Water treatment system with moisture detector

The present invention relates to water treatment systems, and more particularly to electrically powered water treatment systems.

Many systems utilize running water. The water may be used many ways, ranging from cooling the system to providing cleaner water.

Water treatment systems (WTS) are well know and widely used throughout the world. A particularly efficacious point-of-use WTS is disclosed in U.S. Pat. No. 7,166,216 to Woodard et al and entitled “Point-of-Use Water Treatment System.” Among other functions, such a system kills bacteria and viruses in the water by exposing the water to ultraviolet (UV) light as the water flows through the system. A UV bulb is housed within a protective transparent sleeve. Water flows around the protective sleeve to bring the water into close physical proximity to the UV bulb within the sleeve to enhance the “kill rate.”

Occasionally, the integrity of the protective sleeve can be compromised, and water can enter the sleeve, for example if the sleeve is broken or if a seal fails. In such a situation, the efficacy of the system can be reduced; the UV bulb may break if contacted by the water; and electrical power problems can arise. However, users of the system sometimes are unaware that water has penetrated the sleeve, because the sleeve is not visible within the assembled system. Indeed, the UV treatment area typically is shrouded to avoid UV light exposure to human eyes. While prior artisans have included a light sensors to detect extinguishment of the UV light (e.g. because of bulb breakage or power interruption), users continue to be unaware of water penetration into the sleeve that does not result in bulb extinguishment, but in which the system may not be operating at maximum efficacy.

The aforementioned problems are overcome by the present invention comprising a water treatment system (WTS) having a light source, a sleeve separating the water from the light source, and a moisture detector within the sleeve, and a control circuit responsive to the moisture detector.

Although the present invention is disclosed within the context of a WTS, the moisture detector and the control circuit have applicability in a wide variety of lighting applications in which the detection of moisture in inappropriate or undesired locations is desired.

The invention provides an effective, simple, and efficient approach for detecting moisture and for taking action in response to that detection.

These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.

FIG. 1 is a fragmentary skeletal perspective view of the water treatment system.

FIG. 2 is an exploded perspective view of the ultraviolet subassembly and related components.

FIG. 3A is an exploded perspective view of the lamp assembly.

FIG. 3B is an elevational view of the lamp assembly.

FIG. 3C is a top plan view of the lamp assembly.

FIG. 3D is a sectional view of the lamp assembly taken along line 3 D- 3 D of FIG. 3C .

FIG. 4 is an enlarged fragmentary section view of the area within line 4 E in FIG. 3D .

FIG. 5 is a perspective view of the lamp including the moisture detection device.

FIG. 6 is a fragmentary perspective view of the lower end of the lamp, the moisture detection device, and the lamp cap.

FIG. 7 is a schematic circuit diagram of the lamp power circuit.

FIG. 8 is a schematic circuit diagram of the moisture sensing device.

A water treatment system (WTS) constructed in accordance with a preferred embodiment of the invention is illustrated in the drawings and designated 10 . The WTS includes an ultraviolet (UV) subsystem 14 to destroy microorganisms in water flowing through the WTS. The WTS further includes a moisture detection or sensing device 102 on the UV lamp to detect the presence of moisture in a location that is inappropriately close to the lamp. The UV lamp control circuit 120 is responsive to the device 102 , and therefore the presence of moisture, to cause action such as termination of power to the UV lamp or indication to the system user of the inappropriate condition.

With the exception of the moisture detector and the control circuit to be described, the WTS 10 is generally well known to those of ordinary skill in the art. In the current embodiment, the WTS 10 is generally as disclosed in U.S. Pat. No. 7,166,216 (noted above), and the disclosure of that patent is specifically incorporated herein.

As illustrated in FIG. 1 , the WTS unit 10 generally includes a filter subsystem 12 , a UV subsystem 14 , a water pipe assembly 16 , a display 18 , a base assembly 20 , a manifold assembly 22 , and hoses 24 for conveying water into and out of the WTS 10 . The arrows indicate the flow of water through the system, including the rotary flow through the UV subsystem 14 .

The UV subsystem 14 and related components are shown in FIG. 2 . The components include a support plate 26 , a PC board 32 , a UV lamp assembly 34 , a UV tank (or light source chamber or water chamber) 36 , a bulb cover 38 , and a cap assembly 39 .

The PC board 32 includes a circuit board 40 upon which electronic components and circuitry are mounted. A female plug 42 is located near the base of the circuit board 40 for receiving power from a male pin (not shown). A pair of contacts 44 are located near the base of circuit board 40 and are used to communicate with display 18 (see FIG. 1 ) regarding the status of the UV lamp (i.e. whether the lamp is lit).

The UV lamp assembly 34 is illustrated in FIGS. 3A-D and 4 . The lamp assembly 34 includes a quartz sleeve 50 and a bulb assembly 56 received therein. A bumper O-ring 52 spaces the lower end of the bulb assembly 56 from the sleeve 50 , and a compression nut 54 threadedly receives the upper end of the bulb assembly. As best seen in FIG. 3A , the bulb assembly 56 has a molded body 58 including a pair of radially extending flanges 60 , an annular hub 62 , and a knob 64 . An annular slot 66 (see FIG. 4 ) in the hub 62 receives the upper open end of the quartz sleeve 50 . A light pipe 68 is press-fit within an opening in the knob 64 and is exposed to the UV bulb 100 .

Electrical terminals 70 ( FIG. 4 ) are disposed within radially extending slots 72 in the flanges 60 . The terminals 70 are electrically connected to the UV bulb 100 to provide power to the filaments 74 and 76 . Access slots 78 provide access during manufacture of the bulb assembly so that the filaments 74 and 76 can be soldered to the terminals 70 . Detector wires 104 and 106 (FIGS. 3 D and 5 - 8 ) also are connected to the terminals 70 . The exposed radial ends of the terminals 70 electrically connect to a power circuit (not shown) when the UV lamp assembly 56 is mounted within the sleeve 50 .

A moisture sensing or detecting device or element 102 is attached, for example using adhesive or tape, to the lower end of the UV lamp 100 . The device 102 is illustrated in detail in FIG. 8 . The wires 104 and 106 are connected at 112 and 114 respectively on a nonconductive substrate 110 . Extending from wire connection 112 is a first printed serpentine pathway or trace 116 of copper or other conductive material, and extending from wire connection 114 is a second printed pathway or trace 118 of copper or other conductive material. The two pathways are configured to be in spaced relationship along their entire lengths.

When moisture is not present on the device 102 ( FIG. 8 ), no current flows between the two pathways 116 and 118 , and the element 102 is nonconductive. However, when moisture accumulates on the device 102 , the moisture provides a conductive connection or path between the printed pathway 116 and the printed pathway 118 . This allows current to flow across moisture sensing circuit 102 , and the device is conductive. So, the device 102 has relatively high impedance when dry and relatively low impedance when wet.

The power circuit 120 into which the device 102 is incorporated is illustrated in FIG. 7 . The circuit 120 includes a secondary 101 inductively coupled to a primary (not shown) to provide alternating current (AC) power to the bulb 100 through a capacitor 122 . A conventional pre-heat circuit 99 is in series between the two bulb filaments 74 and 76 .

The power circuit 120 ( FIG. 7 ) operates “normally” when no moisture is present. The device 102 (in the absence of moisture) is nonconductive, and all current within the circuit 120 flows through the UV lamp 100 and the pre-heat circuit 99 when it is activated. If moisture is present on the device 102 , and more specifically on the substrate 110 and both pathways 116 and 118 , the device becomes conductive with relatively low resistance. Moisture should not be present on the device 102 , because that would indicate that moisture is within the sleeve 50 , which would indicate a sleeve breakage, a seal failure, or some other undesirable condition. At this point, all current within the circuit 120 flows through the device 102 rather than the higher resistance UV bulb 100 . Consequently, power is terminated to the UV bulb 100 , and the bulb is not illuminated. An appropriate indication preferably is displayed on the display 18 (see FIG. 1 ) to let the system user know that the system is not operating as desired. For example, one of the visual indicators in the display 18 could be responsive to a UV light detector (not shown) monitoring the UV output of the bulb 100 .

Although the present invention is disclosed and described in conjunction with a consumer water treatment system, the invention has applicability well beyond such a system. Specifically, the invention can be used in virtually any lighting environment where it is necessary or desirable to monitor for the presence of water or moisture.

The above description is that of the current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.