Description: The present disclosure relates generally to the field of water filtration. In particular, it pertains to a reverse osmosis potable water system that provides improved yield and thus reduces wastage of water.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] A large population of the world especially in third world countries and in remote areas does not have access to potable water supply. Installation of water purification and distribution infrastructure is expensive and therefore beyond the capacity of many communities. Even at places where such infrastructure exists, piped water is further purified to be suitable for human consumption such as drinking and using for cooking food as bulk of piped water is consumed for other purposes such as washing etc.
[0004] While pure drinking water is essential to good health of humans, our water resources are getting more and more polluted with pollutants and so a variety of water purification devices are being developed and marketed to meet the domestic as well as other drinking water requirements such as that of restaurants and hotels, public places etc. Reverse Osmosis (RO) water purification units are used widely nowadays for providing pure water for drinking and cooking.
[0005] Reverse Osmosis is a water purification technology that uses a semipermeable membrane to remove the larger dissolved particles of impurities from drinking water. In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property (property of a solution that depends upon the ratio of the number of solute particles to the number of solvent molecules in the solution), which is driven by chemical potential. Reverse osmosis can remove many types of molecules and ions from solutions, as well as microbes including bacteria, and is commonly used in both industrial processes and the production of potable water. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. To be "selective", this membrane should not allow large molecules or ions through the pores (holes), allowing only smaller components of the solution such as the solvent (water in our case) to pass freely.
[0006] A RO water filtration system generally comprises of a water source under pressure, a filter cartridge having a water inlet, a purified water outlet, and a discard water outlet and a purified water storage tank. The cartridge contains a semipermeable membrane, also known as a Nano-filter, for separating salts and other contaminants from the feed water. The incoming water may be pre filtered by other means, such as ultrafiltration or microfiltration to enhance life of the semipermeable membrane.
[0007] In accordance with the principle of Reverse Osmosis, feed water is fed to one side of the semipermeable membrane. The water molecules then permeate to the other side of the membrane under reverse pressure that overcomes the osmosis pressure, to provide pure filtered water. The feed water on feed side of the membrane is continuously replenished with fresh supply. Only a small amount of water gets filtered through the semipermeable membrane and the bulk of water supply is discarded.
[0008] Loss of major portion of water during RO filtration is a big disadvantage of such systems especially when discarded water cannot be put to any other use on account of dispersed installation of such systems as in domestic applications. Moreover, water shortage in many areas of the world has increased the need for judicious use of water resources. Social and environmental needs would be better served if wastage of water during RO filtration can be reduced.
[0009] There is therefore a need for a RO filtration system that can increase the yield of pure water from RO filtration units while reducing wastage of feed water, water being a precious natural resource.
[0010] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. [0011] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about." Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0012] As used in the description herein and throughout the claims that follow, the meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
[0013] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0014] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. OBJECT OF THE INVENTION
[0015] An object of the present invention is to provide an RO based potable water system that can provide an improved yield of pure water from RO filtration units.
[0016] Another object of the present invention is to provide an RO based Potable water system that provides multi stage purification for providing potable water.
[0017] Another object of the present invention is to provide an RO based potable water system that reduces wastage of water - a precious natural resource.
[0018] Another object of the present invention is to provide an RO based potable water system that can provide potable water using water of different TDS (total dissolved solids) level.
[0019] An object of the present invention is to provide for a RO based potable water system that maintains required flow and appropriate pressure level of feed water at different stages so as to get high yield of pure water and minimize the risk of damage to the semipermeable membranes. ,

Claims:The system of claim 1 , wherein the membrane(s) is a semi-permeable membrane or a nano- filter membrane.
3. The system of claim 1, further comprising a first pump configured to supply the partially treated feed water to the first RO unit at the high pressure side of the first RO unit with required pressure and flow parameters.
4. The system of claim 1, further comprising a second set of one or more filters preceding the second RO unit configured to pre-treat the mixed water from the junction point before supplying the mixed water to the second RO unit.
5. The system of claim 1 and 4, wherein the first set of one or more filters is one or combination of anti-scalant, a water softener, a scale inhibitor, means of pre-filtration comprising chemical coagulation, flocculation, clarification, gravity setting, multi media filtration, activated carbon, adsorption media, microfiltration and ultra-filtration.
6. The system of claim 1 and 4, wherein the second set of one or more filter is one or combination of an anti-scalant, water softener and scale inhibitor.
7. The system of claim 1, further comprising a second pump configured to supply the mixed water from the junction point to the second RO unit with required pressure and flow parameters.
8. The system of claim 1, wherein pure water from the first RO unit and pure water from the second RO unit passes through a mineral cartridge configured to add required minerals in the pure water.