Title of Invention

A SANITIZING SYSTEM FOR CHEMICAL SANITIZING AGENT AND A WATER PURIFICATION SYSTEM

Abstract

The present invention relates to a sanitizing system adapted to retain the chemical sanitizing agent for use in drinking water purification devices and to provide regulated release of chemical sanitizing agent. The sanitizing system according to the invention can be suitable for any device which regulates the release of fluids/water/dissolving liquids in domestic water purification processes such as (i)under gravity flow bucket type water purification device (ii) on tap devices and institutional water purification device such as community water purification systems.

Full Text

FORM -2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See Section 10) A SANITIZING SYSTEM FOR CHEMICAL SANITIZING AGENT HINDUSTAN LEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India The following specification particularly describes nature of the invention and the manner in which it is to be performed AND A WATER PURIFICATION SYSTEM \ FIELD OF THE INVENTION i . ■■ ' ) The present irvention relates to a sanitizing system adapted to retain the chemical sanitizing age for use in drinking water purification devices and to provide regulated release of chemical sanitizing agent. The sanitizing system according to the invention can be suitable for any device which regulates the please of fluids/water/dissolving liquids in .-mestic water purification process?" such as (i)'inder gravity flow bucket type water purificatic device (ii) on tap devices a * institutional water purification device such as community water p "ification systems, "he invention is also directed to a water purification system involving the said sanitizing system in which chemical sanitizing agent e.g.chlorine can be dosed continuously with precise control on the delivery of chlorine into water which is an essential requirement for drinking water purification purposes. BACKGROUND ART It is very important to improve the technology relating to water purification as the water supplies are becoming increasingly polluted. Many water bodies have become contaminated to a great degree and thus requires superior water purification systems. The presence of unwanted and potentially harmful contaminants in water, especially drinking water, is of concern to many people. This concern creates a desire for water treatment devices in the home and elsewhere. Many water treatment devices and methods have been developed to remove or neutralize chemical and particulate contaminants. Some of these devices and methods incorporate chemically active materials to treat the water. For example, activated carbon is capable of removing the bad taste and odor from water as well as chlorine and other reactive chemicals. Ion exchange resins are useful for removing metal and other ions from water. However, no single material or chemical has been found that will remove all contaminants. In addition to chemical and particulate contaminants, water often contains biological contaminants. These contaminants often can not be entirely removed by activated carbon, ion exchange resins, or other chemically active water purifiers. 2 It is well known that purification means/units usually require the fluids/water to be treated or used as a treatment media to traverse under gravity flow through various filtration / purification /sanitizing means/units to thereby effect contact with the active for such treatment or release of the active into the liquid/water to effect the treatment of the water/fluid or serve as a treatment media. US 458 4106 discloses a chforination system for distributing chlorine as the active in a hot tub or spa. The system regulates the flow of water through a mixing chamber with a valve or stopcock to control the rate of chlorine distribution. An assembly of venturies and baffles also regulates the flow of water through the mixing chamber and controls the size of particles of chlorination tablets that will flow out of the chlorination system. US6413416, discloses a water treatment apparatus comprising a water treatment vessel providing a water treatment zone which in use will contain a volume of water to be treated. It is also provided with a water treatment cartridge having a plurality of spokes at the lower end of the cartridge such that the lower most of the stack of water treatment tablets rests on the spokes. US 6298871 B1 discloses yet another chemical feeder that produces a solution of a chemical-treating agent for example sodium hypochlorite comprising a housing defining a cavity, and elongated substantial vertical hollow container is centrally located within the cavity. The bottom wall of the side wall of the container is adjacent to the base and contains a plurality of perforations in the lower portion of the side wall which is spaced from the inside wall of the housing. At least one hollow canister having a plurality of perforations in its base and the lower portion of its side-wall is interposed for examples slidably receive within the container. Conduits for delivering the liquid in which the chemical treating agent is provided to a chamber below the perforations in the canister and for removing the liquid stream containing the chemical treating agent from the feeder are also provided. 3 It would be apparent from the above that while several sanitizing/chlorination systems are well known and available to the art and also there exists several systems which involve the purification/chlorination/disinfecting by contact of the active with fluid/water to be treated, as regards the control over the rate of the water flow into the active dissolving zone of such systems it is mostly attended to by manually operable gadgets such as control valves or pumps, with or without perforation plates and venturies. Various water purification devices that are either gravity fed or on tap devices are known. Water purifiers for drinking water purposes have to be designed to achieve to kill 6 log bacteria and 4 log polio virus through regulated contact between chemical sanitizing agent and water. The delivery of the active agent from the chemical sanitizing agent which are generally used as tablets depends on the contact time between the tablet and water. This in turn depends on the flow rate of water and the surface area of tablet in contact with water. In a water filter the flow rate of water will be different depending on the available head e.g. the head is the height of water column in a gravity fed filter. There could be various other factors that control the flow rate in various different types of filters. In order to provide a regulated delivery of the active it is essential to ensure appropriate contact of inflowing water with the chemical sanitizing agent even when the flow rate of water changes substantially. In the co-pending application No.927/MUM/2002 a device for controlled release of fluid/water under gravity flow comprising an inlet end for the water/fluid entry from a source/supply and an outlet end for the regulated/controlled outflow of the fluid/water, said inlet end and the outlet end of the fluid/water path operatively connected to define at least one fluid/water flow path, said fluid/water flow path comprising a combination of straight path and at least one bend adapted for controlling the flow rate of water flowing there through under gravity. SUMMARY OF THE INVENTION Thus according to the basic aspect of the present invention there is provided a sanitizing system for chemical sanitizing agents comprising : - a sanitizing unit containing the chemical sanitizing agents and having opening at the bottom thereof - means for feeding in water to be sanitized having a nozzle like top selectively disposed adjacent thereunder and facing said opening at the bottom of said unit said nozzle like top having a selective angular conical outer surface such as to 4 favour regulated contact and delivery of said active sanitizing agent upon contact of the flowing stream of the water with the exposed sanitizing agent through said opening. In accordance with a preferred aspect of the sanitizing system of the invention the lower end of the chemical sanitizing unit is open to allow passage of water and positioned at a distance of at least 0.25 mm from the tip of the nozzle through which the water can enter the sanitizing unit such that the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the said unit. In accordance with another aspect of the present invention there is provided a water purification system comprising - a particulate filter unit adapted to filter particulate living and/or non-living matter of size greater than 2 microns operatively connected to a sanitizing system for chemical sanitation comprising , - a sanitizing unit containing the chemical sanitizing agents and having opening at the bottom thereof - means for feeding in water to be sanitized having a nozzle like top selectively disposed adjacent thereunder and facing said opening at the bottom of said unit said nozzle like top having a selective angular conical outer surface such as to favour regulated contact and delivery of said active sanitizing agent upon contact of the flowing stream of the water with the exposed sanitizing agent through said opening. It has now been possible by way of the above discussed sanitizing system to provide a regulated delivery system for uniform delivery of the active from the chemical sanitizing agent into the flowing system of water to be sanitized. Importantly, the system selectively provides a flow rate dependent contact between the surface of the chemical sanitizing agent and water which would enable maintenance of a steady active delivery within a narrow band. The system is also adapted to ensure that there is no stagnation of water within the chemical sanitizing unit. 5 Description of the Invention: It is found by way of the above invention that in the chemical sanitizing system of the invention, the disposition of the nozzle with respect to the base of the sanitizing unit containing chemical sanitization agent and the angular convex surface of the nozzle are critical to achieve the desired regulated delivery of the sanitizing agent in the water. Importantly, the disposition of the housing/sanitizing unit base at least 0.25 mm from the tip of the nozzle for supply of the water and the convex outer surface of the nozzle having a selective angular disposition of 15-80° with respect to the base of the sanitizing unit is found to be selectively advantageous for regulated flow. In accordance with other important aspect of the invention the water purification system comprisges a particulate filtration unit adapted to filter particulate living and/or non-living matter of size greater than 2 microns and a chemical sanitizing unit in fluid communication with said particulate filtration unit, wherein the lower end of the chemical sanitizing unit is open to allow passage of water and positioned at a distance of at least 0.25 mm from the tip of the nozzle through which the water is capable of entering the canister such that the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the canister/sanitizing unit. Thus according to the preferred aspect of the present invention there is provided a water purification system comprising, a particulate filtration unit adapted to filter particulate living and/or non-living matter of size greater than 2 microns and a chemical sanitizing system in fluid communication with said particulate filtration unit, wherein the lower end of the sanitizing unit of said sanitizing system has one or more perforations to allow passage of water and positioned at a distance of at least 0.25 mm from the tip of the nozzle through which the water is capable of entering the sanitizing unit such that the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the canister. According to a particularly preferred aspect of the invention the inlet flow rate of water is in the range 500-50 ml/min and the chemical sanitizing sytem is in the form of a 6 sanitizing unit having the chemical sanitizing agents in the form of tablets and the base of the canister has a plate with one or more perforations. The invention thus essentially comprises of a delivery system to provide uniform delivery of the active from the chemical sanitizing agent. The system consists of a nozzle through which water enters into the chemical sanitizing unit where water impinges the lower surface of a chemical sanitizing unit positioned at a distance of at least 0.25 mm from the tip of the nozzle. The water after providing a contact with the exposed tablet surface at the lower end of the chemical sanitizing unit trickles down along the conical outer body of the nozzle. Importantly, as stated above the invention provide for selectively (1) distance between the tip of the nozzle and the chemical sanitizing unit (2) the angle that conical outer surface of the nozzle makes with the lower end of the chemical sanitizing unit to thereby achieve the required regulated delivery of the actives. It is preferred to incorporate any flow-throttling device known in the art between the prefiltration unit and the chemical sanitizing unit. Examples of such flow throttling devices may be selected from manually operable gadgets such as control valves or pumps, with or without perforation plates and venturies, or other electrically, electronically, pneumatically or hydraulically actuated control valves or flow stop cocks, globe valves, taps or any such flow restricting devices. They can also be in the form of angular bends, spiral coils, or even a tube of proper diameter. The active can be any suitable purification/sanitizing agent in powdered, granular or tablet form preferably as tablets. It is also possible to use other conventional chlorine releasing compounds such as potassium dischloroisocyanurate, sodium dichloroisocyanurate, chlorinated trisodium phosphate, calcium hypochlorite, lithium hypochlorite, monochloramine, dichloramine, [(monotrichloro)-tetra(monopotassium dichloro)] pentaisocyanurate, 1,3 dichloro-5,5-dimethylidanotone, paratoluene sulfodichloroamide, thrichloromelamine, N-chloramine, N-chlorosuccinimide, N,N'- 7 dichloroazodicarbonamide, N-chloroacetyl-urea, N,N-dichloroazodicarbonamide, N-chloroacetyl-urea, N,N-dichlorbiurile, chlorinated dicyandiamide. Chemical sanitizing unit. This consists of a canister which is an elongated chemical sanitizing unit preferably of cylindrical cross-section holding biocide either in a sachet if the biocide is powder or tablets stacked one over the other on a perforated disc or a non woven fabric. There is an water inlet centrally located under the biocide holder. Water enters through the inlet, touches the surface of the tablets and exits through the windows (openings) on the periphery of the holder. In order to achieve this, the distance between the disc and water inlet is critical. The base of the canister is provided with one or more perforations to enable water to pass through. It is particularly preferred that the base is formed by a plate provided with one or more perforations. The number of perforations range from 5-100 but more preferably 5-60. The distance between the base of the canister and the nozzle through which the inlet water flows is critical and is maintained to be 0.25 to 10 mm, more preferably 0.25 to 5 mm and it is particularly preferred that it is 0.5-2 mm. The diameter of the nozzle is in the range 1-30 mm. The angle formed between the conical outer surface of the nozzle and the lower end of the chemical sanitizing unit is in the range 15-80 degrees and is preferably 15-60 degrees. The inlet flow is preferably 500-50ml/min. Description in relation to the drawings: The details of the invention, its objects and advantages are explained hereunder in greater detail in relation to non-limiting exemplary embodiments of the water 8 purification system of the invention in combination with a chlorinating sanitizing system under gravity feed situation as per the accompanying figures wherein- Fig 1: Shows in detail of a chemical sanitizing system in accordi ance with the invention. In a gravity fed water purification system the purification would take place in three stages (1) pre-filtration: water will be pre-filtered using a particulate filter unit such as a carbon block to remove suspended matters and organic impurities in the water and cysts (2) germ-kill by chemical sanitizing agent that releases for e.g chlorine (3) chlorine scavenger: is provided to remove free chlorine from the treated water before water can be consumed. While in the case of gravity fed system a dwell chamber would provide the minimum residence time required to achieve the target kill, in the on tap device chlorine delivery will be so adjusted that a flow through kill is delivered by the system. In accordance with the water purification system of the invention the water after passing through a pre-filter in which the water is pre-filtered using a particulate filter unit such as a carbon block to remove suspended matters and organic impurities in the water and cysts is passed through the chemical sanitizing system of the invention as illustrated in detail in Fig. 1. For the purpose,, the water after passing through the pre-filter is lead through a tube which conveys it through a flow throttling device into the chemical sanitizing system (CSU) through a nozzle (N). There is provided a selective distance (D) as discussed above between the lower part of the canister (C) and the tip of the nozzle (NT). The convex outside (CO) of the nozzle makes an angle of 15-80 degrees with the base of the canister (C), which is provided with one or more > perforation (P). The chemical sanitizing agent (For e.g Trichloro isocyanuric acid, TCCA) stacked as tablets (TB) releases the agent for e.g chlorine from the chemical sanitizing unit into the water which flows out of the openings (O) and is then passed through a carbon scavenger. The carbon scavenger is provided to remove free chlorine from the treated water before water can be consumed. The water from the outlet can enter the carbon scavenger either directly or through a dwell chamber. While in the case 9 of gravity fed system a dwell chamber would provide the minimum residence time required to achieve the target kill, in the on tap device chlorine delivery will be so adjusted that a flow through kill is delivered by the system. The operation of the system is detailed as hereunder: The purification system comprises of a top chamber fitted with a pre-filter made of a coarse sediment filter and activated carbon to enable removal of chlorine, organics, particulate matter and pathogenic cysts. The filtered water then goes through a flow throttling device that provides a flow rate of 500-50ml/min before the water flows into a chemical purification unit which has a chemical purifying agent such as trichloroisocyanuric acid (TCCA) tablets. As the water passes through the chemical purification unit it leaches out a certain amount of the chemical purifying agent from the tablet. The chemical purifying agent is then scavenged by passing the water through a unit comprising bacteriostatic activated carbon and/or ion exchange resin or any other known means after a residence time which is a period of not less than 2 minutes and preferably up to 60 minutes of its exit from the chemical purifying unit. Examples: Determination of chlorine concentration in filtered water: 1200 litres of Mumbai municipal supply of tap water was contaminated with 107 counts/ml of bacteriophages, 105 counts/I cysts, and 108 counts/ml bacteria. The water was passed through the water purifier according to the invention as described above. This water passes through a flow regulator and then into the chemical sanitizing unit comprising the canister/sanitizing unit holding the TCCA tablets. The base of the canister/sanitizing unit is formed by a sieve plate. The distance between the sieve plate and nozzle through which the inlet water flows (Referred to as "Distance"), the angle made by the convex outside of the nozzle with the base of the canister (Referred to as "Angle"), and the chlorine concentration are presented in Table 1. The sieve plate had a diameter 18 mm and the number of perforations in the sieve plate was maintained 9 where one of the perforation had a diameter of 4mm and the others had a diameter of 2 10 mm. The inlet flow rate was about 80 ml/min. The outlet water from the canister was passed through a scavenger unit and then the chlorine concentration in the purified water was measured using the procedure described in British / European Standard BS EN 12933:2000. A control unit with the chemical purifying device without the required gap between the inlet water but the angle made by the convex outside of the nozzle with the base of the canister was 30 degrees (Example 1) and where the required gap between the inlet water was 1 mm and the angle made by the convex outside of the nozzle with the base of the canister was greater than 80 degrees (Example 2) were maintained as controls. Table 1 Examples Distance (mm) Angle (Degrees) Chlorine Concentration (ppm) Example 1 nil 30 High chlorine > 40 ppm Example 2 1 >80 Very low Example 3 1 30 12.5 Example 4 1 45 8.2 Example 5 1 60 6.5 Experiments were also done with a 170 mm and 50 mm height of water column with the angle maintained at 30 degrees and by varying the distance: The data is presented in Table 2. Table 2 Examples Height of water (170 mm) Height of water (50 mm.) Distance (mm) Chlorine Concentration (ppm) Distance (mm) Chlorine Concentration (ppm) Example 6 0.5 17.7 0.5 32.8 Example 7 1.0 10.5 1.0 12.5 Example 8 1.5 3.4 1.5 1.43 11 The data presented in Table 1 and 2 show that the distance and the angle in the chemical sanitizing unit is critical in controlling dissolution of the chemical sanitizing agent. It is thus possible by way of the present invention to achieve a simple device for regulation of flow rate related contact and thus release of the chemical sanitizing agent especially in water purification systems operated under gravity. The device is compact and can be available in the form of a cartridge for ready and diverse applications for such flow control. The device is further adapted for use in or with any conventional water source /pipeline, tap or purifying/sanitizing/disinfecting/filtration system requiring regulated supply of the sanitizing agent and should have wide utility especially for domestic and simple applications for like purposes. 12 WE CLAIM : 1. A sanitizing system for chemical sanitizing agents comprising : a sanitizing unit containing the chemical sanitizing agents and having opening at the bottom thereof means for feeding in water to be sanitized having a nozzle like top selectively disposed adjacent thereunder and facing said opening at the bottom of said unit and said nozzle like top having a selective angular conical outer surface such as to favour regulated contact and delivery of said active sanitizing agent upon contact of the flowing stream of the water with the exposed sanitizing agent through said opening. 2. A sanitizing system as claimed in claim 1 wherein the lower end of the chemical sanitizing unit is provided with opening to allow passage of water and positioned at a distance of at least 0.25mm from the tip of the nozzle through which the water can enter the sanitizing unit and the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the said unit. 3. A water purification system comprising - a particulate filter unit adapted to filter particulate living and/or non-living matter of size greater than 2 micron operatively connected to a sanitizing system as claimed in claim 1 for chemical sanitation comprising a sanitizing unit containing the chemical sanitizing agents and having opening at the bottom thereof means for feeding in water to be sanitized having a nozzle like top selectively disposed adjacent there under and facing said opening at that bottom of the said unit and nozzle like top having a selective angular conical outer surface such as to favour regulated contact and delivery of said active sanitizing agent upon contact of the falling stream of the water with the exposed sanitizing agents through said opening. 13 4. A system as claimed in anyone of claims 1 to 3 adapted to selectively provide a flow rate dependent contact between the surface of the chemical sanitizing agent and water to maintenance a steady active delivery within a narrow band. 5. A system as claimed in anyone of claims 1 to 4 adapted to ensure that there is no stagnation of water within the chemical sanitizing unit. 6. A system as claimed in anyone of claims 3 to 5 comprising a particulate filtration unit adapted to filter particulate living and/or non-living matter of size greater than 2 microns and a chemical sanitizing system in fluid communication with said particulate filtration unit, wherein the lower end of the chemical sanitizing unit is open to allow passage of water and positioned at a distance of at least 0.25 mm from the tip of the nozzle through which the water is capable of entering the canister such that the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the canister/sanitizing unit. 7. A system as claimed in anyone of claims 1 to 6 wherein the lower end of the sanitizing unit has one or more perforations to allow passage of water and positioned at a distance of at least 0.25 mm from the tip of the nozzle through which the water is capable of entering the sanitizing unit such that the convex outside of the nozzle makes an angle of 15-80 degrees with the base of the canister. 8. A system as claimed in anyone of claims 1 to 7 adapted for an inlet flow rate of water is in the range 500-50 ml/min and the sanitizing unit having the chemical sanitizing agents in the form of tablets and the base of the unit having a plate with one or more perforations. 9. A system as claimed in anyone of claims 3 to 8 comprising a flow throttling device between the prefiltration unit and the chemical sanitizing system. 14 10. A system as claimed in claim 9 wherein said flow throttling devices is selected from manually operable gadgets such as control valves or pumps, with or without perforation plates and venturies, or other electrically, electronically, pneumatically or hydraulically actuated control valves or flow stop cocks, globe valves, taps or any such flow restricting devices including in the form of angular bends, spiral coils, or even a tube of proper diameter. 11. A system as claimed in anyone of claims 1 to 10 wherein the active is selectively any suitable purification/sanitizing agent in powdered, granular or tablet form preferably as tablets. 12. A system as claimed in anyone of claims 1 to 11 wherein said active comprise any conventional chlorine releasing compounds including potassium dischloroisocyanurate, sodium dichloroisocyanurate, chlorinated trisodium phosphate, calcium hypochlorite, lithium hypochlorite, monochloramine, dichloramine, [(monotrichloro)-tetra(monopotassium dichloro)] pentaisocyanurate, 1,3 dichloro-5,5-dimethylidanotone, paratoluene sulfodichloroamide, thrichloromelamine, N-chloramine, N-chlorosuccinimide, N,N'-dichloroazodicarbonamide, N-chloroacetyl-urea, N,N-dichloroazodicarbonamide, N-chloroacetyl-urea, N,N-dichlorbiurile, chlorinated dicyandiamide. 13. A system as claimed in anyone of claims 1 to 12 wherein said sanitizing agent comprise a canister which is an elongated chemical sanitizing unit preferably of cylindrical cross-section holding biocide selectively in a sachet if the biocide is powder or tablets stacked one over the other on a perforated disc or a non woven fabric . 14. A system as claimed in claim 13 wherein the water inlet is centrally located under the biocide holder and disposed such that water enters through the inlet, 15 touches the surface of the tablets and exits through the windows ( openings ) on the periphery of the holder. 15. A system as claimed in anyone of claims 13 or 14 wherein the base of the canister is provided with one or more perforations to enable water to pass through preferably the base is formed by a plate provided with one or more perforations. 16. A system as claimed in claim 15 wherein the number of perforations range'from 5-100 but more preferably 5-60. 17. A system as claimed in anyone of claims 13 to 16 wherein the distance between the base of the canister and the nozzle through which the inlet water flows is critical and is maintained to be 0.25 to 10 mm, more preferably 0.25 to 5 mm and it is particularly preferred that it is 0.5-2 mm. 18. A system as claimed in anyone of claims 1 to 17 wherein the diameter of the nozzle is in the range 1-30 mm and the angle formed between the conical outer surface of the nozzle and the lower end of the chemical sanitizing unit is in the range 15-80 degrees and is preferably 15-60 degrees and adapted for the inlet flow preferably 500-50ml/min. 19. A sanitizing system for chemical sanitizing agents and a water purification system involving the same substantially as hereindescribed and illustrated with reference to the accompanying figures. Dated this 21st Day of October 2003. Hindustan Lever Ltd. (S Venkatramani) Patents Manager 16

Documents:

926-mum-2002-abstract(04-01-2005).doc

926-mum-2002-abstract(04-01-2005.pdf

926-mum-2002-claims(granted)-(04-01-2005).doc

926-mum-2002-claims(granted)-(04-01-2005).pdf

926-mum-2002-correspondence 1(21-10-2003).pdf

926-mum-2002-correspondence 2(09-04-2007).pdf

926-MUM-2002-CORRESPONDENCE(8-2-2012).pdf

926-mum-2002-correspondence(ipo)-(08-12-2004).pdf

926-mum-2002-drawing(04-01-2005).pdf

926-mum-2002-form 1(24-10-2002).pdf

926-mum-2002-form 19(21-10-2003).pdf

926-mum-2002-form 2(granted)-(04-01-2005).doc

926-mum-2002-form 2(granted)-(04-01-2005).pdf

926-mum-2002-form 3(21-10-2003).pdf

926-mum-2002-form 3(24-10-2002).pdf

926-mum-2002-form 5(21-10-2003).pdf

926-mum-2002-power of attorney(18-05-2004).pdf

926-mum-2002-power of attorney(18-11-2002).pdf

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