Field of the Invention This invention relates to an apparatus and a method that can be used for purifying liquid, including tap water from national or municipal sources, to render it suitable for drinking.

Background

In many areas of the world, the drinking water distributed from national or municipal sources is unsafe absent further treatment . These impurities in the water typically include various microbes such as bacteria, protozoan cysts and viruses as well as other particulates. These microbes and particulates, if ingested, can cause serious discomfort, leading to illnesses or even death.

Even where the drinking water is normally safe for consumption, natural disasters, such as floods, earthquakes, hurricanes, and the like, may affect the national or municipal purification plant, resulting in impure drinking water. Also, waterborne microbes, may pass untreated through municipal purification systems. For example, in 1993 in Milwaukee, Wisconsin,

Cryptosporidiam, a protozoan cyst, entered the municipal water supply and passed untreated through the filtration system. This untreated impure water reached many Milwaukee residents, causing substantial discomfort and illness among them. Additionally, well and spring water may have various waterborne microbes which are not removed by the filtration systems therein.

To alleviate the hazards associated with impure drinking water, individuals have typically boiled the water prior to drinking it. On a larger scale, countries and municipalities have disinfected drinking water with bleach dosing systems, ozone generation systems and ultraviolet radiation systems. While those systems are effective, they have serious drawbacks.

Specifically, their set up and maintenance requires substantial amounts of capital, their continued reliability is questionable, and they use large amounts of electricity, which may not be readily available in certain areas of the world.

Iodinated resin systems have also been employed to disinfect drinking water. These systems involve iodide (I ₃ ) molecules in a resin bed, formed of beads of iodide (I ₃ ) molecules tightly bound to a base copolymer, ion exchange resin, usually a styrene/divinyl benzene (DVB) copolymer. Water passing through the resin bed becomes turbulent . The turbulence forces the microbes, such as bacteria, protozoan cysts and viruses, into substantial contact with the iodinated beads. As a result of these contacts, iodine is transferred to the microbes as molecular iodine (I ₂ ) , where it undergoes a redox reaction with the microbes, deactivating them.

The iodine is also is eluted into the water in minute amounts, typically about 0.5 parts per million (ppm) . The exact amount of residual iodine given off is a function of residence time, temperature, flow rate, as well as the level and type of ions in the input water. As a result, the water tastes medicinal. Additionally, the high iodine levels in the water pose serious health concerns in areas where diets are already high in iodine. For example, on the island of Hokkaido in Japan, the main staple is seafood, particularly kombu seaweed, which contains high levels of iodine.

SUMMARY OF THE INVENTION

The present invention provides an improved liquid purification system for water or other similar liquids having a liquid receiving structure which leads into a disinfecting unit. In the disinfecting unit, bacteria, viruses and other liquid borne contaminates contact disinfecting media and then enter a wait time chamber. This wait time chamber is designed for near

plug flow conditions, whereby a continuous liquid stream proceeds uniformly such that the first portion of liquid to enter the wait time chamber leads the liquid stream and does not short circuit or mix appreciably with liquid that has entered the chamber prior to or after it. Liquid flows continuously and uniformly through this wait time chamber and remains in this chamber for a minimum wait time such that bacteria, viruses and other contaminants in the liquid are deactivated. The liquid then moves into a treatment unit, where it contacts scavenger resins which remove molecular iodine and iodide ions from the liquid. Once through this treatment unit, the liquid is received by a second structure, and passed on for ultimate use. The present invention can be practiced in several aspects. In one aspect, the liquid purification system of the invention can be practiced in the form of a cartridge for use in in-line or countertop systems. In another aspect, the liquid purification system of the invention includes an integral purification unit within a portable carafe.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described with reference to the accompanying drawings, wherein like reference numerals identify corresponding or like components .

In the drawings :

FIG. 1 is a front view of a water purifier employing the cartridge of the present invention;

FIG. 2 is a side view of a water purifier of FIG. 1;

FIG. 3 is a cross sectional view of a first apparatus of the present invention taken along line 3-3; FIG. 4 is a cross sectional view of the present invention taken along line 4-4;

FIG. 5 is a cross sectional view of the present invention taken along line 5-5;

FIG. 6 is a cross-sectional view of a second apparatus of the present invention; FIG. 7 is a cross sectional view of the pour tray of the present invention taken along line 7-7 with the cup and purification unit removed.

FIG. 8 is a rear view of the pour tray of the present invention with the cup removed; and FIG. 9 is a cross sectional view of the present invention taken along line 9-9.

DETAILED DESCRIPTION OF THE DRAWINGS Turning now to FIGs. 1 and 2, there is shown an in-line water purifier 20 that employs the cartridge apparatus 30 of the present invention. This cartridge 30 attaches to a main body 22, which includes an inlet tube 24 and an outlet tube 26. The inlet tube 24 is connected to an end of life indicator unit 28 which passes water to the cartridge 30 and receives water therefrom upon purification. The purified water is carried from the end of life indicator unit 28 through the outlet tube 26 directly to the end user or back to the plumbing system and then the end user. The end of life indicator unit 28 described here is the subject of U.S. Patent Application Serial No. 08/207,380, filed March 8, 1994, entitled Water Treatment Device, which is incorporated herein by reference. While an end of life indicator unit 28 is preferably used, it may be bypassed altogether and the cartridge 30 mounted to a latch actuator or other unit which connects the inlet tube 24 and the outlet tube 26 ^" to the corresponding inlet port 68, and exit port 140 (FIG. 3) on the cartridge 30. FIG. 3 shows the cartridge 30 of the present invention. The cartridge 30 is formed by two cylinders 32, 34 connected by a crossover passageway 36, for

liquid flow between the cylinders 32, 34. The cross- sectional shape of the first and second cylinders 32, 34 is such that the overall cartridge 30 is somewhat "figure 8" shaped (FIGs. 4 and 5) . The cartridge 30 may include a mechanism 38 for providing additional attachment to the end of life indicator unit 28 or other equivalent device on the main body 22 of the in-line purifier 20.

The first cylinder 32 includes an inner cylinder 40, or disinfecting unit, which is defined by an annular wall 42. An annular chamber 46 is formed in the space between the annular wall 42 of the inner cylinder 40 and the inner wall 50 of the first cylinder 32. The inner cylinder 40 is maintained in place at its upper end by being integral with the first cylinder 32, and at its lower end by a molded screen 52.

The molded screen 52 is a unitary member which includes a central portion 54 bounded by a circumferential flange 56, the flange having a diameter slightly greater than the outer diameter of the inner cylinder 40, for frictional engagement and retention, and an outer ring portion 58, with a diameter approximately equal to that of the first cylinder 32, to abut the inner wall 50 in a sealing engagement. While a unitary or one piece molded screen is preferred, multiple piece screens may be used provided they meet the tolerances necessary for maintaining the inner cylinder 40 firmly within the first cylinder 32.

The first cylinder 32 is sealed by a cap 60 at its lower end. The cap 60 is configured to form a mating attachment with the first cylinder 32 at a circumferential beveled rim 62. The cap 60 is bonded to this beveled rim 62 by sonic or spin welding, forming a liquid tight seal. Other similar bonding methods such as adhesive bonding or frictional bonding, as well as other mating arrangements, such as threaded arrangements, may also be used, provided they form the

necessary liquid tight seal. The cap 60 forms the bottom wall 64 of the first cylinder 32. There is a cavity 66 between the molded screen 52 and the bottom wall 64 of the first cylinder 32, sufficient for accommodating liquid flow from the inner cylinder 40 to the annular chamber 46.

The inner cylinder 40 includes an inlet port 68, which serves as a conduit for liquid to enter a filter chamber 70. The filter chamber 70 includes a perforated core member 72 which runs the length of the filter chamber 70 and a pleated filter 74 (FIG. 4) which surrounds the core member 72 along its length. A plate 76, impervious to liquid, made of a material such as plastic or the like, is attached to the top of the core member 72. This plate 76 is configured such that there is cavity 78 between it and the top wall 80 and annular wall 42 of the inner cylinder 40, such that liquid enters the filter chamber 70 by flowing around the plate 76 and contacting the pleated filter 74 (FIG. 4) prior to moving to the core member 72. Bumps 81 on the top wall 80 of the inner cylinder 40 maintain the integrity of the cavity 78 and assist in distributing liquid around the plate 76.

The core member 72 terminates at a plate 82, having a central opening 84, which receives and attaches to the bottom of the core member 72. This plate 82 also supports and retains the pleated filter 74 (FIG. 4) within the filter chamber 70. The plate 82 is made of a material impervious to liquid, such as plastic or the like, and fictionally engages the annular wall 42 of the inner cylinder 40, forming a liquid tight seal. O-ring 86 provides additional sealing.

Immediately below the filter chamber 70 is a disinfectant resin chamber 88. The disinfectant resin chamber 88 includes a resin bed 90, the resin of which, upon contact with a microbe will undergo a redox reaction, forming an iodide ion (I ^" ) , which complexes

with the microbes, deactivating them. A foam diffuser 92 maintains the resin bed 90 at the upper end of the disinfectant resin chamber 88. The molded screen 52, which attaches to the inner cylinder 40 and the inner wall 50 of the first cylinder 32, supports the resin bed 90 at the bottom of the disinfectant resin chamber 88. The central portion 54 of the molded screen 52 has openings sized to allow liquid flow from the disinfectant resin chamber 88 while maintaining the beads in the resin bed, while the outer ring portion 58 of the molded screen 52 has openings, preferably larger than those of the central portion 54, these openings on the outer ring portion 58 are sized to allow liquid passage while maintaining a proper pressure differential so as to minimize turbulence, as explained below. The molded screen 52 includes a stiffening member 94, which extends into the cavity 66 and into contact with the bottom wall 64 of the first cylinder 32. This stiffening member 94 maintains the integrity of the cavity 66 to ensure continuous liquid flow to the annular chamber 46.

The disinfectant resin for the resin bed 90 is a Triiodide (I ₃ ) ion exchange resin, such as described in U.S. Patent 3,923,665 to Lambert and Fina. Other disinfectant resins such as Penta-Iodide (I ₅ ) , Bromide resins, and the like may also be used. The disinfectant resin is preferably in the form of beads, although other powder, granular, or sheet forms are also permissible. The second cylinder 34 includes a "D-shaped" channel 96 and a scavenger chamber 98, or treatment unit. Both the "D-shaped" channel 96 and the scavenger chamber 98, share a dividing wall 100 which is integral ^" with the second cylinder 34. The dividing wall 100 is retained in place and restrained from moving by a molded screen 102. The molded screen 102 is a unitary member having a first portion 103, bonded by a peripheral flange 104, adapted to the cross sectional shape of the

scavenger chamber 98 which fictionally engages the side walls 106 of the scavenger chamber 98 and a D-shaped portion 108, adopted to the cross sectional shape of the "D-shaped" channel 96, to abut the peripheral wall 110 of the "D-shaped" channel 96 in a sealing engagement. While a unitary or one-piece molded screen is preferred, multiple piece screens may be used provided they meet the tolerances necessary for maintaining the dividing wall 100 firmly within the second cylinder 34, and maintaining the sealing engagement in the "D-shaped" channel 96.

The second cylinder 34 is sealed by a cap 112 at its lower end. The cap 112 is configured to form a mating attachment with the second cylinder 34 at a circumferential beveled rim 114. The cap 112 is bonded to this beveled rim 114 by sonic or spin welding, forming a liquid tight seal. Other similar bonding methods such as adhesive bonding or frictional bonding, as well as other mating arrangements such as threaded arrangements, may also be used, provided they form the necessary liquid tight seal. The cap 112 forms the bottom wall 116 of the second cylinder 34. There is a cavity 118 between the molded screen 102 and the bottom wall 116 of the second cylinder 34, sufficient for accommodating liquid flow from the "D-shaped" channel 96 to the scavenger chamber 98. The molded screen 102 includes a stiffening member 120, which extends into the cavity 118 and into contact with the bottom wall 116 of the second cylinder 34. This stiffening member 120 maintains the integrity of the cavity 118 to ensure continuous liquid flow to the scavenger chamber 98.

Within the second cylinder 34, the "D-shaped' ^r channel 96 extends approximately the entire length of the second cylinder 34, from the crossover passageway 36 to the molded screen 102. The "D" shape is preferred, although other shapes such as circular or rectangular may also be used.

The volumes of the "D-shaped" channel 96 in the second cylinder 34, the crossover passageway 36 between the first and second cylinders 32, 34, and the annular chamber 46 in the first cylinder 32, collectively form the wait time chamber. The volume of the wait time chamber may be varied, but the minimum theoretical volume (V _TH ) is proportional by the fluid flow rate (f) and the wait time (t) , the time necessary to deactivate the microbes, in accordance with the equation:

V _TH = f x t

In practice, a small volume (v) , accounting for the minimal turbulence, must be added to the theoretical volume (V^) to yield the actual minimum volume (V-) for the wait time chamber. This actual minimum volume (V _A ) is expressed in accordance with the equation:

V _A = (f x t) + v

The scavenger chamber 98 receives liquid from the "D-shaped" channel 96. A foam screen 122 divides this scavenger chamber 98 into a lower section 124 and upper section 126. The lower section 124 includes an I ₂ scavenging resin bed 128, while the upper section 126 includes an I ^" scavenging resin bed 130.

The I ₂ scavenging resin bed 128, in this lower section 124, is confined between the molded screen 102, and the foam screen 122. The first portion of the molded screen 103 underneath the resin bed 128 has openings sized to allow liquid flow into the resin bed ^" 128 while maintaining the beads of I ₂ scavenger resin in the I ₂ scavenging resin bed 128. The "D-Shaped" portion of the screen 108 has openings, preferably larger than those of the first portion of the molded screen 103, these openings on the "D-shaped" portion of the screen

108 are sized to allow liquid passage while maintaining a proper pressure differential so as to minimize turbulence, as explained below. Within this lower section 124, tapered ribs 132, attached to the side walls 106 of the scavenger chamber 98, extend downward into abutment with the molded screen 102, retaining it in place by assisting in inhibiting its movement.

The I ₂ scavenger resin in the I ₂ scavenging resin bed 128 functions to remove iodine from the liquid passing through, and consists of activated carbon. The activated carbons may be either extruded block carbons or granular carbons of the coconut shell or bituminous type. Barnaby Sutcliffe 3036 coconut shell carbon 20 x 50 mesh is the preferred activated carbon, but other similar carbons may also be used.

The I ^" scavenging resin bed 130, in the upper section 126, includes an I ^" scavenger resin. The I ^" scavenging resin bed 130 in the upper section 126 is longer than the I ₂ scavenging resin bed 128 below it, since more resin is needed for ion exchange as the kinetics of I ^" for Cl ^" ion exchange are slower than for the adsorption of I ₂ on carbon in the I ₂ scavenging resin bed 128. The ion exchange resin is confined between a lower foam screen 122 and an upper foam screen 134. The foam screens 122, 134 allow liquid passage and are such that ion exchange resin of the I ^" scavenging resin bed 130 can not escape. The foam screens 122, 134 frictionally engage the scavenger chamber side walls 106. This ion exchange resin is a strong base gel resin such as polystyrene/divinyl benzene copolymer with quaternary ammonium functionality in the chloride form. Dow Marathon A, available from Dow Chemical, Midland, Michigan, is one such resin which may be used.

There is a cavity 136 between the upper foam screen 134 and the upper wall 138 of scavenger chamber 98. Exit port 140 provides a conduit for this purified liquid to leave the second cylinder 34 in order to reach

the user. Turning now to FIG. 4, there is shown the cartridge 30 of the invention with the filter chamber 70 having a pleated filter 74. Pleating the filter 74 maximizes surface area for removing various large liquid borne particulates. The filter 74 is porous, and preferably made of a sturdy paper or the like. The preferred filter is one capable of three log reduction for 99% removal of four-micron particles. Other filters which perform the equivalent particulate removal may also be used.

The first cylinder 32 also includes the annular chamber 46, while the second cylinder 34 includes the "D-shaped" channel 96 and I ^" scavenging resin bed 130. Tube 142 extends from the annular chamber 46 through the crossover passageway 36 (Fig. 3) to the "D-shaped" channel 96 to allow for liquid passage between the first and second cylinders 32, 34.

In FIG. 5, there is shown the lower portion of the cartridge 30 of the invention. The cartridge includes the first cylinder 32 having the annular chamber 46 and disinfecting resin bed 90 and the second cylinder with its "D-shaped" channel 96 and I ₂ scavenging resin bed 128 and ribs 132.

In operation, liquid such as water enters the first cylinder 32, through the inlet port 68 and onto a plate 76 in the filter chamber 70. Bumps 81 on the top wall 80 of the inner cylinder 40 assist in distributing the liquid. Once around the plate 76, the liquid passes through the pleated filter 74, where large particulates are removed. The liquid is received in the core member 72 and forced by gravity through the central opening 84 in the plate 82 and into contact with the foam diffuser 92. The foam diffuser 92 causes the liquid to travel substantially parallel through the resin bed 90 of the disinfectant resin chamber 88 and through the molded screen 52. This parallel flow insures that the microbes

in the liquid are exposed to the ions in the resin bed 90 for a maximum amount of time.

While in the disinfectant resin chamber 88, the liquid contacts the resin. The resin bed 90 is designed to maintain each portion of liquid for at least two seconds, in order for minimum contacts between the microbes in the liquid and the beads forming the disinfectant resin bed 90. Once a contact is made, the molecular iodine (I ₂ ) undergoes a redox reaction with the microbe. On the average, a microbe will collide with about thirty beads to transfer an amount of iodine sufficient to deactivate the microbe, which on the average is about 10 ⁵ iodine (I ₂ ) molecules for each microbe. Upon leaving the disinfectant resin chamber

88, the liquid flows into the cavity 66 between the disinfectant resin chamber 88 and the bottom wall 64 of the first cylinder 32. Additional liquid entering this cavity 66 forces the liquid radially outward, such that it moves through the outer ring portion 58 of the molded screen 52 and into the annular chamber 46, the first portion of the wait time chamber. The liquid travels upward in the annular chamber 46, where it enters a tube 142, and travels through the crossover passageway 36, the second portion of the wait time chamber, leaving the first cylinder 32.

In combination with the inner cylinder 40, the annular chamber 46, which forms a portion of the wait time chamber, is designed for near plug flow conditions. These conditions are achieved in the annular chamber 46 as it is configured to allow for liquid to flow continuously and uniformly through its volume without short circuiting or mixing appreciably with the liquid that has entered the annular chamber 46 prior to or after it.

This condition is achieved by minimizing turbulence in the annular chamber 46 and by minimizing

the head loss in the crossover passageway 36 at the top of the cartridge 30. Turbulence is minimized by small diameter openings (approximately 0.010 inches to 0.015 inches wide) in the molded screen 52. The openings in the molded screen 52 cause a significant pressure drop across the screen 52 in the cavity 66 between the disinfectant resin chamber 88 and the bottom wall 64 of the first cylinder 32. Once the liquid reaches the annular chamber 46, the pressure around the outside of the inner cylinder 40 is evenly distributed. The openings in the molded screen 52 central portion 54 are used not only to cut down the cross-sectional flow area, but also to introduce a larger orifice loss coefficient to make this pressure loss more significant without introducing too much jetting in the annular chamber 46.

The uniform flow up the annular chamber 46 is maintained by minimizing the turbulence, or Reynold's number (R) . The Reynold's number (R) is a measurement of the turbulence represented by the equation:

R = (D x s)/k where,

D is the effective diameter; s is the fluid (liquid) velocity; and k is the kinematic viscosity (a material parameter of the fluid under study - in this case water at room temperature) .

Since the Reynold's Number (R) is to be minimized for minimal turbulence, fluid velocity (s) should be minimized by using a narrow crossover passageway 36 which has a large enough flow area to maintain a relatively small area and therefore small velocity. Additionally, head loss in the crossover passageway 36 needs to be relatively small with respect to other friction factors in the annular chamber 46.

This is accomplished by having a annular chamber 46 with a cylindrical passageway of a large aspect ratio, or

length to diameter ratio, and a crossover passageway 36 with a fairly large area. These two factors contribute to uniform head loss across the circumferential flow area and therefore, there is minimal stagnant liquid in the section of the annular chamber 46 opposite the crossover passageway 36.

From the crossover passageway 36, the liquid enters the second cylinder 34 through the "D-shaped" channel 96, the third portion of the wait time chamber. This flow is over a predetermined wait time necessary for deactivating any microbes in the liquid. Once through the "D-shaped" channel 96, the liquid moves through the "D-shaped" portion 108 of the molded screen 102, and into the cavity 118 between the bottom wall 116 of the second cylinder 34 and the scavenger chamber 98. Similar to the annular chamber 46 in the first cylinder 32, this structural arrangement facilitates near plug flow conditions to minimize mixing.

The liquid now flows into the first section of the scavenger chamber 98, and into contact with the resin bed 128 of activated carbon. It is important that the liquid remain in the wait time chamber for the proper amount of time, such that the microbes are deactivated prior to entering the resin bed 128. The activated carbon of the resin bed 128 adsorbs about half of the iodine (I ₂ ) molecules in solution with the liquid, onto or into the carbon structure. The carbon also acts as a catalyst in reducing about half of the iodine (I ₂ ) molecules to iodides (I ^" ) . Once through the activated charbon resin bed

128, the liquid contacts the foam screen 122, which causes the liquid entering the I ^" scavenging resin bed 130 to flow parallel through it. This parallel flow insures that the microbes in the liquid are exposed to the ions in the resin bed 130 for a maximum amount of time. This second resin bed 130 of the scavenger chamber 98 includes a strong base gel ion exchange resin

with a high affinity for iodide (I ^" ) ion. The ion exchange resin replaces the iodide (I ^" ) ions with chloride ions (Cl ^" ) , eliminating iodine from the liquid as well as the medicinal taste. The purified liquid then exits the I" scavenging resin bed 130 by flowing around or through the foam screen 134 and into a cavity 136 between the foam screen 134 and the upper wall 138 of the scavenger chamber 98. The liquid moves through the exit port 140 to the main body 22, where it is now ready for use. Turning now to FIGs. 6-8, there is shown a second embodiment of the invention. This embodiment is a portable unit which can purify large amounts of tap water in relatively short periods of time. The portable unit is a carafe 200 having a pour tray 202, with an upper section 204 for holding liquid, and a lower section 206, including a cylindrical pocket 208 having an open base, and a cylinder member 210 for retaining a purification unit 212. The carafe 200 has a main body container 214 which serves to receive and store liquid once it has been purified in the purification unit 212 and stored until use is desired. The carafe 200 includes a spout 216 from which purified liquid leaves, and a handle 218 for assisting in pouring. The carafe 200 also includes a lid 220 which fits over the pour tray 202. The lid 220 includes an indented section 222 for a grill 224 (FIG. 9) into which tap water or other liquid is deposited.

The purification unit 212 is enclosed by a cup 226, which fits over the lower section 206 of the pour tray 202. The cup 226 has a circumferential "L-shaped" flange 228 with threaded portions 232 which attach to correspondingly threaded portions 233 of lip 234 of the pour tray 202. The threaded portions 233 on the lip 234 of the pour tray 202 are interrupted by an opening 236 at the side of the pour tray 202 on the rear or handle side of the carafe 200. While this threaded arrangement

is preferred, other frictional, mechanical or adhesive engagements are also permissible, provided that a liquid passage remains open for liquid to exit the cup 226 and enter into the main body container 214. Turning now to FIG. 9, the purification unit

212 is provided in detail. The upper section 204 of the pour tray 202 has a central opening 238 into which a disinfectant resin cartridge 240 is placed. The disinfectant cartridge 240 is retained in position in a cylindrical pocket 208, which together forms the disinfecting unit. The pocket 208 is integrally formed in the lower section of the pour tray 206. The pocket 208 includes two portions of decreasing diameter 242, 244 separated by a band 246 having a decreasing diameter, to provide a lead in to the smaller diameter portion 244 which provides a sealing surface 248 for an O-ring 250 which seals the outer diameter of the cartridge 240. An interrupted shoulder 254 on the cartridge 240, having a greater diameter than the pour tray opening 238, also assists in retaining the cartridge 240 in position within the pocket 208.

The cartridge 240 is a single unit. Screens 256, 258 at the upper and lower ends of the disinfectant resin cartridge 240 have openings sized to maintain the resin within the disinfectant resin bed 260, while allowing liquid to pass through. The disinfectant resin bed 260 is a Triiodide (I ₃ ) ion exchange resin, which has been described above. Once the resin bed 260 is depleted the cartridge 240 can be removed from the pocket 208 of the lower section 206 of the pour tray 202 by lifting the handle 262 attached thereto, and replaced with a new cartridge.

An insert member 264 surrounds the pocket 208, forming a liquid receiving chamber 266 on its inner side and a helical wait time chamber 268 on its outer side. The insert member 264 is preferably unitary, but may be formed from multiple pieces.

The inner side of the insert member 264 is designed with a circumferential wall 270, and is closed at its base 272. It surrounds the pocket 208 holding the disinfectant resin cartridge 240 to receive the liquid treated in the disinfectant resin cartridge 240. There is space 274 between the pocket 208 and the circumferential wall 270. This space 274 serves as a passageway for water as it is forced upward towards openings 276 in the circumferential wall 270 in the top of the insert member 264, which permits liquid to enter the wait time chamber 268.

The wait time chamber 268 includes a helical- shaped platform 278. The portions which form the platform 278 extend from the wall of the insert member 268 into abutment with the cylinder member 210 on the lower section 206 of the pour tray 202, forming a sealing engagement. As a result of this structure, the liquid travels downwardly in a helical path in the wait time chamber 268. The wait time chamber 268 described is similar to the first embodiment above. The helical platform 278 is designed for a specific volume, dependent upon the fluid (liquid) flow rate and the wait time necessary to deactivate the microbes. The helical design also simulates a near plug flow conditions in that the water first entering the helix cannot easily mix with the water further down the helix that entered a few seconds earlier. This flow pattern ensures that all water entering the purification unit 212 is uniformly treated. A scavenger cartridge 280 is positioned below the wait time chamber 268. The scavenger cartridge 280 functions to remove iodine from the purified liquids and includes a scavenging resin bed 282, held in place by screens 284. The screens 284 have openings sized to allow liquid passage while maintaining the resin bed 282. The scavenger resin for the scavenging resin bed 282 is a mixture of activated carbon for the removal of

molecular iodine (I ₂ ) and a strong base gel resin such as polystyrene/divinyl benzene copolymer with quaternary ammonium functionality in the chloride form, for iodide (I ^" ) removal. For example, the activated carbon in the mixture may be either extruded block carbons or granular carbons of the coconut shell or bituminous type. Barnaby Sutcliffe 3036 coconut shell carbon 20 x 50 mesh is the preferred activated carbon, but other similar carbons may also be used. The base gel (ion exchange) resin used may be Dow Marathon A, from Dow Chemical Co., Midland, Michigan.

This scavenger cartridge 280 is a single unit. It is fictionally held within the cylinder member 210 of the lower section 206 of the pour tray 202. This arrangement is collectively known as a treatment unit . Once the resin bed 282 is depleted, the cartridge 280 can be removed by accessing the it through cut-outs 286 on the lower portion of the cylinder member 210 and lifting a handle (not shown) attached thereto and replaced with a new cartridge. Alternately, the cartridge 280 can be removed as described above and the resin bed 282 refilled with resin by opening the cartridge 280 at the pinch tab 287.

The scavenger cartridge 280 terminates at a point slightly above the cup 226. Water treated in the cartridge 280 enters the space 288 between the cartridge 280 and the cup 226 and is forced upward in the space between the cylinder member 210 and the cup 226. This arrangement of the cup 226 and the cylinder member 210 maintains near plug flow conditions.

Referring also to FIG. 8, liquid passes from the cup 226 to the main body container 214, by moving through the opening 236, formed by interruptions in the threaded portion 233 of the pour tray lip 234, and spilling over the "L-shaped" flange 226 of the cup 226. The location of the opening 236 on the rear side of the pour tray 202 is preferred, for should a user seek to

pour water stored in the main body container 214 while purification is in progress, tipping the carafe 200 to pour liquid will not release any untreated water from the purification unit 212. In operation, tap water is poured through the grill 224 in the lid 220, filling the pour tray 202. The water then flows through the disinfectant cartridge 240, contacting the disinfectant (I ₃ ) resin bed 260. Once through the disinfectant cartridge 240, the water flows upward in the space 274 between the pocket 208 and the insert member 264. The water then enters the helical wait time chamber 268, where it flows within the chamber 268 by traveling downward along the helical shaped platform 278, for a predetermined time. The predetermined time is the time the water takes to travel through this helical wait time chamber 268, such that the organisms are deactivated before reaching the scavenger cartridge 280. This is important, for if the microbes are deactivated in the wait time chamber, less activated carbon in the scavenger cartridge 280 is used for it will only adsorb iodine, not microbes. This leads to longer life for the scavenging resin bed 282 in the scavenger cartridge 280. In this cartridge 280, water contacts the scavenging resin bed 282 where iodine is removed by adsorption. In addition to activated carbon, the scavenging bed 282 also contains a chloride form ion exchange resin that removes the iodide (I ^" ) ions.

After passing through the scavenging resin bed 282, the purified water collects in the cup 226 and moves upward in the cup 226 in the space between the cylinder member 210 of the lower section 206 of the pour tray 202 and the cup 226, to an opening 236 at the lip ^" 234 of the pour tray 202. Once reaching this opening 236, water spills over the cup 226 and into the main body container 214 of the carafe 200, where it is stored until use is desired. The entire carafe 200 can be placed in a refrigerator to cool the purified water.

While embodiments of the present invention have been described so as enable one skilled in the art to practice the techniques of the present invention, the preceding description is intended to be exemplary and should not be used to limit the scope of the invention, which should be determined by reference to the following claims.