CA2201706A1

CA2201706A1 - Portable water sterilizer

Info

Publication number: CA2201706A1
Application number: CA002201706A
Authority: CA
Inventors: Walter Edmond Petrowich
Original assignee: Individual
Current assignee: International Water-Guard Industries Inc
Priority date: 1995-08-04
Filing date: 1996-08-02
Publication date: 1997-02-20
Also published as: WO1997006108A1; AU6652296A

Abstract

A portable water purifier comprises a housing including a waterproof container and a power supply. The container includes an upper chamber with a water entry porthole, a water exit porthole and a replaceable filter. A lower chamber includes a UV source and an enclosure for the electrical components. The filter cartridge, when in place, partitions the upper chamber from the lower chamber and separates a pre-sterilization area in the upper chamber from a post-sterilization area.

Description

PORTABLE WATER STF,RTT,~7,~.R
FIELD OF THE INVENTION
The present invention relates to portable water purifiers and sterilizers and, iD particular, to devices capable of portable ultra-violet sterilization.
S BACKGROUND OF THE INVENTION
Obtaining pure drinking water in many foreign countries is difficult, if not impossible, from the local water supply. Travellers, therefore, are often plagued with various sicknesses caused by micl ool g~ m.~ and pathogens, such as coliform bacteria, endemic to those countries and against which they have no hlllllulliLy.
10 In addition to travellers, those partaking in rural activitiessuch as camping, hiking and b5~ p~r~in a require a clean, safe water supply. The bacteriological content of water supplies in rural areas may be vely high due to the local animal population.
St~rili7ing tablets are known but their efficacy is questionable and they often impart an unpleasant taste to the water. It is known that ultra-violet("uv") radiation can be used to 1~ kill organic cu~ ;on within water supplies and it is on this basis that a number of sterilizing devices have been developed.
US Patent No. 4 755 292 to Merriam describes a battery powered uv sterilizerhaving a water reservoir in a bottom housing and a top housing or lid encasing a uv lamp and the batteries. This device is simple, but there is no means by which particulatematteror 20 inorganic co~ t~ may be removed.
US Patent No. 4 762 613 to Snowball discloses a portable st~rili7.q,rwith a uv lamp forming the core of a first chamber which is connected to a water reservoir chamber. The water passes by the uv lamp as it is being poured. There are numerous difficulties with this device. Firstly, thereis asignificantrisk of re-conlz~..lin~l;onof the sterilizedwateras 25 it may flow back through the horizontal passage connecting the two chambers. Secondly, this design does not seem to afford an ap~l v~liate uv exposure time for the water to ensure pathogen destruction.
US Patent No. 4 849 100 to Papandrea describes a briefcase style sterilization unit comprising, in series, a plurality of filters and a uv chamber. The briefcase itself is the 30 main chamber into which the water to be sterilized is poured. The water is then pumped from charnber to chamber via a series of conduits or delivery lines. The main problem with this type of arrangementis co~t~ tionas waterlGIl~illingin these conduits during SUBSTITUTE SHEET (RULE 26) W O 97/06108 2 2 0 1 7 0 6 PCT/CA96/00529 ~

periods of non-use may contain bacteria, which will grow and then rec~ . . .i n~t~ the subsequent water cycle. The only solution to this problem is chemical disinfection of the unit prior to each use which is time consuming, inconvenient and costly.
US Patent No. 5 106 495 to Hughes discloses a solar-powered system using uv light as an 5 ozone generator. The device comprises, among other components, a venturi means, an ozonation means including the uv source and a circulation pump. As with the patent to Papandrea described above, this product is at risk of co~ f ion due to the nature of the pumping and circulation system.
US Patent No. 4 151 085 to Malik describes a device, the crux of which appears to be a 10 control mech~ni ~m to regulate water flow through the purification system.
None of these devices provides a simple, effective and reliable uv sterilization unit which is truly portable and which is not at co~ t risk of reco"t;...~ t;on.
It is an object of the present invention to obviate or mitigate the above disadvantages.
SUMMARY OF THE INVENTION
15 The present invention provides a portable water purifier which comprises a housing including a waterproof containerand a power supply, said containercomprising an upper chamber having a water entry portal, a water exit portal and a replaceable filter cartridge and a lower chamberin which is disposed a uv source and an enclosure for the electrical components. The filter cartridge, when in place, selectively partitions the upper chamber 20 from the lower chamber and separates, in the upper chamber, a pre-sterilization area adjacent the entry portal from a post-sterilization area adjacent the exit portal.
Wateris thereby passable via the entry portal to the pre-sterilization area and through a first part of the filter cartridge to the lower chamber where it is exposed to uv radiation for a pre-determined length of time, and then, on disposing the container to the pouring position, the 25 water is removed by passage through a second part of the filter cartridge and finally through the exit portal The present invention also provides various types of replaceablefilter cartridges for use in the purifier as described herein. The filter cartridge, in a most desirable form, comprises a base plate on which is disposed a first, entry filter, a second, exit filter and a partition to 30 separate the first filterfrom the second filter.
The water purifier of the present invention is compact and effective and may be used under any conditions in which pure, clear water is required. Pumps and conduits, which are SUBSTITUTE SHEET (RULE 26) WO 97/06108 2 2 0 1 7 0 6 PCT/CA96/005~9 breeding grounds for bacteria, are not necessary. Without limiting the generality of the forego~ng, the purifier may be readily carried by travellers, both business and pleasure, to Iocales in which the water supply is suspect. It may also be used by campers, hikers or backpackers in areas of potentially high coliform counts. In addition, the purifier is ideal 5 for rural worksites such as mines, logging camps and construction areas. Lastly, it is contemplatedthat the purifier may be of particularuse as part of emergency ~lc;p~u~;dlless programs for earthquakes, fires, tornadoes, hu;ricanes, etc., in both consumer and co,po,~le contexts.
BRIEF DESCRIPTION OF THE DRAWINGS
10 Figure 1 is a perspective view of a water purifier and sterilizerwith the housing in the closed position;
Fi~ure 2 is a perspective view of a water purifier and sterilizerwith the housing in the open position to show its contents;
Figure 3 is an exploded perspective view of the container co,~lpone,l~ of a water purifier 1~ and st~r~li7~rshowing an upper chamber, a filtercartridge, a lower chamber, a uv lamp and some electrical cc,lnl>onents;
Figure 4 is a cross sectional view of a cont~ine" and Figure 5 is a perspective view of a filter cartridge.
PREFERRED EMBODIMENTS OF THE INVENTION
20 Referring to Figure 1, there is provided generally at 10 a water purification and sterilization unit. Housing 12 is depicted in a closed position suitable for transportation, with handle 14 disposed at the top of the housing.
Figure 2 depicts unit 10 with housing 12 opened about a hinge (not shown) to expose a removable container 16, a power supply 18 and a containersecuring means 20. This25 securing means includes any type of arrangement which reasonably holds the container within the housing when not in use. Preferably, the securing means may be a belt, strap, mesh or fabric cover arrangement or it may comprise a set of retractable arms. Most preferable, the securing means comprises a set of fabric or plastic straps connectable by velcro strips. It is to be understood, however, that depending on the shape of the housing, 30 a securing means may not be necessary.

SUBSTITUTE SHEET (RULE 26) _ WO 97/06108 2 2 0 1 7 0 6 PCT/CA96/00529 ~

Figure 2 depicts contamer 16 in a position "removed" from cradle 22 and thereby ready for operation as described further hereinbelow. Cradle 22 may additionally comprise an insert made of, for example, foam or rubber, to protect the con~illel from movement of the housing during transportation.
5 As may be seen in Figure 2, but more particularly in Figure 3, container 16 comprises upper chamber 24 which is removably connected to lower chamber 26. In a preferred form, the upper charnberforms a "lid" of container 16. Upper chamber24 includes an entry portal 28 (shown in Figure 4) adjacent pre-sterilization zone 29 and exit portal 30 adjacent post-st~nli 7~tion zone 31. A cap 32 is provided for removable sealing of exit 10 portal 30. A hinged door or cap 33 is provided for removable sealing of entry portal 28.
These caps may be either integral with the body of upper chamber 24, hinged to upper chamber 24 or they may be separate and distinct parts.
Lower chamber26 includes waterreservoir34, uv lamp36 and enclosure 38 for storage of the electricalcomponents including receptacleor socket 40 through which uv lamp36 may 15 be connected to power supply 18. This connection is enabled by, for example, connector cable42. W lamp 36, which is preferably mercury, is encased within a vacuum sealed quartz sheath or other means by which contact between the water and the uv lamp is avoided.
Removable filter cartridge 44 is engagable within upper chamber 24. This filter cartridge 20 selectively partitions upper chamber 24 from lower chamber 26 and within the upper chamber itself, defines pre-st~rili7~tion zone 29 and post-sterilization zone 31, which zones are distinct when the filter cartridge is in place. In a preferred embodiment, upper chamber 24 comprises partition 46 which separates pre-sterilization zone 29 from post-sterilization zone31.
25 As shown best in Figure 5, filter cartridge 44 preferably comprises platform 48 which is divided into two filtration regions. The first filtration region is indicated at 50 and may comprise any general particulatefilter which enables removal of large debris and matter such as sand, silt and sludge from the water. Most preferably, region 50 includes a sediment or turbidity screen formed of a porous fabric, mesh, cellulose or plastic. When 30 filter cartrid e 44 is in place within upper chamber 24, filtration region 50 is adjacent and below pre-~t~rili7~tion zone 29.
A second filtration region is indicated at 52 and provides, when the device is in operation, a filtering system after uv sterilization. Flltration region 52 includes a COI11,~ II llllent within post-sterilization zone 31 for different types of purification media so that a wide range of SUBSTITUTE SHEET (RULE 26) wo 97/06108 2 2 0 1 7 0 6 PCT/CA96/00529 !

pollutants may be elimin~terl hltration rep,ion 52 may include wall 53 between pre-st~rili7~tion zone 29 and post-sterilization zone 31 abutting partition 46 of upper chamber 24. Media within filtration region 52 may be selected to target specific inorganic or organic cont~min~nt~ In a preferred form, the media within filtration region 52 may be selected 5 from activated carbon or granular activated charcoal (GAC) for the removal of trace chemicals such as chlorine and trace organic compounds and ion exchange chelate resins or zeolite for the removal of trace metals such as lead and copper. An exhaustive list of resins is not provided herein as ap~l Upl iate ones are well known and documented in the art. For example in US Patent No. 5 174 879, which is incorporated herein by reference, a number 10 of nitrate-specific anion exchange resins are disclosed. Similarly, there are many disclosures of cationic resins used in water purification.
Preferably, the activatedcarbon is a blend of high grade activatedcarbons including, bituminous and coconut shell carbons. These carbons may be blended for the optimal reduction of organic chemicals, herbicides, pesticides and industrial solvents. The average 15 grain size of the activated carbon, in a preferred form, is between 5 to 100 meshes, more preferably between 8 to ~0 meshes.
Optionally, the GAC may be silver i,~ ated to retard growth of bacteria within the filter. For the most part, however, this precaution will not be required as the design of the unit of the present invention ensures uv st~nli7~tion prior to exposure of the water to GAC
20 thereby killing the bacteriological c ~ n~
The exact selection of media to be incolpoldl~d within filtration region 52 depends on the context in which the unit will be used. For example, if water is to be purified in a rural area (i.e. c~mpino, worksites, etc.) the user will primarily be concerned with the removal of bacteriological co~ t~ via uv sterili_ation. In this context, the focus may not be 25 on the removal of trace chemicals and trace metals. Accordingly, the filter cartridge which may be chosen need not necessarily include the secondary filter c~ ollents in filtration region 52. Conversely, if tap water from an inclnstri~li7~cl urban area is to be purified, the selection of GAC and/or resins within the cartridge becomes more illlpOI ~lt. In a deluxe version of the filter cartridge, filtration region 52 is intemally apportioned to contain several 30 different types of purification media as described herein.
Flter cartridge 44 may be easily removed and replaced. It is cont~ latedthat the user of the unit of the present invention will purchase replacellle-llrllter cartridges as required and select the cartridge for each use based on the media disposed therein.

SUBSTITUTE SHEFT (RULE 26) WO 97/06108 2 2 0 1 1 0 6 PCT/CAg6/00529 ~

In the embodiment of the invention depicted in the ~lgures, filtration region ~2 includes an outlet orifice 54 which is functionally aligned with exit portal 30 when filter cartridge 44 is in place.
Power supply 18 comprises at least one rechargeable battery operatively connected to a S battery char2ing array which can function at 12 V DC, 115 V AC or æo v AC. Power supply 18 additionally comprises a printed circuit board (PCB) which provides, through a step down transformer, 12 V DC to the unit. In a preferred forrn, a rectifierwithin the transformer raises the voltage to the l lS V generally necessary for the operation of uv lamp 36 when the unit is supplied with either an AC or DC power source. Preferably, the 10 transformer is a Class 2 transformer. The battery may be any cadmium or deep charge acid lead varietywhich is preferably 12 V DC. Power supply 18 is arranged eitherto power the uv lamp directly through an electronic circuit or to charge the battery when the unit is not in use but plugged in via electrical outlet connector 56 (shown in ghost outline in Figure 2) .
The PCB is powered by the battery within power supply 18 and is designed to activate the 15 uv lamp when switch 58 (which is preferably pressure sensitive) is depressed. The circuitry contained with power supply 18 is generally known in the art and is described only briefly herein. In a most preferred form, the activation and operation of uv lamp 36 is signalled by a light emitting diode (~ED) indicator (preferably green). The PCB may additionally comprise a timer circuit which indicates the completion of one, typically 10 20 second cycle. The timer circuit then activates an audible alarm (by way of an amplifier circuit) or a visual alarm, preferably an LED. The circuitry may be designed to ically turn off the uv lamp at a predete~ ed time after the completion of one cycle i.e. ~ to 10 seconds, to COnSGI VC; battery power.
In another preferred embodiment~ a series of LED indicators operatively connected to the 25 PCB andindicatedat60inFigure2, areprovidedonthecasingofpowersupply 18, one of which indicates the charging level of the battery (eg: green for fully charged; yellow for 60% power; red for 50% power), another of which indicates that the battery is being recharged and another of which indicates that the uv lamp is in operation.
In operation, and with reference to Figure 4, ~snming that the battery has been properly 30 charged, the unit of the present invention may be carried in ba~,gage, knapsacks, briefcases and the like to remote areas at which there may be no available electrical power supply, and used to purify and sterilize water. Recharging the battery prior to use is simple and convenient. Voltage is applied to power supply 18 through electrical outlet connector 56 using an AC outlet or DC source. Alternately, if an electrical power supply is available, the SUBSTITUTE SHEET (RULE 26) ~ =

~ Wo 97/06108 2 2 0 1 1 0 6 PCT/CA96/00529 battery can be bypassed by connecting the power supply directly to an electrical outlet, for examplein a vehiclecigarettelighter. If the electricalpower supply is not 12 V DC, a suitable adapter may be required.
Container 16 is removed from cradle 22 in p.~ dtion for purification and cteri1i7~ion of S the water. Connector plug 42 is removed from enclosure 43 within the power supply casing and attachedto both colltainer 16 and power supply 18. Wateris poured through entry portal 28 to pre-st~n1i7~tion zone 29. Gravity flow directs the water through first filtration region 50 of filter cartridge 44 for the removal of large debris and particulate matterto reservoir 34 in lower chamber26. Within the reservoir, the wateris exposed to 10 uv radiationfor a predeterminedtime period once the user activatesthe PCB through switch ~. On most occasions, a IO second cycle of uv radiation generating a dosage of approximately30 000 MWScm2will be sufficient. The user may, out of an abundance of caution, repeat the cycle for an additional 10 seconds thereby gene,dting a total dosage of 60 000 MWScm2. Once the cycle(s) are completed, container 16 is disposed in a pouring lS position thereby allowing the water to pass through second filtration region ~2 of filter cartridge 44 to post-sterilization zone 3 I and finally out of the co~t~ihle. via exit portal 30.
Connector plug 42 and electrical outlet connector 56 may then be stored within enclosure 43 and con~iller 16 returned to cradle 22.
It is suggested that after continued operation, the unit may be cleaned by passin bleach 20 (one or two teaspoons) therethrough. Such a cleaning is not, however, required after each use.
The uv lamps which may be used in accordance with the present invention generally have a lifespan of ap~ le]y 5000 to 7000 running hours. It is reco.. e1-~ed that the uv lamp be replaced accordingly. The design of the unit described herein allows simple and 25 convenient removal of the uv lamp from socket 40.
In a preferred form, housing 12, colllahlel 16 and filter cartridge 44 may be made of any suitable polymer based material such as plastic. It is not essential that the housing be rigid i.e. it may be made of a soft, yet padded materialnot unlike a cameracase.
The housing and containermay be of any reasonably portable size and dimension. ln a 30 preferred form, the reservoir in the contai-lel holds approximately 13 oz of water.

SUBSTtTUTE SHEET (RULE 26)

Claims

WE CLAIM:

1. A portable water purifier which comprises a housing, said housing including a removable container and a power supply, saidcontainer comprising an upper chamber having a water entry portal, a water exit portal and a replaceable filter cartridge, and a lower chamber comprising a uv source and an enclosure for electrical components, said filter cartridge, when in place, selectively partitioning the upper chamber from the lower chamber and in the upper chamber, separating a pre-sterilization area adjacent the entry portal from a post-sterilization area adjacent the exit portal, whereby, in operation, water is passable through the entry portal into the pre-sterilization area, through a first part of the filter cartridge to the lower chamber where the water is exposed to uv radiation for a pre-determined length of time, and as the container is disposed in the pouring position, the water is passable through a second part of the filter cartridge to the post-sterilization area and through the exit portal.

2. The purifier of claim 1 wherein the upper chamber is a removable lid of the container.

3. The purifier of claim 1 wherein the first part of the filter cartridge comprises a sediment screen.

4. The purifier of claim 1 wherein the second part of the filter cartridge comprises granular activated charcoal.

5. The purifier of claim 1 wherein the second part of the filter cartridge comprises a resin.

6. The purifier of claim 1 wherein the second part of the filter cartridge comprises activated carbon.

7. The purifier of claim 1 wherein the second part of the filter cartridge comprises any combination of granular activated charcoal, resin and activated carbon.

8. The purifier of claim 1 wherein the power supply comprises a battery.

9. The purifier of claim 1 wherein the power supply comprises at least one battery operatively connected to a battery charging array.

10. The purifier of claim 1 further including a timer means for intermittently operating said uv source for pre-determined time periods.
.

11. The purifier of claim 1 further including a timer means for intermittently operating said uv source for pre-determined time periods and an alarm means operatively connected to said timer means for indicating the end of the pre-determined time periods.

12. The purifier of claim 1 wherein the power supply comprises a battery and thehousing includes a signal means to indicate the level of performance of the battery.

13 . The purifier of claim 1 wherein the power supply comprises a battery and the housing includes a signal means which comprises a plurality of coloured light emitting diodes, said signal means indicating the level of performance of the battery.

14. A filter cartridge for use in a portable water purifier comprises a base platform on which is disposed a first filter, a second filter and a water-impermeable partition to separate the first filter from the second filter.

15. The filter cartridge of claim 14 wherein the first filter comprises a sediment screen.

16. The filter cartridge of claim 14 wherein the second filter comprises granular activated charcoal.

17. The filter cartridge of claim 14 wherein the second filter comprises resin.

18. The filter cartridge of claim 14 wherein the second filter cartridge comprises activated carbon.

19. The filter cartridge of claim 14 wherein the second filter cartridge comprises any combination of granular activated charcoal, resin and activated carbon.