Abstract:
A liquid treatment system includes a housing and a lamp system formed from at least one wall, the lamp system in the housing together defining a flow path for liquid that passes between a housing wall and the wall with the lamp, and then between another side wall of the lamp housing and another wall of the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority to Provisional Application No. 60/519,463, filed Nov. 12, 2003, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Ultraviolet (UV) light, continuous or pulsed, can be used to treat water, including to disinfect water and deactivate pathogens therein.  
         [0003]     Known pulse light systems for various uses generally include a power supply, a capacitor bank charged by the power supply, a pulse configuration circuit for shaping the height and width of a pulse, and a pulse lamp, which can include xenon or mercury.  
       SUMMARY OF THE INVENTION  
       [0004]     Systems and methods are described here for treating liquids. While the present application is described in the context of water treatment, it should be understood that other liquids can be treated in this manner.  
         [0005]     Features of systems and methods described herein can include one or more of the following: creating a flow path of liquid in one or more paths, including rectangular cross-section paths; creating flow paths with variable depths; the ability to control the depth of a flow path, including for the purpose of providing a shallower path for more contaminated liquids; allowing the use of lower treatment energy to avoid damaging desirable components in the liquid, such as protein in water; the use of reflective surfaces; and/or the ability to have multiple treatment modules. The different depths in the flow path can make it easier to destroy contaminants, and/or to provide greater reliability. Other features and advantages will be come apparent from the following detailed description, drawings, and claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIGS. 1A and 1B  are a perspective view and side view, respectively, of a single module, adjustable flow system according to a first embodiment.  
         [0007]      FIG. 2  is a perspective view of a multiple module adjustable pulse light sterilization system.  
         [0008]      FIG. 3  is a perspective view of embodiment including a “lamp basket.” 
         [0009]      FIGS. 4 and 5  are perspective views of other embodiments. 
     
    
     DETAILED DESCRIPTION  
       [0010]     Referring to  FIGS. 1A and 1B , a water treatment system  10  has an input  12  for receiving relatively untreated water, and an outlet  14  for providing treated water (or some other liquid). The water that is provided could have been treated previously by other means, such as with filtering or chemical treatments, or could be further treated after being provided from the outlet. System  10  has a rear wall  16  with input  12 , a front wall  18  with outlet  14 , side walls (not shown), and a top wall  28  ( FIG. 1B ). Between rear wall  16  and front wall  18  is a center wall  20 , preferably vertical and parallel to both the front and rear walls. These walls define a first chamber  22  between wall  16  and wall  20 , and a second chamber  24  between wall  20  and wall  18 , both of which chambers are preferably but not necessarily rectangular in cross-section as the water flows.  
         [0011]     Wall  20  has a height that is less than the height of walls  16  and  18 , so that a gap is created between a top surface  26  of wall  20  and top wall  28  to provide a flow path from chamber  22  to chamber  24 . As indicated in  FIGS. 1A and 1B , the liquid has a flow path whereby it enters through input  12 , passes upwardly through chamber  22 , over top surface  26  of wall  20 , and downwardly through chamber  24  before exiting at outlet conduit  14 .  
         [0012]     The inputs and outlets are shown here as cylindrical tubes, but the configurations could have other geometries, including funnel shapes or with multiple conduits, or could include a single conduit that fans out to provide water along a slot so that it is more evenly distributed along the width of chamber  22 .  
         [0013]     Wall  20  has UV-transparent sides  20   a  and  20   b,  and encloses one or more UV lamps  32 . Lamps  32  can have one of several different configurations or combinations of configurations, including linear lamps, spiral lamps, or serpentine lamps (including U-shaped configurations). Inwardly facing surfaces  16   a  and  18   a  of walls  16  and  18 , respectively, are preferably (but need not be) designed to reflect UV light so that light energy from lamps  32  passes through the water in chambers  22 ,  24  and is further reflected back to provide additional UV energy to the water for disinfection or decontamination.  
         [0014]     One or more of walls  16 ,  18 , and  20  can be movable relative to other walls to alter the depth of chambers  22  and/or  24  to control the depth (or “thickness”) of the flow path. The depth of the flow path incorporates certain tradeoffs: a deeper chamber and flow path will allow more water to pass, but will allow less opportunity for energy from lamps  32  to treat the water, while a shallower flow path will provide more water treatment, but at a slower flow rate.  
         [0015]     If the unit shown as system  10  is used in a modular manner with other units of the same or similar type, it may be desirable to have multiple units with different chamber sizes. Alternatively, there could be a number of units with smaller chambers and slower flow paths that feed into a single unit. For example, two different units each having a first flow rate could feed into second unit that has a flow rate that is twice that of each of the first units. In such a case, the initial treatment from the UV light would be more intense, followed by a less intense treatment of the water that has already been partially treated.  
         [0016]     Within a single unit, wall  16 ,  18 , and/or  20  can be made adjustable. In one implementation, wall  20  remains stationary with respect to floor  30 . Walls  16  and  18  each have a sealing material, such as a gasket, that extends around the perimeter, thereby allowing the position of the wall to be adjusted within the unit (typically after the unit is cleaned out of any liquid) so that the unit can essentially be reassembled with a different chamber thickness. Markings can be provided on floor  30  to indicate different depths of the chamber to allow adjustment.  
         [0017]     The adjustability feature could be provided such that the unit is field adjustable or could be made so that it is adjustable in the way that parts are initially created, but then are adjusted before the unit is provided to a customer using it for water treatment.  
         [0018]     Lamps  32  can be either mercury or xenon lamps, and provide continuous or pulsed light. Because wall  20  that houses lamps  32  is covered on two sides by a liquid, the liquid can provide cooling for the lamp.  
         [0019]     Referring to  FIG. 2 , in a second embodiment, a multi-module unit  40  has an inlet  42  and an outlet  44 , both of which are shown as cylindrical conduits, but could have alternative configurations, with multiple modules of a type shown in  FIG. 1A . As shown in  FIG. 2 , there are four chambers  48 ,  50 ,  52 , and  54 , separated by dividing walls  56 ,  58 , and  60 , each of which has a respective opening  62 ,  64 , and  66  (or multiple openings) for allowing water to flow, respectively, from the first chamber to the second chamber, from the second chamber to the third chamber, and from the third chamber to the fourth chamber. Each chamber has two side walls, one of which may be shared with another chamber or may be an end wall of the entire unit, and also a partial wall  68 ,  70 ,  72 , and  74 , respectively. Each partial wall has a height that does not extend the full height of the unit, thereby allowing a gap so that water can flow up over wall  68 - 74 . Each wall  68 - 74  houses one or more lamps, which, as indicated above, can be linear, spiral, serpentine, or some other desired configuration, can be a single lamp or a combination of multiple lamps, and can be continuous or provide light with pulses. The walls preferably are UV-transparent on two opposite sides to allow them to treat water as it passes one side of the wall and again as it passes another side of the wall.  
         [0020]     Referring to  FIG. 3 , in another embodiment, a device referred to here as a “lamp basket”  80  looks like a basket, except that the side walls of the basket each house lamps  82  suitable for providing energy to treat water and can have an open bottom. Lamp basket  80  can be removably inserted into an outer box  84  that has an inlet  86  for water flow to pass up through the interior of the basket, and then down a gap region that is outside basket  80  and inside outer box  84 . Outer box  84  can have openings around the outside periphery of the box. The basket can be used in boxes of different sizes, or different sized baskets can be used with a single outer box, thereby providing the ability to control the depth of the flow path by changing the basket or the outer box. Like the previous embodiment the water can flow in one direction, over a wall, and back in an opposite direction, and can be treated on each side of the wall. As shown, the basket can have a rectangular cross-section when viewed from the top, but it could have different shapes, including any other polygon or circular.  
         [0021]      FIG. 4  shows an embodiment with some similarities to that shown in  FIG. 3 . As indicated in  FIG. 4 , a system  100  has a box  102  with an input  104  and an outlet  106 . The box has four side walls, each of which can include lamps (e.g., mercury) arranged in linear or serpentine manner (including a U-shape). Another unit  108  can be provided inside box  102  and can also include sterilizing lamps. In this case, the water flows into conduit  104 , passes over the top of unit  108 , and then down an annular region within unit  108  to outlet  106 .  
         [0022]     Another embodiment is shown in  FIG. 5 , which has a unit  120  with an inlet  122  and an outlet  124 . The water passes upwardly from inlet  122  and first reaches a lamp plate  126  that can have a series of linear or serpentine or spiral lamps. The water is then directed to an annular region  128  with an outer wall and an interior wall defined by a removable annular lamp unit  130 , that can be circular or have any other desired shape, including a square ring. The water is directed to flow between outer wall  128  and unit  130 , and thus to pass upwardly past a second lamp plate  132  and then out the outlet  124 .  
         [0023]     Exemplary operating parameters for a pulsed lamp include the following: a pulse duration of 1-1000 msec, measured at ⅓ peak value for a pulsed light system; energy per pulse of 1 joules-2000 joules; single to continuous pulsing; linear, spiral, or serpentine lamp configuration; 100-1000 nm spectral output; and quartz, suprasil, or sapphire housing window.  
         [0024]     Having described several embodiments, it should be apparent that modifications can be made without departing from the scope of the invention as defined by the appended claims. The description refers to water, but other liquids can be treated with this system.