Abstract:
A germicidal water purification unit in which a plurality of light sources operating in the visible light frequency range or the ultraviolet frequency range are disposed along a conduit that carries water and radiate radially inward toward the axis of the conduit to kill microbiological pathogens present in the water.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates, in general, to water purification and, in particular, to a germicidal water purification unit that employs light sources operating in the visible light frequency range or the ultraviolet frequency range to kill microbiological pathogens present in the water. 
       BACKGROUND OF THE INVENTION 
       [0002]    It is well known that specific microbiological organisms that can be harmful or distasteful to consumers are present in water that is consumed in many homes and public places. Some of the known microbiological pathogens are:
       Coliform bacteria are common in the environment and are generally not harmful. However, the presence of these bacteria in drinking water is usually a result of a problem with the treatment system or the pipes through which the water is distributed and indicates that the water might be contaminated with germs that can cause disease.   Fecal Coliform and  E coli  are bacteria the presence of which indicates that the water might be contaminated with human or animal wastes. Microbes in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms of an underlying condition caused by a water supply borne pathogen.       
 
         [0005]    Cryptosporidium is a parasite that enters lakes and rivers through sewage and animal waste and causes cryptosporidiosis which is a mild gastrointestinal disease. However, this disease can be severe or fatal for individuals with severely weakened immune systems. The Environmental Protection Agency and the Center for Disease Control have prepared advisories for those individuals with severely compromised immune systems who are concerned about Cryptosporidium.
       Giardia lamblia is another parasite that enters lakes and rivers through sewage and animal waste. It causes gastrointestinal illness, such as diarrhea, vomiting, and cramps.       
 
         [0007]    The efforts of the water departments of cities and suburban communities in purifying potable water are extensive and to be admired. However, more and more incidences of illnesses related to microbiological pathogens that escape normal germicidal treatments are being reported. 
         [0008]    Consequently, many private and public facilities, such as office buildings, factories, and sports arenas, are equipped with a germicidal water purification system that typically is installed in proximity to the point at which the water enters the facility. As a result, all consumers of water in the facility consume water that has passed through the germicidal water purification system. Light sources that operate in the visible light frequency range or the ultraviolet frequency range are commonly used to kill microbiological pathogens present in the water. 
         [0009]    Typically, such germicidal water purification systems are arranged with the light sources disposed within the conduit through which the water passes. Such arrangements, for the most part, can be difficult to service and maintain and can result in inconvenience to the consumers of water in the facilities where the water purification systems are installed. With the light sources disposed in the water flow, leakage of water into the light sources is a concern. In addition, the supply of water necessarily is interrupted when the light sources are to be serviced or replaced. 
       SUMMARY OF THE INVENTION 
       [0010]    A germicidal water purification unit, constructed in accordance with the present invention, includes a housing and a conduit extending within the housing axially of the housing and having an inlet end through which water is introduced to the germicidal water purification unit and an outlet end through which the water is conducted away from the germicidal water purification unit. A plurality of light sources, operating in at least one of the visible light frequency range and the ultraviolet frequency range, is disposed along the conduit radially outward from the axis of the conduit. Power supply means supply power to the light sources to energize the light sources. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]      FIG. 1  is a side view, partially in section, of a first embodiment of a germicidal water purification unit constructed in accordance with the present invention. 
           [0012]      FIG. 2  is a side view, partially in section, of a second embodiment of a germicidal water purification unit constructed in accordance with the present invention. 
           [0013]      FIG. 3  is a sectional view, taken along line  3 - 3  of  FIG. 1 , of an array of light sources used in the  FIG. 1  embodiment of the present invention. 
           [0014]      FIG. 4  is a sectional view, taken along line  4 - 4  of  FIG. 2 , of an array of light sources used in the  FIG. 2  embodiment of the present invention. 
           [0015]      FIG. 5  is a diagram of a circuit for selective activation of the power supply of the present invention. 
           [0016]      FIG. 6  is a perspective view, partially in section, of a third embodiment of a germicidal water purification unit constructed in accordance with the present invention. 
           [0017]      FIG. 6A  is a perspective view of the water conduit of the  FIG. 6  embodiment of a germicidal water purification unit constructed in accordance with the present invention. 
           [0018]      FIG. 6B  is a perspective view, partially in section, of the  FIG. 6A  water conduit. 
           [0019]      FIG. 6C  is an exploded perspective view, partially in section, of the  FIG. 6  embodiment of a germicidal water purification unit constructed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    Referring to  FIG. 1 , a germicidal water purification unit, constructed in accordance with the present invention, includes a housing  10 . A conduit  12  extends within housing  10  axially of the housing. Conduit  12  has an inlet end  14  connected to a water delivery pipe  16  by suitable means, such as a threaded coupling  18 . For the  FIG. 1  embodiment of the present invention, water delivery pipe  16  is a water faucet of conventional construction and operation, with water flow controlled by a control knob (not shown) in the usual manner. Water is introduced to the germicidal water purification unit from faucet  16  through threaded coupling  18  at inlet end  14  of conduit  12 . Conduit  12  has an outlet end  20  at which a water discharge port  22  is connected to conduit  12  by suitable means, such as a coupling  24 . Water is conducted away from the germicidal water purification unit through water discharge port  22  and coupling  24  at outlet end  20  of conduit  12 . 
         [0021]    A germicidal water purification unit, constructed in accordance with the present invention, also includes a plurality of light sources  26  of conventional construction and operation that operate in either the visible light frequency range or the ultraviolet frequency range. Light sources  26  are disposed along conduit  12  radially outward from the axis of the conduit. In the  FIG. 1  embodiment of the present invention, light sources  26  are mounted in housing  10 , recessed from the inner surface of conduit  12 , and only partially surround the conduit for example, in semicircular arrays as illustrated in  FIG. 3 . Arrows  28  in  FIGS. 1 and 3  indicate radiations from light sources  26 . LED&#39;s, available from Opto Technology, Inc., operating in the visible light range or at 253.7 nanometers in the ultraviolet light range can serve as the light sources  26 . 
         [0022]    Preferably, a germicidal water purification unit, constructed in accordance with the present invention, further includes means within conduit  12  for impeding water flow through the conduit. As illustrated in  FIG. 1 , such means can take the form of fins  30 , disposed along the axis of conduit  12 , that increase the path of water flow through the conduit and the time of exposure of the water to radiation from light sources  26 . To further increase the effectiveness of the radiations from light sources  26 , a reflector formed, for example, of a polymer with a reflective aluminum surface can be inserted in conduit  12  or applied to the inside surface of the conduit or the means for impeding water flow through conduit  12  can be made, for example, of a polymer with a reflective aluminum surface. In this way, the water passing through conduit  12  is exposed to an increase in the radiation from light sources  26 . 
         [0023]    A germicidal water purification unit, constructed in accordance with the present invention, also includes power supply means for supplying power to light sources  26  to energize the light sources. As illustrated in  FIG. 1 , the power supply means can be a rechargeable battery  32  that is charged when a male plug  34  is inserted into a power source such as a wall outlet. It will be apparent that alternative power sources can serve to power light sources  26 . 
         [0024]    As illustrated in  FIG. 1 , light sources  26  and the power supply means are positioned in a second housing  36  that is detachably secured to housing  10  by clamping members  38 . This option of a separable housing that contains the power supply means may be preferred, under certain circumstances, to a permanently connected power cord that can create a hazardous condition when the power cord is in close proximity to water passing through conduit  12  and discharged from water discharge port  22 . Positioning a rechargeable battery in a separable housing permits removal of the power supply means for recharging the battery at a remote location. 
         [0025]    In  FIG. 5 , which illustrates a circuit for selective activation of the power supply means of the  FIG. 1  and  FIG. 2  embodiments of the present invention, a flow sensor, in the form of a pair of capacitance plates  40   a  and  40   b,  for example, senses the passage of water through inlet end  14  of conduit  12  as represented by an arrow  42 . A signal, representative of water flow, is conducted from the flow sensor to processing circuitry  44  of conventional construction and operation to produce a control signal that closes a solid state relay  46  to connect a battery  48  to light sources  26 . In this way, light sources  26  are powered on an as needed basis, thereby resulting in savings in energy costs and lengthening the useful life of the light sources. It will be understood that the various other flow sensors (for example, optical, electrical, or mechanical) can be used. 
         [0026]      FIG. 2  illustrates a second embodiment of a germicidal water purification unit constructed in accordance with the present invention. Although the second embodiment differs from the  FIG. 1  embodiment, it should be understood that certain components or features that are included in one of the embodiments can be incorporated in the other or substituted for like components and features in the other. 
         [0027]    The germicidal water purification unit of  FIG. 2  is arranged for insertion into the water line at a point between entry of the water into the water system and the point at which the water is actually consumed. One example is locating the germicidal water purification unit beneath a sink. In such an application, an inlet end  50  of a conduit  52  is adapted for connection to a first section  54  of a water delivery system and an outlet end  55  of the conduit is adapted for connection to a second section  56  of the water delivery system. In  FIG. 2 , the connection of conduit  52  to first section  54  is by a threaded coupling  58  at inlet end  50  of the conduit and the connection of the conduit to second section  56  is by a coupling  60  at outlet end. 
         [0028]    In the  FIG. 2  embodiment of the present invention, light sources  60  completely surround conduit  52  as illustrated in  FIG. 4 . In addition, all of the components are contained in a single housing  62 . 
         [0029]    Referring to  FIGS. 6 and 6A  through  6 C, this embodiment of a germicidal water purification unit, constructed in accordance with the present invention, is generally similar in construction and operation to the first two embodiments. Among the differences are the means for impeding water flow through conduit  62 . As illustrated in  FIG. 6B , water flow through conduit  62 , represented by arrows  63 , is impeded by a spiral structure  64 , mounted on a column  65  that forms a helical passage through conduit  62 , that increases the path of water flow through the conduit and the time of exposure of the water to radiation from light sources  66  mounted in the conduit. It will be apparent that spiral structure  64  can be substituted for fins  30  in the first two embodiments of the present invention and that fins  30  can be substituted for spiral structure  64  in the third embodiment of the present invention. Also, spiral structure  64  can be formed with a reflective aluminum surface, as are the means for impeding water flow through conduit  12  in  FIG. 1 , to increase the exposure of the water flow through conduit  62  to the radiation from light sources  66 . 
         [0030]    The germicidal water purification unit illustrated in  FIGS. 6 and 6A  through  6 C also includes an aerator  68  that produces uniform water flow and results in water conservation. Aerator  68  may be of conventional construction and operation, such as the aerators that are commonly attached to water faucets at the present time. It will be apparent that an aerator can be included in the first two embodiments of the present invention illustrated in  FIGS. 1 and 2  and described above. 
         [0031]    The  FIGS. 6 and 6A  through  6 C embodiment of the present invention is arranged for detachment of the power supply means from housing  70 , within which water conduit  62  is positioned, to permit charging of a rechargeable battery when plugged into a power source at a remote location. This is shown most clearly in  FIG. 6C . In particular, a power supply means housing  72 , within which a rechargeable battery is located, is detachably secured to housing  70  by clamping members  74 . A mail plug  76 , shown in  FIGS. 6 and 6C  in an extended position as indicated by arrow  78 , is connected to the rechargeable battery by a pair of flexible wires  80  that collapse to accommodate retraction of the male plug, in a direction opposite to arrow  78 , after the battery has been charged as indicated by illumination of an indicator light source  82 . Blinking illumination of a second indicator light source  84  indicates that the charge of the rechargeable battery is low and that the rechargeable battery should be recharged. 
         [0032]    Also mounted in conduit  62  are light detectors  86  that determine the real time emission level of light sources  66 . A third indicator light source  88 , responsive to light detectors  86 , illuminates when the emission level of light sources  66  drops below a prescribed level, signifying that the rechargeable battery should be recharged. Light detectors, available from Denicom Co., Ltd., can be used as light detectors  86 . 
         [0033]    As indicated by reference numerals  49  and  61  in  FIG. 3  and  FIG. 4 , respectively, the feature of determining the real time emission level of light sources  26  and  60 , respectively, can be incorporated in the first and second embodiments of the present invention. 
         [0034]    As indicated by reference numeral  90  in  FIGS. 6 and 6C , which represents processing circuitry  44  in  FIG. 5 , the feature for selectively activating the power supply can be incorporated in the third embodiment of the present invention. A signal, representative of water flow, is conducted to processing circuitry  90  via wires  92  and the control signal produced by the processing circuitry is conducted from the processing circuitry via wires  94 . 
         [0035]    Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.