Patent Application
20130153514
1. Field of the Invention
The present invention is directed to apparatuses and methods for treating fluids with ultraviolet light.
2. Background
Ultraviolet (UV) disinfection of drinking water and waste water has been performed in various forms. Typically, a quartz-shielded UV lamp is placed directly in a stream of water. Although such designs provide high exposure of the water to the UV light, the lamps proximity to the quartz causes it to warm, eventually resulting in mineral deposits that significantly reduce the UV transmittance over time.
What is needed is an apparatus for treatment of a fluid using ultraviolet (UV) light in which the fluid is irradiated efficiently and without significant warming of the fluid.
The present invention is directed to an apparatus for the treatment of a fluid, comprising: a cylindrical chamber that includes a reflective inner surface, wherein the cylindrical chamber has an elliptical cross-section that includes a major axis; an ultraviolet-transmissive conduit suitable for transmitting a fluid, the ultraviolet-transmissive conduit positioned at a first point on the major axis of the elliptical cross-section and traversing a length of the cylindrical chamber; a mixing system configured to induce mixing of the fluid; a first ultraviolet light source and a second ultraviolet light source positioned within the cylindrical chamber, wherein the first and second ultraviolet light sources are substantially equidistant from the ultraviolet-transmissive conduit and on opposite sides of the major axis of the elliptical cross-section, wherein the first and second ultraviolet light sources provide a non-uniform irradiance of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowed through the ultraviolet-transmissive conduit is irradiated by ultraviolet light.
In some embodiments, the first ultraviolet light source and the second ultraviolet light source are equidistant from the major axis of the elliptical cross-section, and the elliptical cross-section has an eccentricity of 0 to 0.5. In some embodiments, the elliptical cross-section has a focal length of 10 mm to 50 mm. In some embodiments, a central point of an axis passing through the centers of the first and second ultraviolet light sources is positioned at a first focus of the elliptical cross-section. In some embodiments, the ultraviolet-transmissive conduit is positioned at a second focus of the elliptical cross-section.
The present invention is also directed to an apparatus for the treatment of a fluid, comprising: a cylindrical chamber having a double-elliptical cross-section provided by partially overlapping first and second ellipses, wherein the ellipses have co-linear major axes and overlapping second focal points, wherein the cylindrical chamber includes a reflective inner surface; an ultraviolet-transmissive conduit suitable for transmitting a fluid, the ultraviolet-transmissive conduit positioned at the overlapping second focal points of the first and second ellipses, wherein the ultraviolet-transmissive conduit traverses a length of the cylindrical chamber; a mixing system configured to induce mixing of the fluid; a first ultraviolet light source and a second ultraviolet light source positioned within the cylindrical chamber, wherein the first and second ultraviolet light sources are substantially equidistant from the ultraviolet-transmissive conduit and on opposite sides of the major axis of the first ellipse of the double-elliptical cross-section; and a third ultraviolet light source and a fourth ultraviolet light source positioned within the cylindrical chamber, wherein the third and fourth ultraviolet light sources are substantially equidistant from the ultraviolet-transmissive conduit and on opposite sides of the major axis of the second ellipse of the double-elliptical cross-section, wherein the first, second, third, and fourth ultraviolet light sources provide a non-uniform irradiance of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowed through the ultraviolet-transmissive conduit is irradiated by ultraviolet light.
The present invention is also directed to an apparatus for the treatment of a fluid, comprising: a cylindrical chamber having a double-elliptical cross-section provided by partially overlapping first and second ellipses, wherein the ellipses have co-linear major axes and wherein the cylindrical chamber includes a reflective inner surface; an ultraviolet-transmissive conduit suitable for transmitting a fluid, wherein a first portion of the ultraviolet-transmissive conduit traverses a length of the cylindrical chamber and is positioned at a first point on the major axis of the first ellipse, wherein a second portion of the ultraviolet-transmissive conduit traverses a length of the cylindrical chamber and is positioned at a first point on the major axis of the second ellipse; a mixing system configured to induce mixing of the fluid; a first ultraviolet light source and a second ultraviolet light source positioned within the cylindrical chamber, wherein the first and second ultraviolet light sources are substantially equidistant from the ultraviolet-transmissive conduit and on opposite sides of the major axis of the first ellipse of the double-elliptical cross-section; a third ultraviolet light source and a fourth ultraviolet light source positioned within the cylindrical chamber, wherein the third and fourth ultraviolet light sources are substantially equidistant from the ultraviolet-transmissive conduit and on opposite sides of the major axis of the second ellipse of the double-elliptical cross-section; and a fifth ultraviolet light source positioned within the cylindrical chamber between the first and second portions of the ultraviolet-transmissive conduit and on the overlapping major axes of the first and second ellipses, wherein the first, second, third, fourth, and fifth ultraviolet light sources provide a non-uniform irradiance of the first and second portions of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowed through the ultraviolet-transmissive conduit is irradiated by ultraviolet light.
In some embodiments, the first portion of the ultraviolet-transmissive conduit is positioned at a second focus of the first ellipse and the second portion of the ultraviolet-transmissive conduit is positioned at a second focus of the second ellipse. In some embodiments, the first and second ultraviolet light sources are equidistant from the major axis of the first ellipse of the double-elliptical cross-section and the third and fourth ultraviolet light sources are equidistant from the major axis positioned on the major axis of the second ellipse of the double-elliptical cross-section. In some embodiments, a central point of an axis passing through the centers of the first and second ultraviolet light sources is positioned at a first focus of the first ellipse and a central point of an axis passing through the centers of the third and fourth ultraviolet light sources is positioned at a first focus of the second ellipse. In some embodiments, the ultraviolet light sources are U-shaped ultraviolet bulbs, H-shaped ultraviolet bulbs, or a combination thereof.
The present invention is also directed to an apparatus for the treatment of a fluid, comprising: an ultraviolet-transmissive conduit suitable for containing a flowing fluid, the ultraviolet-transmissive conduit positioned within and traversing a length of a cylindrical chamber that includes a reflective inner surface; a mixing system configured to induce mixing of the fluid; and a plurality of ultraviolet light sources positioned in an even distribution around the ultraviolet-transmissive conduit, each ultraviolet light sources including a parabolic reflector, wherein the ultraviolet light sources provide a non-uniform irradiance of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowed through the ultraviolet-transmissive conduit is irradiated by ultraviolet light.
In some embodiments, the elliptical cross-section includes a minor axis and the ultraviolet-transmissive conduit and ultraviolet light source(s) are on opposite sides of the minor axis.
In some embodiments, an apparatus of the present invention comprises an ultraviolet-transmissive sheath surrounding the ultraviolet light sources. In some embodiments, an apparatus of the present invention comprises an ultraviolet-transmissive sheath surrounding the conduit. In some embodiments, the substantially reflective inner surface of the cylindrical chamber comprises aluminum.
In some embodiments, the ultraviolet-transmissive conduit has a substantially circular cross-section of 10 mm to 125 mm in diameter. In some embodiments, the ultraviolet-transmissive conduit has a length of 10 cm to 300 cm. In some embodiments, the ultraviolet-transmissive conduit comprises quartz. In some embodiments, the ultraviolet-transmissive conduit comprises an anti-corrosive inner surface. In some embodiments, at least 80% of a volume of the ultraviolet-transmissive conduit is irradiated by the ultraviolet light sources.
In some embodiments, an apparatus of the present invention is for treatment of water contained within an ultraviolet-transmissive conduit. In some embodiments, the ultraviolet light sources generate oxygen radicals.
In some embodiments, an apparatus of the present invention comprises a wiper suitable for traversing at least a portion of the ultraviolet-transmissive conduit. In some embodiments, the wiper includes a contact surface suitable for mechanically cleaning an inner surface of the ultraviolet-transmissive conduit. In some embodiments, the wiper comprises a rigid member suitable for controlling the position of the wiper within the ultraviolet-transmissive conduit, wherein the wiper is connected to the rigid member by one or more spokes.
In some embodiments, the mixing system is located at least partially in the ultraviolet-transmissive conduit. In some embodiments, the mixing system comprises an angular feed and at least one mixing device. In some embodiments, the angular feed is attached to the ultraviolet-transmissive conduit such that a fluid flowing into the ultraviolet-transmissive conduit undergoes rotational mixing. In some embodiments, the angular feed comprises an inlet having a first diameter and an outlet having a second diameter, wherein the second diameter is greater than the first diameter.
In some embodiments, the mixing device is at a fixed position within the ultraviolet-transmissive conduit. In some embodiments, the mixing device comprises one or more fixed or rotating fins, baffles, or a combination thereof.
In some embodiments, an apparatus of the present invention comprises a flow diffuser located before the angular feed such that a fluid flowed through the flow diffuser into the angular feed is a fully developed flow. In some embodiments, the flow diffuser induces a pressure drop in a flowing fluid of 10 kPa or less.
The present invention is also directed to a method of treating a fluid, the method comprising directing a flowing fluid through the ultraviolet-transmissive conduit of an apparatus of the present invention, and generating ultraviolet light using the ultraviolet light sources, wherein substantially all of the fluid flowing through the ultraviolet-transmissive conduit is irradiated by the ultraviolet light.
In some embodiments, the ultraviolet-transmissive conduit has a substantially circular cross-section of 25 mm to 75 mm in diameter, and the first and second ultraviolet light sources provide a total dosage of 5 mJ/cm2 to 75 mJ/cm2 to the fluid flowing through the ultraviolet-transmissive conduit. In some embodiments, a fluid enters the ultraviolet-transmissive conduit at a rate of 100 gallons per minute or less. In some embodiments, a fluid entering the ultraviolet-transmissive conduit has an ultraviolet transmission of at least 60%.
In some embodiments, the ultraviolet-transmissive conduit has a substantially circular cross-section of 60 mm to 125 mm in diameter, and the ultraviolet light sources provide a total dosage of 50 mJ/cm2 to 250 mJ/cm2 to the fluid flowing through the ultraviolet-transmissive conduit. In some embodiments, a flowing fluid enters the ultraviolet-transmissive conduit at a rate of 25 gallons per minute or more. In some embodiments, a fluid entering the ultraviolet-transmissive conduit has an ultraviolet transmission of 90% or less.
In some embodiments, an apparatus of the present invention comprises a flow diffuser located before the angular feed such that a fluid flowed through the flow diffuser into the angular feed is a fully developed flow. In some embodiments, the flow diffuser induces a pressure drop in a flowing fluid of 10 kPa or less.
The present invention is also directed to an apparatus for the treatment of a fluid, comprising: a cylindrical chamber that includes a reflective inner surface, wherein the cylindrical chamber has an elliptical cross-section; an ultraviolet-transmissive conduit suitable for transmitting a fluid, traversing a length of the cylindrical chamber; an angular feed attached to the ultraviolet-transmissive conduit, wherein the angular feed comprises an inlet having a first diameter and an outlet having a second diameter, wherein the second diameter is greater than the first diameter; one or more ultraviolet light sources positioned within the cylindrical chamber, wherein the ultraviolet light sources provide a non-uniform irradiance of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowed through the ultraviolet-transmissive conduit is irradiated by ultraviolet light
Methods of cleaning at least an inner surface of UV transmissive conduit are also provided.
Further embodiments, features, and advantages of the present inventions, as well as the structure and operation of the various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
One or more embodiments of the present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers can indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number can identify the drawing in which the reference number first appears.
This specification discloses one or more embodiments that incorporate the features of this invention. The disclosed embodiment(s) merely exemplify the invention. The scope of the invention is not limited to the disclosed embodiment(s). The invention is defined by the claims appended hereto.
The embodiment(s) described, and references in the specification to “some embodiments,” “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment(s) described can include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
In one embodiment, the present invention provides apparatuses for the treatment of a fluid, including water (e.g., drinking water, municipal waste water, industrial waste water, sewer water, storm water, etc.). Additional fluids that can be treated include polymeric fluids (e.g., ultraviolet light-curable polymers, and the like), gases, etc. As shown in
As used herein, a “cylindrical chamber” refers to a structure having a tubular shape with a length, and a substantially uniform cross-section throughout the length. It should be noted that a cylindrical chamber, while suitably having an elliptical cross-section, when present in an apparatus of the present invention can be positioned within a structure or enclosure of arbitrary shape (i.e., any shape). For example, referring to
A cylindrical chamber suitably includes a reflective inner surface. Referring to
As used herein “reflective” refers to a surface having a reflectivity of 50% or more, such that the intensity of a light impinging upon a reflective inner surface is diminished by 50% or less by reflection from the inner surface (i.e., losses from absorption, transmission, and other processes total 50% or less of the total intensity of the incoming light). In some embodiments, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, at least 99%, or 100% of the area of the inner surface of a cylindrical chamber is reflective. An inner surface of a cylindrical chamber can be prepared using an inherently reflective material, can be polished to provide a reflective surface, or can be covered with a reflective material. In some embodiments, an inner surface, 114, is made reflective by affixing, adhering, or otherwise covering an inner surface of the cylindrical chamber with a reflective material.
Reflective materials suitable for use with the present invention include any material that reflects at least 50% of ultraviolet light having a wavelength of about 250 nm to about 400 nm. Suitably, a reflective material reflects at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, at least 99.9%, or about 100% of ultraviolet light having a wavelength of about 250 nm to about 400 nm that impinges upon an inner surface. Exemplary reflective materials include plastics, polymers, glasses, metals, ceramics, composites, etc. Reflective materials suitable for use with the present invention include, but are not limited to, metals (e.g., aluminum, chromium, gold, silver, tungsten, tin, titanium, and the like, oxides thereof, and alloys thereof), ceramics and glasses (e.g., carbides, nitrides, oxycarbides, oxynitrides, carboxynitrides, borocarbides, boronitrides, borophosphides, and the like, and combinations thereof), and the like. In some embodiments, the reflective surface comprises polished aluminum.
Suitably, reflective material comprises a metal such as Al, or glass, and is suitably polished to increase its reflectivity. In suitable embodiments the ends of chamber are also suitably covered or capped with a reflective material, such as a metal or glass, including Al mirrors and the like. The ends are suitably positioned perpendicular to the axis of chamber.
A reflective material can be coated, layered, deposited, formed, sprayed, or otherwise disposed on an inner surface of a cylindrical chamber, or chamber can be prepared from a reflective material. In some embodiments, a reflective inner surface of a chamber is treated with an antibacterial coating, for example a Ag or Cu coating, and/or an anti-corrosive coating to minimize corrosion, including chemical, particle and bacterial deposits. Additional coatings or treatments include non-stick and anti-fouling coatings and treatments. Examples of include chemical surface treatments, such as spraying, dipping, coating, layering, painting, etc., with a chemical compound, as well as physical treatments, including roughening, etc., to make the inner surface anti-corrosive.
In further embodiments, an additional reflector, for example a flat or substantially flat panel (not shown) can be included in the cylindrical chamber opposite the ultraviolet light source, i.e., on a far side of the ultraviolet-transmissive conduit away from a light source. Additional components can also be included within a cylindrical chamber to aid in maintaining the temperature of a fluid flowed through the ultraviolet-transmissive conduit. Such components can include fans or air-vents, as well as tubing to circulate cooled liquid. Sensors can also be included within or around the cylindrical chamber that provide data on the power output of the UV light source in real time, as well as the temperature within the chamber and/or of the fluid.
Referring to
wherein the origin of coordinates is the center of geometric symmetry of the ellipse, and the coordinate axes are its axes of symmetry (i.e., the ellipse is symmetrical around the X and Y axes, see
In exemplary embodiments, an elliptical cross-section of a cylindrical chamber has an eccentricity of 0 to 0.5, suitably 0 to 0.4, 0 to 0.3, 0 to 0.2, 0 to 0.1, and more suitably, about 0.20, about 0.21, about 0.22, about 0.23, about 0.24, about 0.25 about 0.26, about 0.2, about 0.28, about 0.29 or about 0.30. Referring to
Referring to
Ultraviolet-transmissive conduit 106 comprises an inlet and outlet that allow for introduction of fluid 108 into the ultraviolet-transmissive conduit, so as to flow a fluid through chamber 102. Suitable inlet and outlet connectors are known in the art, and include liquid-tight connectors that allow fluid flow without leakage. Thus, in suitable embodiments, apparatus 100 can be removed from a larger device and interchanged with another apparatus 100.
In some embodiments, the ultraviolet-transmissive conduit comprises an inlet and outlet that allow a fluid enters and exits at different ends of a chamber. In some embodiments, the ultraviolet-transmissive conduit comprises an inlet and outlet that allow a fluid enters and exits at the same end of a chamber. In some embodiments, the ultraviolet-transmissive conduit has a U shape. In some embodiments, the ultraviolet-transmissive conduit has an H-shape.
Referring to
An ultraviolet-transmissive conduit can have a length of 10 cm to 300 cm, 10 cm to 250 cm, 10 cm to 200 cm, 10 cm to 175 cm, 10 cm to 150 cm, 10 cm to 125 cm, 10 cm to 100 cm, 20 cm to 300 cm, 20 cm to 250 cm, 20 cm to 200 cm, 20 cm to 150 cm, 20 cm to 100 cm, 30 cm to 300 cm, 30 cm to 250 cm, 30 cm to 200 cm, or 30 cm to 150 cm. It should be noted that other dimensions of transmissive conduit can also be utilized, including longer or shorter conduits, or conduits with larger or smaller diameters.
Methods for optimizing the diameter of ultraviolet-transmissive conduit include the use of irradiance mapping and curve fitting. An irradiance map of a transmissive conduit can be either determined experimentally or estimated via simulation and modeling. A Gaussian function can then be curve-fitted to the cross-section of the irradiance map, for example, using a least squares fitting. The standard deviation, σ, of the Gaussian profile is then used to determine the optimal diameter of the ultraviolet-transmissive conduit, suitably 2√2σ to 4√2σ. See Example 1.
As shown in
As used herein, “substantially all” when referring to the irradiation of a fluid flowing within transmissive conduit 106 indicates that greater than 50%, greater than 60%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, or about 100% of the fluid flowing through the cross-section is irradiated.
Referring to
In some embodiments, an ultraviolet-transmissive conduit comprises a mixing system to assist in mixing a fluid that is flowed through the apparatus so as to expose more of the fluid to UV light and/or to uniformly expose a flowing fluid to UV light. Mixing systems suitable for use with the present invention include, but are not limited to, an angular feed, a mixing device, and combinations thereof.
In some embodiments, an apparatus of the present invention comprises an angular feed attached to the ultraviolet-transmissive conduit such that a fluid flowed into the ultraviolet-transmissive conduit undergoes rotational mixing. Not being bound by any particular theory, mixing of the fluid within the ultraviolet-transmissive conduit provides that substantially all of the flowing fluid is irradiated despite non-uniform irradiance of the ultraviolet-transmissive conduit.
In some embodiments, an ultraviolet-transmissive conduit comprises a scraper to assist with cleaning the ultraviolet-transmissive conduit and remove deposits from an interior surface thereof, such as mineral deposits, bacteria, and the like that can form on an inner surface of the ultraviolet-transmissive conduit.
Referring to
Referring to
Ultraviolet light source 104, suitably is a UV lamp or bulb having a diameter of 5 mm to 70 mm, more suitably 10 mm to 50 nm, 10 mm to 40 mm, 15 mm to 40 mm, 20 mm to 40 mm, 20 mm to 30 mm, or about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, about 20 mm, about 21 mm, about 22 mm, about 23 mm, about 24 mm, about 25 mm, about 26 mm, about 27 mm, about 28 mm, about 29 mm, or about 30 mm in diameter. The diameter of ultraviolet light source 104 is measured across the largest cross-section of the ultraviolet light source. Length of UV light source 104 can be the full length of chamber 102, or can be shorter. Suitably UV light source is 10 cm to 200 cm in length. In exemplary embodiments, UV light source is a P
UV light source suitably generates light at a wavelength of 10 nm to 400 nm. Suitably, UV light generated by UV light source is UV-C, or short wave UV light, with a wavelength (λ) of 100-280 nm, suitably about 254 nm. UV-A, or long wave UV light (λ=320-400 nm), as well as UV-B, or medium wave UV light (λ=280-320 nm), can also be utilized. In further embodiments, a cylindrical chamber can comprise additional ultraviolet light sources (e.g., additional UV lamps), to maximize the irradiation of a flowing fluid in the ultraviolet-transmissive conduit. Suitably UV light source can generate UV light that serves to reduce or kill bacteria in a fluid (e.g., water), for example, light at about 254 nm, and can also generate UV light which generates oxygen radicals, for example, light at about 185 nm. The shorter UV light at about 185 nm generates oxygen radicals (e.g., ozone) within an aqueous fluid that is flowed into the apparatus, which in turn oxidizes organic molecules that are present in the aqueous fluid.
In other embodiments, a diffuser, lens, or other optical element can be placed between an ultraviolet light source and an ultraviolet-transmissive conduit to control the intensity or amount of irradiation of a fluid flowed into the apparatus. Referring to
In further embodiments, the present invention provides additional apparatus for the treatment of a fluid. In exemplary embodiments, as represented in
Exemplary dimensions, characteristics, and materials, for the components of apparatus 100 are described herein. In suitable embodiments, the elliptical cross-section has a focal length of 20 mm to 40 mm (e.g., 35 mm to 40 mm). Suitably, reflective material 118 comprises Al, and the ultraviolet-transmissive conduit 106 comprises quartz. Ultraviolet-transmissive conduit 106 suitably has a substantially circular cross-section 120 of 50 mm to 75 mm in diameter, and a length of 20 cm to 175 cm, and can be treated with an anti-corrosive coating. Suitably at least 80% (e.g., at least 90%, at least 95% or at least 99%) of the transmissive conduit, and thus the fluid within the ultraviolet-transmissive conduit, is irradiated by the ultraviolet light source.
The dimensions of chamber 102, ultraviolet light source 104, conduit 106, as well as the relationship between the components of the apparatus of the present invention, can readily be scaled in increasing or decreasing amounts to accommodate larger or smaller fluid volumes as desired. For example, the apparatus of the present invention is readily scalable to accommodate flow rates within conduit 106 on the order of 0.01 to thousands of gallons per minute, or more (0.01 to 1,000+ gallons/min). The ability to scale the dimensions of the apparatus of the present invention is well within the skill of one in the art.
As shown in
Modeling simulations that examined the effect of moving the ultraviolet light source away from a first focal point were conducted, the results of which are provided graphically in
As illustrated in
Referring to
In some embodiments, a fluid flowing through an angular feed and an ultraviolet-transmissive conduit is fully developed. As used herein, “fully developed flow” refers to a flow through a pipe, conduit, tube, and the like, in which the boundary layer of the fluid that is flowing past the inner surface of the pipe, conduit, tube, and the like has a stabilized velocity. In some embodiments, a fluid having a fully developed flow has a Reynolds Number of 2,000 or greater, 2,100 or greater, 2,200 or greater, 2,300 or greater, 2,500 or greater, 3,000 or greater, 4,000 or greater, 5,000 or greater, or 10,000 or greater.
Not being bound by any particular theory, a flow of a fluid can become fully developed upon entering a pipe, conduit, tube, and the like after traveling through the pipe a distance of several diameters. The distance that a flowing fluid travels through a pipe, conduit, tube, and the like, can be decreased by introducing a flow diffuser into the pipe.
In some embodiments, an apparatus of the present invention comprises a flow diffuser located before the angular feed such that a fluid flowing through the flow diffuser into the angular feed is a fully developed flow. As used herein, a “flow diffuser” refers to a diaphragm, a membrane, a filter, an insert, a grating, and the like having holes, continuous pores, perforations, and the like there through. A flow diffuser can be prepared from any solid, porous, or flexible material, such as, but not limited to, metals (e.g., stainless steel, and the like), ceramics, plastics, wires (i.e., mesh), and the like, and composites thereof.
In some embodiments, a flow diffuser has a plurality of holes with a diameter of about 5 mm and a pitch of about 7 mm. In some embodiments, a flow diffuser has a plurality of holes with a diameter of about 3 mm and a pitch of about 5 mm.
In some embodiments, a flow diffuser comprises two or more groups, or three or more groups of holes having different lateral dimensions. A schematic diagram of a flow diffuser having two groups of holes of different lateral dimensions is provided in
In some embodiments, a flow diffuser is located at a point immediately before an angular feed. In some embodiments, a flow diffuser is located at a point immediately after an expansion in the diameter of a tube or conduit.
In some embodiments, a flow diffuser induces a pressure drop in a flowing fluid of 10 kPa or less, 9 kPa or less, 8 kPa or less, 7 kPa or less, 6 kPa or less, 5 kPa or less, 4 kPa or less, 3 kPa or less, or 2 kPa or less. In some embodiments, a flow diffuser induces a pressure drop in a flowing fluid of 1 kPa to 10 kPa, 1 kPa to 7.5 kPa, 1 kPa to 5 kPa, 2 kPa to 10 kPa, 2 kPa to 7.5 kPa, 3 kPa to 9 kPa, 4 kPa to 8 kPa, or about 2 kPa, about 3 kPa, about 4 kPa, about 5 kPa, about 6 kPa, about 7 kPa, about 8 kPa, or about 10 kPa.
In reducing the distance between the light source and the ultraviolet-transmissive conduit by reducing the eccentricity of the elliptical cross-section, the temperature effect on fluid within conduit should also be considered. As noted above, increasing the temperature of a fluid, for example, water that is being treated, can increase the deposition of minerals, metals, and the like on an inner surface of the ultraviolet-transmissive conduit.
The present invention also provides methods of treating a fluid, e.g., disinfecting water. As described herein, in exemplary embodiments, the fluid that is treated/disinfected by irradiation with ultraviolet light is water, including drinking water, municipal waste water, industrial waste water, sewer water, storm water, etc. In some embodiments, an apparatus and/or method of the present invention is suitable for inactivating a pathogen, a bacterium, a spore, an indicator, an organism, or a combination thereof. In some embodiments, the bacterium, spore, virus, protozoan, and the like is a bacterium, spore, virus, or protozoan found in human feces, sludge, and the like.
Non-limiting examples of pathogens, indicators, and organisms suitable for inactivation using an apparatus and/or method of the present invention include: spores such as, but not limited to, Bacillus subtilis ATCC6633, Bacillus subtilis WN626, and the like; bacterium such as, but not limited to, Aeromonas hydrophila ATCC7966, Aeromonas salmonicida, Campylobacter jejuni ATCC 43429, Citrobacter diversus, Citrobacter freundii, Escherichia coli ATCC 11229, Escherichia coli ATCC 11303, Escherichia coil ATCC 25922, Escherichia coli C, Escherichia coli O157:H7, Escherichia coli O157:H7CCUG 29193, Escherichia coli O157:H7CCUG 29197, Escherichia coli O157:H7CCUG 29199, Escherichia coli O157:H7 ATCC 43894, Escherichia coli O25:K98:NM, Escherichia coli 026, Escherichia coli O50:H7, Escherichia coli O78:H11, Escherichia coli K-12 IFO3301, Escherichia coli Wild type, Halohacterium elongata ATCC33173, Halobacterium salinarum ATCC43214, Klebsiella pneumoniae, Klebsiella terrigena ATCO33257, Legionella pneumophila ATCC 43660, Legionella pneumophila ATCC33152, Pseudomonas stutzeri, RB2256, Salmonella spp., Salmonella anatum, Salmonella derby, Salmonella enteritidis, Salmonella infantis (from human feces), Salmonella typhi ATCC 19430, Salmonella typhi ATCC 6539, Salmonella typhimurium, Shigella dysenteriae ATCC29027, Shigella sonnei ATCC9290, Staphylococcus aureus ATCC25923, Streptococcus faecalis ATCC29212, Streptococcus faecalis, Vibrio anguillarum, Vibrio cholerae ATCC25872, Vibrio natriegens, Yersinia enterocolitica ATCC27729, Yersinia ruckeri, and the like; protozoans such as, but not limited to, Cryptosporidium hominis, Coptosporidiwn parvum, Cryptosporidium canis, Cryptosporidium felis, Cryptosporidium meleagridis, Cryptosporidium muris, Encephalitozoon cuniculi (microsporidia), Encephalitozoon hellem (microsporidia), Encephalitozoon intestinalis (microsporidia), Giardia lamblia, Giardia marls, Giardia beckeri, Giardia heltrani, Giardia botauri, Giardia bovis, Giardia hradvpi, Giardia canis, Giardia caprae, Giardia cati, Giardia caviae, Giardia chinchillas, Giarclia dasi, Giardia equii, Giardia floridae, Giardia hegneri, Giardia herodiadis, Giardia hyderahadensis, Giardia irarae, Giardia marginalis, Giardia melospizae, Giardia nycticori, Giardia ondatrue, Giardia otomyis, Giardia pitymysi, Giardia pseudoardeae, Giardia recurvirostrae, Giardia sanguinis, Giardia serpentis, Giardia simoni, Giardia sturnellae, Giardia suricatae, Giardia tucani, Giardia varani, Giardia viscaciae, Giardia wenyoni, Plasmodium, Toxoplasma, and the like; viruses such as, but not limited to, PRD-1 (Phage), B40-8 (Phage), MS2 (Phage), MS2 DSM 5694 (Phage), MS2 ATCC 15977-B1 (Phage), MS2 NCIMB 10108 (Phage), MS2 (Phage), PHI X 174 (Phage), Staphylococcus aureus phage A 994 (Phage), Calicivirus canine, Adenovirus type 2, Adenovirus type 15, Adenovirus type 40, Adenovirus type 41, Poliovirus Type 1 ATCC Mahoney, Poliovirus Type 1 LSc2ab, Poliovirus 1, Coxsackievirus B5, Coxsackievirus B3, Reovirus-3, Reovirus Type 1 Lang Strain, Rotavirus, Rotavirus SA-11, Hepatitis A, Hepatitis A HM175, Echovirus I, Echovirus II, and the like, and combinations thereof.
Referring to
In a further embodiment, the present invention provides additional apparatuses for the treatment of a fluid, including water. As shown in
Suitably, the first ultraviolet light source, 1004, and the second ultraviolet light source, 1005, are aligned along the major axis, 1008, of the elliptical cross-section of the cylindrical chamber 1002, as shown in
As shown in
As described herein, ultraviolet-transmissive conduit 1006 comprises an inlet and outlet that allow for introduction of a fluid into the ultraviolet-transmissive conduit, so as to pass fluid through chamber 1002. Suitable inlet and outlet connectors are known in the art, and include liquid-tight connectors that allow fluid flow without leakage. In some embodiments, an angular feed is attached to the ultraviolet-transmissive conduit to induce rotational mixing of a fluid that will be flowed into the ultraviolet-transmissive conduit. Thus, substantially all of a fluid flowed within the ultraviolet-transmissive conduit will be irradiated with UV light despite an optical configuration for the apparatus that provides non-uniform irradiance of the ultraviolet-transmissive conduit by the first and second UV light sources.
In some embodiments, an apparatus comprises a mixing device at a fixed position within the ultraviolet-transmissive conduit, wherein the mixing device comprises two or more fixed or rotating fins. For example, the mixing device can comprises two fixed fins similar in shape and position to the spokes, 1704, of a wiper, as shown in
Not being bound by any particular theory, a mixing device located at a fixed point within the ultraviolet-transmissive conduit can facilitate uniform rotational mixing through the length of the ultraviolet-transmissive conduit, thereby enhancing dosage uniformity.
Referring to
In some embodiments, multiple single-bulb or U-shaped bulbs are placed in series within the apparatus along the length of the ultraviolet-transmissive conduit (i.e., one after the other along the length of the chamber parallel to the ultraviolet-transmissive conduit). Thus, the orientation of elements depicted in cross-section of chamber 102 shown in
Referring to
In suitable embodiments, elliptical cross-section of cylindrical chamber 102 and 1002, respectively, for use in the apparatus shown in
Referring to
The positioning of light sources 1004 and 1005, and conduit 1006, within chamber 1002, and selection of appropriate characteristics of the light sources, as well as eccentricity of the ellipse, and an angular feed, provide that substantially all the fluid within ultraviolet-transmissive conduit 1006 is irradiated by the ultraviolet light source(s), despite a non-uniform irradiance of the ultraviolet-transmissive conduit, 1006, by the UV light source(s).
In contrast, utilizing an inlet angle θ=90° produces a flow profile with the orientation shown in
First and second UV light sources suitably generate light at a wavelength of 10 nm to 400 nm. Suitably, UV light generated by UV light source is UV-C, or short wave UV light, with a wavelength (λ) of 100-280 nm, suitably about 254 nm. UV-A, or long wave UV light (λ=320-400 nm), as well as UV-B, or medium wave UV light (λ=280 nm to 320 nm), can also be utilized. Suitably, first and second UV light sources can generate UV light that serves to reduce the activity of bacteria, or kill bacteria, in a fluid (e.g., water), for example, light at about 254 nm, and can also generate UV light which generates oxygen radicals, for example, light at about 185 nm. The shorter-wavelength UV light at about 185 nm generates oxygen radicals (e.g., ozone) upon irradiation of an aqueous fluid that is flowed into the apparatus, which in turn oxidizes organic molecules present in the aqueous fluid.
Referring to
Referring to
In some embodiments, the apparatus depicted in
Referring to
Referring to
Referring to
In some embodiments, the apparatus depicted in
In some embodiments, an apparatus of the present invention comprises a mixing system configured to induce mixing of the fluid, wherein the mixing system is located at least partially in the ultraviolet-transmissive conduct. For example, the mixing system comprises an angular feed and at least one mixing device. In some embodiments, an apparatus of the present invention comprises an angular feed attached to the ultraviolet-transmissive conduit such that a fluid flowing into the ultraviolet-transmissive conduit undergoes rotational mixing. In some embodiments, the angular feed comprises an inlet having a first diameter and an outlet attached to a conduit having a second diameter, wherein the second diameter is greater than the first diameter. Not being bound by any particular theory, mixing of the fluid within the ultraviolet-transmissive conduit provides that substantially all of the flowing fluid is irradiated despite non-uniform irradiance of the ultraviolet-transmissive conduit.
Referring to
Referring to
In some embodiments, a mixing system for use with the present invention comprises a mixing device. Mixing devices suitable for use with the present invention include, but are not limited to, fixed fins, rotating fins, fixed-angle baffles, variable-angle baffles, propellers (having, e.g., 2, 3, 4, 5, 6, 7, 8, or more radii), and the like, and combinations thereof. In some embodiments, a mixing device moves within the ultraviolet-transmissive conduit (i.e., traverses the length of the conduit). In some embodiments, a mixing device moves to change its angular position relative to a fluid path (e.g., a change in an angle of a baffle or fin). In some embodiments, a mixing device is in a fixed position within the ultraviolet-transmissive conduit. Not being bound by any particular theory, a mixing device located at a fixed point within the ultraviolet-transmissive conduit can facilitate uniform rotational mixing through the length of the ultraviolet-transmissive conduit.
In some embodiments, an apparatus of the present invention for the treatment of a fluid comprises a cylindrical chamber that includes a reflective inner surface, wherein the cylindrical chamber has an elliptical cross-section. The apparatus also comprises an ultraviolet-transmissive conduit suitable for transmitting a fluid, traversing a length of the cylindrical chamber, and an angular feed attached to the ultraviolet-transmissive conduit, wherein the angular feed comprises an inlet having a first diameter and an outlet having a second diameter, wherein the second diameter is greater than the first diameter. One or more ultraviolet light sources positioned within the cylindrical chamber, wherein the ultraviolet light sources provide a non-uniform irradiance of the ultraviolet-transmissive conduit, and wherein substantially all of a fluid flowing through the ultraviolet-transmissive conduit is irradiated by ultraviolet light
As discussed herein elsewhere, in some embodiments an apparatus comprises an ultraviolet-transmissive sheath surrounding the ultraviolet light sources. In some embodiments, the substantially reflective inner surface of the cylindrical chamber comprises aluminum.
The present invention also provides methods of treating a fluid, e.g., disinfecting water, utilizing the apparatus of the present invention. As described herein, in exemplary embodiments, the fluid that is treated/disinfected is water, including drinking water, municipal waste water, industrial waste water, sewer water, storm water, etc.
In some embodiments, the methods are suitable for treating water that is not heavily contaminated with light-absorbing species and the like. In such embodiments, an ultraviolet-transmissive conduit has a substantially circular cross-section of 25 mm to 75 mm, 25 mm to 60 mm, 25 mm to 50 mm, 30 mm to 75 mm, 30 mm to 60 mm, 40 mm to 75 mm, 40 mm to 60 mm, 50 mm to 75 mm, about 25 mm, about 40 mm, about 50 mm, about 60 mm, or about 75 mm in diameter, and the ultraviolet light sources (e.g., first and second UV light sources) provide a total dosage of 5 mJ/cm2 to 125 mJ/cm2, 5 mJ/cm2 to 100 mJ/cm2, 5 mJ/cm2 to 75 mJ/cm2, 10 mJ/cm2 to 125 mJ/cm2, 10 mJ/cm2 to 100 mJ/cm2, 10 mJ/cm2 to 75 mJ/cm2, 25 mJ/cm2 to 125 mJ/cm2, 25 mJ/cm2 to 100 mJ/cm2, 25 mJ/cm2 to 75 mJ/cm2, 50 mJ/cm2 to 125 mJ/cm2, 50 mJ/cm2 to 100 mJ/cm2, or 50 mJ/cm2 to 75 mJ/cm2 to the fluid flowing through the ultraviolet-transmissive conduit. In such embodiments, a fluid enters the ultraviolet-transmissive conduit at a rate of 100 gallons per minute or less, 90 gallons per minute or less, 80 gallons per minute or less, 70 gallons per minute or less, 60 gallons per minute or less, 50 gallons per minute or less, 40 gallons per minute or less, 30 gallons per minute or less, 20 gallons per minute or less, 10 gallons per minute or less. In some embodiments, a fluid entering the ultraviolet-transmissive conduit has an ultraviolet transmission of at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% (i.e., at λ=254 nm for a fluid sample having a path length of 1 cm).
In some embodiments, the methods are suitable for treating water that is heavily contaminated with light-absorbing species and the like. In such embodiments, the ultraviolet-transmissive conduit has a substantially circular cross-section of 60 mm to 125 mm, 70 mm to 125 mm, 80 mm to 125 mm, 90 mm to 125 mm, 100 mm to 125 mm, about 75 mm, about 100 mm, or about 125 mm in diameter, and the ultraviolet light sources provide a total energy density of 50 mJ/cm2 to 250 mJ/cm2, 50 mJ/cm2 to 200 mJ/cm2, 50 mJ/cm2 to 150 mJ/cm2, 100 mJ/cm2 to 250 mJ/cm2, 100 mJ/cm2 to 200 mJ/cm2, 100 mJ/cm2 to 150 mJ/cm2, 125 mJ/cm2 to 250 mJ/cm2, 125 mJ/cm2 to 200 mJ/cm2, or 125 mJ/cm2 to 150 mJ/cm2 to the fluid flowing through the ultraviolet-transmissive conduit. In some embodiments, a flowing fluid enters the ultraviolet-transmissive conduit at a rate of 25 gallons per minute or more, 50 gallons per minute or more, 75 gallons per minute or more, 90 gallons per minute or more, 100 gallons per minute or more, 125 gallons per minute or more, or 150 gallons per minute or more. In some embodiments, a fluid entering the ultraviolet-transmissive conduit has an ultraviolet transmission of 90% or less, 80% or less, 70% or less, 60% or less, or 50% or less (i.e., at λ=254 nm for a fluid sample having a path length of 1 cm).
In further embodiments, the present invention provides a system for cleaning at least an inner surface of a UV transmissive conduit. Such a system suitably comprises an interior conduit cleaning unit. In some embodiments, a cleaning unit includes a cleaning material coupled to a magnetic support, and an exterior conduit sleeve having at least one magnetic component. Suitably, the cleaning material is UV-resistant or coated with a UV-resistant material. Methods of cleaning at least an inner surface of UV transmissive conduit are also provided.
In some embodiments, an apparatus comprises a cleaning system. Continuous high-intensity irradiance of a wide variety of different fluids can lead to deposition of minerals and/or metals from the fluid as well as cross-linking reactions of organic compounds that can coat the interior of the ultraviolet-transmissive conduit. For example, iron, manganese, humic acids, tannins, and the like can deposit from water onto the interior surface of an ultraviolet-transmissive conduit.
The cleaning system 1501 includes an exterior (or outer) sleeve 1503 disposed around the outer surface of ultraviolet-transmissive conduit 106. The exterior sleeve 1503 can be a hollow cylindrical sleeve that either fully or partially surrounds the circumference of conduit 106. Exterior sleeve 106 includes at least one magnetic component 1507. The magnetic component can be embedded in, encapsulated, affixed to, or otherwise integrated with the exterior sleeve as either fully integrated (i.e., fully within the surrounding material) or partially integrated (i.e., partially within and partially protruding from the material), and can include structures formed by, e.g., press-fitting, forming, molding, gluing, etc. As used herein, “magnetic” refers to materials “having the properties of a magnet,” “capable of being magnetized,” or “capable of being attracted by a magnet.” In one embodiment, exterior sleeve 1503 includes a plurality of discreet magnetic components 1507. In another embodiment, exterior sleeve 1503 includes a single magnetic component 1507. In another embodiment, exterior sleeve 1503 includes one magnetic component 1507 having the form of a hollow cylinder embedded in exterior conduit sleeve 1503. Magnetic components 1507 can be formed of ferromagnetic materials such as, but not limited to, iron, cobalt, nickel, and the like, and alloys thereof. Magnetic components 1507 can be cube shaped or cylindrically shaped (or any other shape). Magnetic components 1507 can range in size from cubic millimeters to cubic centimeters, suitably from 1 mm3 to 50 mm3, or 1 mm3 to 10 mm3, suitably 1 mm3 to 3 mm3.
Cleaning system 1501 also includes a wiper 1505 disposed within conduit 106. The wiper 1505 can take the form of a hollow cylindrical ring adjacent to the interior surface of conduit 106. The wiper 1505 includes at least one magnetic support 1509 embedded therein. In one embodiment, the wiper 1505 includes a plurality of discreet magnetic supports 1509. In another embodiment, wiper 1505 includes one magnetic support 1509. In yet another embodiment, wherein wiper 1505 includes one magnetic support 1509, such magnetic support takes the form of a hollow cylinder embedded in the wiper 1505. Magnetic supports 1509 can be formed of ferromagnetic materials, including iron, cobalt, nickel, composites thereof, or materials equivalent thereto. Magnetic supports 1509 can be cube shaped or cylindrically shaped (or any other shape). Magnetic supports 1509 can range in size from cubic millimeters to cubic centimeters, suitably from 1 mm3 to 50 mm3, or 1 mm3 to 10 mm3, suitably 1 mm3 to 3 mm3.
Suitably, both the wiper 1505 and the exterior sleeve 1503 are substantially permeable to UV light so as to not impact or limit the amount of UV light reaching the fluid 108. In other embodiments, simply by utilizing a wiper 1505 and exterior sleeve 1503 that are small (i.e., having a short length), the impact on the amount of UV light reaching fluid 108 can be minimized.
In one embodiment, wiper 1505 takes the form of a glass ring having magnetic supports 1509 embedded therein. Use of a glass ring negates the need for a UV resistant coating on interior conduit cleaning unit 1505. In one embodiment, the wiper 1505 can be designed as thin as 1 mm to 5 mm in thickness, and thus provide minimal interference with the flow of fluid 108 through conduit 106. In alternative embodiments, wiper 1505 can be formed of any machinable or moldable material that can be easily coated. The wiper 1505 is preferably formed of a water-resistant/water-proof material. For example, the wiper 1505 can be formed of polymers such as PVC, polyesters, teflon, plexiglass (polycarbonates), or materials equivalent thereto.
In one embodiment, wiper 1505 further includes a contact surface 1512 for cleaning the inner surface of conduit 106, as further described below. As used herein, “contact surface” refers to any material that functions to clean the interior surface of conduit 106. The contact surface can comprise rubber, teflon, or any other equivalent material that exhibits appropriate friction force when moved against the surface of conduit 106 (e.g., a polymer, a sponge (natural or synthetic), and the like). In one embodiment, the contact material is UV-resistant. In another embodiment, the contact material is coated with a UV-resistant coating. For example, the wiper 1505 (and/or contact material 1512) can include a thin layer (e.g., 100 nm to 10 mm) of a UV-resistant material such as a metal, an oxide, a UV-resistant plastic, or any material equivalent thereto, disposed thereon. As used herein “UV-resistant coating” refers to a material that substantially limits or eliminates degradation of the contact material 1512 and/or wiper 1505, when exposed to UV light. The UV-resistant material can be coated, sprayed, painted, deposited, electrodeposited, deposited electrolessly, or vapor deposited on the various surfaces. In one embodiment, exterior sleeve 1503 further comprises a contact surface 1513 for cleaning the outer surface of conduit 106.
Exterior sleeve 1503 is disposed around the outer surface of ultraviolet-transmissive conduit 106 in concentric alignment with the wiper 1505 such that magnetic components 1507 correspond to, and align with, magnetic supports 1509 in interior conduit cleaning unit 1505. The terms “correspond to” or “align with” are intended to merely imply that the arrangement creates a magnetic attraction between wiper 1505 and exterior sleeve 1503. Thus, movement, e.g., a sliding motion (or rolling motion) of exterior sleeve 1503 along the outer surface of conduit 106 (represented by arrows 1511) causes a respective movement of the wiper 1505 along the inner surface of the ultraviolet-transmissive conduit. The magnetic attraction between wiper 1505 and exterior sleeve 1503 is suitably strong enough so as to move the wiper 1505 despite the counteracting force of the fluid 108 flowing through the ultraviolet-transmissive conduit. For example, small and strong magnets, e.g., neodymium magnets or magnets equivalent thereto, can be used for the design of the interior conduit cleaning unit 1505 and exterior conduit sleeve 1503.
Exterior sleeve 1503 can be moved (i.e., driven) manually or by a motor. For example, a lead screw system or motor-wheel system that rides on the outer surface of the ultraviolet-transmissive conduit 106 can be employed. In addition, rollers can be used between the exterior sleeve 1503 and ultraviolet-transmissive conduit 106. When system 1501 is not in use, the wiper 1505 suitably rests against a lip on the connecting pipe, as shown in
As such, system 1501 can be used in a method of cleaning at least an inner surface of an ultraviolet-transmissive conduit (e.g., conduit 106) in an apparatus of the present invention. The method of cleaning includes providing within ultraviolet-transmissive conduit 106 a wiper 1505 having a contact material 1512 coupled to a magnetic support 1509. The method also includes positioning an exterior sleeve 1503, having at least one magnetic component 1507, on an outer surface of ultraviolet-transmissive conduit 106 so as to create a magnetic attraction with the wiper 1505. The method further includes moving exterior (i.e., sliding) sleeve 1503 along the outer surface of ultraviolet-transmissive conduit 106 so as to create a respective movement (i.e., sliding) of the wiper 1505 along the inner surface of the ultraviolet-transmissive conduit 106.
Further provided herein is a method of cleaning an apparatus of the present invention, the method comprising providing a wiper within the ultraviolet-transmissive conduit and positioned in contact with an inner surface of the ultraviolet-transmissive conduit, wherein the wiper is formed of a contact material embedded with a plurality of magnetic supports and coated with a UV-resistant coating. The method comprises positioning an exterior sleeve around an outer surface of the ultraviolet-transmissive conduit in concentric alignment with the wiper, wherein the exterior sleeve includes a plurality of magnetic components corresponding to the plurality of magnetic supports in the wiper such that there is a magnetic attraction between the wiper and the exterior sleeve. The method also includes moving the exterior sleeve along the outer surface of the ultraviolet-transmissive conduit to cause a respective movement of the wiper along the inner surface of the ultraviolet-transmissive conduit.
In some embodiments, an apparatus of the present invention comprises a wiper suitable for traversing at least a portion of the ultraviolet-transmissive conduit.
In some embodiments, a rigid member and/or a wiper comprises a metal such as stainless steel and the like. In some embodiments, a contact material comprises rubber, a perfluorinated polymer (e.g., T
An apparatus of the present invention can include one or more wipers. In some embodiments, an apparatus comprises a single wiper that traverses the length of the ultraviolet-transmissive conduit. Alternatively, a plurality of wipers (e.g., two, three, four, five, six, seven, eight, or more wipers) are placed within the ultraviolet transmissive conduit, wherein each wiper cleans a section of the conduit (i.e., in series). The sections can be partially overlapping or separate from one another.
In some embodiments, a wiper comprises a reservoir suitable for containing a chemical. As used herein, a “reservoir” is a compartment or portion of the wiper suitable for containing a chemical and releasing the chemical in a controlled manner. A reservoir can include an adsorbent material and the like suitable for taking up and then slowly releasing a chemical. Chemicals suitable for use with a cleaning apparatus of the present invention such as a wiper include those materials “Generally Recognized As Safe” by the United States Food and Drug Administration. Chemicals suitable for use in and/or with an apparatus of the present invention include, but are not limited to, detergents, surfactants, metal chelators (e.g., EDTA and the like), and the like, and combinations thereof.
It will be readily apparent to one of ordinary skill in the relevant arts that other suitable modifications and adaptations to the methods and applications described herein can be made without departing from the scope of the invention or any embodiment thereof. Having now described the present invention in detail, the same will be more clearly understood by reference to the following examples, which are included herewith for purposes of illustration only and are not intended to be limiting of the invention.
The irradiance profile of the ultraviolet-transmissive conduit was mapped to a Gaussian curve and solved for the theoretical optimum diameter. Assumptions included in the model (all to take into account a worse-case scenario) were: (a) no axial fluid mixing within the ultraviolet-transmissive conduit; (b) a uniform velocity distribution in the ultraviolet-transmissive conduit; (c) the irradiance map is independent of conduit diameter change; and (d) the irradiance profile has a Gaussian distribution from the given geometry of the reflective chamber.
The irradiance profile was then fit with a Gaussian bell curve. The variables μ and σ in Equations 2 and 3 below were then determined to model the center position and width of the Gaussian curve.
For a 1-dimensional irradiance profile:
For a 2-dimensional irradiance profile:
Ultraviolet light dosage transmitted to the fluid within the ultraviolet-transmissive conduit is a function of diameter of the ultraviolet-transmissive conduit. For a fixed flow rate (Q), conduit radius (x), flow speed (v) and residence time (t) are governed by
Equation 4:
Q=(π·x2)·v (4).
As the length of conduit (d) is constant, the residence time (t), equals:
Dosage (D) is equal to irradiance (1) multiplied by residence time (t), thus:
By differentiating D(x), x can be solved to achieve a maximum dosage. An example demonstrating the use of this analysis is shown in
In summary, a theoretical optimal conduit diameter of 2√2σ (assuming no axial mixing) was determined. Increasing the velocity of fluid through the ultraviolet-transmissive conduit by reducing the diameter resulted in a more uniform dosage distribution. However, below an optimal value, the decrease in diameter resulted in a decrease in the average dose delivered to the fluid. In addition, at diameters larger than an optimal value, although average dosage delivered was higher, it caused a dramatic decrease in dosage at the circumference of the ultraviolet-transmissive conduit. Suitably, where a conduit does introduce positive fluid mixing effects, a conduit diameter slightly larger than the estimated optimal value can be used in order to take advantage of the high dosage at the center of the ultraviolet-transmissive conduit that occurs at lower fluid velocity.
An apparatus of the present invention was prepared using an ultraviolet-transmissive conduit (A Grade 214LD fused quartz pipe from GE) having a diameter of 7 cm, a length of 0.9 m, and a thickness of 5 mm. The ultraviolet-transmissive conduit was located within a cylindrical chamber having a polished aluminum reflective inner surface. The cylindrical chamber has an ellipsoidal cross-section with a major axis length of 15 cm, a minor axis length of 14.5 cm, and an eccentricity of 0.26. The ultraviolet-transmissive conduit was positioned at a second focal point of the ellipsoidal cross-section, and a first ultraviolet light source was positioned at a first focal point of the ellipsoidal cross-section. The distance between the first ultraviolet source and the outer surface of the ultraviolet-transmissive conduit was 1-5 cm. A second ultraviolet light was positioned on the major axis of the ellipsoidal cross-section at a point between the first ultraviolet light source and the ultraviolet-transmissive conduit. Both the first and the second ultraviolet light sources were 60 W Philips TUV PL-L high output U-lamps. Each lamp had a length of 41 cm and had two bulbs connected at the far end from the socket where the two bulbs had a spacing of 39 mm. Each bulb had a diameter of 18 mm. The distance between the second ultraviolet source and the outer surface of the ultraviolet-transmissive conduit was 2-6 cm.
Angular feeds (double-90° stainless steel piping having a 7 cm diameter) were affixed to the inlet to and outlet from the ultraviolet-transmissive conduit. A flow diffuser was attached to the inlet angular feed, and immediately before the flow diffuser, a 2.5 cm diameter pipe was expanded to a diameter of 7 cm.
Water for treatment was flowed into the apparatus at a rate of 15 GPM and the flowing water was irradiated with a total dose of 52 mJ/cm2.
A bateriaphage virus MS-2 that infects a specific strain of E. Coli was used in the testing. The test followed the protocol as described in NSF/ANSI Standard 55. MS-2 was introduced to the apparatus by passing through the unit as described in details in Example 2. Influent and effluent samples were collected at the same time at different flow rates. The samples with different dilutions were introduced to the E. Coli-loaded agar plates, wherein the E. Coli. was genetically modified such that it can grow if and only if MS-2 is present. The number of E. Coli colonies on each plate was then counted after an incubation time of 1824 hours for E. Coli. colonies to grow to sufficient size. The Log MS-2 reduction was determined by subtracting the counts of the effluent sample from the corresponding counts of the influent sample on a log scale.
A calibrated, collimated ultraviolet source test was used to create standard curve to correlate the Log MS-2 reduction to UV dose by following the same plating procedure described herein for samples irradiated for a set of time with a calibrated UV source. The log reduction was 2.29+/−0.07 at a rate of 15 GPM and 2.91+/−0.13 at a rate of 10 GPM. The sterilight system was a Sterilight Platinum SPV-950 system, NSF certified to Class A (NSF/ANSI Standard 55) for 14.9 GPM. The overall Log MS-2 reduction performance of the apparatus of the current invention was comparable to Class A-certified, bulb-in-water Sterilight system.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
All documents cited herein, including journal articles or abstracts, published or corresponding U.S. or foreign patent applications, issued or foreign patents, or any other documents, are each entirely incorporated by reference herein, including all data, tables, figures, and text presented in the cited documents.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US10/61138 | 12/17/2010 | WO | 00 | 2/28/2013 |
| Number | Date | Country | |
|---|---|---|---|
| 61288084 | Dec 2009 | US |
