to a mating flange that forms part of the passageway that brings water into the apparatus for treatment.

Apparatus 10 has fluid-flow passageway 16 that passes through flange 12 and through apparatus 10. Fluid-flow passageway 16 has passageway deflector 18 that defines fluid-flow passageway 16. Fluid-

flow passageway 16 additionally has first moveable baffle 20 and second moveable baffle 22 that extend downwards through fluid-flow passageway 16, and are located at the entrance to the apparatus 10.

Quartz sleeve 24 extends downwards through fluid-flow passageway 16, and encloses ultraviolet lamp 26. In Figure 1, only one ultraviolet lamp 26 is shown, but in normal use at least two such lamps would be used. The number of lamps will depend on the flow of water to be treated and on the required level of treatment. Thus, more than two lamps may be required, and typically would be used.

It will be appreciated that the quartz sleeves on the elongated ultraviolet lamp assemblies will normally have devices for cleaning of the sleeves during use. Such devices are not shown but examples include scrapers, brushes and chemical cleaning systems. Examples of the latter are described in US Patents 5 418 370 and 5 590 390, both of J. M. Maarschalkerweerd, and US Patent 5 874 740 of E. Ishiyama.

Baffle 20 is held in position by baffle mountings 28 and 30 that are located in wall 32 of apparatus 10. Further details of mountings 28 and 30 are shown as detail C in Fig. 4. As discussed herein, baffles 20 and 22 are freely moveable in the respective mountings, so that the baffles will move in the current of water passing through passageway 16. It is the flow of water that causes movement of the baffles in the pivot holes.

Fig. 2 shows a cross section of apparatus 10, along A-A of Fig.

1. Apparatus 10 has two ultraviolet lamps 26 and 26A, with their respective quartz sleeves 24 and 24A. Quartz sleeve 24, which encompasses lamp 26, extends from lower lamp support 46 to upper lamp support 48. Similarly, quartz sleeve 24A extends from lower lamp support 46A to upper lamp support 48A. It is understood that each of ultraviolet lamps 26 and 26A would have a ballast and electrical

connections thereto for operation of the lamp, which are not shown in Fig. 2.

Second baffle 22 is shown in fluid-flow passageway 16, approximately at the location of flange 12. Thus, second baffle 22 is located upstream from ultraviolet lamp 26. Arrow 50 shows the direction of flow of water through fluid-flow passageway 16 of apparatus 10.

Fig. 3 shows a section of apparatus 10, through B-B of Fig. 2. In this embodiment, first baffle 20 and second baffle 22-are shown as being located within fluid-flow passageway 16, at a location that is in advance of the first ultraviolet lamp 26. The direction of flow of water is indicated by arrow 50. In addition, first baffle 20 and second baffle 22 are shown as being near, but separate from, passageway deflectors 18, which also cause turbulence in the water flowing into fluid-flow passageway 16.

In Fig. 3., apparatus 10 is shown with two ultraviolet lamps, but is understood that the apparatus could have more than two lamps. It would not normally have only one lamp, although one lamp could be used : Apparatus 10 is also shown with two baffles, but could have one or more than two baffles. The locations of the baffles can be varied, but will be in advance of ultraviolet lamps in the fluid-flow passageway.

Figure 4 shows detail of a mounting, indicated by"C"shown in Fig. 1. Baffle vane 40 of a baffle e. g. 20 or 22, is attached to wall 42 of apparatus 10. The mounting, generally indicated by 30 has bushing 44 in wall 42. Bushing 44 has a female thread and spindle 52 connects to bushing 44 by a corresponding male thread. Seal 46 is located between bushing 44 and spindle head 48. Baffle vane 40 has housing 53. Spindle 52 is inserted in housing 53 in baffle vane 40 to hold the baffle vane in place, permitting baffle vane 40 to freely rotate or swing

around spindle 52. It is understood that other means may be used to mount baffle vane 40 into pipe wall 42 so that baffle vane 40 is free to swing or rotate.

Fig. 5 shows an end view of an alternate attachment of baffles into apparatus 10. Baffle vane 60 is attached at opposed ends to spindles 62, which in turn are connected to threaded shaft 64 that extends through ring plate 66, and is held in place by end 68 of threaded shaft 64. Seal 70 is located between end 68 and ring plate 66.

Fig. 6 shows a cross-section of Fig. 5 through D-D. Apparatus 10 has wall 42, which forms fluid-flow passageway 16. Ultraviolet lamps 26 and 26A extend across fluid-flow passageway 16, as described previously. Apparatus 10 has end flanges 12 and bolt holes 14. Attached to the forward flange 12 is ring plate 66 with baffle vane 60. Ring plate 66 is between flange 12 and flange 72 of pipe 74. Pipe 74 forms the inlet for water entering apparatus 10 for treatment, the direction of flow being indicated by arrow 50.

The moveable vortex generator of the present invention creates turbulence, especially in a pipe reactor, using vortex generators that are capable of being moved by the flow of water through the apparatus.

The moveable vortex generators are placed upstream of the first of the ultraviolet lamp assemblies, and thus, do not shade water that is being treated in the apparatus. The moveable vortex generators are simple to manufacture and to install, and can be used to retrofit pre-existing ultraviolet water treatment systems. The vortex generators may be fitted into the apparatus in a manner that permits removal for cleaning.

Creation of turbulence permits wider spacing between the lamps. This lowers the overall head loss of the ultraviolet purification system, and allows the treatment of more water per lamp.

Consequently, the ultraviolet water treatment system is more cost effective.

During use, the flow of water will result in changes of water pressure on opposed sides of the baffle vane, which will cause the vane to move. The side of the vane with the higher pressure will alternate, causing the vane to move from side to side in the flow of water, and consequently causing interruptions in the flow and turbulence in the water.

The invention has been particularly described herein with respect to a pipe reactor and the location of the vortex generators being upstream of the elongated ultraviolet light assemblies. In embodiments in which the apparatus is an open channel water purification apparatus, the vortex generators may also be located between elongated ultraviolet light assemblies. In embodiments in which ballasts form part of the elongated ultraviolet lamp assemblies under water, the vortex generators are preferably located upstream or adjacent to the ballasts but may also be located between the ultraviolet lamps.

The movement of the vortex generators creates additional turbulence i. e. additional turbulence to that created in the absence of movement of the same vortex generators. The flow of water will be disturbed by the change of flow direction resulting from the use of the moveable vortex generators, thereby creating more turbulence.

Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit-of the invention.