Liquid purification or separation – Processes – Liquid/liquid solvent or colloidal extraction or diffusing...
Reexamination Certificate
2001-03-12
2003-02-25
Drodge, Joseph W. (Department: 1723)
Liquid purification or separation
Processes
Liquid/liquid solvent or colloidal extraction or diffusing...
C137S015010
Reexamination Certificate
active
06524483
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally concerns reverse osmosis (RO) systems, and zero-waste RO systems.
The present invention particularly concerns (i) the retrofit of diverse existing non-zero-waste RO systems to become zero waste RO systems, (ii) the partitionment and packaging of the multiple components of RO systems particularly as are of the zero waste type, and (iii) the modular construction of zero-waste RO systems.
2. Description of the Prior Art
2.1 General Requirement to Abate Water Wastage Attendant Upon RO
Conventional systems for purifying water by process of-reverse osmosis (RO) produce, in addition to purified water, a considerable amount of waste water. This waste water, which is a by-product of the RO process, is also called concentrate water or reject water. It is typically put down the drain of the residence or business in which the RO system is installed. Although called “waste”, the waste water is in no way contaminated or unsafe. It simply contains a somewhat higher proportion of the elements—mostly minerals—removed from the supply water by the RO process than does the supply water itself. This additional concentration is, of course, resultant from the addition to the waste water of those elements that were previously present in the purified water.
This waste water is of increasing concern, particularly in increasing widespread areas of the world where water is scarce, and even a precious commodity. It is economically inefficient to pump water to distances ranging to thousands of miles, as in the American west, only to put it down the drain. For example, the ratio of concentrate or reject water to purified water can range from about 3:1 to about 15:1 depending on the particular system. This means that for every gallon of purified water produced, from 3 to 15 gallons is considered as concentrate water and is customarily sent to a drain.
It should be understood that recognition of, and concern over, this wastage is not limited to just the inventor of the present application (and a related patent), and to the inventors of still other related patents. Improvements in RO systems have already been made. RO systems sold in the United States up until about 1991 did not necessarily incorporate a shut-off switch—shutting off the flow of water when the tank reservoir of purified water became full, and preventing a RO system from constantly dripping water—until 1991 when the State of California mandated this wastage-abating feature for all RO systems sold within that state.
Legislatures in several states of the American West now seem poised to act again, and to mandate that newly sold and installed RO systems be of the new “zero waste” type. The Uniform Plumbing Code (UPC) of the International Association of Plumbing and Mechanical Officials (IAPMO) is presently (circa 2000) in process of being specifically revised so as to set standards for the plumbing of zero-waste RO systems. Unfortunately, such a legislative mandate and/or plumbing code revision will do nothing to abate the cumulative wastage of many millions of RO systems that are already installed. For example, an estimated 3 million RO systems are already installed in the State of California alone.
As fresh water resources become more remote and more costly, certain areas of the world, including areas in America, are very willing to consider further water conservation measures—especially as would have no discernable performance impact on the water consumer. Zero waste RO systems are such an improvement: the consumer sees no change in the quality of the purified water.
Accordingly, it would be useful if some way could be devised for efficiently and economically retrofitting existing non-zero-waste RO systems to become of the zero-waste type. Such retrofitting would seemingly best use the labor of the homeowner, or a commercial building maintainer, or an installation team of semi-skilled laborers so as to avoid the expense of a journeyman plumber. According to the use of unskilled or semi-skilled labor, the retrofit would desirably be very simple, easy and foolproof. According to (i) the diversity of deployed RO systems, and (ii) the difficulty in eliciting from the building owner any specific information by which any retrofitted items might be selected or customized to a particular pre-installed RO system or a particular building, it would be preferable if any parts used in the retrofit process were (i) universally, or nearly universally, common, with (ii) little wastage of any unused parts.
If the cost of the waste water from an RO system is—as is typical in the U.S. circa 2000—but some few dollars per month, while the cost of a retrofit kit, even as may be self-installed, is—as may be projected—some hundreds of dollars then the only owners of non-zero-waste RO systems who will be incentivized to retrofit to a zero waste type will likely be avid conservationists. However, a water district, or a municipality, can dictate retrofit of all non-zero-waste RO systems, provide a monetary incentive if desired. For example, a water district can simply (i) amortize the cost of an RO retrofit kit and its installation—which are both likely offered at no initial charge to district consumers—by amortizing the price therefore over a period of some years on a consumer's water bill, while (ii) penalizing with higher water rates those consumers who refuse to retrofit to, or install new, zero-waste RO systems.
In the case of consumers self-installing all new zero-waste RO systems, then these systems might typically be subject to cash rebates and other incentives (such as reduced water rates) by the water district; much as similar rebates are currently given in many U.S. water districts for the installation of low flush volume toilets.
However, merely offering a consumer either (i) a reduced rate or, more likely, (ii) the avoidance of a penalty rate, for water consumption if and when a consumer accepts and allegedly installs a zero-waste RO retrofit kit is not a complete solution. Some consumers may accept the kits to get the favorable rate, or avoid the penalty rate, but languish in performing the actual installation. And it is difficult for the water district to confirm installation, by monitoring water consumption or otherwise. It would therefore be useful if this entire retrofit process was well thought through prior to beginning a water-district-wide retrofit effort. It will be seen that the present invention accords for the return of a small and simple, but indispensable, used part from any non-zero-waste RO system to the water district to confirm either (i) retrofit to a zero-waste system, or (ii) dismantlement of the existing non-zero-waste system (whether attendant upon installation of a new zero-waste system or not) The part is normally readily easily unambiguously detectable as used, and it is not realistically feasible for the building owner to buy the (used) part in a hardware store and send to his or her water district as (fraudulent) “proof” of compliance.
2.2 Specific Previous Zero Waste RO Systems
The present invention will be seen to be primarily concerned with the physical partitionment, and packaging, of reverse osmosis (RO) systems, particularly of the zero-waste type. Being so focused, the present invention is not primarily directed to the flow paths and apparatus used to realize a zero-waste reverse osmosis system—of which there are several variant types—per se. Since it is useful to understand the principles of a zero waste RO system, and of the several variants of such systems, in assessing the structure and function of highly-integrated and compactly-packaged zero-waste RO systems in accordance with the present invention, the reader may care to make reference to the prior art in order to specifically understand zero waste RO systems.
Among this prior art, U.S. Pat. No. 4,626,346 to Hall discloses a reverse osmosis water purification system useful in limited water supply installations such as are found in recreational vehicles, boats and the like whic
Cecil Terry K.
Drodge Joseph W.
Fish & Richardson P.C.
Watts Regulator Co.
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