Abstract:
An improved portable water purification system with reduced leaks and the capability of automatic draining of its boiling tank, as well as to a method of preventing water spillage from a portable water purification system and a method of draining a boiling tank of a portable water purification system. The system includes a control tank that is connected to a water supply, a boiling tank that is connected to the control tank for boiling water, a condenser that is connected to the boiling tank for receiving steam from the boiling tank and for condensing the steam to form distilled water, and a distilled water tank that is connected to the condenser for collecting distilled water from the condenser. An inlet solenoid control valve is disposed between the water supply and the control tank, with the inlet solenoid control valve controlling flow of water to the control tank. The system further includes a UV light sanitizer, leak prevention and leak detection features, and a mechanism for detecting water quality.

Description:
FIELD 
     The invention disclosed herein relates to portable water purification systems. More particularly, the invention disclosed herein relates to an improved portable water purification system with reduced leaks and the capability of automatic draining of a boiling tank. 
     BACKGROUND 
     One known water treatment method to improve the purity and taste of drinking water is distillation. Distillation involves boiling water to generate steam, and then condensing the steam to form water with a reduced amount of contaminants. The contaminants, which have a vaporization temperature higher than that of water, remain in the boiler, while solvents having a boiling point lower than water may be separated from the steam by venting prior to condensation. 
     Previous attempts at forming portable distillation systems for use in purifying drinking water are known from U.S. Pat. Nos. 5,281,309 and 5,464,531. The devices in these patents are adapted to be directly mounted onto a water cooler dispensing unit as a replacement for the conventional water bottle. These devices utilize a control mechanism disposed between the feed tank and the boiler to prevent backflow from the boiler to the feed tank and to control the water level within the boiler. In addition, these devices utilize a filter between the condenser coil and the distilled water tank to filter the water before the water enters the distilled water tank. A float switch disposed in the distilled water tank prevents overfilling of the tank. However, in the event of failure of the float switch, the distilled water tank can overflow and lead to water spillage. Further, the location of the filter is less than optimal, since the parts of the system must be designed to allow the filter to be accessible from outside the housing of the distilling unit. 
     There is, however, a continuing need for improved portable distillation systems that are simpler in design and which prevent water spillage and leaks. 
     SUMMARY 
     The invention provides an improved portable water purification system with reduced leaks and the capability of automatic draining of a boiling tank, as well as a method of preventing water spillage from a portable water purification system and a method of draining a boiling tank of a portable water purification system. 
     One aspect of the invention is a portable water purification system that comprises a control tank that is connected to a water supply, a boiling tank that is connected to the control tank for boiling water, a condenser that is connected to the boiling tank for receiving steam from the boiling tank and for condensing the steam to form distilled water, and a distilled water tank that is connected to the condenser for collecting distilled water from the condenser. An inlet solenoid control valve is disposed between the water supply and the control tank, with the inlet solenoid control valve controlling flow of water to the control tank. 
     Another aspect of the invention is a portable water purification system that comprises a control tank connected to a water supply, a boiling tank connected to the control tank for boiling water, a condenser connected to the boiling tank for receiving steam from the boiling tank and for condensing the steam to form distilled water, a distilled water tank connected to the condenser for collecting distilled water from the condenser, a drain line connected to the boiling tank, a solenoid operated drain valve controlling flow through the drain line, and a cooling water line extending between the water supply and the drain line. 
     A further aspect of the invention is a water purification system that comprises a control tank connected to a water supply, a boiling tank connected to the control tank for boiling water, a condenser connected to the boiling tank for receiving steam from the boiling tank and for condensing the steam to form distilled water, a distilled water tank connected to the condenser for collecting distilled water from the condenser, and means for preventing water spillage from the system. 
     Yet another aspect of the invention is a method of preventing water spillage in a portable water purification system that includes a control tank, a boiling tank, and a distilled water tank. The method comprises providing an inlet solenoid control valve between the control tank and a water supply line, with the inlet control valve capable of controlling the inflow of water to the control tank; providing a switch in at least one of the control tank and the distilled water tank, the switch being activated and providing a signal when the control tank or the distilled water tank is full; and closing the inlet solenoid control valve in response to the signal from the switch, thereby preventing further inflow of water to the control tank. 
     An additional aspect of the invention is a method of draining a boiling tank of a portable water purification system. The method comprises opening a drain valve to drain water at a first temperature from the boiling tank through a drain line, and mixing inlet water at a second temperature with the water at the first temperature from the boiling tank, wherein the mixing occurs within the drain line and the second temperature is lower than the first temperature. 
    
    
     These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description, in which there is described a preferred embodiment of the invention. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a portable water purification system according to the invention. 
     FIG. 2 is an exploded view of the components forming the portable water purification system. 
     FIG. 3 is a diagrammatic view of the water purification system. 
     FIG. 4 is a schematic illustration of another version of the water purification system equipped for automatic draining of the boiling tank. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 illustrates a portable water purification system  10  according to the invention. The system  10  is designed to be portable to enable the system to be transported from one location to another location where water purification is desired. The system  10  is preferably designed to rest upon a generally flat surface, such as a countertop, adjacent a source of water which is to be purified. The system  10  can also rest upon a water cooler dispensing unit as a replacement for the conventional water bottle. 
     The system  10  includes a housing  12  with a distilled water tank  14  mounted on the housing  12  and disposed at the front thereof. A display panel  16  and a plurality of input buttons  18  are provided on the front of the housing  12  adjacent the top thereof. The input buttons  18  permit control inputs controlling operation of the system  10 , with the display panel  16  displaying a variety of system information, such as an operating state of the system  10 . 
     With reference now to FIG. 2, the details of the system  10  will be discussed. The housing  12  is formed from three housing portions  20   a ,  20   b ,  20   c . The housing portion  20   a  forms a base upon which the remainder of the system  10  rests, with the housing portion  20   a  designed to rest upon a suitable support surface, such as a countertop. The housing portion  20   b  connects to the housing portion  20   a  and defines the central portion of the housing, and forms an enclosure for a number of the components of the system  10 , including a control tank  22 , a boiling tank  24 , and various pipes, fittings and control circuitry of the system  10 . The housing portion  20   c  connects to the top of the housing portion  20   b  and defines a separate enclosure for a condenser  26  and cooling fan  28 . 
     As is evident from FIGS. 1 and 2, the housing portion  20   b  is recessed relative to the housing portions  20   a ,  20   c  thereby defining an area in which the water tank  14  fits between the housing portions  20   a ,  20   c . FIG. 2 illustrates a plate  30  that separates the enclosure defined by the housing portion  20   b  from the enclosure defined by the housing portion  20   c . A plate  32  extends upwardly from the plate  30  to divide the enclosure of the housing portion  20   c  into a rear enclosure containing the condenser  26  and cooling fan  28 , and a front enclosure containing a removable lid  34  on the tank  14  that permits access to the interior of the water tank  14  as well containing a circuit board associated with the display panel  16  and input buttons  18 . 
     The condenser  26  itself is held between two insulating pieces  36 ,  38 , and the cooling fan  28  fits within a hole  40  defined in the insulating piece  38  so that the fan  28  is disposed within the circumference of the condenser  26  to provide effective heat dissipation from the condenser  26 . A cover  42  connects to the housing portion  20   c  and closes off the housing  12  and defines the top thereof. The cover  42  includes a grill  44  located above the fan  28  to permit air flow out of the housing portion  20   c . In addition, the housing portion  20   c  is provided with vents  46  to permit air to enter the enclosure defined by the housing portion  20   c.    
     Attention is now directed to FIG. 3, along with FIG. 2, which illustrates in schematic fashion the connection between the elements within the system  10 . An inlet water supply line  50  enters the housing  12 , preferably through the rear thereof, and connects to an inlet water control valve  52 , preferably a solenoid valve. A flow line  54  leads from the control valve  52  to the control tank  22 . Likewise, a flow line  56  connects the control tank  22  to the boiling tank  24 . A flow line  58  connects the boiling tank  24  to the condenser  26 , and a flow line  60  connects the condenser  26  to the water tank  14 . A drain valve  62 , such as a manually operated spigot valve, connects to the flow line  56  to permit draining of the boiling tank  24 . As is further evident from FIG. 3, an overflow line  68  connects to the top of the water tank  14  and discharges into the control tank  22 . The flow into the system can be controlled by a mechanical float valve assembly  70 ,  72 ,  74  to be later described, or by the valve  52 . 
     In addition, a distilled water outlet line  64  extends from the water tank  14 , with flow through the line  64  monitored by a total dissolved solids (TDS) probe  66  connected to the valve  52  to control operation of the valve  52 . The TDS probe  66  monitors the purity of the water by measuring the conductivity thereof which provides an indication of the amount of total dissolved solids in the water. In one implementation, the TDS probe  66  and its related software sample the water quality every 1 second. However, other sampling intervals, either longer or shorter than 1 second, could be used. If the purity of the water, as measured by the TDS probe  66  is not sufficient, the valve  52  is closed. On the other hand, if the purity of the water measured by the TDS probe  66  is acceptable, the valve  52  is open. The TDS probe  66  and the valve  52  are preferably connected to a controller  78  which controls operation thereof. The TDS probe  66  preferably measures the water purity on a predetermined periodic basis, controlled by the controller  78 . Other means for measuring water purity, such as a pH sensor, could be used in place of or in addition to, the TDS probe  66 . 
     In addition, with reference to FIGS. 2 and 3, the system  10  utilizes a filter  84 , such as a carbon filter, that is placed in the outlet line  64 , downstream from the TDS probe  66 , and which is located outside of the housing  12 . By placing the filter  84  on the outlet line  64 , the need to run additional lines from the condenser to the filter and from the filter back to the distilled water tank, as is required in the systems disclosed in U.S. Pat. Nos. 5,281,309 and 5,464,531, is eliminated. 
     The system  10  can also optionally include a delivery pump  86  and a ultraviolet (UV) light sanitizer  88  in the outlet line  64 , as illustrated in FIG.  3 . The pump  86  is preferably mounted inside the housing  12 , while the UV light sanitizer  88  is preferably mounted on a rear panel of the housing  12  on the exterior of the housing. However, the UV light sanitizer could be disposed in the interior of the housing  12  as well. 
     The pump  86 , which is preferably controlled by the controller  78 , facilitates delivery of water from the system  10 , particularly in those instances when the location of the system  10  during use prevents adequate gravity feed of the water. However, the system  10  can also be utilized without the pump  86 , instead relying on gravity to deliver water. The pump  86  is preferably a demand pump that turns on and operates to keep the outline line  64  pressurized when a dispensing valve (not illustrated) located at the end of the outlet line  64  is opened by a user to dispense water. In addition, the pump operation is preferably controlled by a float (not illustrated) in the water tank  14  that indicates water availability in the water tank  14 . The float prevents operation of the pump  86  if insufficient water is present in the water tank  14 . 
     The UV light sanitizer exposes the water prior to delivery to UV light for sanitizing the stored water in the tank  14  from microbe contaminants. Like the pump  86 , the UV light sanitizer  88  is optional. In the preferred embodiment, the UV light stays on continuously to prevent bulb and starter wear and tear. However, it is contemplated that the UV light could be operated on a demand basis, rather than continuously. Moreover, other mechanisms capable of sanitizing water could be used in place of or in addition to the UV light sanitizer, including, but not limited to, ozonation, ultra-filtration, and chemical sanitizers. 
     The control tank  22  is designed to regulate the inflow of water to the boiling tank  24  and control the water level within the boiling tank. Included within the control tank  22  is a float  70  connected to an end of an arm  72 , with the opposite end of the arm  72  connected to a valve member  74 . When the level of water in the control tank  22  reaches a predetermined level, the valve member  74  is actuated to shut the flow of water from the flow line  54  into the control tank  22 . In addition, the control tank  22  includes a float switch  76  therein that is electrically connected, via the controller  78 , to the control valve  52 . The float switch  76  acts as a safety feature to prevent overfilling of the control tank  22  and the boiling tank  24  and water tank  14  downstream from the control tank  22 , in the event of a failure in one of the float  70 , arm  72  and valve member  74 . If the valve member  74  fails to shut the flow of water, the water level in the control tank  22  will increase, eventually actuating the float switch  76 . The float switch  76 , when actuated, sends a signal through the controller  78  to the control valve  52  to close the control valve  52  and thereby prevent further inflow of water to the control tank  22 . 
     The boiling tank  24  receives water from the control tank  22  and boils the water to remove contaminants therefrom as is well-known in the art. The boiling tank  24 , as illustrated in FIG. 2, includes a heating element  80  therein for accomplishing the boiling of the water. As is understood in the art, steam that is generated by the boiling of water exits the top of the boiling tank  24  and enters the condenser  26 , where the steam is condensed back into water, with the water flowing through the flow line  60  into the tank  14 . Boiling of the water separates contaminants from the water, with steam having contaminants removed therefrom exiting the boiler to the condenser and the contaminants remaining behind in the boiling tank  24 . Since contaminants remain in the boiling tank  24 , it is necessary to periodically drain the boiling tank  24  thereby removing the contaminants and preventing build-up thereof. As shown in FIG. 3, draining of the boiling tank  24  is accomplished manually by opening the drain valve  62 . 
     The water tank  14  is also provided with measures to prevent overfilling of the tank  14 , thereby preventing water spillage from the system  10 . As mentioned previously, the overflow line  68  leads from the top of the tank  14  back to the control tank  22 . In the event that the water level in the tank  14  gets to high, excess water will flow from the tank  14  through the overflow line  68  back to the control tank  22 . This excess water will contribute to filling of the control tank  22  and actuation of the float switch  76  to close the inlet valve  52 . In addition, the tank  14  includes a float switch  82  associated with the lid  34  of the tank  14  that actuates when the water level in the tank  14  becomes too high. When the float switch  82  is actuated, a signal is sent, via the controller  78 , to the inlet valve  52  to close the valve and prevent further water inflow into the system  10 . 
     It is to be realized that the inlet valve  52 , the float switches  76 ,  82  and the overflow line  68  each act to prevent water spillage from the system  10 , by preventing overfilling of the control tank  22 , the boiling tank  24  and the water tank  14 . In addition, the construction of the system  10  is simplified compared with conventional systems, such as those found in U.S. Pat. Nos. 5,281,309 and 5,464,531 which utilize both a feedwater tank and a water level control tank/housing upstream of the boiler. The use of a feedwater tank takes up space, and provides additional apparatus that can fail and needs to be cleaned. In addition, a feedwater tank permits buildup of bacteria and/or algae and like contamination, particularly when water has been stagnant in the feedwater tank for a period of time. 
     The system  10  shown in FIGS. 1-3 eliminates the use of a feedwater tank and the detriments thereof. The inlet water supply line  50 , which is preferably connected to a continuous water supply source such as a household or building water supply line, connects directly to the control tank  22  via the inlet valve  52 . Thus, presuming that the water in the water supply line is fresh, the water entering the control tank  22  is fresh as well. 
     With reference now to FIG. 4, an alternative portable water purification system  100  is illustrated. Elements within the system  100  that correspond to elements within the system  10  are referenced by the same reference numerals. The system  100  is provided with the capability for automatic draining of the boiling tank  24  as well as cooling of the water that is to be drained. As shown in FIG. 4, a line  102  extends from the flow line  56 . A drain valve  104 , such as a solenoid valve, is disposed within the line  102  for controlling flow therethrough. In addition, a cooling water line  106  extends from the line  54  to the line  102 , with flow through the line  106  controlled by a valve  108 , such as a solenoid valve. It is to be noted that the drain spigot  62  is still present in this embodiment, in order to permit manual draining of the boiling tank  24 . 
     Operation of the valves  104 ,  108 , as well as the valve  52  and the TDS probe  66 , and other electronic components, are controlled by the controller  78 , with the float switches  76 ,  82  providing inputs to the controller  78 . The controller  78  preferably includes a timer mechanism that can be set by a user, using the input buttons  18  to select the desired time interval(s) between draining operations, so that the valve  104  opens at periodic intervals in order to drain the boiling tank  24 . Alternatively, as indicated above, the drain valve  62  can be opened manually when it is desired to drain the boiling tank  24 . 
     Often times the water being drained from the boiling tank is extremely hot and needs to be cooled before the water can be discharged through line  102  to a drain. In order to accomplish cooling of the drain water, the valve  108  is opened by the controller  78 , thereby allowing cool water from the inlet supply line  50  to mix with the hot water from the boiling tank  24  in the line  102  before the water exits the line  102  to the drain. Connecting the line  50  to the line  102  eliminates the need to add cooling water directly into the boiling tank  24 . This is especially important when the boiling tank is at its maximum capacity of water, as dictated by the control tank which prevents further introduction of water when the boiling tank is full. If the boiling tank is full, no cooling water can be introduced because the control tank prevents further flow of water to the boiling tank. The embodiment described in FIG. 4 permits cooling of the water in a full boiling tank, since the cooling water is introduced in the line  102 . The water in the boiling tank, which is typically at a high temperature, is cooled by the water from the inlet water supply which is typically at a lower temperature, to produce drain water at a temperature generally between the boiling tank water temperature and the inlet supply water temperature. 
     The cooling water line  106  is preferably connected to the line  102  by a two-way flow divider  110 . The flow divider  110  is preferably a Y-shaped flow divider, although a three-way (or more) flow divider, with extra flow paths closed off to leave two flow-paths, could be used as well. The cooling water line  106  intersects the drain line  102  at an acute angle. As a result of this connection, the drain line  102  pulls a slight vacuum during draining due to the venturi effect. The slight vacuum pulls water from the boiling tank  24  and the control tank  22 , and facilitates complete removal of contaminants from the boiling tank  24 , as well as from the control tank  22 . 
     The system  100  in FIG. 4 is shown without the overflow line  68  between the tank  14  and the control tank  22 . However, it is to be realized that the system  100  could be utilized with the overflow line  68  shown in FIG. 3 if desired. 
     As an added safety feature, the system  10  can be provided with a moisture sensor  114  as illustrated in FIG.  2 . The moisture sensor  114  is mounted on or within the housing portion  20   a  for detecting water spillage or leaks from the system  10 . The sensor  114  is preferably connected to the valve  52 , via the controller  78 , for closing the valve  52  when water spillage is detected. 
     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.