Irradiation device and irradiation method

Abstract

An apparatus and method for irradiating a fluid containing a substance to be irradiated, comprising: at least one irradiation chamber having at least one inlet port; one or more UV radiation sources inside the irradiation chamber optically coupled to the fluid in the irradiation chamber through at least one UV-transmissive window in contact with the fluid; one or more seals or gaskets disposed adjacent the radiation source to protect the radiation source from the fluid; and at least one heat exchange mechanism inside the irradiation chamber thermally coupled to the radiation source and to the fluid; the UV radiation source and the at least one heat exchange mechanism are at least partially submerged in the fluid in the irradiation chamber.

Description

[Technical field]

[0001] The present invention relates generally to an apparatus and method for disinfecting a fluid by irradiation, and more particularly, to an apparatus and method for disinfecting a fluid containing a substance to be irradiated using one or more UV radiation sources. [Background technology]

[0002] The use of ultraviolet (UV) radiation for the purpose of disinfecting fluids, such as liquids and gases, is well known. The process of using ultraviolet radiation to inactivate microbial contaminants within a fluid is referred to as ultraviolet germicidal irradiation (UVGI). Ultraviolet radiation is also used to oxidize organic and inorganic materials in the fluid, a process called advanced oxidation process (AOP), and many commercial AOP systems are in use today. Systems utilizing UVGI and AOP rely on the ability to deliver UV radiation to the fluid in a predictable manner.

[0003] Both AOP and UVGI use a UV source. For practical purposes, the output irradiance of the UV source should be maintained and attenuated in a predictable manner over the useful life of the UV source. This allows for prediction of the replacement cycle of the UV source and the overall performance of the system. Some NSF and EPA controls require testing of UV disinfection systems with the UV source operating at a predicted end of lamp life (EOLL) optical output power. To adhere to UV disinfection system performance specifications over a predicted period of time, the UV source should be attenuated in a predictable manner. There is also a commercial advantage to having a longer EOLL resulting in a longer system life and / or replacement interval of the UV source.

[0004] There are many types of UV sources. Historically, low pressure mercury lamps, medium pressure mercury lamps, and amalgam lamps have been used as UV sources for disinfection applications. Other UV sources include deuterium lamps, light emitting diodes (LEDs), lasers, microplasma sources, and solid-state field effect phosphorescent devices. Microplasma lamps operate on the same principle as large gas discharge lamps, but have planar electrodes that generate small localized pockets of UV radiation (light emission). Solid-state UV sources, such as LEDs, generate light in semiconductor materials via charge recombination in the active layer, where carrier injection is applied to the anode and cathode of a semiconductor heterostructure. All of these UV sources have different optimal operating temperatures at which the flux and / or lifetime of the UV output is maximized. Most gas discharge lamps are difficult to operate at very low ambient temperatures due to reduced mercury vapor pressure. Conversely, solid-state UV sources have maximized output at ambient temperatures lower than those of mercury lamps. For example, the output power of a low pressure mercury lamp may peak at an ambient temperature of 40° C., while the optical output power of a 265 nm LED shows a linear relationship with ambient temperature. The slope of the LED curve may vary from device design to device design, but the trend is the same: greater optical output power is seen at lower ambient temperatures.

[0005] All UV sources generate waste heat, and the wall plug efficiency of UV LEDs, for example, is currently less than 10%. This means that more than 90% of the input power to the device is not converted into UV photons, but into waste heat. Even more mature technologies (e.g., mercury lamps) have efficiencies below 40%, indicating that waste heat management remains important throughout the technology development cycle. When encapsulating the light source for use, measures must be taken to handle the waste heat. This can be achieved by passive convection in the air. However, as the power and number of LEDs used inside the lamp increases, the heat load may become too great for the LEDs to operate properly. Alternatively, the ambient temperature may be too high for passive convection to be effective in lowering the temperature of the LEDs.

[0006] Many LED manufacturers specify a maximum junction temperature that must not be exceeded during operation. The LED junction temperature is the temperature of the active layer sandwiched between the n-type and p-type semiconductor layers of the LED. Exceeding the maximum rated junction temperature may cause degradation of the LED's life or other characteristics. In a simplified model, an LED can be represented as a series of thermal resistances. For example, a UV LED package may be a surface mounted device (SMD) mounted on a circuit board (board), which is itself mounted on a heat sink or other cooling device. The heat sink may be any heat exchanger or cooling method, such as a passive heat sink, a Peltier element, active airflow, heat pipes, etc. LEDs may be mounted on various electrically and thermally conductive circuit boards, such as a printed circuit board (PCB), a metal core printed circuit board (MCPCB), or a chip on board (COB). Each point of junction from the junction of the LED itself to the ambient environment has a temperature gradient associated with it. These include the junction temperature of the LED, the temperature between the LED package on the circuit board, the temperature between the circuit board and the heat sink, and the ambient temperature. At each point of the junction, R JS is the thermal resistance of the surface mount LED package, R SB is the thermal resistance of the circuit board, R BA Thermal resistance (°C / W) may be modeled such that is the thermal resistance of the heat sink or cooling method. The LED junction temperature can be modeled as the sum of each thermal resistance multiplied by the power dissipated to heat in the device, added to the ambient temperature. This relationship is shown in Equation 1. T J(LED) =T 周囲 +Σ i (R i ×P 熱 ) Equation 1

[0007] LEDs are unique among most UV sources in that heat is removed through the side of the chip that is electrically connected to the power, as opposed to the side that is responsible for the majority of the UV light emission. This contrasts with mercury lamps, which have heat emission primarily in the same direction as the light emission through the quartz sleeve, and also function to contain a plasma similar to an arc discharge tube. LEDs do not require a quartz window, as they emit light directly from the active layer of the semiconductor, and the light is transmitted through the epitaxial and substrate layers and out to the surroundings. However, LEDs can be sensitive to static discharge, moisture, and ambient gases such as oxygen or nitrogen, which can degrade the LED's electrical contacts and the performance of the semiconductor. For this reason, a quartz window is often placed on the surface of the LED's SMD package. In UVGI systems where the LED is protected from fluids through a window, a window on the SMD surface becomes unnecessary if the environmental effects mentioned above can be mitigated. A single window on a substrate with one or more LEDs can be used as an optical window for a fluid disinfection system if the LEDs are sealed between the substrate and the window so that the window can act as part of the pressure vessel for the disinfection system to isolate the LEDs from the fluid. A potting compound such as epoxy or silicone can be used between the substrate and the window to achieve this. A similar sealing of the space around the LEDs can be achieved by appropriate use of a gasket or other mechanical seal. The potting may be done in a low relative humidity environment or even purged with dry air or an inert gas to ensure that any gap between the LEDs and the window does not have undesirable moisture or gases within it. This may also increase the output power of the LEDs since light may pass through one quartz window versus two quartz windows. An additional advantage of this type of single window lamp package is that the LEDs do not heat the window nearly as much as a mercury vapor UV source, which transfers a large amount of heat to the window. Lower window temperatures correlate with less contamination of the window. Contamination of a window reduces the overall UV transmittance of the window, which in turn reduces the performance of UVGI and AOP systems. Therefore, in a robust product design utilizing a UV source, the temperature of the UV source during operation is taken into consideration by considering heat transfer.By such methods, the lifetime and output power of the UV source can be better controlled. Additionally, the method of assembling the UV source into the secondary packaging can be used to improve the output power, lifetime, and effective performance of the UV source.

[0008] The UV source is a key component of a UVGI system, but is only one component in the overall system efficiency. System efficiency can be expressed as the product of the reactor efficiency and the UV source efficiency. It is good practice in the design of UVGI systems to maximize the exposure time of the fluid to the UV irradiance (often called the "residence time"), thereby maximizing the dose the fluid encounters. The efficiency of the reactor is a combination of the residence time efficiency and the optical efficiency. The optical efficiency of the reactor is a measure of how efficiently the reactor uses the photons from the UV source to increase the probability that a microbial contaminant in the fluid will absorb the photon. One way to increase this probability is to use reflective materials in the reactor so that if a photon from the UV source is not absorbed during its first pass through the reactor, it can be reflected. If there are few absorbers in the fluid and the materials in the reactor are highly reflective, the photon can be reflected multiple times inside the reactor. The use of reflective materials, and the resulting multiple passes through the reaction chamber, has the added benefit of improving the uniformity of the illumination of the fluid. This can similarly be viewed as the probability that a microbial contaminant within the reaction chamber may absorb a photon, since increasing the uniformity of illumination (fluence rate) across the reaction chamber reduces the spatial and temporal variations in photon flux that the target microorganisms may experience.

[0009] Microorganisms may proliferate, grow, and even form biofilms in the environment, either of which may pose a human health hazard or interfere with the intended process. Products such as coffee makers, water dispensers, and cooling (water) tanks use reservoirs to store water for human consumption or other processes (e.g., in manufacturing). Even when potable or filtered water is bottled, the reservoir may contain sufficient nutrients for microbial growth and biofilm growth. Additionally, contamination may be present in the tank or potable water prior to bottled, or contamination may be introduced at a later date from environmental sources or otherwise. Biocides are often used in treated water to inhibit the growth of biofilms and microbial contaminants in storage tanks and distribution lines. Many public drinking water distribution systems use chlorination to chemically disinfect the water, and the results are provided. However, biocides lose their effectiveness over time and may need to be replenished, leaving water storage reservoirs susceptible to microbial growth. Even with continuous application and monitoring, sterility is rarely achieved and cannot be expected outside of a few specialized cases such as laboratories, surgical equipment, and pharmaceutical manufacturing. Microbial contamination is therefore an ever-present concern across created and natural environments.

[0010] Compact UV light sources that provide germicidal effects on surfaces, gases, gels, liquids, and other fluids or solids are increasingly becoming available commercially with optical output powers ranging from submilliwatts to several watts. Thus, arrays of such UV light sources can be formed from milliwatts to over kilowatts of power. The availability of these UV light sources, including light emitting diodes (LEDs), plasma lamps, and solid-state emitters, has led to increased use of such devices for pathogen inactivation in a variety of products. LED-based UV light sources are particularly useful due to their low DC voltage requirements, instant on / off actuation upon power application, and miniaturized size. The use of UV light sources for disinfection and biofilm inhibition of storage tanks is desirable, but there are many challenges to implementation.

[0011] One challenge is to package the UV light source so that it can be protected from the fluid in the container in which it is used to sterilize the fluid. Gaskets and seals can be used to provide protection from the fluid while maintaining areas of UV transparency to allow UV radiation to be exposed to the fluid and / or surfaces of the container. These UV light sources can be packaged to various levels of ingress protection, isolating the electrical and electronic components of the UV source from the environment (such as water and other liquids, humidity, steam, gas, dust and debris) that could potentially damage the tank.

[0012] Another challenge is that many UV sources have an optimal operating temperature range. Ultraviolet LEDs (UVLEDs), for example, maximize their optical output at lower temperatures, and operating the LED at a higher temperature results in a larger drop in optimal output power over a given period of time. This is an acceptable characteristic of UVLEDs, and most LED manufacturers specify a maximum LED solder or junction temperature that should not be exceeded for their devices. Vapor-emitting lamps emit heat through a glass envelope around the arc of the lamp, while semiconductor UV sources such as UVLEDs emit heat through the portion of the device where the electrical connection of the anode and cathode is made. Typically, this is made in a surface mount device package, via electrical connections, or directly by having the LED mounted on a circuit board. This means that UV photons are emitted from the entire periphery of the LED, but because the electrical connections to the LED are typically opaque or obscured, the majority of the photons come from an emission (emission) angle of 180° or less. This suggests that most of the heat is conducted through the electrical connections of the LED, while most of the UV light is emitted in the opposite direction. Thermal management is therefore typically done through the non-emitting side of the LED lamp, which has the greatest impact on the LED junction temperature. Thermal management is a key criterion for any profitable design.

[0013] Yet another challenge of using UV radiation to effectively disinfect a container is the effective distribution of UV radiation through the water volume. In comparison, shadow areas and "dark spots" through which few photons from the UV source pass may not achieve sufficient disinfection even after long exposure periods, significantly limiting the overall system effectiveness. The negative impact of "dark spots" in UVGI devices, which cause the device to have limited effectiveness on a portion of the target medium, as well as the impact on efficacy and efficiency in disinfection applications, have been reported in the literature. Because fluids in a tank may not circulate for extended periods, microorganisms may grow in the shadow areas due to lack of mixing of the fluids. Mixing fluids in a container with shadow areas or uneven UV radiation within it is one means to ensure disinfection of the entire volume. While this may not be sufficient as a means for biofilm control, it may slow the formation of biofilms by minimizing the microbial load in the fluid volume. Besides theoretical design, the unevenness of UVGI across the target volume is an unavoidable characteristic of such systems and negatively impacts efficacy. Proper and effective mixing of such fluids can circulate the irradiated material from "dark spots" to areas of higher exposure, thus increasing processing effectiveness.

[0014] One means to preferentially alter UVGI transmission and distribution within the tank system is by careful positioning of the UV source so that radiation transmitted through the window is preferentially directed toward a specific target area or to reduce non-uniformity throughout. Removal of the UV source from the wall of the reaction chamber may improve this capability and may be achieved by the use of stem supports. Such protrusions may further improve heat transfer efficiency by affecting the ability of the fluid to flow around the heat transfer surface. The optimal positioning of the UV source within the three-dimensional fluid volume varies based on the disinfection objectives (e.g., biofilm inhibition across the chamber surface, bulk disinfection of the fluid within the tank, targeted treatment of a portion of the fluid), the geometry of the irradiation chamber, the reflectivity of the interior surfaces, thermal management considerations, and other operational considerations.

[0015] US Patent Application Publication No. 2014 / 0161664A1 and US Patent No. 10,500,295 disclose various devices, materials, and methods useful for disinfecting fluids by irradiation, the disclosures of which are incorporated herein by reference. However, there continues to be a need for irradiation devices and methods useful for treating or maintaining microbial quality in various fluid housings or flow cells, particularly drinking water tanks, that provide good efficiency and heat management while maintaining a compact footprint. The present invention addresses the need for incorporation into a more generalized irradiation device, for example, in the treatment of drinking water storage tanks where the natural fluid flow (fluid flow) may be slow, intermittent, or ineffective in mixing the entire fluid volume. Summary of the Invention

[0016] In one embodiment, the present invention relates to an irradiation apparatus comprising: at least one irradiation chamber for a fluid containing a substance to be irradiated, the chamber having at least one inlet port for a fluid flow entering the chamber; one or more UV radiation sources inside the at least one irradiation chamber optically coupled to the fluid in the at least one irradiation chamber via at least one UV-transmissive window in contact with the fluid in the irradiation chamber; one or more seals or gaskets disposed adjacent to the one or more radiation sources to protect the one or more radiation sources from the fluid in the irradiation chamber; and at least one heat exchange mechanism inside the at least one irradiation chamber thermally coupled to the one or more radiation sources and to the fluid in the at least one irradiation chamber; wherein the one or more UV radiation sources and the at least one heat exchange mechanism are at least partially submerged in the fluid in the irradiation chamber.

[0017] In another embodiment, the present invention relates to a method for irradiating a fluid containing a substance to be irradiated disposed in an irradiation chamber, the irradiation method comprising the steps of: (1) providing an irradiation apparatus comprising: at least one irradiation chamber for a fluid containing a substance to be irradiated, the at least one irradiation chamber having at least one inlet port for a fluid flow entering the chamber; one or more UV radiation sources inside the at least one irradiation chamber optically coupled to the fluid in the at least one irradiation chamber via at least one UV-transmissive window in contact with the fluid in the irradiation chamber; one or more seals or gaskets disposed adjacent the one or more radiation sources to protect the one or more radiation sources from the fluid in the irradiation chamber; and at least one heat exchange mechanism inside the at least one irradiation chamber thermally coupled to the one or more radiation sources and to the fluid in the at least one irradiation chamber; wherein the one or more UV radiation sources and the at least one heat exchange mechanism are at least partially submerged in the fluid in the irradiation chamber; and (2) irradiating the fluid containing the substance to be irradiated using the irradiation apparatus.

[0018] The invention is herein described with reference to several drawings, in which like reference numerals indicate like elements of the device. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a plan side view illustrating one exemplary embodiment of an illumination device of the present invention. [Diagram 2] 2 is a cross-sectional view of the device of FIG. 1 taken along line 2-2. [Diagram 3] 2 is a cross-sectional view of the apparatus of FIG. 1 taken along line 2-2, illustrating the convective cooling flow induced in the fluid within the irradiation apparatus. [Figure 4] FIG. 4 is an enlarged view of a portion of the illumination device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention provides a UV irradiation device, disinfection system and method, including at least one irradiation chamber for a fluid containing a substance to be irradiated, and one or more UV radiation sources inside the irradiation chamber, optically coupled to the fluid in the irradiation chamber through at least one UV-transmitting window in contact with the fluid. One or more seals or gaskets are disposed adjacent to the radiation source to protect the radiation source from the fluid in the irradiation chamber. At least one heat exchange mechanism inside the irradiation chamber is thermally coupled to the radiation source and to the fluid in the irradiation chamber. The UV radiation source and the heat exchange mechanism are at least partially submerged in the fluid in the irradiation chamber. In some cases, the heat exchange mechanism may not be of a material suitable for contact with fluids for human consumption, or may not be of a material suitable for fluids used in medical processes. In this case, the portion of the heat exchange mechanism exposed to the fluid may be coated with a material approved for drinking water, food contact, or medical material compatibility.

[0021] The UV irradiation device, disinfection system, and method are designed such that at least a portion of the radiation from one or more radiation sources is transmitted to the surface of at least one irradiation chamber to provide a disinfecting effect and inhibit the spread of microbial contaminants on the surface. Microbial adhesion to the surfaces of the irradiation device (hereinafter referred to as "biofilm" formation) can increase health risks due to possible migration of such contaminants to the fluid flowing through such surfaces. The migration of contaminants can also be natural. Biofilm inhibition in disinfection systems is desirable because the process of UV irradiation does not impart residual biocide to the fluid being treated. In one embodiment, only a portion of the radiation emitted by the UV source may be redirected to irradiate the surfaces of the treatment device and system. Because the fluid contact surfaces of the reactor are stationary, the irradiation period of any segment is equal to the entire period of irradiation by the UV source. Thus, the irradiance required to achieve biofilm inhibition is much lower than the irradiance that may be required for transient irradiation, for example, for a fluid flowing through the reactor chamber. By requiring low irradiance and relatively low UV power, only a small fraction of the power emitted by the UV source can be scavenged for biofilm inhibition without significantly affecting the fluid disinfection performance of the reactor. Thus, a portion of the radiation from the one or more radiation sources can be transmitted to the surfaces of the one or more irradiation chambers to inhibit biofilm formation thereon.

[0022] The above considerations motivate the design of a system for mounting a UV radiation source such that the UV-transmitting window and at least one heat exchange mechanism are both wetted by a liquid (which may or may not be the intended irradiation target fluid). In the specific case of disinfecting a water tank, the UV source and protective housing are at least partially submerged in water, providing both good optical and thermal coupling of the UV source to the target fluid. However, the location of the UV source within the water volume or within the structure of the irradiation chamber itself may result in a portion of the water volume not receiving sufficient UV radiation exposure for disinfection. Advantageously, the heat generated by the UV source, and any material thermally connected to the UV source, may induce convective flows within the fluid volume in an otherwise non-circulating tank. These flows may circulate fluid from UV-occluded areas to more UV-exposed areas such that they provide a more uniform and effective disinfection effect. Furthermore, components of the UV source intended to protect the UV source from the environment may be designed in such a way as to improve convective cooling and mixing of the fluid volume. Structures may be added to the housing of the UV source to preferentially direct or increase the velocity of convection. This is conceptually similar to how a thermal chimney works in a building containing air, except in this invention the flow is induced in water. In one embodiment of the invention, this convection effect is shown in the model of flow velocity in a stationary tank in FIG.

[0023] The UV radiation source (or sources) may include one or more UV-C radiation sources, or a combination thereof. The UV radiation source (or sources) is typically coupled to a support structure inside at least one irradiation chamber. The support structure holds the UV radiation source to selectively direct (guide) the UV radiation into the interior of the irradiation chamber where the material to be irradiated is placed. The peak wavelength may be (dynamically) selected and / or adjusted, and multiple wavelengths may be utilized to target the action spectrum of a given organism, thereby improving disinfection efficiency. For example, one or more wavelengths of the one or more UV radiation sources may be selected based on the identification of contaminants in the material to be irradiated. The one or more UV radiation sources may transmit one or more wavelengths, or a combination of these wavelengths, to the material to be irradiated. The wavelengths may induce fluorescence in the material to be irradiated, thereby allowing the identification of contaminants in the material to be irradiated. Optionally, the material to be irradiated may be placed adjacent to an n-type single crystalline semiconductor, and hydrogen peroxide may be generated at the semiconductor surface via band gap electronic photoexcitation for disinfection.

[0024] Heat is managed and possibly restored in the irradiator using one or more of the following heat exchange mechanisms in contact with the UV radiation source: printed circuit boards, metal core printed circuit boards, thermoelectric cooling devices, vapor chambers, heat sinks, heat dissipation structures, heat transfer materials, and materials thermally coupled to the fluid. The irradiator may be made moisture resistant using moisture seals bonded and / or disposed within the support structure. The irradiator assembly may include monitoring / detection mechanisms and control circuitry to dynamically control the delivery of UV radiation to the material to be irradiated based on flow rate, water quality, user input, sensor measurements, or other operating conditions. Finally, relevant performance data may be stored on-board or in an external data storage unit and used to feed back signals to the monitoring circuitry to communicate system status. System status may be indicated by a current or voltage signal linked to a visible or audible alarm.

[0025] In various embodiments of the present invention, a modular semiconductor UV LED packaging arrangement may be provided that includes a UV radiation source package having a single LED or multiple LED "dice" arranged in a matrix or array. The LED dice can be selected to provide multiple wavelengths in both the UV and visible radiation spectrum from about 200 nm to about 800 nm. In one exemplary embodiment, the matrix or array includes LED dice that emit wavelengths in the range of about 200-320 nm to saturate the absorption mechanism of the nucleocapsid (which has a peak emission centered at about 280 nm) while simultaneously targeting the peak absorption of nucleic acid with its peak emission wavelength ranging from about 250-280 nm. In another exemplary embodiment, a matrix or array of LED dice utilizes multiple wavelengths, including at least one of about 240-260 nm, about 260-344 nm, about 350-380 nm, about 400-450 nm, or about 500-600 nm, intended to mimic the optical output spectrum of low or medium pressure Hg-based UV lamps used to target various bacteria and viruses. A further exemplary embodiment is a matrix or array of LED dice emitting germicidal wavelengths in the range of about 250 nm to 300 nm combined with LED dice emitting wavelengths in the range of about 350 nm to 400 nm to enable photocatalytic oxidation of pathogens or contaminants in water adjacent to a crystalline film of an n-type semiconductor such as TiO2, NiO, or SnO2. A still further exemplary embodiment is a modular packaging arrangement containing multiple LED dice emitting at wavelengths of about 250-320 nm and about 320-400 nm arranged in a matrix or array to enable fluorescence spectra of NADH and tryptophan of the biogenic particles. In another exemplary embodiment, a commercially available SETi UV Clean™ LED package is used. Individual LED dice or a single die bonded to a thermally conductive metal core circuit (MCPCB), such as those available from The Bergquist Company™, may be used.

[0026] The packaged UV LED, or a matrix or array of multiple UV LEDs, may be attached to a heat sink. Multiple UV wavelengths may be used to optimize effectiveness against specific microorganisms. Backside heat extraction may be assisted by thermoelectric cooling (TEC) and / or a vapor chamber. Additionally, the UV LED package may be topside cooled by conduction through a highly thermally conductive coating layer, such as a silicone polymer (which may be of single crystalline structure) impregnated with diamond nanoparticles.

[0027] Components for electrical and / or electronic control of the UV radiation source may optionally be included in a sealed unit as described above, so that these components may act on the UV radiation source while maintaining protection from the external environment by hermiticity, use of desiccants, or a combination thereof, as described above. Furthermore, the collocation of these components on the MCPCB or otherwise, and subsequent thermal union to a heat exchange mechanism, may be used to extract heat generated, for example, by the power conversion components. Additionally, these electrical and / or electronic components may include sensors, such as, but not limited to, photodiodes, thermocouples, thermistors, acoustic sensors, Hall probes, current probes, etc., that may determine the operating conditions and status of the UV radiation source.

[0028] The radiation emitter modules may be user-replaceable units that optionally include attached electronics and desiccant materials to combat moisture and humidity. The attached electronics may include individual identification and telemetry tracking, as well as interconnects for easy disconnection from a larger system.

[0029] UV radiation can be transmitted from the LED die into the irradiation chamber through a transmissive window, polymer, air, and / or apertures having a transmission spectrum suitable for the choice of LED used (e.g., in the UV-C range).

[0030] Fused silica, fused quartz, or similar glasses are commonly used for this purpose, as well as UV-stable silicones (e.g., DOW Silastic, LEDiL VIOLET). These window materials therefore constitute part of the optical coupling system, and their efficiency for transferring light from the radiation source to the target medium can affect the overall system efficiency. Fresnel's equations are well understood in their description of the transmission efficiency across refractive index boundaries. If the UV source is positioned so that the window is "dry", i.e., not in contact with the water volume of the storage tank, the UV radiation must pass through three large refractive index boundaries (air-quartz-air-water) and then undergo three significant losses of transmitted power (due to reflected portions). For such an air-quartz-air-water system, up to 9.8% of the UV radiation emitted by the radiation source does not reach the water target volume (calculation done for monochromatic radiation at 280 nm, considering normal incidence light on a series of planar refractive index boundaries, using literature values ​​for the refractive index). However, if the quartz window is wetted by the target water volume, this loss drops to just 4.1%. It is therefore beneficial for optical coupling to position and design a UV source, such as a UV window, to be wetted by the target water volume.

[0031] The interior surfaces of the irradiation chamber are typically constructed from materials that primarily reflect UV radiation from the UV source and minimally transmit or absorb UV radiation.

[0032] In another embodiment, the UV source is an LED that is electrically and thermally connected to a heat transfer material, such as a metal core printed circuit board (MCPCB), printed circuit board (PCB) or other dielectric material. The heat transfer material is in direct contact with the fluid in the cooling chamber 2 and provides a heat flow path between the LED and the fluid. In this case, the fluid provides cooling to the LED when the temperature of the fluid (e.g., water) is lower than the junction temperature. The heat transfer material acts as a heat exchange mechanism that is thermally connected or coupled to the radiation source and to the fluid in the cooling chamber.

[0033] In another embodiment, the UV source is an LED electrically and thermally connected to a heat transfer material, e.g., a metal core printed circuit board (MCPCB), printed circuit board (PCB) or other dielectric material, which is in contact with a separate second heat transfer material that is in direct contact with the fluid in the irradiation chamber 1, providing a heat flow path between the LED and the fluid. In this case, the fluid provides cooling to the LED when the temperature of the fluid (e.g., water) is lower than the junction temperature. The second heat transfer material may be a metal, dielectric, semiconductor, plastic or any other thermally conductive material. The heat transfer material acts as a heat exchange mechanism that is thermally connected or coupled to the radiation source and to the fluid in the cooling chamber.

[0034] Radiation transmitted to the surfaces of the irradiation chamber through the UV-transparent window inhibits biofilm formation on the surfaces and potential microbial contamination in downstream regions of the device. If the device has a fluid outlet structure optically coupled to the irradiation chamber by direct irradiation, by one or more portholes or other openings in the irradiation chamber, or via partial transmission through the material of the chamber, the surface of the outlet structure may be illuminated to inhibit biofilm formation thereon. UV radiation may be used as a biofilm inhibitor in integrated UV disinfection devices, systems, and methods. This may include intelligent control of the devices, systems, and methods with periodic "on cycles" during periods of stagnation, which may result in a constant bacteriostatic effect. On-board sensing of UV source status may optionally be a thermistor, photodiode, or voltage detection scheme, etc. In one embodiment, these sensors may be used to predict the life or operational quality of the UV source. In one embodiment, optical coupling between the irradiation chamber and one or more additional chambers may be achieved through at least one small porthole through the interior of the irradiation chamber, allowing UV radiation to enter the additional chamber. The portholes may also be fluidly connected to the additional chambers to increase fluid communication between the chambers. Radiation transmitted through the portholes and / or via partial transmission through the material of the chambers to the surfaces of the additional chambers may inhibit biofilm formation on the surfaces of the additional chambers and potential microbial contamination in downstream regions of the device.

[0035] In another embodiment, a UV radiation source provides radiation into the interior of the irradiation chamber. The UV radiation source has a thermal connection to the fluid in the irradiation chamber. The thermal connection is between the rear and / or front side of at least one heat exchange mechanism thermally connected or coupled to the UV radiation source and to the fluid in the irradiation chamber. In one embodiment, the heat exchange mechanism is a heat sink. A single quartz optical window is located on top of the UV radiation source and protects the UV radiation source from the fluid in the irradiation chamber. The UV radiation source is sealed between the heat exchange mechanism and the window such that the window serves to isolate the UV radiation source from the fluid in the irradiation chamber. The irradiation chamber is constructed from a material that primarily reflects UV radiation from the UV source and minimally transmits or absorbs UV radiation.

[0036] In another embodiment, the UV radiation source is thermally connected to a heat transfer material that is partially or completely coupled to or attached to the interior of the irradiation chamber. The heat transfer material provides conductive heat transfer from the UV source to the fluid in the irradiation chamber through the interior of the chamber. In one embodiment, the UV source is an LED that is electrically and thermally connected to a heat transfer material, such as a metal core printed circuit board (MCPCB), printed circuit board (PCB) or other dielectric material. The heat transfer material is in direct contact with the fluid in the irradiation chamber and provides a heat flow path between the LED and the fluid. In this case, if the temperature of the fluid (e.g., water) is lower than the junction temperature, the fluid provides cooling for the LED. The heat transfer material functions as a heat exchange mechanism that is thermally connected or coupled to the radiation source and to the fluid in the cooling chamber.

[0037] In another embodiment, the UV source is an LED electrically and thermally connected to a heat transfer material, e.g., a metal core printed circuit board (MCPCB), printed circuit board (PCB) or other dielectric material, which is in contact with a separate heat transfer material that is in direct contact with the fluid in the irradiation chamber, providing a heat flow path between the LED and the fluid. In this case, if the temperature of the fluid (e.g., water) is lower than the junction temperature, the fluid provides cooling for the LED. The heat transfer material may be a metal, dielectric, semiconductor, plastic, or any other thermally conductive material. The heat transfer material serves as a heat exchange mechanism that is thermally connected or coupled to the radiation source and to the fluid in the cooling chamber.

[0038] 1-4 show one exemplary embodiment of the present invention. The irradiation device A comprises a three-dimensional irradiation chamber 1 having an inlet port 4 for the flow of a fluid (water 5 in this embodiment) containing the substance to be irradiated into said chamber. The irradiation chamber may have one or more additional inlet ports for the flow of fluid into the chamber and / or one or more outlet ports for the flow of fluid out of the chamber. One or more UV radiation sources in the irradiation chamber, for example UV radiation source 17 (FIG. 4), provide radiation into the interior of the irradiation chamber. The radiation source is optically coupled to the water in the irradiation chamber through a UV-transparent quartz optical window 16 (FIG. 4), which is placed over the UV radiation source and protects it from fluids in contact with the window in the irradiation chamber. A gasket 15 is placed adjacent to the radiation source and protects it from fluids in the irradiation chamber. The gasket 15 seals the UV radiation source 17 between the cooling plate heat exchange mechanism 12 and the window 16. End caps 14 hold the UV lamp module assembly 6 tightly together (FIG. 2) and prevent fluids from contacting the UV radiation source.

[0039] Figures 2-4 show the air 2 and water surface 3 in the irradiation chamber, with the UV radiation source and heat exchange mechanism partially submerged in the water in the irradiation chamber. The heat exchange mechanism is thermally coupled to the radiation source and water in the irradiation chamber. Figure 2 shows the UV lamp module assembly 6 secured inside the irradiation chamber 1 by retaining nut 8 and sealing O-ring 9 via a supporting stem 10. A power wire 7 inside the stem 10 provides electrical current to the UV radiation source 17.

[0040] Heat generated by the UV radiation source 17 induces convective currents 11 within the water in the irradiation chamber (FIG. 3). These currents circulate the water from UV blocked areas to more UV exposed areas resulting in a more uniform and effective disinfection effect. The design of the UV lamp module assembly 6 improves convective cooling and mixing of the water volume. The present invention presents a solution to the problem of shadowing and packaging a UV source to protect the liquid and cool the UV source.

[0041] In another embodiment, the UV source is a microplasma lamp that is in direct contact with the fluid in the irradiation chamber of the reactor, providing a direct heat flow path between the lamp and the fluid. In this case, the fluid provides cooling for the lamp. The microplasma lamp UV radiation source provides radiation to the interior of the irradiation chamber. Because the microplasma lamp is in direct contact with the fluid in the irradiation chamber, it provides a direct heat flow path between the lamp and the fluid, thereby cooling the lamp. In one embodiment, the microplasma lamp is thermally connected to a heat transfer material that is in direct contact with the fluid in the irradiation chamber, providing a heat flow path between the lamp and the fluid. The heat transfer material may be a metal, a dielectric, a semiconductor, a plastic, or any other thermally conductive material. The heat transfer material may reflect a portion of the UV radiation from the lamp. In another embodiment, the heat transfer material is in contact with a separate heat transfer material that is in direct contact with the fluid in the irradiation chamber, providing a heat flow path between the lamp and the fluid. In these cases, the fluid provides cooling for the lamp. As such, this embodiment may be used as an irradiation chamber in other irradiation devices shown and described herein.

[0042] In another embodiment, the present invention provides a plurality of UV radiation sources and a plurality of irradiation chambers, each having at least one inlet port and one outlet port. Each UV radiation source is primarily optically coupled to a single irradiation chamber. All irradiation chambers are fluidically coupled such that all fluids flowing through any irradiation chamber also flow through the other irradiation chambers. In this way, the fluid flux through the irradiation chamber is equal to the sum of the fluid fluxes through all irradiation chambers. In addition, all UV sources are thermally coupled to the fluid flux through the interior of the irradiation chamber.

[0043] In another embodiment, the present invention provides a plurality of UV radiation sources and a plurality of irradiation chambers, each having at least one inlet port and one outlet port. Each UV radiation source is primarily optically coupled to a single irradiation chamber. All of the UV radiation sources are thermally coupled to all of the irradiation chambers. The one or more irradiation chambers are in fluid communication, and the outlet of one chamber is the inlet for another chamber.

[0044] In the above embodiments, the multiple irradiation chambers are fluidly coupled such that all fluid flowing through any irradiation chamber also flows through the other irradiation chambers. Just as multiple irradiation chambers can be fluidly coupled to form a single unit, sets of these individual units can also be arranged in parallel or series combinations, with the inlet to each unit being made up of a portion of the total inlet flow (in the parallel case) or total flow (in the series case), or a blend of the series and parallel arrangements of each unit.

[0045] In another embodiment, heat transfer from the UV source to the fluid flux is achieved via conductive heat transfer through nominally flat surfaces integrated into the chamber and in thermal contact with the fluid flux within the chamber. For example, in the embodiment shown in Figures 1-4, heat transfer from the UV source to the fluid within the irradiation chamber is achieved via conductive heat transfer through nominally flat surfaces of heat sinks integrated into the outer and inner surfaces of the irradiation chamber and in thermal contact with the fluid flux within the chamber.

[0046] In another embodiment, the transfer of heat from the UV source to the fluid flux is accomplished via conductive heat transfer through a porous structure placed in some or all of the flow paths of the fluid flux. The porous structure may be designed such that surface area is maximized to provide efficient conductive heat transfer to the fluid flux. The porous structure used to maximize conductive heat transfer may also promote turbulent mixing of the fluid flux and / or laminar flow characteristics in the fluid flux.

[0047] In yet another embodiment, the two three-dimensional chambers have at least one inlet port and at least one outlet port for the flow of fluids into and out of the chambers. The UV source is a planar source, such as a microplasma lamp, that emits UV radiation from both sides. The UV source is located between the irradiation chambers and provides radiation to both chambers. In one embodiment, the two chambers are fluidly connected, and the inlet of one chamber is the outlet for the other chamber. In another embodiment, each side of the planar UV source serves as a portion of the sidewall of each chamber.

[0048] In another embodiment, the irradiation device includes two three-dimensional irradiation chambers, each having an inlet port and an outlet port for the fluid flow into and out of the chamber. The irradiation chambers are fluidly connected and in fluid communication, with ports serving as an outlet port for one chamber and an inlet port for the other irradiation chamber. The UV radiation source is a microplasma lamp that provides radiation to the interior of both irradiation chambers. The UV source is located between the irradiation chambers and provides radiation to both chambers. Each side of the planar UV source serves as a portion of the sidewall of each chamber. The UV radiation source has a quartz sleeve or optical window covering each of its sides, protecting the UV radiation source from the fluid in the irradiation chamber. The UV radiation source is sealed between the windows, such that the windows serve as a portion of the pressure vessel for the disinfection system and isolate the UV radiation source from the fluid in the irradiation chamber.

[0049] In another embodiment of the present invention, the UV source described herein may include a UV emitter embedded inside an environmentally sealed housing that partially or completely confines the UV emitter between a heat transfer material or conductor, such as a metal core printed circuit board, and a UV transparent window. In another embodiment, the sealed housing includes primarily a UV transparent window and a heat sink (e.g., a primarily thermally conductive cup) that combine to form a closed volume in which one or more UV LEDs on the circuit board are located and thermally connected to the cup. The potting compound fills the void between the thermally conductive cup and the window, resulting in less of a small keep-out area around the periphery of the LEDs. In one embodiment, the thermally conductive cup is created by deformation of a single metal sheet. The thermally conductive cup may have one or more ports for electrical connection inlet and / or outlet of liquid potting compound and / or for injection of liquid potting compound. In another embodiment, the thermally conductive cup includes at least one surface that is primarily intended for heat transfer to / from the UV emitter.

[0050] In other embodiments of the present disclosure, the optically transparent window is made of quartz or sapphire, or primarily UV transparent polymers. The potting compound primarily holds the optically transparent window in the thermally conductive cup and may function as a structural component to the assembly. The UV emitter may include a UV radiation source mounted on a substrate with a control system mounted on the substrate. The UV radiation source may include at least one of an LED, a plasma emission source, or a solid state field effect phosphorescent device, or a combination thereof. The substrate may include a printed circuit board. The substrate may be designed to generate an efficient heat flow path between the UV radiation source and the external thermal enclosure. The substrate may be provided as a means to prevent contact between the potting compound and the UV radiation source. The substrate may provide a means to fix the relative positions of the UV radiation source and the optically transparent window. The control system may include a constant flow source or a constant flow sink.

[0051] The present invention has many potential applications. Primarily, it may be considered as a means to treat or maintain the microbial quality of drinking water tanks. However, the breadth of applications is much broader. Conservation of water and other liquids is necessary for many processes, including, but not limited to, crop irrigation, coolant circulation and injection systems, grey water, washing fluids, humidifiers, dehumidifiers, flushing and cooling systems, wastewater treatment, food processing and distribution, pharmaceutical manufacturing, etc. In such applications, the objective may be to control microbial contamination for the purpose of avoiding disease or other undesirable effects of bacterial or mold growth, such as aesthetics, clogging, corrosion, spoilage, digestion, etc. Furthermore, the application of an in-tank disinfection system may be desirable during nominal operation, for example, when the tank is filled with the target liquid, or as a means of maintaining operational readiness during outages, when the tank surface itself may be the primary disinfection target.

[0052] While the present invention is shown and described herein with reference to specific embodiments and examples thereof, it will be readily apparent to those skilled in the art that other embodiments and examples may perform a similar function and / or achieve similar results. Similarly, it will be apparent that other applications of the disclosed technology are possible. All such equivalent embodiments, examples, and applications are within the spirit and scope of the present invention and are intended to be covered by the following claims.

Claims

1. at least one irradiation chamber including a container for containing a predetermined amount of a fluid to be irradiated; at least one UV lamp module assembly; An irradiation device comprising: The UV lamp module assembly includes: (i) one or more UV radiation sources within the at least one irradiation chamber; (ii) one or more seals or gaskets; (iii) at least one heat exchange mechanism within the vessel; and Equipped with the vessel having at least one inlet port for fluid flow into the vessel; the UV radiation source is optically coupled to the fluid in the irradiation chamber through at least one UV-transmissive window in contact with the fluid in the vessel; the seal or gasket is positioned adjacent to the radiation source to protect the radiation source from the fluid within the container; the heat exchange mechanism is thermally coupled to the radiation source and to the fluid within the vessel; the UV lamp module assembly is disposed within the irradiation device; the one or more UV radiation sources and the at least one heat exchange mechanism are at least partially submerged in the fluid within the irradiation chamber; 10. An irradiation apparatus, wherein heat generated by the UV radiation source generates convective currents in the fluid within the irradiation chamber, mixing the fluid.

2. 2. The irradiation device of claim 1, wherein the UV lamp module assembly is disposed within the irradiation device at a level lower than the level of the inlet port.

3. 3. The irradiation device of claim 1 or 2, further comprising a stem support for moving a UV source from a wall of the irradiation chamber.

4. 3. The irradiation device of claim 1 or 2, wherein the heat exchange mechanism comprises one or more of a printed circuit board, a metal core printed circuit board, a thermoelectric cooling device, a vapor chamber, a heat sink, a heat dissipation structure, a heat transfer material, a material thermally coupled to a fluid, and is preferably a heat sink or a heat transfer material, or a combination thereof.

5. 3. The irradiation device of claim 1, further comprising one or more sensors used to dynamically control power to the one or more UV radiation sources based on measurements of the one or more sensors, and optionally circuitry for monitoring a status of the one or more UV radiation sources and providing feedback to the monitoring circuitry.

6. 3. The irradiation device according to claim 1, wherein the one or more UV radiation sources comprise at least one selected from one or more UV-C radiation sources, or a combination thereof, and a plurality of radiation sources arranged in an array.

7. 3. The irradiation device of claim 1 or 2, wherein the one or more UV radiation sources comprise microplasma lamps.

8. 3. The irradiation device of claim 1, comprising a plurality of UV radiation sources and a plurality of irradiation chambers, each of the plurality of irradiation chambers having at least one inlet port and one outlet port, and all of the plurality of UV radiation sources being thermally coupled to the plurality of irradiation chambers.

9. 3. The irradiation device of claim 1 or 2, wherein a portion of the radiation from the one or more radiation sources is transmitted to surfaces of one or more irradiation chambers to inhibit biofilm formation on the surfaces.

10. 1. A method of irradiating a fluid containing a substance to be irradiated, the fluid being disposed in an irradiation chamber, the method comprising: (1) a step of preparing an irradiation device, the irradiation device comprising: at least one irradiation chamber for a fluid containing a substance to be irradiated; one or more UV radiation sources within the at least one irradiation chamber; one or more seals or gaskets; at least one heat exchange mechanism within the at least one irradiation chamber; Equipped with the irradiation chamber having at least one inlet port for a fluid stream entering the irradiation chamber; the UV radiation source is optically coupled to the fluid in the irradiation chamber through at least one UV-transmissive window in contact with the fluid in the irradiation chamber; the seal or gasket is disposed adjacent to the radiation source to protect the radiation source from the fluid in the irradiation chamber; the heat exchange mechanism is thermally coupled to the radiation source and to the fluid within the irradiation chamber; the one or more UV radiation sources and the at least one heat exchange mechanism are at least partially submerged in the fluid within the at least one irradiation chamber; (2) using the irradiation device to irradiate a fluid containing a substance to be irradiated; An irradiation method comprising:

11. 11. The irradiation method of claim 10, wherein the heat exchange mechanism comprises one or more of a printed circuit board, a metal core printed circuit board, a thermoelectric cooling device, a vapor chamber, a heat sink, a heat dissipation structure, a heat transfer material, and a material thermally coupled to a fluid.

12. 12. The irradiation method according to claim 10 or 11, wherein the heat exchange mechanism is coated with water, a medical-grade material, or a food-safe material.

13. 12. The irradiation method according to claim 10 or 11, wherein one or more wavelengths of the one or more UV radiation sources are dynamically adjustable.

14. 12. The method of claim 10 or 11, wherein one or more wavelengths of the one or more UV radiation sources are selected based on an identification of contaminants in the material to be irradiated.

15. 12. The irradiation method according to claim 10 or 11, wherein the one or more UV radiation sources deliver to the material to be irradiated one or more wavelengths that induce fluorescence in the material to be irradiated, thereby enabling identification of the contaminants in the material to be irradiated.

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