Patent Application
20050178705
The present invention relates to the field of water treatment cartridges, and, more particularly, to the field of water treatment cartridges that comprise a shutoff for arresting the flow of water through the water treatment cartridge.
Water may contain many different kinds of contaminants including, for example, particulates, chemicals, and microbiological organisms, such as bacteria, viruses, and protozoa. In a variety of circumstances, these contaminants must be reduced in concentration or completely removed from the water before it is potable.
The quality of water varies widely around the world. In the U.S. and other developed countries, drinking water is typically municipally treated. During that treatment, contaminants, such as suspended solids, organic matter, heavy metals, chlorine, bacteria, viruses, and protozoa are removed from the water before it is discharged to the homes of consumers. However, equipment malfunction and/or infrastructure breakdown and other problems with water treatment utilities can lead to incomplete removal of the contaminants.
Many developing countries are without water treatment utilities. As such, there are deadly consequences associated with exposure to contaminated water, as many developing countries have increasing population densities, increasingly scarce water resources, and no water treatment utilities. It is common for sources of drinking water to be in close proximity to human and animal waste, such that microbiological contamination is a major health concern.
As a result of waterborne microbiological contamination, an estimated six million people die each year, half of which are children under 5 years of age. In 1987, the U.S. Environmental Protection Agency (herein “EPA”) introduced the “Guide Standard and Protocol for Testing Microbiological Water Purifiers”. This guide standard and protocol provides guidelines and performance requirements for drinking water treatment systems that are designed to reduce specific health related contaminants in public or private water supplies. The requirements are that the effluent from a water treatment system exhibits 99.99% (or equivalently, 4 log) removal of viruses, 99.9999% (or equivalently, 6 log) removal of bacteria, and 99.9% (or equivalently, 3 log) removal of protozoa (cysts) against a challenge.
The EPA guide standard and protocol, as well as other National Sanitation Foundation (herein “NSF”) testing standards for the removal of chemicals and particulates (e.g., chlorine, volatile organic compounds, trihalomethanes, turbidity, etc.), require that the water treatment cartridges are tested to their rated capacity (e.g., 100 gallons) or slightly above that (e.g., 120 gallons), depending on the presence of life indicators. It is typically expected that water treatment cartridge performance will decrease when a water treatment cartridge is used beyond its rated capacity, such that chemicals and microorganisms can pass through the water treatment cartridges into effluent water. In order to protect the users of these water treatment cartridges from harm, manufacturers of water treatment cartridges typically instruct the user to dispose of the water treatment cartridges after a predetermined period of time and/or capacity. However, based on common practices by consumers, it is expected that such instructions will be ignored or lost, resulting in use of the water treatment cartridge beyond its rated time and/or capacity. Thus, there is a need to provide water treatment cartridge users with water treatment cartridges that at least substantially arrest the flow of water therethrough after a predetermined amount of time to ensure the user's compliance, thus ensuring the user's safety and well-being.
Additionally, because the of the above mentioned health concerns associated with contaminated water, especially in developing countries, there is a desire to provide a water treatment cartridge that at least substantially arrests the flow of water therethrough after contaminated water breaches the intended flow path through the water treatment cartridge. That is, from the time that contaminated water first breaches the intended flow path through the water treatment cartridge, there is a desire to at least substantially arrest the flow of water therethrough after a relatively short predetermined amount of time.
A water treatment cartridge may comprise an inlet for receiving water into the water treatment cartridge, an outlet for egress of water from the water treatment cartridge, a water treatment material for treating the water, and a shutoff for at least substantially arresting the flow of water through the water treatment cartridge. The shutoff may comprise an engine. At least a portion of the engine may expand upon exposure to water, such that the shutoff at least substantially arrests the flow of water through the water treatment cartridge after a predetermined amount of time, as a direct or indirect result of expansion of the engine. The arrest of the flow of water through the water treatment cartridge may be irreversible.
As used herein, the phrase “highly water swellable material” refers to a material that has an equilibrium length change of at least about 5% in at least one direction upon saturation with DI water at 25° C. and normal atmospheric pressure. Examples of highly water swellable materials include, but are not limited to, water soluble polymers, cross-linked water soluble polymers, hydrogels, copolymers; clays (e.g. bentonite), and wood. Examples of water soluble polymers include, but are not limited to, polyethers (e.g. poly(ethylene oxide) and poly(ethylene glycol)), polyimines (e.g. poly(ethylene imine)), acrylic polymers (e.g. poly(acrylic acid) and its salts, poly(methacrylic acid) and its salts, and polyacrylamide), cellulosics (e.g. hydroxyalkyl cellulose, hydroxyalkyl alkyl cellulose, and carboxymethyl cellulose), vinyl polymers (poly(vinyl alcohol), poly(vinyl amine) and poly(vinyl pyrollidone)), natural gums and resins (xanthan gum and guar gum), and starches and modified starches. Examples of hydrogels include, but are not limited to, poly(hydroxy ethyl methacrylate), poly(ethylene glycol monomethacrylate), cross-linked poly(acrylic acid), potassium or sodium salts of cross-linked poly(acrylic acid), potassium salt of poly(acrylic acid-co-acrylamide), sodium salt of cross-linked poly(acrylic acid-graft-poly(ethylene oxide), poly(2-hydroxyethyl methacrylate), poly(2-hydroxypropyl methacrylate), sodium salt of cross-linked poly(isobutylene-co-maleic acid), etc.), and superabsorbers (e.g., cross-linked polyethylene oxide). Examples of copolymers include, but are not limited to, block copolymers (e.g. polyamide polyether block copolymers), random copolymers, and graft copolymers.
As used herein, the phrase “water swellable material” refers to a material that has an equilibrium length change of between about 0.5% and about 5% in at least one direction upon saturation with DI water at 25° C. and normal atmospheric pressure. Examples of water swellable materials include, but are not limited to, certain polyamides, polycaprolactam, nylon 6-6, and nylon 4-6.
As used herein, the phrase “non water swellable material” refers to a material that has an equilibrium length change of less than about 0.5% in any direction upon saturation with DI water at 25° C. and normal atmospheric pressure. Examples of non water swellable materials include, but are not limited to, polyolefins (e.g., polyethylene, and polypropylene), styrenics (e.g., polystyrene, acrylonitrile butadiene styrene—ABS), polyesters, and polycarbonate.
As used herein, the term “MV 1074” refers to the commercially available block copolymer of polylaurylactam and poly(ethyleneglycol) Pebax® MV 1074 from ATOFINA Chemicals, Inc., 2000 Market Street, Philadelphia, Pa., 19103-3222, USA.
As used herein, the term “MH 1657” refers to the commercially available block copolymer of polycaprolactam and poly(ethyleneglycol) Pebax® NMH 1657 from ATOFINA Chemicals, Inc., 2000 Market Street, Philadelphia, Pa., 19103-3222, USA.
As used herein, the term “MV 3000” refers to the commercially available block copolymer of polyamide and polyether Pebax® Mv 3000 from ATOFINA Chemicals, Inc., 2000 Market Street, Philadelphia, Pa., 19103-3222, USA.
As used herein, the phrase “highly water permeable material” refers to a material that has a moisture vapor transmission rate (herein, “MvTR”) greater than about 600 g·μm/m2·day at 90% relative humidity (herein, “RH”) and 38° C. Examples of highly water permeable materials include, but are not limited to, polyamides, block copolymers of polyamides and polyethers, cellulosics, polystyrene, polycarbonate, porous ceramics, porous metals, and porous polymers. Herein, the MVTR is measured per ASTM F 1249-90 standard.
As used herein, the phrase “water permeable material” refers to a material that has a MVTR between about 75 g·μm/m2·day and about 600 g·μm/m2·day at 90% RH and 38° C. Examples of water permeable materials include, but are not limited to, polyethylene, polypropylene, polar olefin copolymers such as ethylene-vinylacetate (herein, “EVA”), ethylene-acrylic acid (herein, “EAA”), ethylene-methacrylic acid (herein, “EMA”), ethylene-vinylalcohol (herein, “EVOH”).
As used herein, the phrase “water impermeable material” refers to a material that has a MVTR less than about 75 g·μm/m2·day at 90% RH and 38° C. Examples of water impermeable materials include, but are not limited to, polyvinylidene chloride (herein, “PVDC”), non-porous ceramics, non-porous metals, and metalized polymers.
As used herein, the phrase “growth” refers to the transient geometry change of a material as it absorbs water. If the material is constrained such that growth occurs in substantially one direction, then growth is quantified by the length measured in the direction of growth at various times. If the material is unconstrained such that growth can occur in all directions, then growth is quantified by the length measured along the direction of maximum initial length at various times.
As used herein, the phrase “equilibrium growth” refers to the final geometry of a material that has absorbed its equilibrium amount of water and is also quantified with a length similar to the “growth” definition.
As shown in
The housing 20 may be cylindrical, however, it may be various shapes and sizes. The housing may comprise a top portion 21 and a bottom potion 23. The housing 20 may be made from one or more of a variety of materials, including, but not limited to, one or a combination of plastics, metal and alloys thereof, fiberglass, etc. The housing 20 may form a well-defined compartment that holds the water treatment material 26. Alternatively, the housing may simply cap at least one of the end portions of the water treatment material 26 (not shown). Additionally, the portion of the housing 20 which forms the inlet 22 or outlet 24 may be supported by one or more ribs 32.
The inlet 22 may be a plurality of openings (defined by ribs 34) where the top portion of the housing 20 meets the main portion of the housing 20. The inlet 22 may be located at the first end of the water treatment cartridge 10 (see also
The outlet 24 may be a circular opening, concentric with the longitudinal axis of the water treatment cartridge 10. The inlet 22 and outlet 24 may be of varying size and oriented in any manner that best serves the application. Thus, the inlet 22 and outlet 24 can be oriented in the same proximity (e.g., sharing the same opening), in near proximity (e.g., sharing the same surface or end), or in distant proximities from one another (e.g., located at opposite ends).
The water treatment material 26 may be contained within the housing 20. The water treatment material 26 may have a core region 36. As used herein, “core region” means the hollow formed within the water treatment material 26. The core region 36 may be concentric with the longitudinal axis of the water treatment cartridge 10. The core region 36 may extend continuously from the first end, to the second end of the water treatment material 26, or may extend only partially into the water treatment material 26.
Examples of the water treatment material 26 are described in U.S. Pat. Nos. 2,167,225, 2,335,458, 4,172,796, 4,493,772, 4,764,274, 4,025,438, 4,094,779, 5,679,248, 6,274,041, 6,337,015, and U.S. patent application Ser. Nos. 10/464,209, 10/464,210, 09/935,810, 09/935,962, 09/628,632, 09/832,581, 09/832,580, 09/736,749, 09/574,456, 09/564,919, and 09/347,223. For example, the water treatment material 26 may include, but is not limited to, one or a combination of carbon (e.g., activated carbon, such as a tube of porous carbon, or a block of porous carbon, or carbon powder or particles sintered with a thermoplastic binder or the like), ion exchange material (e.g., in the form of resin beads, flat filtration membranes, fibrous filtration structures, etc.), zeolite particles, or modified zeolite particles (e.g., silver loaded), polyethylene, or charge-modified melt-blown or micro-fiber glass webs, alumina, metal oxides, diatomaceous earth, cationically-modified diatomaceous earth, cationically-modified activated carbon, etc.
The pre-treatment material 28 may be used for the purpose of keeping the water treatment material 26 from clogging, providing protection to the treatment material 26, trapping fines, etc. The pre-treatment material 28 may be in the form of a sheet, which may be pleated or unpleated and wrapped in one or more layers around the water treatment material 26. The pre-treatment material 28 may include, but is not limited to, one or a combination of porous membranes, non-woven fabric sheets, woven fabric sheets, open cell foamed sheets, carbon (consistent with the above-mentioned treatment material 26), untreated glass fiber papers, treated cellulosic or glass fiber papers, webs including nanofibers, cationically-charged porous membranes, webs including cationically-charged nanofibers, etc.
As shown in
The casing 40 may be tubular and fixed within the core region 36 via glue (or by friction fitting, welding, etc.). At least a portion of the core region 36 may be lined by the casing 40. The casing 40 may be made from, but not limited to, a combination of plastics, metal, ceramics and alloys thereof. The casing 40 may comprise one or a combination of highly water permeable, water permeable, or water impermeable materials. In the case where water impermeable materials are used, water may only enter the engine 42 from areas not covered by the casing 40. The casing 40 may be constructed such that substantial physical rigidity is obtained and engine 42 growth is constrained, in all but substantially one-direction, by the casing 40. As such, the casing 40 may be constructed of materials with inherent rigidity such as polypropylene, polycarbonate, metal, ceramics, etc. The casing 40 may be of thickness sufficient to constrain the engine 42 growth. In the case where water permeable materials are used in casing 40, the thickness of the casing 40 may prevent appreciable water from entering the engine 42 through the casing 40 and water may only enter the engine 42 from areas not covered by the casing 40. In such cases, the casing 40 is said to be substantially water impervious.
The casing 40 may have one or more flow ports 46 in its side portion such that water may flow from the water treatment material 26, through the flow port 46, then into the casing 40, then through the outlet 24 of the water treatment cartridge 10. The flow port 46 may be various sizes and/or shapes (including circular, rectangular, oval, etc.). Alternatively, the interior portion of the core region 36 may serve as the casing 40.
The engine 42 may be a solid slug of material of various shapes (e.g., cylindrical, round, elliptical, conical, etc.). Alternatively, the engine 42 may be a powder, pellets, etc. The engine 42 may also be hollow (e.g., a tube). The engine 42 may be partially encased (i.e., at least one side, face, or continuous surface of the engine 42 may be exposed to water which enters the casing 40) within the casing 40 such that only a portion of the engine 42 is exposed to water that enters the casing 40, and/or such that it may grow or swell in a substantially single direction.
While an engine 42 that is not encased (i.e., under unconstrained conditions) may grow to its final (or substantially final) length within hours, an engine that is partially encased (i.e., under constrained conditions) may not grow to its final (or substantially final) length for several months. The final length of the engine 42 grown under constrained conditions may be greater than the final length of the engine 42 grown under unconstrained conditions. Two factors may contribute to this extended growth period in the constrained conditions. First, the area exposed to water is relatively small compared to the total surface area of the engine 42, and second, the diffusion pathway of the water throughout the engine 42 is increased. Partial exposure of the engine 42 may be accomplished by tightly seating the engine 42 within the casing 40 (wherein the engine 42 is in the general shape of the casing 40), or by coating all but a portion of the engine 42 with a material that can be either a highly water permeable, water permeable, or water impermeable, depending upon the desired attributes.
The engine 42 may be made from a single water swellable material and/or a single highly water swellable material. Alternatively, the engine 42 may also be made from, but are not limited to, a water swellable material and/or a highly water swellable material in combination with other materials which may include, non water swellable materials, water impermeable materials, water permeable materials, and/or highly water permeable materials (e.g., engine 42,
The valve 44 may be a hollow tube slideably fitted within the casing 40 and in physical contact with the engine 42. The valve 44 may be physically connected to or may be separate from the engine 42. The valve 44 may fit within the casing 40 such that it is capable of blocking the flow of water through the flow port 46. Blocking the flow of water through the flow port 46 may be accomplished a number of ways, including, dimensioning the valve 44 to fit tightly within the casing 40, and/or by placing O-rings 48 around the valve 44 such that, at the time the flow is arrested, the O-rings 48 may be located at either side of the flow port 46 (see
One possible flow path will now be described (
The shutoff 30 may be set in motion after an initial use. A volume of at least about 1 mL may be needed to be in substantially constant contact with the engine 42 to start and maintain the motion of the shutoff 30 until the engine 42 blocks the flow port 46 with the valve 44, arresting the flow of water through the water treatment cartridge 10. After a period of time without exposure to water (after about 2 days, about 20 days, about 40 days, about 100 days, about 200 days, or about 300 days), or to less than 100% relative humidity air, the engine 42 may begin to shrink. However, in circumstances where the valve 44 has blocked off the flow port 46 and the valve 44 is not connected to the engine 42, the valve 44 may remain in place, blocking the flow port 46. Thus, if a user sets their water treatment cartridge 10 aside after the initial blocking of the flow port 46 and sufficient time/energy is supplied to evacuate the water in contact with the engine 42, the engine 42 may shrink and pull-back (herein, “drying out” or “dry out”), from the valve 44, leaving the flow port 46 blocked by the valve 44.
However, if “dry out” occurs before the flow port 46 is blocked by the valve 44, then the time required to block the flow port 46 could be increased by the “drying out” of the engine 42, which may shrink to a position below the valve 44. The engine 42 would then have to grow back to its original position before the valve 44 could be further advanced to block the flow port 46. This effect may be minimized by utilizing an engine 42 composed of a permanently deformable material (e.g., certain block copolymers of polyether and polyamide, such as block copolymers of polycaprolactam and poly(ethyleneglycol)) that irreversibly yields after a given deformation created by the swelling response to water. After a given amount of growth and due to the restriction of growth in one-direction, the engine 42 may effectively yield in the growth direction. Therefore, upon “drying out”, the engine 42 may shrink in all directions, and in particular, may shrink in diameter. When the user attempts to re-use the water treatment cartridge 10, the engine 42 will be wetted with water and growth will recommence. However, the growth rate may be significantly faster than the previous growth rate due to the increased surface area exposed as a result of the shrinkage in diameter of the engine 42. The engine 42 may rapidly return to its pre-“dry out” length such that the time required to block the flow port 46 will not be significantly delayed. In effect, the user would be unable to extend the lifetime of the water treatment cartridge 10 by “drying out” the water treatment cartridge 10 at any time.
The effects of “drying out” may also be minimized or eliminated by orienting a valve or diaphragm (not shown) in a manner that ensures intimate water contact with the engine 42. For instance, a one-way valve or diaphragm may be placed at the top of the casing 40 such that operating water pressure through the water treatment cartridge 10 may be able to move water through the one-way valve or diaphragm, but water remaining in the casing 40 when the water treatment cartridge 10 is disconnected from the water treatment device, or when the water treatment device is not being operated, is not able to move through the one-way valve or diaphragm. Thus, an amount of water will always remain in the casing 40 after initial charging of the water treatment cartridge 10, regardless of its orientation.
It may be desirable to consistently and predictably arrest water within a residential-scale water treatment cartridge 10 in order to assure user safety, and/or to comply with government standards. For instance, it may be desirable to arrest the flow of water through the water treatment cartridge 10 after a predetermined time, including, but not limited to, after about 20 days, after about 40 days, after about 60 days, after about 90 days, after about 200 days, after about 300 days, after about 365 days, after about 400 days, or after about 720 days from the time of initial use of the water treatment cartridge 10 (that is, after the time the water treatment cartridge 10 is first charged with water). However, several factors may impact engine 42 growth, and thus, overall consistency and predictability of arresting water flow through a water treatment cartridge 10, including, but not limited to, engine 42 and casing 40 composition and geometric configuration, water pH, water temperature, water pressure, and air bubbles at the interface between engine 42 and valve 44.
Engine 42 and casing 40 composition and geometric configuration may fundamentally determine engine 42 growth and movement of the valve 44. In general, engine 42 materials that cause substantial valve 44 movement tend to grow very rapidly compared to materials with less growth. In order to use the faster growing engine 42 materials, their kinetics may be controlled via geometry. In order to use water swellable, and especially highly water swellable, materials in this application, the geometry may be designed such that limited surface area is exposed to water and such that the diffusion pathway greatly increased. As shown in
In order for the time to substantially arrest the flow of water to be consistent, the growth of the engine 42 may be kept relatively independent of environmental factors experienced in consumer use areas. Environmental factors may include, but are not limited to, the supply water's pH, temperature, and pressure. The swelling response (volume change due to water absorption) may vary according to the engine 42 material selected and may be dependent on environmental factors. The transient water absorption characteristics may be influenced by the interplay of water solubility and water diffusivity. The initial water flux (rate of water entering the engine 42 per unit area normal to engine 42 surface area exposed) is approximately proportional to water permeability, which is the product of water solubility and water diffusivity. If environmental factors influence the swelling response, water solubility, and/or water diffusivity, then engine 42 growth and time to arrest may be altered. In addition, the engine must be free of significant water absorption and significant growth prior to installation into the filtration device such as in the manufacturing, shipping, and storage process. In other words, the engine must not have absorbed significant water from the ambient environment to have resulted in swelling sufficient to affect initial length and shut-off life.
Typical residential water pHs may vary between 4 and 10. Water pH variations in this range are expected to influence the swelling response, water solubility, and/or water diffusivity of the engine 42. Unexpectedly, it is observed that certain block copolymers of polyamide and polyether result in growth that is relatively independent of pH variations typically observed in residential applications (see, e.g.,
In typical residential applications, the temperature of the supply water may be highly variable. However, once water reaches the point of filtration, the temperature variation is less extreme and may be approximated by the temperature extremes observed in consumer homes. The typical home may have temperatures ranging from about 65 to about 90° F. Temperature variations in this range are expected to influence the swelling response, water solubility, and/or water diffusivity of the engine 42. With most materials, as temperature increases, water solubility and water diffusivity both increase. Because of this combination, it is expected that growth may be strongly influenced by even small temperature variations. Surprisingly, it is observed that certain block copolymers of polyamide and polyether result in growth that is relatively independent of small temperature variations (approximately 12° F. in this particular case) (see, e.g.,
As observed, certain block copolymers of polyamide and polyether have the unusual characteristic of water solubility decreasing with increasing temperature (see e.g.,
Typical residential water pressures may vary between about 2 psi and 120 psi. Increased pressure may increase the solubility of the water in the engine 42, thus affecting the kinetics of diffusion. The diffusivity and swelling response may also be altered due to the effect pressure has on material density. Certain block copolymers of polyamide and polyether may result in growth that is relatively independent of pressure variations in the range from zero to 55 psig (higher pressures not tested) (see, e.g.,
In typical manufacturing, shipping, and storage environments, the relative humidity of the ambient air can vary widely. The packaging of the shut-off 30 may be designed to limit the exposure to the extremes of humidity. Regardless, the sensitivity of the engine 42 material to humidity may influence the shut-off 30 lifetime. Unexpectedly, it is observed that certain block copolymers of polyamide and polyether do not absorb significant quantities of water or swell significantly when exposed to environments with considerably less than 100% relative humidity (or direct contact with liquid water). For instance, at a temperature of about 73° F. and a relative humidity of about 50%, a constrained MH 1657 slug (¼″ diameter by 1″ long inside a rigid polypropylene casing 40 similar to the description of
Air bubbles at the engine 42/valve 44 interface can create problems with repeatability of growth. If air bubbles exist, then the growth may be greatly slowed due to slow diffusion/convection of the water through the gas phase. If air bubbles do not exist, then the growth rate may be much greater. Therefore, the consistent release or non-release of the air bubble may be important for predictable growth and consistent arrest of water through the water treatment cartridge 10.
If it is desired to consistently release the bubble, then several mechanisms can be included for consistent release. As shown in
In place of using an engine 42 and valve 44 combination, wherein blocking of the flow port 46 is an indirect result of engine 42 growth (e.g., wherein the engine 42 advances the valve 44 into a flow port 46 or outlet 24 blocking position, thus indirectly blocking the flow port 46 or outlet 24), the engine 42 may serve as the valve 44 also, wherein blocking the flow port 46 or sealing of the outlet 24 is a direct result of engine 42 growth (that is, wherein the flow port 46 or outlet 24 is directly physically blocked by the engine 42). This may be achieved by using an engine 42 that is in the shape of a cylinder, such that water entering through the water treatment material 26, contacts the engine 42, and the engine 42 expands and seals the flow port 46. This approach may not prevent the user from extending water treatment cartridge 10 lifetime by “drying-out” the engine 42. However, drying-out may be minimized by creating an environment where the complete removal of water in contact with the engine 42 requires considerable effort, and is thus not practical.
Flow through the water treatment cartridge 10 may be arrested as a result of blocking the outlet 24 instead of blocking one or more flow ports 46. For instance, the outlet 24 may be directly blocked by the engine 42. Alternatively, the valve 44 may be used to block the outlet 24 in the same manner that the valve 44 may be used to block the flow port 46 (explained above).
Alternatively, as shown in FIGS. 13-A and 13-B, a valve 144 may be used that is advanced to a position of blocking the outlet 24 in part by the engine 42 and in part by the flow of water through the casing 40. The valve 144 may comprise a ledge 148. The valve 144 be in physical contact with the engine 42. As the engine 42 grows, the valve 144 may advance. When the valve is advanced to the flow port 46 such that the ledge 148 is in the main stream that flows through the casing 40, the valve 144 may be advanced by the water pressure building behind the ledge 148, such that the valve 144 is advanced to a position of blocking the outlet 24. Thus, while the valve 144 may be first advanced by the engine 42, it may ultimately be advanced to an outlet 24 blocking position by the water which flows through the casing 40, resulting in a nearly instantaneous arrest of water through the water treatment cartridge 10. It would be the interference frictional fit and/or water pressure that maintains the valve 144 in an outlet 24 blocking position.
It may be desirable to consistently and predictably arrest the flow of water within a residential-scale water treatment cartridge 10 a short time period after a breach of the intended flow path of water through the water treatment cartridge 10 and/or a water treatment device has occurred. For instance, it may be desirable to at least substantially arrest the flow of water through the water treatment cartridge 10 after a predetermined time, including, but not limited to, after about 1 minute, after about 5 minutes, after about 10 minutes, after about 30 minutes, after about 1 hour, after about 2 hours, after about 10 hours, after about 12 hours, after about 1 day, after about 2 days, after about 3 days, after about 4 days, after about 5 days, after about 7 days, after about 10 days, after about 12 days, or after about 15 days from the time of an initial breach of the intended flow path through and/or around the water treatment cartridge 10.
As shown in FIGS. 14-A, 14-B, and 15, a water treatment cartridge 10 may interface with a water treatment device (shown in part) such that a first tube 60 and a second tube 62 of the water treatment cartridge 10 may sealingly interface with a first housing 70 and a second housing 72 of the water treatment device (see, e.g., U.S. patent application Ser. No. 10/665,948). The first and second housings 70 and 72 may have O-rings 73 and 75, respectively, around them. The intended flow path (see
The first tube 60 and the second tube 62 sealingly interfacing with the first housing 70 and the second housing 72 may act as a double barrier around the outlet 24, such that any contaminated water that gets past the sealing engagement of the second tube 62 and the second housing 72 will be blocked by the sealing engagement of the first tube 60 and the first housing 70. However, once the first breach occurs, it may be desirable to promptly, or within a reasonable time, arrest the flow of water through the water treatment cartridge 10 before contaminated water has a chance to also breach the interface between first tube 60 and the first housing 70.
As shown in FIGS. 14-A and 14-B, a second shutoff 130 (housed within the top portion 121 of the housing 120) may be used to at least substantially arrest the flow of water through the water treatment cartridge 10 after a substantially short predetermined amount of time period after a breach of the intended flow path through the water treatment cartridge 10 has occurred. In this case, the breach may be about 0.1 mL, about 0.2 mL, about 0.3 mL, about 0.4 mL, about 0.5 mL, about 0.6 mL, about 0.7 mL, about 0.8 mL, about 0.9 mL, about 1 mL, about 1.5 mL, about 2 mL, about 2.5 mL, about 3 mL, or about 5 mL of water leaking past the sealing engagement of the second tube 62 and the second housing 72 or through the sealing engagement of the first tube 60 and first housing 70. The second shutoff 130 may comprise a second engine 342 comprising a highly water swellable material, and a second valve 244. For example, once a breach of contaminated water occurs through the second tube 62 and the second housing 72, the second engine 342 may expand or swell upon contact with the water (via the flow port 246), such that a second valve 244 may be pushed into a position such that the outlet 24 is blocked. Thus, when the intended flow path occurs, the shutoff 30 may function to at least substantially arrest the flow of water through the water treatment cartridge 10, however, when a breach occurs, the second shutoff 130 may function to at least substantially arrest the flow of water through the water treatment cartridge 10.
As shown in
It is foreseeable that other embodiments may be used which utilize the concept of at least substantially arresting the flow of water through the water treatment cartridge 10 after a first predetermined amount of time when an intended flow path of water through the water treatment device or cartridge 10 occurs, and at least substantially arresting the flow of water through the water treatment cartridge 10 after a second predetermined amount of time when an unintended flow path (i.e., a breach) of water through the water treatment device or cartridge 10 occurs. The first predetermined amount of time may correlate to the limitations of the water treatment material 26, whereas the second predetermined amount of time may correlate to the integrity of the water treatment device and/or cartridge 10, or the integrity of the sealing interface therebetween.
Beyond arresting the flow of water through the water treatment cartridge 10, the engine 42 or the valve 44 may be used to actuate a button, move an arm, complete a circuit, etc. for communicating to the user of the water treatment cartridge the approximate life status of the water treatment cartridge 10 (not shown). Alternatively, the engine 42 or the valve 44 may be made visible for communicating to the user of the water treatment cartridge the approximate life status of the water treatment cartridge 10 (not shown). The engine 42 or valve 44 may be made visible through a clear window in the casing 40, and/or a clear window in the water treatment device in which the water treatment cartridge 10 is being used.
The engine 42 and/or valve 44 may be used solely for the purpose of, or the means for, indicating the approximate life status of a water treatment cartridge 10, wherein the engine 42 and/or valve 44 is not used for arresting the flow of water through the water treatment cartridge 10. In this regard, the engine 42 and/or valve 44 may be used for the purpose of being a “wet indicator” or “wet timer”.
As used herein, water absorption is measured gravitmetrically using a standard analytical balance with 4 decimal place accuracy. Free surface water (water not absorbed inside the material to be measured) is removed using a paper towel. The initial mass (defined as the first mass displayed by the balance once the material inertia had nullified) is recorded to assure water did not have sufficient time to diffuse to the surface and evaporate. It is assumed that the initial mass of the material is constant with time and mass change is only due to water ingress. This method neglects the small amount of water soluble materials present in the starting material that would have left and altered the starting material mass and overall moisture fraction calculation. % Weight Change is calculated as 100×{(Mass of sample at present time−Mass of sample at time zero)/(Mass of sample at time zero)}.
As used herein, the length change in the direction of interest of a material with respect to time is measured using a calibrated Omis II optical profilometer device manufactured by Ram Optical Instrumentation, 1791 Deere Ave., Irvine, Calif., 92606. Growth of unconstrained materials is measured by selecting two material points on the ends in the direction of interest on the uppermost surface and monitoring their separation distance with time. For constrained materials, the length change in the axial direction is measured with the aide of a tube of consistent length. The tube is inserted into the open end of the constraining material until it contacts the upper surface of either the engine or the valve. Material points are selected; one on the uppermost surface of the constraining material and one on the uppermost surface of the tubing endpoint. The separation distance between the two material points is measured at various times. The initial length of the engine is determined prior to installation into the constraining material using the method described above. For unconstrained materials, % Length Change is calculated as 100×{(Distance between material points at present time−Distance between material points at time zero)/(Distance between material points at time zero)}. For constrained materials, % Length Change is calculated as 100×{(Distance between material points at present time−Distance between material points at time zero)/(Initial material length)}. For constrained materials, Growth is calculated as (Distance between material points at present time−Distance between material points at time zero).
Examples of the invention are described below. These Examples are solely for illustration and the invention(s) described herein is/are not meant to be restricted by these Examples.
A casing made from polypropylene, having an inner diameter and outer diameter of about ¼″ and ⅜″, respectively, is fitted into a radial flow carbon block (for treating water) having an outer diameter of 2″ and an inner diameter of ⅝″, respectively, (which makes up the core region). The carbon block is capped on both ends. The carbon block has a length of about 3″. The casing extends from the top of the carbon block to approximately 3/4″ from the bottom of the carbon block. The casing has a circular flow port of about 1/16″ in diameter near its end portion adjacent to an outlet. About a 1 g engine made of MH 1657, in the form of a solid cylindrical slug having an outer diameter of about ¼″, is friction fitted into the bottom portion of the casing. The length of the MH 1657 engine is about ⅞″. A valve made from high density polyethylene (HDPE) and in the form of a tube having an inner diameter and an outer diameter of about ⅛″ and about ¼″, respectively, is slideably fitted into the casing, resting upon the engine, and approximately 25/64″ below the flow port. The valve has a length of approximately 13/32″. Two NSF61 O-rings made of nitrile rubber (from Hydr-O-Seal, 20382 Herman Circle, Lake Forest, Calif., 92630) and lubricated (with Dow Corning® #976V High Vacuum Grease, a silicone based lubricant), are positioned on the valve and separated by a distance of approximately 9/32″.
During the initial filling and wet-out of the carbon block, water fills the water treatment cartridge from bottom to top. Water radially flows through the carbon block. Water first enters an air evacuation hole located at the MH 1657 engine/valve interface. The rising action of the water completely evacuates the assembly of air, which establishes intimate water contact with the MH 1657 engine. After a period of a few days, the MH 1657 engine grows sufficiently to cover the air evacuation hole, which allows water to enter only through the flow port. The water passes through and out of the casing and exits via the outlet. The engine continues to grow and move the valve until the valve blocks the flow port, thus preventing the passage of additional water into the casing. The shutoff is designed such that the flow of water through the water treatment cartridge is at least substantially arrested after the engine grows, and the valve is advanced about 25/64″, which is after about 60 days (see
Examples 2-1,2-2, and 2-3 are consistent with Example 1, except as noted in Table 1.
Additionally, instructions or information that will communicate to the user, by words and/or by pictures, that use of a water treatment cartridge 10 comprising a shutoff 30 may provide benefits which includes arresting the flow of water through the water treatment cartridge 10 after a predetermined amount of time, and/or indicating the life status of the water treatment cartridge 10. Further, this information may include the claim of superiority over other water treatment cartridges. Accordingly, the use of packages in association with information may be used to communicate to the consumer, by words and or by pictures, that use of the invention will help to ensure integrity of the performance of the water treatment cartridge 10. The information may include advertising in all of the usual media, as well as statements and/or icons on the water treatment cartridge 10 package, or the water treatment cartridge 10 itself, for the purpose of informing the consumer.
All documents cited herein are incorporated by reference. The citation of any document is not to be construed as an admission that it is prior art with respect to the invention.
While particular embodiments of the invention have been illustrated and described, it would be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims the benefit of priority to U.S. Provisional Application Ser. No. 60/544,425, filed Feb. 13, 2004 and U.S. Provisional Application Ser. No. 60/548,742, filed Feb. 27, 2004, which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60544425 | Feb 2004 | US | |
| 60548742 | Feb 2004 | US |
