MX2011003140A - Water purification device. - Google Patents

Abstract

The present invention relates to a gravity fed water purification device comprising a biocide unit, a reservoir separated by a wall fromand positioned adjacently to a scavenger comprising a media capable of scavenging said biocide or byproducts thereof from water and a dispensing chamber interconnected to define a flow path where the biocide is added by the biocide unit to the waterin the reservoir which flows over the wall into the scavenger and through an outlet to the dispensing chamber, and, the outlet is positioned such that at least 10% by weight of said media is below the lowest level of the outlet, and the wall extends abovethe highest level of the media and above the lowest level of the outlet.

Description

WATER PURIFICATION DEVICE Technical field The present invention relates to a water purification device fed by gravity.

Background and prior art Water purification devices powered by gravity are known in the art. WO2004000732 (Unilever) discloses a gravity-fed water purification device comprising a filter unit adapted to filter particulate material and a biocidal unit containing a biocide, in which the biocide is housed in a sealed chamber and is in fluid communication with the filtration unit, so that the water treated by the filtration unit is then fed by gravity to the biocidal unit and retained there for a predetermined period, after which the water leaves the system via a sweeping means, which is adapted to recover leached biocide. The device includes a purification unit which in turn includes an upper chamber and a lower chamber separated by a division and the filtration unit is secured to the division and housed in the upper chamber and the chemical purification unit is housed in the chamber. lower camera. In use, the water is emptied into the upper chamber and the purified water substantially free of particulate material, chemical purifying agent and microorganisms flows into a dispensing chamber for consumption.

ZA9503286 (Recovery Engineering, 1996) describes a purifier for water and other similar liquids, comprising an inlet, a disinfector unit, a time-out chamber, a treatment unit and an outlet. The time-out chamber has a minimum volume, which is a function of the liquid flow rate and a predetermined time necessary to deactivate bacteria, viruses and other contaminants in the liquid. The purifier is also designed to flow liquid under conditions of almost plug flow, so that the first portion of liquid in the purifier conducts the liquid stream and does not cut the circuit or mix appreciably with liquid that has entered the purifier before or after him.

One of the disadvantages associated with gravity-fed water purification devices is that of relatively high biocide suppression from water upstream of the scavenger, particularly when the device is not used for a relatively long period. One way to ensure the proper concentration of biocide upstream of the scrubbing medium is to design a biocidal unit to add a relatively high amount of biocide in water in which case the scrubbing medium needs to remove a relatively larger amount of the biocide, which either reduces the Sweeper life time or leads to a relatively high amount of the biocide or by-product thereof in the water downstream of the sweeper.

Another disadvantage associated with gravity-fed water purification devices is the relatively lower sweep efficiency, which leads to relatively high concentration of biocide or byproducts thereof downstream of the sweeping medium, which is undesirable and can alter flavor and / or smell of purified water. The half-life of the scavenger is also relatively small, necessitating frequent replacement of half-sweeping, which leads to increased risk of microbial contamination.

Still another disadvantage associated with water purification devices powered by gravity is a possibility of microbial contamination of dispensing chamber, in particular during the replacement of the sweeper by an operator or a user. Once the dispensing chamber or the surface downstream of the sweeping medium is contaminated microbially or contaminated water spills on the dispensing chamber during the replacement of the sweeper, the water in the dispensing chamber remains microbially contaminated since the water reaching the chamber The dispenser is substantially free of the biocide. The problem of microbial contamination can be reduced by cleaning the dispensing chamber and the running surface below the sweeping medium with a disinfectant, such as a hypochlorite solution or if the operator wears sterile gloves. However, the operator in the field or the user who replaces the sweeping means may not have training adequate and / or access to disinfectant or sterile gloves, leading to unsatisfactory performance of the post-replacement of sweeping device.

An objective of the present invention is to overcome or improve at least one of the disadvantages of the prior art, or to provide a useful alternative.

One of the objects of the present is to provide a purification device fed by gravity having a sweeper with relatively long life time and / or reduction of concentration of biocide or by-product thereof in water downstream of the sweeper.

Brief description of the invention According to the present invention, there is provided a gravity-fed water purification device comprising a biocide unit, a deposit separated by a wall from and positioned adjacent to a sweeper, comprising a means capable of sweeping said biocide. or water byproducts thereof and an interconnected dispensing chamber to define a flow path, where the biocide is added by the biocide unit to the water in the reservoir, which flows on the wall to the sweeper and through an outlet to the dispensing chamber, Y to. the outlet is positioned so that at least 10% by weight of said medium is below the lowest level of the outlet, and; b. the wall extends above the highest level of the middle and above the lowest level of the exit.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1: A first embodiment of a water purification device powered by gravity.

Figure 2: A second embodiment of a water purification device powered by gravity.

Figure 3: Water purification device fed by gravity of the second mode before separation of the sweeper.

Figure 4: Water purification device fed by gravity of the second mode after separation of the sweeper.

Detailed description of the invention The sweeper comprises a means capable of sweeping the biocide or byproducts thereof from the water. The medium can sweep biocide by reaction or by adsorption; preferably the medium is an adsorbent medium. Preferably, the adsorbent medium is carbon. More preferably, the adsorbent medium is activated carbon. The activated carbon is preferably selected from one or more of bituminous coal, coconut shell, wood and petroleum tar. The surface area of the activated carbon preferably exceeds 500 m2 / g; more preferably, it exceeds 1,000 m2 / g. From Preferably, the activated carbon has size uniformity coefficient of less than 2, more preferably less than 1.5. Preferably, the activated carbon has carbon tetrachloride number (CCI4) exceeding 50%, more preferably exceeding 60%. Preferably the activated carbon has a number of iodine greater than 800, more preferably greater than 1000. Preferably, the activated carbon can be used in granular form or in powder form. More preferably, activated carbon in the form of a solid block is used. A solid block of activated carbon can be formed by using ceramic or non-ceramic binders by processes known in the art. Binders for making carbon blocks and processes for making blocks are known to a person skilled in the art, for example, from WO0703019 (Unilever), WO0703382 (Unilever), WO07003259 (Unilever), WO06069712 (Unilever) and WO05095284 (A ilever), which are incorporated herein by reference. Polymeric binders are preferred. Particularly preferred binders include high molecular weight polyethylene, high molecular weight polypropylene, ultra high molecular weight polyethylene, ultra high molecular weight polypropylene.

The outlet is positioned so that at least 10% by weight of the medium is below the lowest level of the outlet. Preferably at least 75% by weight of the medium is below the lowest level of the outlet. More preferably, substantially all of the medium is below the lowest level of the outlet.

Preferably, the outlet is included in a division that separates the sweeper from the dispensing chamber and the sweeper is removably removable from the partition, so that the sweeper can be replaced by a person without making contact with the interior of the current device. below the exit. Preferably, the scavenger is removably attachable to the rest of the device. The division is located downstream of the sweeper and upstream of the dispensing chamber. The preference division includes a well-like depression to accommodate the sweeper. The preferred division includes a hollow tubular protrusion extending towards the sweeper. The outlet is preferably included on the hollow tubular protrusion and positioned so that at least 10% by weight of the medium is below the lowest level of the outlet.

Preferably, the outlet is in the form of one or more openings in the partition that allow fluid communication between the sweeper and the dispensing chamber.

Preferably, the shape and / or the size of the outlet is configured so that the human hand can not come into contact with the interior surface of the dispensing chamber while the scavenger is separated from the division. It is possible to prevent the likelihood of the human hand coming into contact with the inner surface by selecting that the cross-sectional area is preferably less than 5 cm2, more preferably less than 3 cm2, and most preferably less than 2 cm2. It is also possible to configure the shape of the outlet in the form of one or more elongated openings preferably having a width of less than 1 cm, more preferably less than 0.5 cm.

The device comprises a wall separating the tank and the sweeper is positioned adjacent to each other. Accordingly, the tank is positioned on one side of the wall and the sweeper is positioned on the other side of the wall. The wall extends above the highest level of the middle and above the lowest level of the exit. Preferably, the wall extends above the sweeper. The upper surface of the wall is preferably flat, so that the wall height does not vary substantially along the width of the wall. The wall is preferably vertical. The wall can be straight, zigzag or curved. The wall preferably is cylindrical.

The volumetric capacity of the device for holding water upstream of the sweeper and downstream of the wall of preference is less than 30%, more preferably less than 20% and most preferably less than 10% of the volumetric capacity of the reservoir.

The biocide unit is adapted to add a biocide in the water in the tank. The biocide can be present as a liquid or solid. Preferably, the biocide unit includes a biocide housed in a sealed chamber and adapted to contact the biocide with water, so that the biocide is added to water. The biocide can be solid or liquid. The biocide is preferably a halogen in dissolved or ionic form. The biocide can be a soluble halogen compound or a halogenated ion exchange resin capable of liberating ionic halogen species. Chlorine and iodine are preferred biocides and chlorine is a particularly preferred biocide. Chlorine compounds that can be used as a biocide include alkali metal or alkaline earth metal salts of hypochlorite or dichloroisocyanuric acid or trichloroisocyanuric acid. When the biocide is used in a solid form, the biocide is preferably in the form of a cylindrical tablet or a stack of tablets adapted to be contacted with water, whereby the biocide is dissolved in the water at a predetermined rate. Preferred biocide tablet materials and biocide unit configurations are described in WO05095284 (U nilever), which is incorporated herein by reference. Preferably, the biocide unit includes a biocide housed in a sealed chamber and adapted to contact the biocide with water, so that the biocide is added to the water.

After the addition of the biocide, the water is preferably retained in the tank for a predetermined period. This can be achieved by any means or suitable device configuration. Preferred means for retaining water in the reservoir during a predetermined residence period or time are known in the prior art, for example, WO2004000732 (Unilever) and WO05095284 (Unilever), which are incorporated herein by reference.

Preferably, the device comprises an upper chamber adapted to receive water to be purified and located upstream of and in fluid communication with the reservoir.

Preferably, the device comprises a filter unit adapted to filter particulate material and located upstream of and in fluid communication with the reservoir. It is preferred that the filtration unit be positioned between the upper chamber and the reservoir defining a flow path where water flows from the upper chamber to the reservoir through the filtration unit. It is particularly preferred that the biocide unit be located between the filtration unit and the reservoir defining a flow path where the water flows from the upper chamber, through the filtration unit, and then through the biocide unit towards the deposit.

Preferably, the dispensing chamber is provided with a dispensing means for supplying the purified water. More preferably, the dispensing means is a key.

Detailed description of the options Referring now to Figure 1, the gravity-fed water purification device (G) comprises a biocide unit (BU) having biocide (B), a reservoir (R), separated by a wall (W) of and positioned adjacent to a sweeper (S) comprising a means (M) capable of sweeping the biocide or by-product thereof from the water and a dispensing chamber (D) interconnected to define a flow path where the biocide is added by the biocide unit (BU) to water in the tank (R), which flows over the wall (W) to the sweeper (S) and through a outlet (O) to the dispensing chamber (D). The outlet (O) is positioned so that approximately 1 5% by weight of the medium () is below the lowest level of the outlet (O), and; the wall (W) extends above the highest level of the medium (M) and above the lowest level of the exit (O). The outlet (O) is included in a division (P), which separates the sweeper (5) from the dispensing chamber (D).

During use, the tank (R) is filled with water from above. A biocide is added to the water in the tank (R) by means of a biocide unit (BU). When the water level in the tank is above the wall (W), the water flows from the tank (R) on the wall (W) to the sweeper (S), where it passes through the medium (M), the which sweeps the biocide and byproducts thereof from the water, which then flows through the outlet (O) to the dispensing chamber (D). When the water level in the tank (R) falls and reaches the top of the wall (W), the flow from the tank (R) to the sweeper (S) ceases by isolating the water in the tank (R) from contact with the medium (M), while the water continues to flow under gravity from the sweeper (S) through the outlet (O) until it reaches the lowest level of the outlet (O). The lowest level positioning of the outlet (O) ensures that at least 10% e weight of medium (M) remains submerged in water until fresh water is added again to the tank (R) when the flow cycle repeats. The device (G) operates in batch mode, where the flow cycle for a period is followed by a period of stagnation during which there is no flow. It will be appreciated that the combination of output positioning (O) and wall height (W) characteristics allows the reduction in amount of biocide or by-product thereof in water leaving the scavenger (S) to the dispensing chamber (D), without causing significant suppression of biocide in the tank (R) during the period of stagnation. The combination of the above features advantageously reduces the leakage of water from the reservoir (R) or the scavenger (S) to the dispensing chamber (D) when the scavenger is separated by the division (P), thereby reducing the possibility of contaminating the dispensing chamber (D) for water leakage, which is likely to have been contacted by a person while separating the sweeper (S) from the division (P).

Referring now to FIG. 2, the gravity-fed ag ue purification device (G) comprises an upper chamber (TC), a filtration unit (F), a biocide unit (BU), a reservoir (R) ), separated by a wall (W) of and positioned adjacent to a sweeper (S) comprising a means (M) capable of sweeping the biocide or water by-product thereof and an interconnected dispensing chamber (D) to define a flow path indicated by dotted arrows where water flows from the upper chamber (TC) and through the filtration unit (F) to the biocide unit (BU) adapted to add biocide (B) to water, which flows through the downpipe (DO) to the tank (R) and on the wall (W) to the sweeper (S) and through an outlet (O) to the dispensing chamber (D) from where the purified water can be drawn by the user through the key (T). The filtration unit (F) is adapted to filter particulate material and the upper chamber (TC) is adapted to receive water to be purified.

The biocide unit (BU) includes sodium isocyanuric trichloro acid biocide (B) tablets housed in a sealed chamber and adapted to contact the tablet with water, so that the sodium trichloro isocyanuric acid is added to the water. The provision of downpipe (DO) allows the water to be retained in the reservoir (R) for a predetermined time before it passes to the sweeper (S). The scavenger (S) comprises activated carbon medium (M) in the form of an annular block attached to base plates (BP) at both ends. The division (P) separates the sweeper (S) from the dispensing chamber (D). The division (P) includes a depression as a cylindrical well and a hollow tubular protrusion (TU) positioned in the center of the depression and extending vertically upwards, defining a housing where the annular sweeper (S) is placed. The hollow tube (TU) is provided with external threads near the upper part to couple with corresponding threads of the clamping cap (FC), so that the sweeper is detachably removable to the division. The outlet (O) is positioned on the hollow tube (TU) so that substantially all of the medium (M) is below the lowest level of the outlet. The cylindrical wall (W) extends above the highest level of the medium () and above the lowest level of the outlet (O).

During use, the upper chamber (TC) is filled from above with water. The water flows through the filtration unit (F), where the particulates are removed and through the biocide unit (BU) where the biocide (B) is added to the water and then through the downpipe (DO) to the reservoir (R) When the water level in the tank is above the wall (W), the water flows from the tank (R) on the wall (W) to the sweeper (S) where it passes through the medium (M) in a radial direction inward, where the biocide and subproducts thereof are swept away from the water, which then flows through the outlet (O) to the dispensing chamber (D). When the water level in the reservoir (R) falls and reaches the top of the wall (W), the flow from the reservoir (R) to the scavenger (S) ceases by isolating the water in the reservoir (R) from contact with the medium (M), while the water continues to flow under gravity from the sweeper (S) through the outlet (O) until it reaches the lowest level of the outlet (O). The lowest level positioning of the outlet (O) ensures that substantially all of the medium (M) remains submerged in water until fresh water is added back to the upper chamber (TC), which then flows to the reservoir (R) when the flow cycle is repeated. The device (G) operates in batch mode, where the flow cycle during a period is followed by a period of stagnation during which there is no flow. It will be appreciated that the combination of output positioning (O) and wall height (W) characteristics allows the reduction in the amount of biocide or by-product thereof in water leaving the scavenger (S) to the dispensing chamber (D), without causing significant suppression of biocide in the tank (R) during the period of stagnation.

Referring now to Figure 3, which shows the device from which the upper chamber (TC), biocide unit (BU) and filtration unit (F) of the reservoir (R) are separated to allow the user to have access to the sweeper to replace it. The clamping cap (FC) is unscrewed from the hollow tube (TU) and the sweeper is removed for replacement. It is possible to replace the sweeper without necessarily replacing other components such as filter unit or biocide unit, thus providing flexibility to provide a relatively longer life sweeper that needs relatively less frequent replacements as compared to other components of the device.

Referring now to Figure 4, which shows the device from which the sweeper has been removed. The division (P) is shown with shaded lines. The division (P) includes a depression similar to cylindrical well and a hollow tube (TU) positioned in the center of the depression and extending vertically upwards, defining a housing where the annular sweeper (S) is placed.

It will be appreciated that the sweeper (S) can be separated to replacing individually by a person without making contact with a device interior running below the outlet (O), thereby significantly reducing the possibility of contamination while the sweeper (S) is being separated. In addition, the wall height (W) and output positioning (O) characteristics advantageously reduce the leakage of water from the reservoir (R) or the scavenger (S) to the dispensing chamber (D) when the scavenger is separated from the partition ( P), thereby reducing the possibility of contaminating the dispensing chamber (D) by leakage of water, which is likely to have been contaminated by a person while separating the sweeper (4) from the division (9).

It is particularly important to significantly reduce the chances of contamination of running water under scrubber (S), which is substantially free of the biocide and once contaminated, can not be decontaminated without complete disinfection of the dispensing chamber (D) and surfaces downstream of the sweeper (S).

Examples The invention will now be demonstrated with examples. The examples are by way of illustration only and do not limit the scope of the invention in any way.

Chlorine suppression during period of stagnation and sweeping efficiency Example 1 was made with the device shown in Figure 2. Comparative Example A was performed with a device identical to the device of Example 1 in all respects except that they did not have a wall separating the tank from the scavenger. The devices of Example 2, 3 and Comparative Example B were identical to the device of Example 1 in all respects, except that the output was positioned so that 50%, 15% or 0% by weight of average, respectively, was below of the lowest exit level.

Measurement procedure of chlorine suppression during stagnation The water (10 I) was added to the upper chamber at the beginning of the experiment. During the flow cycle, water flowed from the upper chamber to the filtration unit where the particulate matter was removed. From the filtration unit, the water flowed after contacting the biocide unit containing a simple trichloroisocyanuric acid tablet (weight 7.5 g), where the trichloroisocyanuric acid biocide was added and then to the tank. At the end of the flow cycle, the water level in the reservoir stagnated near the top of the wall in the devices of Examples 1-3 and Comparative Example B, while the water level in the reservoir stagnated at lowest level of the scavenger output in the device of Comparative Example A. The water was allowed to stagnate for 8 days simulating a condition when the Device is not in use. The amount of chlorine was measured in water samples drawn from the deposit at the start of the stagnation period and every day after the 5th day. The procedure for estimation of chlorine given in "Standard Methods for the examination of water and waste water" (Standard methods for the examination of water and waste water), (ed. Clesceri, L S, Greenberg, A E, Eaton, A D, 20th edition, 1 998, Publishers APHA, AWWA and WEF) was followed. The results are expressed in terms of% chlorine suppressed as compared to initial chlorine (which was identical in both cases).

Procedure to evaluate the sweeping efficiency for removal of biocide or by-product thereof Experimental procedure was similar except that instead of simulating the week-long stagnation, the flow cycles were repeated until the biocide tablet was completely consumed after the passage of approximately 800 I of water through the device. The triazine triol concentration, which is a byproduct of the trichloroisocyanuric acid biocide, was measured in the purified water in the dispensing chamber in all devices after a biocide tablet was consumed. Higher concentration of triazine triol indicates lower sweeping efficiency and vice versa.

Experimental results: elimination and efficiency of sweeper Results From the results it is clear that the devices according to the present invention that combine the wall characteristic with the positioning of the outlet (Examples 1 -3) achieve significantly reduced chlorine suppression during the period of stagnation and sweeping efficiency. relatively better The device of Comparative Example A shows relatively better scavenging efficiency although the cost of chlorine suppression is significantly higher. On the other hand, the device of Comparative Example B shows significantly reduced chlorine suppression although at the relatively lower scavenging efficiency cost. It can also be seen from Examples 1 -3, that the sweeping efficiency increases with the increase in the amount of medium (% by weight) that is below the lowest level of the exit.

Procedure to evaluate the possibility of contamination during the replacement of the sweeper The experiments were performed with the device of Example 1 and a prior art device according to Figure 2 of WO2004000732 (Comparative Example C). The prior art device did not have a division separating the sweeper from the dispensing chamber and the sweeper resided physically in the dispensing chamber.

In simulated pollution experiments, the sweeper was replaced by a gloved hand immersed in a 4% sodium hypochlorite solution for 30 seconds, with sodium hypochlorite being used as a simulated contaminant. The devices were then assembled for use. The water was filled in the chamber at the top. After one hour, water samples were taken from the dispensing chamber (~ 1 I) and analyzed for the presence of sodium hypochlorite according to the procedure for hypochlorite estimation given in "Standard Methods for the examination of water and waste water "(Standard methods for the examination of water and wastewater", (Ed. Clesceri, LS, Geenberg, AE, Eaton, AD, 20th edition, 1998, Publishers APHA, AWWA and WEF). of the dispensing chamber of the device of Example 1 had no detectable sodium hypochlorite (<0.05 ppm) indicating the reduced likelihood of any contaminant on hand contaminating the purified water in the dispensing chamber. On the other hand, the water taken from the dispensing chamber of the device of Comparative Example C showed 2.5 ppm of sodium hypochlorite, indicating very high possibility of water contamination in the dispensing chamber.

It will be appreciated that the gravity-fed purification device according to the present invention provides reduction of concentration of biocide or by-product thereof in running water under the sweeper and has significantly reduced the possibility of water contamination in the dispensing chamber.

Claims (15)

1. REIVI NDICATIONS 1 . A gravity-fed water purification device comprising a biocide unit, a tank separated by a 5 wall and positioned adjacent to a sweeper comprising a means capable of sweeping said biocide or water byproducts thereof and an interconnected dispensing chamber to define a flow path where the biocide is added by the biocide unit to the water in the reservoir, which 0 flows on the wall to the sweeper and through an outlet to the dispensing chamber, and, to. the outlet is positioned so that at least 10% by weight of said medium is below the lowest level of the outlet, and; S b. the wall extends above the highest level of the middle and above the lowest level of the exit. 2. A water purification device powered by gravity as claimed in claim 1, wherein at least 75% by weight of said medium is below the lowest level of the outlet. 3. A water purification device powered by gravity as claimed in claim 1 or 2, wherein substantially all said sweeping means is below the lowest level of the outlet. 4. A water purification device powered by gravity 5 as claimed in any of the preceding claims, wherein the volumetric capacity of the device for holding water upstream of said scavenger and current below said wall is less than 30% of the volumetric capacity of the deposit. 5. A water purification device powered by gravity as claimed in any of the preceding claims, wherein said wall extends above said sweeper. 6. A water purification device powered by gravity as claimed in any of the preceding claims, wherein said wall extends upwards above the lowest level of the outlet. 7. A water purification device powered by gravity as claimed in any of the preceding claims, wherein said medium is carbon. 8. A gravity-fed water purification device as claimed in any of the preceding claims, wherein said biocide unit includes a biocide housed in a sealed chamber and adapted to contact said biocide with water, such that said biocide is added to the biocide. Water. 9. A water purification device powered by gravity as claimed in any of the preceding claims, wherein the water is retained in said reservoir for a predetermined period. 1 0. A gravity-fed water purification device as claimed in any of the preceding claims, comprising an upper chamber adapted to receive water to be purified and located upstream of and in fluid communication with the reservoir. eleven . A gravity-fed water purification device as claimed in any of the preceding claims, comprising a filter unit adapted to filter particulate material and located upstream of and in fluid communication with the reservoir. 12. A gravity-fed water purification device as claimed in claim 1, wherein said filtration unit is positioned between the upper chamber and the reservoir defining a flow path where water flows from the upper chamber to the reservoir at through the filtration unit. 3. A water purification device powered by gravity as claimed in any of the preceding claims, wherein said outlet is included in a division, which separates said sweeper from said dispensing chamber and said sweeper is separable in a removable manner. said division, so that the sweeper can be replaced by a person without making contact with the interior of the device below the outlet. 14. A water purification system fed by gravity as claimed in any of the preceding claims, wherein the shape and / or the size of said outlet are configured so that the human hand can not come into contact with the interior surface of said dispensing chamber while said sweeper is separated from said division. 15. A gravity-fed water purification system as claimed in claim 14, wherein said outlet has a cross-sectional area of less than 5 cm2.