Ultraviolet (UV) liquid disinfection or treatment systems, using UV light source have been long known. The irradiation of the liquid inactivates treats and/or removes microorganisms and other types of contaminations in the liquid, if the irradiation intensity and exposure duration are above a minimum dose level. The UV dose may be measured in units of miliJoules per square centimeter delivered by the UV disinfection system to water to ensure disinfection to the required level. Commercial UV disinfection systems are designed to inactivate known microorganisms using a single type of UV lamps that emits UV light in the germicidal spectrum.
Recent regulations regarding the discharging of ballast water in harbors require the inactivation or removal of various sea water contaminations for example, microorganisms and marine species (ballast water are sea water held in a tank within a sea vessel that balances the vessel). For example, regulations were set by the International Maritime Organization (IMO) and the United States Coast Gourd (USCG) together with the US Environmental Production Agency (EPA). Ballast water pumped from the sea in a first ecosystem (a first harbor) may contain marine species typical for that ecosystem. Discharging the water at a second ecosystem (in a second harbor) may harm the marine environment in the second ecosystem introducing new unnatural species to that ecosystem. The new regulations were set to ensure that only a minimal amount of new species either, microorganisms (e.g., bacteria) or larger organisms (e.g., zooplankton) are discharge into the sea.
Water, either sea water, ballast water, brackish water or fresh water, to be treated and/or disinfected may contain several types of contaminations, for example organism, bacteria, microorganism, microbe, germ, virus, organic contaminator and non-organic contaminator. Each type of entity or contamination may be inactivated or removed after exposure to UV light having different spectra. For example, microorganisms such as Escherichia, coli and Vibrio may be inactivated at the germicidal UV spectrum (e.g., 200-300 nm). The germicidal spectrum is partially in the UVC (100-280 nm) spectrum and partially in the UVB (280-315 nm) spectrum. In yet another example, marine species such as Zooplankton and Phytoplankton may be more sensitive to UV light at the UVC spectrum. Absorption of UV light in organic pollutant such as chloramines and chlorides may cause the oxidation and/or disintegration of the organic pollutant. Each organic compound may have different absorption pick at different part of the UV spectrum. For example, NH2Cl absorbs UV light having a wavelength of 400, 423 and 414 nm at the UVA spectrum; NHCl2 absorbs UV light having a wavelength of 135, 112 and 110 nm at the UVC spectrum; and NCl2 absorbs UV light having a wavelength of 415, 450 and 462 also at the UVA spectrum.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanied drawings in which:
It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits may not have been described in detail so as not to obscure the present invention. It can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the claimed subject matter.
Some embodiments of the invention may include a system for UV water treatment. Such system may include more than one type of UV lamps each having different emission spectra. It will be appreciated that the UV water treatment process according to some embodiments of the invention may include inactivation, disintegration or removal unwanted constituents existing in the liquid such as, for example, organism, bacteria, microorganism, marine species, being, creature, microbe, germ, virus, organic pollutant, non-organic pollutant, oxidizeable toxic or contaminator; any cumulative noxious species of biological or chemical origin; any oxidizing particle, fragment or element, e.g., Hydrogen peroxide or Titanium dioxide, intended to oxidize a contaminator and/or the like. As used herein, throughout the specification and claims, the terns “contaminant”, “entity”, substance” refer to any unwanted constituent existing in the liquid that should be inactivated, destroyed, killed, removed or disintegrated by the ultraviolet treatment.
As used herein, microorganisms are a microscopic organisms, which may be a single cell or multicellular organism that can only be detected under microscope. Some microorganisms may be marine species. Each entity or substance (e.g., microorganism, such as Escherichia coli and Vibrio; marine species such as Zooplankton and Phytoplankton or organic substances to be disintegrated such as NH2Cl or NHCl2) may be inactivated, disintegrated or removed using different portion of the UV spectrum, thus a system designed to remove, disintegrate or inactivate two or more of those specific types of entities may include two or more types of UV lamps to emit light at the desired spectrum.
Different types of UV lamps emit UV light at different spectra, for example, around different central wavelengths (e.g., 200, 280, 300, 400 nm). Assembling different types of UV lamps in a single UV disinfection system may allow treating, removing and/or inactivating various types of entities (referred to herein also as contaminants or substances) is a single process. The location of each of the UV lamps may be designed and determined in order to maximize the absorption of the UV light by the different types of contaminations. In designing the location of each UV lamp in a chamber for carrying the water to be disinfected, one may consider the spectrum emitted from each type of UV lamp, the transmittance of the water at that spectrum and each contamination sensitivity response as a function to the UV spectrum. In some embodiments, more than one UV lamp from each type may be included in the system.
Reference is made to
Conduit or chamber 110 may include an inlet 114 to receive the water and an outlet 116 to discharge the water. Chamber 110 may include walls made from any corrosive resisting material. In some embodiments, the walls of chamber 110 may include material that is not corrosion resistant and the walls may be coated with a corrosion resisting coating. In some embodiment, the walls of conduit 110 may, at least partially, include material transparent to UV radiation such as quartz.
First-type UV lamp 120 may generate UV light of a first UV spectrum. For example, first-type UV 120 lamps may emit UV light in the UVB spectrum or the germicidal spectrum. First-type UV lamps 120 may include for example a low-pressure UV lamp, a medium-pressure UV lamp, light emitting diode (LED) UV lamps and/or a microwave-excited UV lamp, as are all known in the art. First-type UV lamps 120 may be immersed in the water flow in conduit 110 (as illustrated) or may be located externally to conduit 110. In the case that first-type UV lamps 120 are located outside conduit 110, the conduit may include a UV transparent window (not illustrated) and UV lamp 120 may be located in proximity to the UV transparent window, such that UV light emitted from UV lamp 120 may enter conduit 110 and illuminate the water flowing in conduit 110.
Second-type UV lamp 130 may generate UV light of a second UV spectrum different than the first spectrum. For example, second-type UV lamp 130 may emit UV light in the UVC or UVA spectra. Second-type UV lamps 130 may include, for example, a low-pressure UV lamp, a medium-pressure UV lamp, light emitting diode (LED) UV lamps and/or a microwave-excited UV lamp. Second-type UV lamps 130 may be immersed in the water flowing through conduit 110 (as illustrated) or may be located externally to conduit 110. Although two types of UV lamps are illustrated in
First-type UV lamps 120 and second-type UV lamps 130 may be located substantially orthogonal to the water flow in chamber 110 (as illustrated). Each of lamps 120 or 130 may be protected by a UV transparent sleeve. In some embodiments, the location of one or more first-type UV lamps 120 and one or more second-type UV lamps 130 may be determined such that a combined UV spectral impact, from all the UV lamps matches with a combined sensitivity response function of two or more different predetermined types of substances in the water, each having a different response function. For example, the location of the UV lamps may be designed such that the combined UV emission function of the lamps would substantially match the combined sensitivity response function of the substances. Some examples of spectral impact of various medium pressure UV lamps are given in
As used herein, sensitivity response function is a curve of the UV absorption efficacy as a function of the wavelength for a specific contaminant. The sensitivity response function shows how efficient is the absorption of UV energy for the specific contaminant at a spectrum of UV wavelengths. A combined sensitivity response function is a curve or curves for two or more different contaminants shown in a single graph. A spectral impact of a lamp indicates the impact of UV light emitted from a specific type of lamp has on a specific type of contamination. The emission spectrum of a specific lamp (e.g., intensity as function of wavelength) is multiplied by the UV sensitivity response function of a specific contaminant to receive the spectral impact of the specific lamps on that contaminant.
Exemplary system 100 may be designed to treat, remove and/or inactivate at least two specific contaminants. For example, system 100 may be designed to inactivate Coli (microorganism) and Phytoplankton (marine organism). System 100 may include three (3) second-type lamps 130 placed in a front row facing the water flow (from inlet 114) and five (5) first-type UV lamps 120 placed in two rows; two lamps 120 in-between lamps 130 and 3 lamps 120 in a row behind the second row (before outlet 116). In some embodiments, lamps 120 may be Hg-based UV lamps configured to emit UVC germicidal spectrum to treat microorganisms and lamps 130 may be Hg doped Ga—In UV lamps configured to emit UVB spectrum for treating Phytoplankton at far field.
A calculated diagram showing UV dose distribution in system 100 is given in
Reference is made to
In some embodiments, lamps 120 may be Hg-based UV lamps configured to emit UVC germicidal spectrum to treat microorganisms and lamps 130 may be Ga—In doped Hg UV lamps configured to emit UVB spectrum for treating marine species at far field. A calculated diagram showing the UV dose distribution in system 200 is given in
Reference is made to
A calculated diagram showing UV dose distribution in system 300 is given in
In some embodiments, systems 100, 200 and 300 may be located on a watercraft or a sea vessel traveling between two or more locations (e.g., harbors). The vessels may include ballast tanks for carrying ballast water. Before discharging the ballast water, for example, in order to rebalance the sea vessel, the ballast water may be treated in a system such as systems 100, 200 and 300 to inactivate and remove marine organisms and marine microorganisms that may harm an ecosystem in the water in which the ballast water is to be discharged. Water treated by a system according to some embodiments of the invention may stand in international regulation for discharging ballast water.
In some embodiments, systems 100, 200 and 300 may further include two or more UV detectors (not illustrated). The UV detectors may be any illumination source status detectors that may be used for on-line real-time measurements and calculations of UV light transmittance of the water. The UV light transmittance of the water may be calculated from the measurements of the detectors in terms of Ultraviolet Water Transmission (UVT), commonly used in the UV industry and defined as the UV transmittance of a one centimeter water column at 254 nm.
In some embodiments, systems 100, 200 and 300 may further include a valve or faucet (not illustrated) to control a water flow rate in the conduits. Systems 100, 200 or 300 may further include a flow meter to measure the water flow rate either before or after the valve. The flow meter may be any commercial flow meter that is configured to measure a flow of water in a pipe or a conduit. In some embodiments, UV lamps 120 and 130, the UVT detectors, the flow meter and/or the valve may be coupled to a controller (not illustrated) configured to receive data and measurements from the UVT detector and the flow meter and adjust various working parameters of system, for example, the intensity of the UV lamps (e.g., the power applied to the lamps) and/or the water flow rate (e.g., by controlling the valve).
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In some embodiments, the types of the UV lamp may be selected by combining the combined sensitivity response function and emissions spectra of various types of UV lamps and determining which type of lamp may better treat the first or second types of known contaminants. In some embodiments, the system may be designed to treat three or more types of contaminants and the combined sensitivity response function may include all the various types of contaminants that the system may treat. In such additional types of UV lamps may be required to cover the entire UV spectrum needed to treat the different types of contaminants. In other embodiments, additional lamps emitting at wavelengths outside the UV spectrum may be added.
In operation 710, the method may include determining the location of one or more first-type ultraviolet (UV) lamps (e.g., lamps 120) having a first UV emission spectrum and one or more second-type UV lamps (e.g., lamps 130) having a second UV emission spectrum different than the first spectrum in conduit that is designed to carry the water. The design of the locations is based on computerized simulations and is aimed to match a combined UV impact function from all the UV lamps to the combined sensitivity response function of the specific contaminants or substances. In some embodiments, the location of each lamp from the first and the second type is determined such that a combined UV impact function from all the UV lamps substantially matches with a combined sensitivity response function of predetermined two or more different types of substances in the water each having a different response function, for example, the combined sensitivity response function illustrated in
In some embodiments, the UV spectrum emitted from each of the selected UV lamps may be analyzed from known data with respect to the transparency of the water to be treated. The transparency of the water may be predetermined based on known data regarding various types of water (e.g., sea water, ballast water, brackish water, fresh water or the like). The number and location of each type of lamp may be determined based on the transmittance, such that the longer the wavelength the larger is the penetration depth of the light and the larger may be the distance between two adjacent lamps from the same type, for example, as disclosed with respect to lamps 120 and 130 of system 300.
In some embodiments, a computerized optimization calculation may be made (e.g., by a processor) in order to determine the best location and the number of lamps for each type of lamps. One goal of the optimization calculation is to receive the highest possible minimal UV dose level that is applied to the water, to gain the most from the UV power applied to the water.
In operation 720, the method may include placing the one or more first-type UV lamps and one or more second-type UV lamps in the determined location. Placing of first-type and second-type UV lamps may be done during the assembling of the UV treatment system. The assembling of the system may include assembling additional components.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application claims priority of U.S. Provisional Application No. 61/736,860, filed Dec. 13, 2012, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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61736860 | Dec 2012 | US |