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(11) Patent Number: KE 34
(45) Date of grant:06/05/1997
(51) Int.CL4:B 0 1D 35/24
(21) Application Number:1995/000163
(22) Filing Date:05/06/1995
(54) Title: MODULAR WATER PURIFICATION SYSTEM
(73) Owner:AQUARIUS WATERPURJFICATION SYSTEM of, P.O. BOX
74895 NAIROBI KENY A, Kenya
(72) Inventor: SIMONLUDEKI
(57)Abstract: A water purification apparatus (10) for household use in treating municipa1ly supplied water for removal of so1id and chemicalcontainers in which serially connected first (16) second(18) and third(20) water purifications stage units are contained inacompact cabinet
WATER PURIFICATION APPARATUS
BACKGROUND OF TBE INVENTION
This invention relates to water purification and,more particularly, it concerns apparatus for removing chemicals , solids and other contaminates from municipallytreated water to provide purified water having thecharacteristics of high quality "bottled water" , asneeded, from a conventional pressurized municipal watersupply.
The need for improving the quality of watersupplied to households by municipal ties is well knownand made evident by dramatic recently increased demandfor bottled water and/or a variety of commerciallyavailable purification devices designed for attachmentto househo1d water taps, a11 for the purpose of obtainingpalatable drinking water. Although commercially available bottled water represents an acceptablealternative to tap water supplied from municipa1 treatment centers from the standpoint of avoiding the objectionable and possibly harmful effects of drinking or otherwise consuming the municipa11y supplied tap water, it obviously is not only very expensive, but space consuming and otherwise cumbersome in its use.
These characteristics of bottled water have made it competitive with a wide variety of soft drinks not commonly substituted for drinking water needs.
Contaminants in municipal1y supp1ied tap water which detract from its desirability ty and possibly its fitness for consumption by people include a combination of particulate solid materials such as sand, chips of various metal ox1des and the like and of chemicals, principally chlorine or other chemicals used in the municipal purification process but including as wellsuch chemicals as lead, mercury, iron and nitratesusual1y associated with I1hard" water. The removal of the solid contaminates, initself, can be effected by filtration without excess1ve difficulty. Whi1e filter clogg1ng will result ult1mately, its presence is readily discernible as a result of reduced water flow of pressure at the outlet of the f i1ter and thus cleaning or changing of the solids contaminate remov1ng filter un1ts 1s a possibility. Chemical contaminates in tap water may be removed by passing the water through a bed of granular activated carbon. Additionally, it is known that when granular active carbon is impregnated with a small percentage of metallic silver, the growth of bacteria in the activated carbon may be inhibited for as long as the activated carbon is effective to adsorb or absorb the chemical contaminates on the other hand, the granules of activated carbon can in themselves contribute to the solid contaminates in the water unless care is taken to restrict passage of carbon particles to the water to be consumed.
Commercially available filtering or other water purification appliances designed for easy installation to a mun1cipally supplied water tap, though quite popular, fall short of an adequate solution to purification of tap water e1ther as a result of 1nabi1ity to remove all contaminates from the water or as a result of diminishing in effectiveness after a relatively short period of use; U.S. Patents No. 3,184,064 ~ Sampson et al and No. . 4,540,489 - Barnard exemplify such appliances in the sense that they disclose compact assemblies of multiple filter stages in which one stage includes activated carbon to remove chemical contaminants from municipal water. The other filter stages remove varying sizes of particulate solid contaminants. While the disclosures of these patents as well as other similar appliances available commercially are believed to be effective for their intended purpose, both disclosures rely on access to the filter stage components for cleaning or reconditioning rather than on design criteria intended to supply purified water for extended periods of time, such as several years, without need for servicing or maintenance. The need for regular servicing detracts not only from the use of such appliances but a1so results ultimately in use under conditions where the appliance is no longer effective to provide water of the same quality and under the same flow rates which occurred when it was initially placed in service. There is a need, therefore, for a household water purification appliance, which like the aforementioned patent disclosures, 18 compact and easily installed but
whi.ch i8 capable of providing for human consumption, the equivalent of high quality bottled water and which is effective to that end for several years of operation without maintenance.
SUMMARY OF THE INVENTION
In accordance with the present invention, a compact cabinet enclosed water purification unit which is capable of positioning on a conventional kitchen countertop, is provided with separately contained serially connected first, second and third water purification stages of a construction to optimize respective pre-filtering, chemical adsorption and/or absorption and final filtering functions during effective operation in a household water system for periods as long as five years without maintenance. The construction is based in part on restrictive flow through the first and third stages to develop highly turbulent flow of water during the filtering operations provided by these stages as well as to effect a self-cleaning or scrubbing of these filter stages during use. The second stage is characterized as a bed of loosely contained granular activated carbon containing a small percentage of silver to inhib1t growth of bacteria in the activated carbon bed. Loose containment of the granular carbon coupled with a reduction in the flow rate of water through the bed 1nsures complete removal of chemical contaminants and maximizes the life of the bed.
In a preferred embodiment, each of the purification stages is in the form of a sealed vertically oriented cylindrical enclosure, the three enclosures, being connected in a manner so that water flow is vertical and upward through each stage. The cylindrical containers of the first and third filter stages are small relative to the container of the central silver impregnated granular activated carbon or bacteriostatic filter stage and both the first and third stages have restricted inlet and outlet to insure a high velocity turbulent flow of water there through. Each of the first and third stages, moreover, contains an adequate number of multifaceted silicon beads, preferably four or five, which act as scrubbers for fi1ter screens at opposite ends of the first and third filter stages. The second or granular activated carbon stage, as indicated, is loose1y packed to assure movement of the individual carbon granu1es during water flow through this stage and is additiona11y provided with fi1ter screen means at opposite ends to ensure containment of the granular activated carbon within the enclosures of the second stage.
A principal object of the present invention is, therefore, the provision of a compact water purification apparatus for use in households to convert municipally supplied water to water having the characteristics of high qua1ity bottled water and to provide such a purification apparatus which may be placed in service and used in a convent1on household to supply such purified water for periods of time as long as 5 years without servicing. Other objects and further scope of applicability of the present invention Wil1 become apparent from the detai1ed dlsc10sure to fol1ow taken in conjunction w1th the accompanying drawings in which like parts are designated by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a fragmentary perspective view il1ustrating the installation of the water purification apparatus of the present invention;
Fig 2 isan enlarged cross section taken general1y on 1ine 2-2 of Fig. 1;
Fig. 3 is a rear e1evation of the cabinet i11ustrated in Fig5. 1 and 2 with the back panel removed;
Fig. 4 i5 a composite schematic view il1ustrating the cross sectional structure of each of the purification stages.
Fig. 5 is an exploded perspective view i1lustrating', on an enlarged scale, end components of the first and third fi1ter stages;
Fig. 6 is a simi1ar exploded perspective view illustrating components incorporated in the second
Purification stage and
Fig﹒7 is a side elevation illustrating in general the configuration of scrubbers used in the first and third filter stages.
DETAILED DESCRIPTI0N OF THE PREFERRED EMBODIMENT
In Figs. 1-3, a preferred embodiment of the water purification apparatus of the present invention is generally designated by the reference numera1 10 and shown to inc1ude an exterior cabinet1ike enclosure having a back panel 14 for containing first , second andthird stage water purification units 16 , 18 and 20,respective1y. 1n the i11ustrated embodiment, the cabinet 12 is intended to be mounted on the top of a conventiona1 kitchen sink counter 22 adjacent to or otherwise in the region of a faucet or tap 24 to whichmunicipa1 water is supp1ied through a plumbing 1ine 26.
The exterior dimensions of the cabinet are approximately12 inches in width, 9 inches in depth and 14 inches in height to accommodate the i11ustrated countertop installation. A unit in1et conduit 28 may be coup1edwith the municipal water supply 1ine 26 using a conventiona1
sadd1e va1ve assemb1y 30 for the discharge ofpurified water, on demand, through a tap 32 connected to an out1et conduit 34 of the apparatus 10. 1t iscontemplated, however, and w111 be apparent form the description of the functioning components of theapparatus 10 that other types of installation might beemp10yed. For examp1e, the cabinet 10 cou1d be simp1ified and reduced somewhat in size for storage in thespace beneath the counter 22 with the out1et conduit 34connected to a faucet or tap mounted adjacent to thefaucet 24.
The physical construction of the cabinet 12 may be a:-preciated particu1arly from Figs. 2 and 3 of the drawings in which the front, side, top and bottom wallsare defined by a unitary mo1ding of appropriate p1asti material such as p01yviny1 ch10ride (PVC) the front wall is formed with a rectangu1ar recess 36 having a rear wall portion 38 and being of a depth to accommodatethe tap 32. A1so, a drip tray 40 is positioned in thebottom wall of the recess 36 under the outlet tap 32 and may either be removable from the cabinet 12 for periodicemptying or may be equipped w1th a drain (not shown) asdesired. Stage unit mounting straps 42 are secure preferably by solvent welding to the rear surface of therecess rear wall 38 to facilitate mounting the units 16,
18 and 20 in place within the cab1net 12. Also, theside walls of the molded cabinet 12 may be formed withinterior bosses or ribs 44 for st1ffening and to facilitate removable securement of the back panel 14 byscrew bolts (not shown).
The structural design of 位1e cabinet 1 2 in theil1ustrated embodiment, though preferred, may vary fromthat shown and described without sacrifice of its intended purpose to retain and enclose the purificationstage .units 16 , 18 and 20 now to be described. Thefirst and third stage units 16 and 20 are of substantiallyident1cal construction except for filter sieve size employed in each and parts of the units 16 and 20 which are interchangeable are designated by the samereference numerals in Figs. 3-5 of the drawings.
As shown in Figs. 3 and 4, each of the units 16and 20 includes an outer sealed housing defined bycylindrical body 46 closed at opposite ends by inlet an outlet caps 48 and 50 respectively. Preferably, the cylindrical body portions 46 are formed of 2 inch ID PVC tubing of a length approximating 4 inches. The caps 48and 50 are formed of a similar material to facilitatesealing bysolvent welding in a manner well known in the handling of plastic plumbing fixtures. An aperture filter screen supporting PVC plate 52 is nested in andsecured by solvent welding at the bottom of each of the units 16 and 20 whereas a similar plate S4 is secured inthe top end of the body 46 in each of the units 16 and 20. As may be seen in Fig. 5, the apertured plates 52 and 54 are hat-shaped to define a peripheral flange 56engageab1e with the end of each of the tubu1ar bodies 46 and a cy1indrlca1 portion 58 of reduced diameter to fit snugly within the tubu1ar bod1es 46. Each of the p1ates52 and 54 is formed with a s1ng1e opening 60 approxlmately 3/8 inches in diameter to effect a restr1cted flow orifice at the in1et and out1et ends of each of thestage units 16 and 20. The p1ates 52 and 54 further support filter screens of varying sieve size to bedescribed.
The physica1 configuration of the filter screenssupported by the aperture p1ates 52 and 54 are essentially the same and are constituted by a f1brous network of po1ypropy1ene, approximate1y 1/8 inch in thickness and which are available commerc1ally from Fiber-Taxis, Inc. of New Jersey. Such 5creens may be secured bysol vent we1ding direct1y against the p1ates 52 and 54, it being important on1y that care be taken to avoid placement of solvent on the area of the screens which overlie the apertures 60. The screen 62 secured to theplate 52 at the inlet end of the first stage un1t 16 is of a sieve size to prevent passage of solid particles onthe order of 10 microns and larger. The screen 64 atthe outlet end of the first stage un1t 16 on the otherhand is des1gned to prevent passage of such particles which are larger than 5 microns in diameter. The fi1terscreens 66 and 68 1n the th1rd stage un1t 20 differ from those of the f1rst unit 16 on1y in that they are ofsmaller sieve size. Specifically, the screen 66 15 at the inlet of the third stage 20 is a 5 micron screen whereas the screen 68 at the out1et end of the third unit 20 is a 1 micron screen and thus will ensure that solid partic1es larger than 1 m1cron will not pass to the outlet conduit 34.
The restricted opening 60 in the def1ector p1ates 52 and 54 of both the f1rst and third stage units 16 and20 results 1n a highly turbulent flow of water withinthe bodies 46 of the units and result in aeration of thewater passing through the units 16 and 20 in addition,the turbulent flow of water through each of the units 16 and 20 beings about a motion of scrubbers conta1nedbetween the filter screens of each of these units. Inparticular, and on assembly of the units 1 6 and 20 a plurality, preferably 4 in number, of multifaceted silicon beads 70 , each approximately 1/4 inch indiameter, is placed in the body 46 before closure byone of the end plates 52 , 54. These beads are sold commerciallybyarts and crafts shops to hobbyists and are geodesic in exterior conformation to provide themultifaceted appearance illustrated in Fig. 7.
It has been found by experimentation that when the units 16 and 20,including the apertures 60 T aredimensioned as described, the use of four scrubber beads70 optimizes the intended scrubbing action. More than 5such beads tend to reduce flow rate through the units 16 and 20 whereas less than 3 scrubber beads 70 does not develop the desired filter clearing function.
The second purification stage unit 18 is abacteriostatic water treatment unit in which theprincipal water treatment medium is a column 72 ofgranular activated carbon impregnated with a small percentage, specifically 1.05%, of silver. The columnof granular activated carbon i5 contained in a sealedreceptacle having the physical characteristics of thefirst and third stages 16 and 20 but of a larger size for reasons which will become apparent form the description to follow. In particular that sealed housing ofthe unit 18 i5 formed by a cylindrical body 74 which, inpractice, is constituted by an 8-1/2 inch length of 3 inch ID PVC tubing. The ends of the body 74 are closed by inlet and outlet caps 76 and 78, respectively whichare formed of PVC to facilitate solvent welding about the ends of the tubular body 74. Deflector plates 80and 82 are sealed to the ends of the tubular body 74 with1n the respective 1nlet and outlet caps 76 and 78and each carry a 1/8 inch 5 m1cron filter pad 84. Whilethe deflector plates 80 and 82 are similar in configuration to the deflector plates 52 and 54 described withreference to the f1rst and third stages 16 and 20, theyare both of larger effective d1ameter and are formed with a plurality (3 in the illustrated embodiment) of openings 85 of a size and number to minimize obstruction to flow while at the same time providing adequatesupport for the filter units 84. The column of granular activated carbon 72 is separated from the deflectorplates 82 and 80 by reticulated or open celled polypropylenefoam pads 86 and 88. The pads 86 and 88 prevent passage of particles in excess of 100 microns and in theunit 18 serve primarily to contain the granular activatedcarbon particles in the column 72.
A feature of the granular activated carbon column 72 which 18 important to extending the effective life of the column for removal of chemical contaminants in the water under treatment is that the granular activatedcarbon particles are loosely contained between thereticulated foam pads 86 and 88. Th1s 19 achieved byloading the volume within the body 74 and between thepads 80 and 86 to approximately 90-95% with the granularactivated carbon particles. As a result, the carbonparticles or grains are agitated slightly during passage of water there through. In th1s way, the total effectivesurface area of the individual activated carbon grains in the column 72 is used during the life of the unit 18.The small percentage of silver 1n the granular activated carbon, as 1s know, serves to inhibit any bacterialgrowth with1n the bed. In this respect, the movement ofthe granules 1n the column augments the effectiveness of the silver.
As may be appreciated by reference to Figs. 3 and4 of the drawings, the stage units 16, 18 and 20 are serially interconnected by conduits 90 and 92 in amanner such that the flow of water through each of the three stages is upwardly and vertica1. This direction of flow through the units 16 and 20 ensures effectivemovement of the scrubber beads 70. Vertica1 flowthrough the granu1ar activated carbon column 72 ensuresmovement of the loosely packed carbon particles.
The dimensional proportions of the units 16 and 20 relative to the bacteriostatic second stage unit 18is also important to maximizing the effectiveness of thecarbon column 72. In other words, a relatively high velocity turbulent .flow through the first and thirdunits 15 effected by the restricted size of the openingsin the deflector plates 52 and 54 therein, whereas inthe second stage unit 18relatively slow flow ratesoccur to ensure full contact of the water under treatmentwith the particles of the carbon column 7:1.. The combination of preliminary experimentation and calculationsprincipally with respect to the 1ife of the granular activated carbon column 72 in the unit aprovide a design in the apparatus 10 capable of producing5 and 1/2 gallons of purified water a day for a period as 10ng as 5 years Five and 1/2 ga110ns a day ismore than adequate for water consumed in the averagehousehold each day and the quality of the water provided is equal to or the same as the highest qua1ity ofbottled water presently available commercially.
In light of the fore going it will be appreciatedthat as a result of the present invention, a highlyeffective water purification apparatus 1s provided and by which the stated objective, among others, are completely fulfilled. It is contemplated and will beapparent to those skilled in the art from the precedingdescription that modifications and/or changes may bemade in the embodiment 111ustrated and described withoutdeparture from the present invention. Accordingly, itexpressly intended that the foregoing description andaccompanying drawing illustrations are illustrativeonly, not limiting, and that the true spirit and scope of the present invention be determined by reference to the appended claims.
1. Apparatus for removing chemicals and particulate solid .materials from municipally treated water,said apparatus comprising: a cabinet enclosure having an inlet for connection to a pressurized supply of municipally treatedwater and an outlet for discharging purified drinkingwater to a controlled de1ivery tap on demand; a first purification stage unit in said cabinet for filtering relatively large solid partic1es from water passing from said inlet and for aerating such
water;a second purification stage unit is said cabinetfor removing chemicals from water passing said firststage unit; and a third purification stage unit in said cabinetfor removing re1atively small solid particles from waterpassing said second stage unit and further aerating such
water; each of said first and third stage units includingmeans to define a relatively large chamber andrestricted inlet and outlet openings spaced by saidchamber to maintain a highly turbulent flow throughoutsaid f1rst and third stage units upon discharge ofpurified water from said delivery tap.
2. The apparatus recited in claim 1, whereinsaid second purification stage unit includes a column ofgranular activated carbon.
3. The apparatus recited in claim 2, whereinsaid granulated active carbon includes silver to inhibit growth of bacteria in said column.
4. The apparatus recited in claim 3, wherein said silver comprises 1.05% by weight of the granular activated carbon.
5. The apparatus recited in claim 2, wherein said granular activated carbon is loosely contained insaid column thereby to allow movement of individual carbon grains during passage of water therethrough.
6. The apparatus recited in claim 1, whereineach of said first and third stage units comprise filterpads covering said restricted inlet and outlet openings.
7. The apparatus recited in claim 6, wherein thefilter pad at the inlet of said first stage unit has asieve size of 10 microns and wherein the filter pad atthe outlet of said first stage unit has a sieve size of microns.
8.The apparatus recited in claim 7, wherein thefilter pad at the inlet of said third stage unit has asieve size of 5 microns and wherein the filter pad atthe outlet of said third stage un1t has a sieve size of micron.
9. The apparatus recited in claim 6, includingscrubber means in each of said first and third stageunits for cleansing said filter pads of filteredparticles.
10. The apparatus recited in claim 9, wherein said scrubber means comprises a plurality of multifacetedsilicon beads in the relatively large chambersof said first and third stage units.
11. The apparatus recited in claim 10, whereinthe number of said silicon beads contained in each ofsaid first and third stage units ranges from between 3and 5.
12. The apparatus rec1ted in claim 11, whereinthe approximate diameter of said 6ilicon beads is ¼ inch. 13. The apparatus recited in claim 1, in whicheach of said units comprises a sealed enclosure definedin substantial part by a vertical oriented tubularportion.
14. The apparatus recited in claim 13, including conduit means for serially connect1ng said first, second and third stage units in a manner to ensure upward flow of water through each of said units.
15. The apparatus recited in claim 1, wherein said cabinet enclosure includes a recessed front portion, said delivery tap being mounted in said recessed front portion.
16. The apparatus recited in claim 15, wherein said cabinet enclosure is of rectangular configuration approximating 12 inches in width, 9 inches in depth and 14 inches in height.