Method for atomizer-based liquid disinfection

Abstract

The efficiency of water disinfection can be significantly increased by supplying the ozone in combination with oxygen to an inlet of a cavitation pump or a line atomizer. A compressor can be introduced at an inlet of the cavitation pump or the line atomizer, compressing the gas mixture at a pressure higher than the pressure within pump or the atomizer. The compressed gases are provided to the inlet of the atomizer or the pump, where the compressed gases mix with the water and enter the cavitation pump or the line atomizer (where most of the dissolution of the gases happens). The compressor allows to increase the amount of oxygen and ozone provided to the pump or the line atomizer, increasing their dissolved concentration. In addition to the disinfecting properties, the higher level of oxygen correlates to an improved taste of the water.

Claims

1. A method for atomizer-based liquid disinfection, comprising: supplying through one or more pipes a liquid contaminated by microorganisms to a line atomizer; generating using a gas generator a gas mixture and pumping the gas mixture to a compressor; pressurizing using the compressor the gas mixture, wherein the gas mixture compresses while pressurized, and moving the pressurized gas mixture to one of the pipes at an intake of the line atomizer at a pressure greater than a pressure within the line atomizer; and dissolving using the line atomizer at least a portion of the pressurized gas mixture within the liquid, wherein the dissolved gas mixture reduces a concentration of the microorganisms within the liquid.

2. A method according to claim 1, further comprising: measuring using a flow meter a flow rate of the liquid through one or more of the pipes, wherein an amount of the gas mixture pumped into one or more of the pipes using the gas generator is set based on the measured flow rate.

3. A method according to claim 2, wherein the amount of the gas mixture is increased proportionally to an increase in the flow rate.

4. A method according to claim 1, further comprising: modifying using a computer in control of the gas generator an amount of the gas mixture pumped by the gas generator into the one or more pipes, wherein the amount of the gas mixture pumped by the gas generator into the one or more pipes is modified by the computer based on one or more tests conducted on the liquid following a dissolution of the at least the portion of the gas mixture by the line atomizer.

5. A method according to claim 4, wherein the tests comprise determining a density of the microorganisms within the liquid and determining one or more types of the microorganisms within the liquid.

6. A method according to claim 4, wherein the tests are conducted multiple times a day.

7. A method according to claim 6, further comprising: using one or more sensors under a control of the computer to conduct the tests multiple times a day.

8. A method according to claim 1, wherein the liquid comprises greywater.

9. A method according to claim 1, wherein the line atomizer churns and mixes the gas mixture and the liquid under a pressure of 0.0981 MPa-5.394 MPa.

10. A method according to claim 1, wherein the gas mixture comprises ozone, further comprising: generating using the gas generator the ozone by passing oxygen through an ultraviolet light.

11. A method for cavitation-based liquid disinfection, comprising: supplying through one or more pipes a liquid contaminated by microorganisms to a cavitation pump; generating using a gas generator a gas mixture and pumping the gas mixture to a compressor; using the compressor to pressurize the gas mixture, wherein the gas mixture compresses while pressurized, and moving the pressurized gas mixture to one of the pipes at an intake of the cavitation pump at a pressure greater than pressure within the cavitation pump; and providing cavitation using the cavitation pump to cause a formation in the liquid of ultra-fine bubbles from the compressed gas mixture and to dissolve at least a portion of the compressed gas mixture within the liquid, wherein the dissolved gas mixture reduces a concentration of the microorganisms within the liquid.

12. A method according to claim 11, further comprising: using a flow meter to measure a flow rate of the liquid through one or more of the pipes, wherein an amount of the gas mixture pumped into one or more of the pipes using the gas generator is set based on the measured flow rate.

13. A method according to claim 12, wherein the amount of the gas mixture is increased proportionally to an increase in the flow rate.

14. A method according to claim 11, further comprising: modifying using a computer in control of the gas generator an amount of the gas mixture pumped by the gas generator into the one or more pipes, wherein the amount of the gas mixture pumped using the gas generator into the one or more pipes is modified by the computer based on one or more tests conducted on the liquid following a dissolution of at least the portion of the gas mixture by the cavitation pump.

15. A method according to claim 14, wherein the tests comprise determining a density of the microorganisms within the liquid and determining one or more types of the microorganisms within the liquid.

16. A method according to claim 14, wherein the tests are conducted multiple times a day.

17. A method according to claim 16, further comprising: using one or more sensors under a control of the computer to conduct the tests multiple times a day.

18. A method according to claim 11, wherein the liquid comprises greywater.

19. A method according to claim 11, wherein the ultra-fine bubbles are of a diameter from 1 nm-30,000 nm.

20. A method according to claim 11, wherein the gas mixture comprising ozone, further comprising: generating the ozone using the gas generator by passing oxygen through an ultraviolet light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a block diagram showing a system for gas-based water sterilization in accordance with one embodiment.

(2) FIG. 1B is a block diagram showing a system for gas-based water sterilization in accordance with a further embodiment.

(3) FIG. 1C is a block diagram showing a system for gas-based water sterilization in accordance with a still further embodiment.

(4) FIG. 1D is a block diagram showing a system for gas-based water sterilization in accordance with a still further embodiment.

(5) FIG. 2 is a flow diagram showing a method for gas-based water disinfection in accordance with one embodiment.

DETAILED DESCRIPTION

(6) By introducing a gaseous mixture that includes ozone and oxygen to an inlet of a cavitation pump that is interfaced to a line atomizer, the efficiency of dissolution of the ozone and the oxygen within water, and consequently the degree of water disinfection can be significantly increased. FIG. 1 is a block diagram showing a system 10 for gas-based water sterilization in accordance with one embodiment. The system 10 can be implemented in a water purification plant, though other kinds of implementations are possible.

(7) The system 10 includes a flow meter 12 through which water 11 that needs to be purified flows. The flow meter 12 measures the rate at which the water 11 flows, though other kinds of measurements by the flow meter 12. In one embodiment, the water 11 in need of purification can be greywater, water that has been generated in households or office buildings from streams without fecal contamination, such as from sinks, showers, baths, washing machines and dish washing machines. In a further embodiment, the water 11 may come from other sources. The water may be stored on the same site as the flow meter 12, or delivered from another location, and be supplied to the flow meter 12 via one or more pipes (not shown). Regardless of the source, the water 11 needs to be substantially free of solid sediments prior to passing through the flow meter 12.

(8) The flow meter 12 is also connected via one or more pipes 13 to a cavitation pump 14, with water 11 that has been analyzed by the flow meter 12 flowing through the pipes 13 to the cavitation pump 14. Also connected to the one or more pipes 13 is a gas generator 15. The gas generator generates a gas mixture 16 of oxygen and ozone, such by passing oxygen through an ultraviolet light, though other ways to generate the mixture 16 are possible. In one embodiment, the mixture is composed of about 80% oxygen and about 20% of ozone, though other ratios of oxygen and ozone in the mixture 16 are possible. The gas mixture 16 is pumped through one or more gas supply pipes 17 to one or more of the pipes 13, mixing with the water 11 prior to the water reaching the cavitation pump 14. In a further embodiment, the supply pipes 17 could be connected to the pipes 13 at or near the inlet of the cavitation pump 14. The amount of the gas mixture pumped by the gas generator 15 can depend on the flow rate of the water 15 measured by the flow meter 12. In one embodiment, the flow rate can vary from 120 m.sup.3 of water 11 per hour to 2,000 m.sup.3 of water 11 per hour, and the rate (and consequently the amount) of the gas mixture 16 would increase proportionally with the increase in flow rate (and thus the amount of water 11 being treated). As further described below, the amount of the gas mixture can further be increased if the quality of the purification of the water 11 proves to be below a desired level. The settings of the gas generator 15 regulating the rate at which the gas mixture 16 is pumped via the gas supply pumps 17 can be changed either manually, such as by personnel of a water purification plant, or under computerized control that allows automatic (or under remote user control) changing of the settings of the gas generator 15. In one embodiment, the volume of the gas mixture 16 that enters the cavitation pump 14 does not exceed 15% of the total volume of the water 11 and the mixture 16 within the cavitation pump. In a further embodiment, another ratio of the volume of the water 11 to the volume of the gas mixture 16 could be used. While providing the ozone as part of the mixture 16 is essential for the sterilization of the water, the presence of dissolved oxygen in the water 11 further prevents growth of anaerobic pathogenic microorganisms.

(9) Cavitation is the formation of vapor cavities in a liquid. In pumps, cavitation is caused by an impeller of the pump moving through a liquid, with low-pressure areas being formed as the liquid accelerates and moves past the blades, causing the liquid to vaporize and form small bubbles of gas. While cavitation in most cases is undesirable as damaging to the components of the pump, the cavitation pump 14, while subject to the increased wear due to cavitation, takes advantage of the cavitation effect to help dissolve the gaseous mixture within the 16 within the water 11. In particular, the rotation of the impeller of the cavitation pump 14 is fast enough to slice the formed bubbles into multiple smaller bubbles, thus forming ultra-fine bubbles 22 (of a diameter from 1 nm-30,000 nm). Upon the formation of the bubbles, a portion of the ozone and a portion of oxygen in the gaseous mixture rapidly dissolve within the water 11 causing the destruction of the microorganisms or other molecules present in the water 11.

(10) The cavitation pump 14 operates under a high pressure, which facilitates the dissolution of the ozone (and the oxygen) within the water 11. In one embodiment, the pressure inside the pump 14 is between 0.0981 MPa and 5.394 MPa, though other values of pressure are also possible.

(11) The vapor-liquid mixture 18 of water 11 (with dissolved ozone and partially dissolved oxygen), gaseous ozone and oxygen, and the ultra-fine bubbles 22 within the water 11 is pumped by the cavitation pump 14 via one or more pipes 19 to a line atomizer 20 that completes the dissolution of the ozone within the water 11 by churning and mixing the vapor-liquid mixture 18 under high pressure (approximately 0.0981-5.394 MPa (1-55 kg/cm.sup.2), with the dissolution of the ozone and the oxygen being accelerated due to the tornado effect within the line atomizer 20. In one embodiment, the line atomizer 20 can be the OHRMixer sold by OHR Laboratory Corporation of 536-1, Noda, Irumashi, Saitama 358-0054 Japan. In a further embodiment, other line atomizers 20 can be used. In one embodiment, about 40% of the ozone pumped by the cavitation pump 14 into the water 11 is dissolved at the cavitation pump 14, with the remaining amount of ozone (about 60%) being dissolved in the water 11 in the line atomizer 20. Other amounts of ozone dissolved within the cavitation pump 14 and the line atomizer 20 are possible. While complete dissolution of the provided ozone within the water 11 is possible following the processing by the line atomizer 20, in one embodiment, about 70%-80% of the oxygen dissolves within the water 11. In a further embodiment, other percentage of oxygen dissolution is possible.

(12) The combination of the cavitation pump 14 and the line atomizer 20 allow for substantially complete dissolution of the ozone within the water 11, allowing to achieve the desired concentration of ozone (1-3 ppm) with minimal amount of ozone expended. Thus, despite the inefficiencies caused by the cavitation in the cavitation pump, overall, introducing the gas mixture 16 at the inlet of the cavitation pump 14, with the subsequent processing by the line atomizer 20, increases the overall efficiency of the ozone dissolution and decreases the amount of resources necessary to disinfect the water 11 to a desired degree, including to a degree of sterilization. The efficiency is greater than in alternative solutions involving line atomizers, such as when two line atomizers are connected in a series without the use of a cavitation pump. Further, due to the high efficiency, the system 10 is easily scalable and can be adapted to process at water purification plans of different sizes.

(13) The water 21 that is discharged from the line atomizer 20 can be analyzed to make sure that the sterilization effect of ozone is adequate. Such processing can include testing of the concentration of microorganisms within the water 21 (such as determining optical density of the microorganism) and determining other kinds of microorganisms within the ozonated water 21. Other kinds of tests are possible. In one embodiment, the testing can be done three times a day, though in a further embodiment, other kinds of schedule for the testing is possible. In one embodiment, the testing can be done by humans; in a further embodiment, the testing can be automated, such as using sensors positioned to analyze the disinfected water 21. Based on the analysis, the settings of the gas generator 15 can be changed to increase the rate at which the gas mixture 16 is pumped from the gas generator 15 (and thus increasing the concentration of the ozone in the water 11).

(14) The components of the system 10 can be operated manually or under a control of a computer. Thus, a computer (not shown) can be interfaced (wirelessly or through wired connections) to the gas generator 15, the flow meter 12, any other sensors in the system 10, and control the amount of the gas mixture 16 pumped by the gas generator based on the flow rate of the water 11 or the determined characteristics of the disinfected water 21, either automatically or under local or remote user control.

(15) In a further embodiment, the cavitation pump can be omitted from the system 10. FIG. 1B is a block diagram showing a system 10 for gas-based water sterilization in accordance with a further embodiment. In this embodiment, the system 10 of FIG. 1A is modified and the cavitation pump 14 is omitted from the system. In this embodiment, the liquid 11 into which the gas mixture 18 is added by the gas generator 15 (either at an inlet of the line atomizer 20 or further away from the line atomizer 20) flows directly towards the line atomizer 20, which churns and mixes the gas mixture 18 and the liquid 11 as described above. Though the degree of the dissolution of the oxygen and ozone within the liquid 11 in this embodiment of the system 10 is not as high as when the line atomizer 20 is combined with the cavitation pump 14, the degree is high enough to provide for a sterilization of the liquid sufficient for most circumstances and omission of the cavitation pump can simplify installation of the system 10 at a desired location.

(16) In a still further embodiment, a compressor can be placed at an inlet of the line atomizer 20 to increase the level of the oxygen and the ozone that is provided to the line atomizer at one time. In particular, as the pressure within the line atomizer 20 (up to 5.394 MPa) can far exceed the pressure within gas generator (generally 0.25-0.30 MPa), only some, if any, of the gas mixture 16 enters the line atomizer 20. The issue is further exacerbated if the flow of the water 11 is fast enough to prevent the gas mixture from even entering the pipe 13 through which the water 11 flows to the line atomizer. By having a compressor provide the gas mixture 16 at a pressure higher than the pressure inside the line atomizer, the portion of the gas mixture entering the line atomizer can be increased. FIG. 1C is a block diagram showing a system 10 for gas-based water sterilization in accordance with a still further embodiment. The system 10 of FIG. 1C is a modification of the system 10 of FIG. 1A where the cavitation pump 14 is omitted and a compressor 22 is introduced. The compressor 22 is connected to the pipes 13 by a pipe 29 at or near the inlet of the line atomizer 20. The pressure generated by the compressor 22 exceeds the pressure generated by both the gas generator 15 and the line atomizer 20, and can vary in the range of substantially 6 MPa-10 MPa in one embodiment, though other values are also possible in further embodiments. The compressor 22 is connected via one or more pipes 17 to the gas generator 15 and receives the produced gas mixture 16 from the gas generator 15. The compressor 22 pressurizes the gas mixture 16 and compresses the volume of gas mixture 23. The high pressure applied by the compressor also moves the compressed gases 23 to the inlet of the line atomizer 20, where the compressed gases 23 mix with the water 11. Due the compressed state and the high pressure applied by the compressor 23, a greater amount of undissolved gases 23 is able to enter the atomizer 20 in the same amount of liquid 11 than would be possible if the gases 23 remained uncompressed, allowing to increase the concentration of the oxygen and ozone that gets dissolved in the liquid.

(17) In a still further embodiment, a compressor 23 can be placed at an inlet of the cavitation pump 14 to increase the level of the dissolved oxygen and the ozone level within the water. FIG. 1D is a block diagram showing a system 10 for gas-based water sterilization in accordance with a still further embodiment. The system 10 of FIG. 1D is a modification of the system 10 of FIG. 1A where the line atomizer 20 is omitted and a compressor 22 is introduced. The compressor 22 is connected to the pipes 13 by a pipe 29 at or near the inlet of the cavitation pump 14. The pressure generated by the compressor 22 exceeds the pressure generated by both the gas generator 15 and the cavitation pump 14, and can vary in the range of substantially 6 MPa-10 MPa in one embodiment, though other values are also possible in further embodiments. The compressor 22 is connected via one or more pipes 17 to the gas generator 15 and receives the produced gas mixture 16 from the gas generator 15. The compressor 22 pressurizes the gas mixture 16 and compresses the volume of gas mixture 23. The high pressure applied by the compressor also moves the compressed gases 23 to the inlet of the cavitation pump 14, where the compressed gases 23 mix with the water 11. Due the compressed state and the high pressure applied by the compressor 23, a greater amount of undissolved gases 23 is able to enter the cavitation pump 14 in the same amount of liquid 11 than would be possible if the gases 23 remained uncompressed, allowing to increase the concentration of the oxygen and ozone that gets dissolved in the liquid.

(18) FIG. 2 is a flow diagram showing a method 30 for gas-based water disinfection in accordance with one embodiment. Flow of water 11 in pipes leading to the cavitation pump 14 (in the system 10 shown with reference to FIG. 1A), the line atomizer 20 (in the system 10 shown with reference to FIG. 1B), or the compressor 23 (in the system 10 shown with reference to FIGS. 1C and 1D) is measured using a flow meter 12 (step 31). The settings of the gas generator 15, such as the rate at which the gas generator pumps the gaseous mixture 16 is pumps via the pipes 17, is determined based on the measured flow rate, and the generator 15 is set to run at the determined settings (step 32). The gas generator 15 supplies the gas mixture through the one or more pipes 17 into the one or more pipes 13, where the gas mixture 16 mixes with the liquid 11 (step 33) and from where the gas mixture 16 and the water 11 are optionally pumped towards a compressor 22 if the compressor 22 is present in the system 10 (such as shown with reference to FIGS. 1C and 1D) (step 34). The liquid 11 with the gas mixture 16 is then pumped into at least one of the cavitation pump 14 (where the gas mixture is partially dissolved within the water via cavitation created by the operation of the pump 14) if one is present in the system (such as shown with reference to FIGS. 1A and 1D) or the line atomizer 20 if one present in the system (such as shown with reference to FIGS. 1A, 1B, and 1C) (step 34). Thus, if the method 30 is performed using the embodiment of the system 10 shown with reference to FIG. 1A, the cavitation pump 14 pumps the vapor-liquid mixture 18 of the liquid 11 (with partially dissolved ozone and oxygen), gaseous ozone and oxygen, and ultra-fine bubbles 22 created via the cavitation to the line atomizer 20, where the ozone and the oxygen are further dissolved within the water 11, causing the disinfection of the liquid 11. If the method 30 is performed using the embodiment of the system 10 shown with reference to FIG. 1B, the liquid 11 and the gas mixture 16 is pumped directly to the line atomizer 20, which churns and mixes the liquid with the gas mixture 16 to dissolve at least a portion of the gas mixture 16 within the liquid 11. If the method 30 is performed using the embodiment of the system 10 shown with reference to FIG. 1C or 1D, the liquid 11 and the gas mixture 16 are pumped to the line atomizer 20 or the cavitation pump 14 respectively.

(19) Optionally, the disinfected water 21 extruded from the line atomizer 20 or the cavitation pump 14 is analyzed, such by testing the density and kinds of microorganisms present within the disinfected water 21, though other kinds of analysis are possible (step 36). If the results of the analysis are satisfactory (such as with the density of the microorganisms being below a predefined threshold or absence of certain pathogenic microorganisms) (step 37), the method moves to step 39. If the results are not satisfactory (step 37), the settings of the gas generator 15 are modified, such as by increasing the rate at which the gas mixture 16 is supplied via the one or more supply pipes (step 38), with the method 30 returning to step 33.

(20) If more unpurified water 11 remains (step 39), the method 30 returns to step 31. If no more unpurified water remains to be processed (step 39), the method 30 ends.

(21) While the description above refers to disinfection of water, in a further embodiment, the system 10 and method 30 described above could be used for disinfection of another liquid.

(22) While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.