Patent Application
20170197846
Dogs, cats, and humans alike can suffer from urinary calculi or stones, a dreaded buildup of irritating substances in the urinary tract that causes pain and even obstruction. Urolithiasis refers to calcifications that form in the urinary system, primarily in the kidney (nephrolithiasis) or ureter (ureterolithiasis), and may also form in or migrate into the, lower urinary system (bladder or urethra). The onset of these diseases is when the amount of minerals present in the wine is high enough that the minerals are unable to remain dissolved. Thus, prevention measures include proper diets to reduce the intake of such problem-causing minerals.
Water described as “hard” is high in dissolved minerals, specifically calcium and magnesium. Water supplied as tap water is hard or soft depending on regions, and hard water is normally harmless to humans. However, calcium and magnesium content in generally supplied hard water can be too high for pets, whose bodies are smaller than humans, potentially leading to formation of urinary calculi or stones.
Systems and methods for water softening have been developed primarily for generating high-quality drinking water for humans. In particular, conventional technologies in large scale systems to generate filtered water at the water source or complex devices including filter-regenerating functions. In view of the lack of developments targeted for use for dogs, cats and other small animals, this document provides a water softening device, which is portable, easy to handle and specifically tailored to generate soft water suitable for pets.
The upper and lower shells 108 and 112 may be configured to be attached to and detached from each other by means of fasteners including hooks, screws, pins, latches and other engaging mechanism. In the example illustrated in
Another example of the filter unit 104 may comprise a layer having a generally hollow ellipsoidal shape configured to cover the internal surface of the generally hollow ellipsoidal shape of the shell 200, and an ion exchange resin in the form of beads contained inside the layer. The layer may be made of a nonwoven fabric, and attached to the internal surface of the shell 200 by using an adhesive or other means. Part of the shell, together with the layer covering the internal surface thereof, may be configured to be detachably attached to the rest of the shell so that the part can be detached when the ion exchange resin needs to be replaced. Alternatively, the part of the shell, together with the layer covering the internal surface thereof, may be configured to be non-detachably attached to the rest of the shell once the ion exchange resin is included within the layer and the shell, in this case the replacement of the ion exchange resin is carried out by replacing the entire ball 100.
Yet another example of the filter unit 104 may comprise an ion exchange resin in the form of beads without having a bag, such as the bag 105, or a layer covering the internal surface of the hollow ellipsoidal shape of the shell 200, as in the above example. In this case, the dimensions of each of the openings 116 and 120 need to be configured to prevent any of the beads from leaking out. The diameter of a bead of a typical ion exchange resin nowadays is about 0.5 mm -1 mm. Thus, at least one dimension of each opening should be made less than 0.5 mm to prevent the leak. For example, the shell 200 may be configured to form a fine mesh with at least one dimension of each opening being less than 0.5 mm. Part of the meshed shell may be configured to be detachably attached to the rest of the shell so that the part can be detached when the ion exchange resin needs to be replaced. Alternatively, the part of the meshed shell may be configured to be non-detachably attached to the rest of the shell once the ion exchange resin is included within the shell. In this case, the replacement of the ion exchange resin is carried out by replacing the entire ball 100.
Ion exchange resins are typically polymers that are capable of exchanging particular ions within the polymer with ions in a solution that come in contact with them. In water softening applications, Na+-based or H+-based ion exchange resins are typically used to reduce the mineral content, in particular, the magnesium and calcium ions, found in hard water. For the case of a Na+-based ion exchange resin, when the resin is fresh, it contains sodium ions at its active sites. As the water passes through the resin, the resin takes up magnesium and calcium ions to its active sites, and releases Na+ ions in the water, thereby softening the water. The resin can be recharged by washing it with salt water. The similar ion exchange mechanism can be carried out by using an H+-based ion exchange resin, except that an H+-based ion exchange resin is typically not rechargeable. The ion exchange resin in the filter unit 104 may be Na+-based or H+-based. However, it is preferable to use H+-based ion exchange resin for drinking water. This is because the released Na+ ions in the water inevitably increases the Na+ ion content, thereby making it less suitable for drinking water for a pet. By using an H+-based ion exchange resin, H+ions get released in the water in exchange of the minerals including magnesium and calcium ions. H+ions are generally harmless for a pet.
Water hardness is measure of the concentration of mineral content, in particular, Ca2+ and Mg2+ ions in water, which can be readily measured by using an off-the-shelf measurement device. In general, water hardness is expressed in various units, such as a molar concentration, ppm, mg/L, etc. The unit of mg/L is used herein, where L=liter=1000 cm3. Water hardness of tap water differs from region to region; for example, it is about 30 in New York, 55 in San Francisco and in most areas of Japan, 90 in Los Angeles, 130 in Chicago, and 300 in Las Vegas and San Diego. The amount of ion exchange resin in the form of beads included in the present water softening ball can be predetermined in relation to the amount of water to be softened and the degree of softness to be achieved. Empirical relationships among relevant parameter values are explained below. Although specific numbers are cited herein to explain such relationships and metrics as examples, it should be understood that these are approximate values. The water softening rate, i.e., the hardness reduction, is 100% when the original water hardness of 50 is reduced to 0, and it is 50% when the original water hardness of 50 is reduced to 25. Obviously, there is a trade-off relationship between the amount water that can be softened and the degree of hardness reduction. Table 1 below lists examples showing the relationships between the amount of water that can be softened and the degree of hardness reduction by using different amounts of the ion exchange resin.
40
100
50 → 30
40%
2000
200
40
80
50 → 25
50%
2000
160
40
60
50 → 15
70%
2000
120
40
50
50 → 10
80%
2000
100
40
30
100 → 30
70%
2000
60
40
25
100 → 20
80%
2000
50
As exemplified in Table 1, for the case of a typical ion exchange resin in the form of beads, 100 g of it can reduce the hardness of 100 L of water, which originally had the hardness of 50, to zero; and 100 g of it can reduce the hardness of 50 L of water, which originally had the hardness of 100, to zero. These are the cases for the water softening rate of 100%. By using 40 g of the ion exchange resin with the water softening rate of 100%, the hardness of 40 L of water, which originally had the hardness of 50, can be reduced to 0. By using 40 g of the ion exchange resin, 80 L of water can be softened with the water softening rate of 50% (reduction of the hardness from 50 to 25, for example). Similarly, by using 40 g of the ion exchange resin, about 60 L of water can be softened with the water softening rate of 70% reduction of the hardness from 50 to 15, for example). Typically, a dog, a cat or other small animal needs about 0.5 L of water per day; thus, 60 L of the soft water (reduced from 50 to 15, for example) gets consumed after 120 days, and 80 L of the soft water (reduced from 50 to 25, for example) gets consumed after 160 days. The rightmost column in Table 1 lists the number of days it takes for the corresponding amount of softened water to be consumed, assuming that the pet drinks 0.5 L per day.
Experiments suggested that excessive removal of the mineral content can degrade the taste and flavor of the water, and may even cause mineral deficiency. Thus, the hardness reduction, i.e., the water softening rate, should not be excessive, and yet the concentration of Ca2+ and Mg2+ ions should be reduced to a healthy level. Numerous experiments suggested that the concentration level of the Ca2+ and Mg2+ ions, which can maintain a small animal healthy (e.g., preventing, urinary calculi or stones) and yet keep the taste and flavor of the water, corresponds to the water hardness level in the range of 10-30. This range corresponds to the water softening rate of roughly 40-80% for the water with the original hardness of 50 by using 40 g of the ion exchange resin. The empirical relationships, shown in bold face in Table 1, suggest that 40 g of the ion exchange resin can soften 50-100L of water from the hardness level of 50 to the level in the range of 10-30, which lasts for 100-200 days, assuming that the pet drinks 0.5 L of the water per day. In the case when the water hardness level is reduced from 100 to 30, 40 g of the ion exchange resin can soften 30 L of water, which lasts for 60 days. Thus, the frequency of replacing the ion exchange resin is once in 2-7 months, which is a desirably long interval. On the other hand, a human needs about 2 L of water per day; thus, 50 L of softened water lasts for 25 days, whereby the frequency of replacing the ion exchange resin is less than a month, which may be relatively frequent and costly.
In the present water softening ball 100, the amount of ion exchange resin in the filter unit 104 and the volume of the shell 200 are optimized for generating drinking water soft enough for a pet such as a dog, a cat and other small animal, and yet keeping the original taste and flavor. The volume of the shell 200 is configured to be small enough to be put in a container or a pitcher with a capacity of water that can be handled with one hand. A small animal for a pet typically drinks about 0.5 L of water per day. Certain types of small cats drink even less, such as 0.2 L per day. Accordingly, the volume of the shell 200 is configured to be small enough, to be put in a container having a capacity of at least the daily amount of drinking water for a pet. That is, the diameter or one dimension of the shell 200 may be in the range of 3 cm -6 cm, so that it can be easily accommodated in a container having a capacity in the range of 0.25 L-1.5 L. Here, a measure of the diameter is for the case wherein the shell 200 has a generally spherical shape, and a measure of the one dimension may be twice the length of one of the three semi-principal axes, i.e., 2a, 2b or 2c, for the case wherein the shell has a generally ellipsoidal shape. Correspondingly, the amount of the ion exchange resin may be in the range of 20 g -70 g, Therefore, the present water softening ball is configured as above based on the optimization considerations to generate softened water for a pet, such as a cat, a dog and other small animal.
It should be noted that in the regions where the water hardness is high, for example, 120 or higher, it takes more resin to lower the hardness to a desired level, and/or the resin needs to be replaced frequently. For example, by using 40 g of the ion exchange resin, only 10 L of water can be softened from the hardness level of 300 to 90, as exemplified in Table 1, giving about 20 day supply of soft water for a pet it should be noted that the ion exchange resin itself may not be capable of drastically reducing the water hardness. In the above example, the hardness reduction from 300 to 90 corresponds to the softening rate of 70%, but the resultant water is still as hard as 90. This means, in a region having the water hardness of 300, such as Las Vegas or San Diego, even by using the ion exchange resin with the water softening rate of 80%, the resultant hardness is still 60, which is not suitable for a pet. Thus, one water softening ball 100 configured and optimized for a pet as above may be suitable for use in regions where the water hardness is less than 120. Alternatively, the water softening device disclosed in the commonly-owned U.S. patent application Ser. No. 14/990,081 may be suitable for use in such regions. The entire disclosure of the above U.S. patent application is incorporated herein by reference. In regions where the water hardness is 120 or higher, two or more balls can be used to soften the original water. Alternatively, one or more balls may be added to the water contained in the above mentioned water softening device to further reduce the water hardness, wherein the water can be water contained for processing or water contained after processing in the water softening device.
While this document contains many specifics, these should not be construed as limitations on the scope of an invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be exercised from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.
