OA12592A - Solar water heater and pasteurizer. - Google Patents

Description

1 012592

SOLAR WATER HEATER AND PASTEURIZER

FIELD OF THE INVENTION δ The présent invention relates to the field of liquid heating, and more specifically to the use of solar energy to pasteurize water.

BACKGROUND OF THE INVENTION

Existing batch solar water heaters generally comprise a vessel made of glass,metallic or polymeric material that can contain water and may further be constructed io of an energy absorbent colored material. Disadvantages of présent designs includethe fact that many are bulky and made of expensive materials, and still others areinefficient at recruiting, transferring and adequately storing sufficient heat to achievetempératures adéquate to achieve pasteurization. Moreover, many of the cuirentdesigns are not capable of achieving températures requîred for pasteurizing water. 15 The majority of diseases in developing countries today are infectious diseases caused by bacteria, viruses, and other microbes which are shed in feces (e.g., humanand animal feces) and found in polluted water which people use for drinking orwashing. When people drink the live microbes, they can multiply, cause disease, andbe shed in feces into water, continuing the cycle of disease transmission. 20 Worldwide, unsafe water is a major problem. An estimated one billion people do not hâve access to safe water. It is estimated that diairheal diseases that resuit fromcontaminated water kill about 5 million people and cause about 900 million épisodesof illness each year. In developing countries city water Systems are less reliable, andwater from streams, rivers and some weîls may be contaminated with pathogens 2$ carried by human and animal feces and pose a health threat. For the billion people who do not hâve safe water to drink the only major recommendation is to boil thewater, sometimes for as long as 10 minutes. It has been known since the time of LouisPasteur (more than 130 years ago) that heat of boiling is veiy effective ai killing ailmicrobes which cause disease in milk and water. However, boiling is not uniformly 2 012592 practiced. Reasons for this include the facts that boiling takes too long, boiled watertastes bad, and fuel is often limited or costiy.

There are a number of different disease microbes found in water, but for themost part, they are not unusually beat résistant. For example, the most commoncauses of acute diarrhea among children in developing countries are the bacteriaEscherichia coli and Shigélia and the Rotavirus group of viruses. These are rapidlykilled at températures of 60° C or greater. For example, heating water to 66° C in asolar cooker will provide enough heat to pasteurize the water and kUl substantially aildisease causing microbes. The fact that water can be made safe to drink by heating tothis Iower température (i.e., 66° C) instead of 100° C (boiling) présents a realopportunity for addressing the problem of corrtaminated water in developingcountries. However, solar water heaters are often cunibersome and diffîcult tooperate.

Accordingly, there existe a defînite need for a portable solar water heater thatis efficient and that is capable of heating water to a température and for a time thatresults in pasteurization, thereby providing a ready supply of potable water. Theprésent invention satisfies these needs and provides further related advantages.

BRIEF DESCRIPTION OF THE INVENTION

The présent invention overcomes many of the problems in the art by providing asimple, inexpensive and portable apparatus for heating and pasteurizing liquids, as wellas methods using same. The simple and portable design is useful for providing arenewable supply of drinking water. Moreover, the invention apparatus is relativelyinexpensive to manufacture, is trouble-free and reliable in use, and may be readilycollapsed and folded for storage or transport.

The invention is embodied in a solar water heater having a container, at leastone energy converting structure for collecting solar energy and imparting it to waterwithin the container, and suffîcient insulation to minimize heat loss to surfaces thatmay be in contact with the container, thereby enabling one to achieve water 3 012592 températures of at least 60° C. Solar water heaters according to the présent inventionare thus capable of pasteurizing water by heating the liquid contained therein totempératures of at least 60° C.

Invention apparatus includes a water tight transparent container for the liquid to5 be pasteurized, and at least one energy converting structure for collecting solar energy, converting the solar energy into heat, and traûsmitting the beat to the liquid in thecontainer. The container may hâve energy converting structure(s) included as anintégral part thereof, or the container may be any water tight transparent container, withat least one energy converting structure introduced therein. 1 o In another aspect of the invention, the water heater may comprise an energy reflective structure to further prevent heat loss to the surrounding environment. Thecontainer may also comprise a température indicator that indicates the température ortempérature history of water within the container. In this manner the user can readilydétermine if the température and length of time required for pasteurization hâve been 15 achieved. In addition, température indicators allow the user to monitor the température of water in the container and discontinue exposure to irradiation when thewater reaches an acceptable température. Àlso provided are methods for heating and pasteurizing liquids. Inventionmethods comprise introducing liquid into a water tight transparent container having 20 therein the energy converting structure(s), and exposing the container to a suitableenergy source, e.g., sunlight, for a time suffîcient to heat the liquid to the desiredtempérature. Pasteurization can be achieved by maintaining the liquid at a specifiedtempérature for a specified time.

Other features and advantages of the présent invention will be apparent from 25 the following description of the invention, in conjunction with the accompanyingdrawings, which illustrate, by way of example, the principles of the invention. 4 012592

1 BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a cross-sectional élévation view of one embodiment of an inventionsolarwaterheater. FIG. 2 is a cross-sectional élévation view of another embodiment of an5 invention solar water heater. FIG. 3 is a cross-sectional élévation view of a yet another embodiment of aninvention solar water heater. FIG. 4 is a cross-sectional élévation view of a hirther embodiment of aninvention solar water heater. 1 o Fig. 5 is a cross-sectional élévation view of a still another embodiment of an invention solar water heater.

Fig. 6 is a cross-sectional élévation view of a yet another embodiment of aninvention solar water heater.

Fig. 7 is a top-surface photograph view of a still another fürther embodiment15 of an invention solar water heater.

Fig. S is a bottom-surface photograph view of the embodiment of an inventionsolar water heater shown in Fig; 7.

Fig. 9 is a cross-sectional photograph view of the embodiment of an inventionsolar water heater shown in Fig. 7.

2θ DETAILED DESCRIPTION OF THE INVENTION

In accordance with the présent invention, there are provided solar water heaterscomprising a water tight resealable container, at least one energy converting structureincorporated within said water heater, and one or more insulating structures sufficientto enable said water heater to achieve water températures of at least 60° C. 012592 ( Ih accordance with another embodiment of the présent invention, there are provided solar water heaters comprising a water-tight container, one or more energyconverting structures therein, and sufficient insulation to produce water températuresof at least 60° C. 5 In accordance with yet another embodiment of the présent invention, there are provided solar water heaters comprising a water-tight resealable container, one ormore energy converting structures therein, and at least one insulating structureassociated with said water heater to reduce energy loss from extemal surfaces thereofand provide insulation sufficient to enable said water heater to achieve water io températures of at least 60° C.

In accordance with still another embodiment of the présent invention, there areprovided solar water heaters comprising a water-tight container, wherein saidcontainer comprises a top and a bottom and at least one resealable opening, one ormore energy converting structures therein, and at least one insulating structure to 15 reduce energy loss from extemal surfaces thereof and provide insulation sufficient toenable said water heater to achieve water températures of at least 60° C.

In accordance with a still further embodiment of the présent invention thewater heater may comprise energy reflective surfaces. These surfaces may beassociated with said container, and/or associated with said insulating structures. Such 20 reflective surfaces facilitate capture of photons from incident radiation by the pasteurizer, as well as further reducing energy loss and thus enhancing the efficiencyof the solar water heater.

In accordance with yet another embodiment of the présent invention the waterheater may further comprise lenses which redirect and/or concentrate incident 25 radiation (e.g., Freznel lenses) so as to enhance the capture of photons from incidentradiation by the pasteurizer, thus enhancing the efficiency of the solar water heater.Such lenses may be associated with the insulating structures or may be provided as aseparate element (e.g., as an overlay or additional layer of the invention assembly. 6 012592 * Containers contemplated for use in the practice of the présent invention include any portable water tight container. Thus, containers contemplated for use inthe practice of the présent invention include bags constructed of a flexible material,enclosures of rigid materials (e.g., a bottle, a box, or the like), and the like. The . 5 containers may be constructed of glass, polymeric materials (e.g., polyesters such aspolyethylene terephthalate; polyolefins such as polyethylene and polypropylene;polyamides, polyethers, and the like, as well as combinations of any two or morethereof), and the like. It is presently prefeired that the container be constructed of amaterial suitable for containing potable water, e.g., polyethylene, polypropylene, io polyethylene terephthalate, and the like.

For example, in aparticular embodiment of the présent invention, a standardtransparent polymeric water bottle, or the like, may be employed as the water tightcontainer. Such containers may either comprise an intégral energy convertingstructure or one may be introduced therein. Thus, in one embodiment of the présent 15 invention, a standard transparent polymeric water bottle, or the like may be convertedinto a water heater/pasteurizer by introducing an energy converting structure into thecontainer, and adding an insulating structure and/or a solar or reflective cookeroutside of the container.

In accordance witli still another embodiment of the présent invention, the 20 container comprises one or more pleated structures (e.g., a bellows, or the like) to provide for expansion of the container upon fîlling said container with liquid. Thus, ·the container occupies a smaller volume when not filled with liquid, and iscommensurately more portable and easy to store.

In accordance with yet another embodiment of the présent invention, 25 containers contemplated for use herein can be provided in a variety of shapes toacconunodate a variety of spaces where (or uses for which) the container might bestored (or employed). In addition, invention containers can optionally be equippedwith one or more straps (or grommets to which one or more straps canbe.attached) tofacilitate carrying the containers, for example strapped on one’s back like a backpack, 7 012592 ( hanging the container from a tree limb or free-standing pôle, carrying on one’s head,propping up in any convenient configuration to maximize exposure to incidentradiation, or the like.

Containers contemplated for use in the practice of the présent invention5 preferably comprise at least one resealable opening for introducing and dispensing liquid. Any resealable opening may be employed, including threaded spout and capcombinations, sports-bottletype caps, snap-top spout and cap combinations, filter-containing caps, zippers (e.g., of the ZÏPLOCK™ design, or the like), corks, stoppers,stopcocks, and the like, and/or a shower head or a sprayer type attachaient (taking

io care, of course, that the heated water is allowed to cool to no greater than about 55°C prior to use as a shower to prevent scalding). It is presently preferred that theresealable opening be water-tight. In one aspect, the opening may comprise an airvent to accommodate expansion of the contents due to heat. In another aspect thewater heater may also include a vacuum type lid that enables water to be pump- 15 sprayed out of the container similar to garden sprayers or a water-well pump design.

As used herein, “polymer” or “polymeric” means any material having apolymer structure (e.g., polyolefins (e.g., polyethylene, polypropylene, and the like),polyesters (e.g., polyethylene terephthalate, and the like), polyamides (e.g., nylon, andthe like), polyuréthanes, and the like, as well as combinations of any two or more 20 thereof) and which is suitable for containing potable water. Presently preferredmaterials of construction for the container are polyethylene, polyethylene-nyloncoextruded films, and polyethylene terephthalate. In a particular embodiment of theinvention, materials contemplated for use in the préparation of invention containersare materials which inherently hâve an anti-reflective outer surface (or materials to 25 which such a surface can be applied). This wiîl minimize the amount of incidentenergy which impacts the invention container, but fails to be captured by the water•being treated. As readily recognized by those of skill in the art, polymeric materialsemployed in the practice of the présent invention may optionally include stabilizers,UV absorbera, UV inhibitors, and the like. Such additives can enhance the useful life 30 of the invention container and may also increase the efficiency with which invention 012592 ( solar water heaters capture solar energy. Conversely, in areas where incident radiation is plentiful and heating of water within an invention container can be readilyaccomplished, it may be désirable to use a polymeric niaterial having ahighersoftening point, or polymeric material modified so as to contain agents which impart a 5 higher softening point to said polymeric material and/or actually reduce lighttransmission therethrough to reduce the likelihood of overheating the water to bepasteurized (with the potential to compromise the integrity of the vessel). As analternative to use of polymeric material loaded with one or more additives to reducelight transmission, a thicker sheet of polymeric material can be used, which is also 1 o bénéficiai in providing a more rugged vessel, especially useful when elevated températures are reaehed.

As used herein, “energy converting structure” means a structure having theability to convert light energy to heat, and which is compatible for use in contact with.potable water. Suitable materials include preferably darkly colored polymer sheeting, 15 colored rigid materials such as polymers, metals, or the like. Presently preferredcolors are dark green and/or black due to their ability to absorb light and convert theincident radiation into heat. As those of skill in the art can readily understand, byplacing an energy converting structure in contact with water, and exposing thestructure to sunlight, the energy converting structure will convert the incident 20 radiation to heat, which will be transmitted from the structure'into the water.

Any shape and size energy converting structure may be employed in thepractice of the présent invention. For example, when the envelope-type containerdescribed herein is used, a two-sided panel energy converting structure may beemployed. As will be understood by those of skill in the art, the greater the surface 25 area of the energy converting structure the more efficient the energy recruitment andheat dispersai willbe. Accordingly, it is also contemplated that collapsible energyconverting structures (e.g., pleated, accordion-like structures, or the like) may beemployed in the practice of the présent invention. In this manner, structures ofrelatively large surface area can be introduced into containers having openings of a 30 limited size. It is further contemplated that the internai energy converting structure 9 012592 ( may also be joined to the cap or to an extemal element of the container which iscapable of adjusting the position of the energy converting structure inside thecontainer, or for a mixing or stining effect.

To alleviate heat loss to the suirounding environment, and to increase efficiency 5 of invention heaters, in another eiribodiment of the présent invention, the container mayfurfher comprise at least one insulating structure. Insulating structures may be providedat any portion of the container where minimization of heat loss is desired, including thetop, bottom and/or sides of the container. The insulating structure may be a separatecomponent that is placed over, around and/or under the container, or the insulating 1 o structure may be an intégral part of the container, or a combination of intégral andseparate structures may be employed. For efficient minimization of heat loss to anysurface on which the invention water heater is placed (e.g., the ground), it is presentlypreferred that invention containers employ an insulating structure that is coextensivewith the bottom of the container. It is presently preferred that the insulating structure, 15 if placed on the bottom of the container, also contain an upper surface that comprisesan energy reflective structure to redirect potentially escaping energy back into thecontainer. It is presently preferred that the insulating structure, if placed on the top orsides of the container, be transparent to permit the passage of light energy therethrough.

Any of a variety of insulating structures may be employed in the practice of the 20 présent invention. In its simplest form, the insulating structure may comprise niaterialsdefînirig an airspace. An insulating airspace may be achieved by any way known tothose of skill in the art. For example, in the three ply envelope-type design describedherein, an additional ply of flexible material may be bonded to the container to create aninflatable air space (having one or more separate chambers). The inflatable air space 25 optionally comprises a resealable opening, such as those described herein, for theinflation thereof. This configuration has the benefit of requiring minimal space forstorage when not in use. An additional benefit of this configuration is the ability to usesuch a container in the deflated State to capture heat bÿ conduction even in the absenceof incident radiation. Thus, if a warm surface is available on which to rest the invention 30 pasteurizer (even in the absence of incident radiation), déflation of the insulating layer 10 012592 • would allow more direct contact with the warm surface and facilitate capture of the energy from the warm surface by the water in the container. In a spécifie embodiment,the inflatable airspace can be further equipped with a desiccant to minimise clouding(due to the presence of moisture) upon inflation thereof. 5 Altematively, rather than being inflatable, the insulating air space can be preformed so thaï inflation is not required to achieve the desired insulating effect. Thus,

H maierials such as bubble wrap can be used to provide the desired insulating air space.

The airspace can be any of a variety of structures, including those as simple as amere pillow of air, to more intricaîe structures such as Üiose provided by insulating ίο materials such as bubble-wrap (i.e., an insulating surface divided into numerous smallpockets of air), inflatable multi-clianibered structures, closed-cell foam, open cell foam,styrofoam, TfflNSULATE™, or other such polymeric insulation materials, or the like,ail of which are contemplated for use in the practice of the présent invention. As readilyrecognized by those of skili in the art, insulating materials employed in the top surface of 15 the invention pasteurizer should be sufficiently transparent so that radiant energy canpass therethrough.

Insulating structures contemplated for use in the practice of the présent invention .can be of almost any shape. Thus, for example, round, oblong, funnel shape, and thelike, insulating structures can be employed. In a particular embodiment, the insulating 20 structure is wedge shaped so that it aids in orienting the invention container toward thesource of radiation (e.g., the sun). Thus, for exariiple, if an invention container isequipped with grommets with straps attached thereto, the container can be cairied onone’s back like a backpack, and the insulating structure could be sized to facilitateorienting the container at such an angle that the capture of incident sunlight is 25 maximized, while providing insulation from the heat for the person carrying the bag ontheir back. As another example, the insulating structure could be configured so as to . facilitate carrying the container on one’s head. In this configuration, the insulating structure provides both protection to the carrier from exposure to excessive heat from theheated water therein, and stability to the container to facilitate carrying the container. 11 012592 v Το further alleviate heat loss to the surrounding environment, and to increase efficiency of invention heaters, in another embodiment of the présent invention, thecontainer may further comprise at least one reflective structure capable of redirectingenergy towards energy converting structure(s) contained within the water heater. It is 5 contemplated that any inexpensive material capable of reflecting energy can be used.For example, in accordance with one embodiment of the présent invention a reflectivestructure conld be located on the bottom surface of the water heater either intemallyor extemally. In accordance with another embodiment of the présent invention, areflective structure could be located at the top surface of the water heater either i o intemally or extemally (so as to provide additional collection surface to facilitatecapture of incident radiation). In accordance with additional altemate embodiments,the reflective structure may be placed between the container and an insulatingstructure placed on the bottom surface of the water heater, or the reflective structuremay be placed between the container and an insulating structure placed at the top 15 surface of the water heater (so as to provide additional collection surface to facilitate capture of incident radiation), and the like.

As used herein, “energy reflecting structure” means a structure having theability to reflect potentially escaping energy away from the reflecting structure, and/orthe ability to capture additional radiation that would otherwise fall outside the invention 20 structure. Suitable materials include colored polymer sheeting, colored rigid materialssuch as polymers, metals, or the liké. A presently preferred côlor is silver due to itsreflective properties. As those of skill in the art can readily understand, by placing atleast one energy reflecting structure along an extemal surface of a container,potentially escaping energy (as well as energy that would otherwise fall outside the 25 invention structure) will be redirected back towards energy converting structure(s)and/or the liquid to be heated. Ihus energy loss will be minimized and thermalefficiency will be enhanced.

In accordance with another embodiment of the présent invention, there areprovided energy reflecting structures comprising a flared reflective wrap which can be 30 placed about invention containers. Such a structure maximizes the amount of incident 12 012592 ( energy which is directed toward the container. In an alternative embodiment, thereflective structure can be repositioned from time to time to maximize its ability toredirect the incident energy to tire container.·

In accordance with yet another embodiment of the invention, additional 5 components may be included to fiirther enhance the efficiency with which incidentradiation is collected. For example, one or more battens can be included to constrainthe shape of the container upon introduction of water and/or air therein so as tomaximize the surface of the water heater which is properly oriented to efficientlycapture incident radiation. As another example, one or more concentrating lenses can i o be included on at least a portion of the container, or positioned between the container and incident radiation. For example, one or more Freznel lenses can be incorporatedas part of the insulating layer placed over the top of the water-containing container(e.g., around the edges of the invention pasteurizer to facilitate capture of additionalradiation, or covering substantially ail of the top surface of the invention pasteurizer). 15 Altematively, one or more Freznel lenses can be employed in association with theinvention pasteurizer as a separate add-on feature, e.g., as a ring which surrounds theperiphery of the pasteurizer, or as an overlay covering some or ail of the top surfaceof the invention pasteurizer.

In a spécifie embodiment of the présent invention, containers contempîated for 20 use in the préparation of invention water heaters comprise an assembly of two pièces (i.e., first and second sheets) of flexible polymeric material stacked on top of oneanother and bonded together at or near their perimeters (e.g., to create a bag or anenvelope).

Two piece envelope-type containers may hâve an energy converting structure 25 introduced therein, or the energy converting structure may be integrated into the ·container. For example, in accordance with one embodiment of the présent invention,the energy converting structure can be provided as a third piece of flexible polymericmaterial that is stacked between the first and second sheets and bonded along itsperimeter between the first and second sheets. In this manner a three ply envelope is 13 012592 ζ created with one ply comprising an energy converting structure. In the latterembodiment, it is presently preferred that the third sheet (i.e., energy convertingstructure) hâve perforations therethrough so that liquid in the container can circulatefreely from one side of the energy converting structure to the other. Liquid 5 circulation can also be accomplished in other manners, for example by bonding theenergy converting structure on fewer than ail sides of its perimeter, thereby alsoallowing liquid to flow from one side of the energy converting structure to the other.As noted above, such containers can optionally be equipped with straps, or grommetsto which straps can be attached to facilitate handling (and orientation) of the io container.

Consistent with the foregoing design, in accordance with another embodimentof the présent invention, there are provided assemblies comprising stacked first,second and third sheets of a flexible polymeric material, bonded together at or nearthe perimeters of said sheets to create a three-ply structure, wherein said first and 15 second sheets comprise a water-tight container containing therein said third sheet, andwherein said third sheet is a two-sided panel of an energy converting structure. In oneaspect of this embodiment, the third sheet may be perforated. In another aspect, theassembly further comprises a fourth sheet-of flexible polymeric material stacked ontoand bonded to said first or second sheet of material along the perimeter thereof, said 20 fourth sheet providing an insulating airspace. It is presently preferred that each of the chambers defined by the sheets further comprise a resealable opening for theintroduction of water and air, respectively, therethrough. The présent assembly isfurther embodied by the optional addition of a plurality of sheets creating multipletiers, canals, or the like defining airtight spaces comprising insulating structures. The 25 présent assembly is still further embodied by the optional addition ôf a bottom sheetcomprising energy reflecting properties.

Invention solar heaters are particularly useful as pasteurization devices.

Contrary to popular belief, it is not necessary to boil water to make it safe to drink.Also it is usually not necessary to distill water to make it safe to drink. Heatîng water 30 to as little as 65-70° C (149-158° F) for 6 minutes, or to a higher température for a 14 012592 ( shorter time, will kill substantially ail germs, viruses, and parasites. AU effective timeand température combinations are contemplated for use in the practice of the présentinvention. Furthermore, the température demande of the pasteurization protocol maybe achieved with or without filtration. Optionally, the water may also be filtered or 5 chemically treated as desired to achieve one’s purity preference and/or to achieve aliquid product free from certain undesirable contaminants.

Because the température of a liquid must be known to détermine the timerequired for pasteurization, in one embodiment of the présent invention, invention waterheaters optionally include a température indicator (e.g., a thermometer) for indicating the i o température or the température history of the liquid within the container portion of invention apparatus and assemblies. Any température indicator suitable for determiningthe température and/or température history of a liquid in a container may be employed inthe practice of the présent invention. Easily useable and relatively durable (preferablynon-breakable) température indicators are presently preferred. Accordingly, in one 15 aspect of the invention, the température indicator is a liquid crystal sheet indicator (LCDs), or the like. When LCD indicators are used, they can readily be incorporated inany of a variety of locations within the invention water heaters.

Another means for determining whether water has been heated to atempérature sufficient to achieve pasteurization is to employ a water pasteurization 2o indicator (WAPI). One example of a WAPI is a plastic (or glass) tube with both endsheated, pinched, and sealed, and with a particular type of soybean fat in one end thatmelts at 154° F (e.g., the "MYVEROL" 18-06K, available from Eastman Kodak Co.,Kingsport, TN 37662). The tube itself is buoyant, but is altematively fastened inplace with suitable fastening means, e.g., a washer, or the like, so it sinks to the 25 bottom (coolest) part of the water, with the fat in the high end of the tube. If the fat is found in the low end of the tube at any later time, that is a clear indication that thewater at one time reached the proper température for pasteurization, even though thewater may hâve since cooled down. Altematively, the WAPI can be positionedwithin the cap employed to seal the resealable opening, thereby facilitating 30 introduction and removal thereof from the container. As yet another alternative, the

1S U12592 ( resealable opening itself could be configured so as to receive one or more WAPî’s therein, holding the WAPI in place for ease of introduction and removal. WAPî’sprepared from glass tubes hâve the advantage of being hermetic, which shouldprovide extended life for the wax therein, while still being relatively durable with 5 respect to the handling to which invention water heater is likely to be subj ected.

Additional WAPIs contemplated for use in the practice of the présentinvention include multiple WAPIs, wherein two or more tubes are employed, eachcontaining a component that melts at a different température, so that a minimumrequired température may be indicated by the first component, and additional i o températures indicated by the additional component(s). Each component employed in this aspect of the invention can be treated to appear a different color, therebyfacilitating visual observation thereof. Thus, if the lower melting component hasmelted, but one or more of the higher melting component(s) has(ve) not, one can morereadily establish how long température must be maintained to achieve pasteurization. 15 Altematively, if ail of the indicator materials hâve melted, then one can confinn that the highest indicated température has been achieved, and therefore, less time shouldbe required to achieve pasteurization. As readily recognized by those of skill in theart, other WAPIs may also be employed in the practice of the présent invention.

Any fastening means (e.g., a nylon string, a bracket within the cap for the 20 container, a slot for receiving the température sensing means as part of the energyconverting structure, and the like) is suitable for use in the practice of the présentinvention, so long as there is sortie means provided to facilitate manipulation and/orretrieval of the tube without recontaminating the water. The tube can be readilyreused by flipping it over and attaching the fastening means to the other end of the 25 WAPI after the wax has solidified.

In accordance with still another embodiment of the présent invention,température indicating means can be strategically placed at the interface between thefluid-containing portion and the insulating portion, so as to facilitate détermination ofthe températures to which the container has been subj ected, thus allowing one to 16 012592 ' monitor and make sure that the contents of the container are not excessively heated,witii attendant safety concems, durability of the container, and the like. ht accordance with another embodiment, invention water heaters mayoptionally include any one or any combination of various fîlters including particulate, 5 microbial, and/or odor absorbing charcoal fîlters. While pasteurization can kill dangerous microorganisms, the process does nothing to improve the taste of water orremove any incipient odors. Use of activated charcoal fîlters, or the like, will removeunpleasant odors and tastes from water. Accordingly, in another embodiment of theprésent invention, invention water heaters further comprise an activated charcoal i o filter, or the like. The filter may be nsed either inside or outside of the container. Inaddition, the' filter can be associated with the opening of the container so that watercan be passed through the filter upon introduction of the water into the container,and/or upon pouring the water out of the container. When charcoal fîlters4'areemployed, particularly when a container with rigid sides is used, the filter can be 15 mounted to slide into position at the spout of the container when the container is oriented for pouring, and to otherwise rest at a position removed from the spout whenthe container is in the upright position. In this manner, water can be introduced intothe container without passing through the filter. Numerous other means for mountingof a filter are possible and contemplated for use in the practice of the présent 20 invention.

Invention solar heaters are not only usefiil for pasteurizing water, but may also beused as a shower employing pasteurized water. Thus, in accordance with anotherembodiment of the présent invention, the solar heater may further comprise a shower 25 head in fluid communication with an opening in the container. Ih this manner, solarheated shower water is provided. A further embodiment of the solar heated showercomprises a température indicator which monitors the water température to avoidtempératures greater than 55° C, at which températures scalding injuries are possible.Various structures to facilitate ease of use, such as hang straps, hooks, and the like, are 17 012592 ( also contemplated for use in the practice of this and ofher embodiments of the présentinvention.

In accordance with a stiîl further embodiment of the présent invention, there areprovided methods for the pasteurization of liquids, said methods comprising 5 introducing energy converting structure® and water into a transparent container, andexposing said container to a suitable energy source for a time suffîcient to pasteurizesaid liquid. Another method for the pasteurization of water embodied by the présentinvention comprises introducing energy converting structure® and water into acontainer, surrounding said container with insulating material, and exposing said water i o heater to a suitable energy source for a tirne suffîcient to pasteurize said water. Solar heaters described herein are ail contemplated for use in the practice of this embodimentof the invention. Any methods for the pasteurization of water described herein mayfurther comprise the step of surrounding said container and or entire water heater with asolar cooker, or another energy focusing device. 15 As used herein, “a suitable energy source” means any source of energy that is capable of being converted to heat, and which is compatible for use in contact withpotable water. The presently preferred energy source is solar energy because of itsnatural and inexpensive properties. Alternative non-natural light and energy sourcesare also contemplated for use in conjunction with the présent invention. Thus any 20 combination of natural and/or non-natural energy sources are contemplated for use in the practice of the présent invention.

In accordance with a further embodiment of the présent invention, there areprovided methods of assembly of solar water heaters, said methods comprising stacldngfirst, second and third sheets of a flexible polymeric material, bonding same together at 25 or near the perimeters of said sheets to create a three-ply structure, wherein said first and second sheets comprise a water-tight container containing said third sheet, and whereinsaid third sheet is an energy converting structure. In one aspect of this embodiment,the third sheet may be perforated. In another aspect, the method of assembly furthercomprises stacking a fourth sheet of flexible polymeric material onto and bonding 18 012592 ' same to said first or second sheet of material along the perimeter thereof (and optionally at various pointe across the surface thereof), said fourth sheet providingone or more insuïating (infiatable and/or sealed) airspaces. It is presently prefeiredthat each of the chambers defîned by the sheets further comprise a resealable opening 5 for the introduction of water and air, respectively, therethrough. The présent methodof assembly is further embodied by the optional addition of a plurality of sheetscreating multiple tiers, canals, or compartments comprising energy convertingstructures, adjacent to airtight spaces comprising insuïating structures.

In accordance with a further embodiment of the présent invention, there areio provided solar water heater kits which can be used with existing transparent containers to rentier them suitàble for pasteurization. Invention kits comprise at leastone energy converting structure, and at least one thermal insuïating structure. Theenergy converting structure can be introduced into any suitàble container, which isthen enclosed within the thermal insuïating structure to minimize heat loss therefrom. 15 Optionally, invention kits further comprise one or more particulate, anti-microbial, or charcoal filters. Another optional component of invention kits is a températureindicator for indicating the température history of the water contained within saidwater heater. Additional optional components of invention kits include a universaliyfitting cap, spout, stopcock, sprayer, shower, or sport-cap attachaient compatible with 20 said existing container outlet. In addition to the thermal insuïating structure, invention kits optionally include a reflective cooker, and/or solar cooker, and/or afocusing device to enhance the ability of the resulting water heater to capture incidentenergy. Especially preferred reflective structures contemplated for use herein includethe flared, reflective wraps described above which can be wrapped around almost any 25 structure, and will not only refïect radiation that might otherwise escape back into theinvention container, but it will also increase the amount of incident energy that willactually be collected and directed at the contents of the container.

In accordance with yet another embodiment of the présent invention, there are 30 provided solar water heater kits which can be used with existing containers to rentier · 19 012592 ( them suitable for pasteurization, said kits comprising at least one energy convertingstructure, a reflective cooker, and/or a solar cooker.

Several spécifie embodiments of invention water heaters are now described in5 greater detail by reference to the Figures. For example, FIG. 1 illustrâtes a flexible solar water heater with energy converting structure on the bottom surface thereof.

The solar water heater (100) comprises an insulating air space (103) on the top surfaceof the heater, a water chamber (109) centrally located within the heater, an energyconverting structure (115) located on the internai bottom surface of the water chamber io (109), and an insulating foam or inflatable structure (117) located on the bottomsurface of the container (100). The insulating air space (103) further comprises aplurality of battens (to provide additional support to the insulating airspace and toconstrain the top surface of the heater to a relatively fiat orientation so as to maximizethe capture of incident radiation) and an air opening (105) used to inflate or deflate 15 the insulating air space (103) as needed. The container (100) also includes a watertight, resealable water fîll opening (111) that allows the centrally located waterchamber (109) to be emptied and filled as needed. The water fill opening (111) ismade resealable through the use of a resealable cap (113) located extemally to thecontainer. A water pasteurization indicator (WAPI) (119) is placed into the water 20 chamber (109) through the water fill opening (111), and is used to détermine thewater température history, thus indicating whether températures required to achievepasteurization hâve been attained.

Another embodiment of invention water heaters is described in Figure 2. FIG.2 illustrâtes a flexible solar water heater with a perforated energy converting 25 structure placed centrally in the water chamber. The solar water heater (200)comprises an insulating air space (203) on the top surface of the heater, a waterchamber (209) centrally located within the heater, a perforated energy convertingstructure (215) located in the center of the water chamber (209), and an insulatingfoam structure (217) located on the bottom surface of the container (200). The 30 perforated energy converting structure (215) allows for the free flow of water both 20 012592 ( above and below structure (215) within the water chamber (209) allowing a mixing effect. The bottom surface of the container (200) further includes a refiectivestructure (221) located either on the internai or extemal bottom surface of thecontainer (200) or on the upper surface of the insulating foam structure (217) located 5 on the bottom surface of the container (200). The insulating air space (203) further comprises an air opening (205) used to inflate or deflate the insulating air space (203)as needed. The container (200) also includes a water tight, resealable water fillopening (211) that allows the centrally located water chamber (209) to be emptied andfilled as needed. The water fill opening (211) is made resealable through the use of a ίο resealable cap (213) located extemally to the container. A water pasteurization indicator (WAPI) (219) is placed into the water chamber (209) through the water fillopening (211), and is used to détermine the water température history, thus indicatingthe completion of the pasteurization process.

Another embodiment of invention water heaters is described in Figure 3.i s FIG.3 illustrâtes a rigid solar water heater. The solar water heater (300) comprises a transparent resealable container (301), an insulating air space blanket (303) whichwraps around the container (301), a water chamber (309) which is the innercompartiment of the container (301), an energy converting structure (315) located inthe center of the water chamber (309), and optionally an independent insulating foam 20 structure (317) placed below the bottom surface of the container (301). The energyconverting structure (315) is expansive (i.e., accordian-like), thus allowing a largersurface area structure to be introduced into the container (301) through a relativelysmall resealable container opening (311). The energy converting structure (315)allows for the free flow of water both above and below the structure (315) within the 25 water chamber (309) allowing a mixing effect. The bottom surface of the container(301) further includes a refiective structure (321) located on either the internai orextemal bottom surface of the container (301) (not shown) or on the upper surface ofthe insulating foam structure (317) placed below the bottom surface of the container(as shown here) (301). The insulating air space blanket (303) optionally further 30 comprises an air opening (305) used to inflate or deflate the insulating air space 21 012592 ( blanket (303) as needed (e.g., such air opening is not necessary if bubble wrap is usedas the insulating layer). The container (301) also includes a water tight, resealablecontainer opening (311) that allows the centrally located water chamber (309) to beemptied and filled as needed. The resealable container opening (311) is made 5 resealable through the use of a resealable cap (313) located extemally to the container.A water pasteurization indicator (WAPI) (319) is placed into the water chamber (309)through the resealable container opening (311), and is used to détermine the watertempérature history, thus indicating the completion of the pasteurization process.

Another embodiment of invention water heaters is described in Figure 4. FIG. 1 o 4 illustrâtes a modified flexible solar water heater with energy converting structure onthe bôttom surface thereof. The solar water heater (400) comprises an insulating airspace (403) on the top surface of the heater, a water chamber (409) centrally locatedwithin the heater, an energy converting structure (415) located on the internai bottomsurface of the water chamber (409), an insulating foam structure (417) located on the 15 bottom surface of the container (400) and optional Freznel lenses (423) located at theouter edges of the insulating air space (403). The insulating air space (403) comprisesa plurality of air filled chambers, and optionally may comprise an air opening (notshown) used to inflate or deflate the insulating air space (403) as needed. Thecontainer (400) also includes a water tight, resealable water fill opening (411) that 20 allows the centrally located water chamber (409) to be emptied and filled as needed.The water .fill opening (411) is made resealable through the use of a resealable cap(413) located extemally to the container. A water pasteurization indicator (WAPI)(419) is placed into the water chamber (409) through the water fill opening (411), andis used to détermine the water température history, thus indicating whether 25 températures required to achieve pasteurization hâve been attained.

Another embodiment of invention water heaters is described in Figure 5. FIG.5 illustrâtes a modified flexible solar water heater with a perforated energyconverting structure placed centrally in the water chamber. The solar water heater(500) comprises an insulating air space (503) on the top surface of the heater, a water 30 chamber (509) centrally located within the heater, a perforated energy converting 22 012592 } structure (515) located in the center of the water chamber (509), an insulating foamstructure (517) located on the bottom surface of the container (500), and an extendedreflective surface (522) or an enclosed transparent top with reflective sides (522A) tofacilitate collection of additional incident radiation. The perforated energy 5 converting structure (515) aîlows for the jfree flow of water both above and belowstructure (515) within the water chamber (509) allowing a mixing effect. The bottomsurface of the container (500) may further include an optional reflective structure(521) located either on the internai or extemal bottom surface of the container (500)or on the upper surface of the insulating foam structure (517) located on the bottom i o surface of the container (500). The insulating air space (503) comprises a plurality of air filled chambers, and optionally may further comprise an air opening (not shown)used to inflate or deflate the insulating air space (503) as needed. The container (500)also includes a water tight, resealable water fill opening (511) that allows the centrallylocated water chamber (509) to be emptied and filled as needed. The water fill 15 opening (511) is made resealable through the use of a resealable cap (513) located extemally to the container. A water pasteurization indicator (WAPI) (519) is placedinto the water chamber (509) through the water fill opening (511), and is used todétermine the water température history, thus indicating the completion of thepasteurization process. 20 Yet another embodiment of invention water heaters is described in Figure 6. FIG.6 illustrâtes a cross-section of a modified rigid solar water heater. The solarwater heater (600) comprises a transparent resealable water chamber/container (609),a transparent multi-chambered insulating air space blanket (603) which wraps aroundthe water chamber/container (609), an energy converting structure (615) located near 25 the inner walls of the water chamber/container (609). The energy converting structure (615) is introduced through the chamber/container opening (not shown) and expandscircular about the round chamber, and may over-lap or gap depending on the length ofenergy converting structure (615) used. The insulating air space blanket (603) mayfurther comprise an air opening (not shown) used to inflate or deflate the insulating 30 air space blanket (603) as needed. The water chamber/container (609) also includes a 23 012592 f water tight, reseaiable container opening (not shown) that allows the centrally located water chamber/container (609) to be emptied and filled as needed.

Another preferred embodiment of invention water heaters is depicted inFigures 7-9. FIG. 7 représente a top view photograph of a modified flexible solar 5 water heater with energy converting structure on the bottom surface thereof. Thesolar water heater (700) comprises an insulating air space (703) on the top surface ofthe heater, a handle (731), a reinforcement rod (733), and grommets (735) useful forfacilitating ease of transport of said solar water heater (700). FIG. S represents abottom view photograph of the modified flexible solar water heater with energy 1 o converting structure on the bottom surface thereof. The solar water heater (700) comprises a water fill opening with a reseaiable cap (713) on the bottom surface (727)of the heater that allows the centrally located water chamber (not shown) to beemptied and filled as needed. The solar water heater (700) further comprises a handle(731), a reinforcement rod (733), and grommets (735) useful for facilitating ease of 15 transport of said solar water heater (700). FIG. 9 represents a cross-sectional viewphotograph of the modified flexible solar water heater with energy convertingstructure on the bottom surface thereof. The solar water heater (700) comprises aninsulating air space (703) on the top surface of the heater, a water chamber (709)centrally located within the heater, an energy converting structure (715) located on the 20 internai bottom surface of the water chamber (709), and an insulating foam structureor inflatable airspace (717) located betweên the bottom surface (727) of the container(700) and the bottom surface of the water chamber (709). The insulating air space(703) comprises a plurality of gas filled chambers and may optionally comprise an airvalve (not shown) used to inflate or deflate the insulating air space (703) as needed. 25 While the invention has been described in detail with reference to certain preferred embodiments thereof, it will be understood that modifications and variationsare within the spirit and scope of that which is described herein.

Claims (8)

1. 012592 rJ 24 CLAIMS

   1. A solar water pasteurizer comprising: a flexible water-tight resealable container, wherein said container comprises atop and a bottom, wherein said bottom comprises at least one resealable opening,wherein said resealable opening comprises at least one water-tight spout with a matingresealable cap, and wherein said resealable cap comprises a bracket for receiving oneor more reuseable température indicators for indicating the température history of thewater contained therein, one or more energy converting structures therein, as an intégral part' of saidcontainer, a first insulation structure on the top of said container, wherein said firstinsulation structure comprises gas contained within air-tight structures, and a second insulation structure on the bottom of said container, wherein saidsecond insulation structure is selected from gas contained within air-tight structures,closed cell foam or open cell foam, wherein said insulation structures collectively are sufficient to enable saidpasteurizer to achieve water températures of at least 60°C, wherein said insulationstructures are an intégral part of said container.
2. 2. A water pasteurizer according to claim 1, wherein said températureindicator is made of a glass tube.
3. 3. A water pasteurizer according to claim 1, wherein said energyconverting structure is colored to enhance energy absorption thereof.
4. 4. A water pasteurizer according to claim 1, wherein said insulatingstructure on both the front and back of said container are inflatable.
5. 5. A water pasteurizer according to claim 1, wherein said first and/orsecond insulating structure comprises an energy reflective surface. 012592 25
6. 6. A water pasteurizer according to claim 1 wherein said températureindicator comprises 2 or more different température WAPI’s.
7. 7. A water pasteurizer according to claim 1, further comprising a reflectivepanel, and/or solar cooker placed extemal to said container.
8. 8. A method of assembly of a solar water pasteurizer, said methodcomprising: stacking fîrst, second and third sheets of a flexible polymeric material, bondingsaid sheets together at or near the perimeters of said sheets to create a three-plystructure, wherein said first and second sheets upon bonding, form a water-tightcontainer containing therein said third sheet, wherein at least said first sheet is transparent, wherein said second sheet is insulated and has an energy reflective layerthereon, wherein said second sheet contains at least one water-tight spout with a matingcap, wherein said cap comprises a bracket for receiving one or more re-usabletempérature indicators for indicating the température history of the water containedtherein, intimately associated therewith, and wherein said third sheet is an energy converting structure, and thereafter stacking and bonding a fourth sheet of flexible polymeric material to said firstsheet of material along the perimeter thereof, said fourth sheet providing a transparentinsulating airspace.