Water purifier using UV light and photocatalysis

Abstract

Water purifier (100) comprising: a first UV light source (118), a static mixer (120) comprising a photocatalyst and located around the first UV light source (110), a second UV light source (138) located around the static mixer (120); wherein at least one of the first UV light source (118) and the second UV light source (138) emits light of a wavelength triggering the production by the photocatalyst of hydroxyl radicals and / or ozone in the water. Figure for the abstract: Fig. 2

Description

Title of the invention: Water purifier using UV source and photocatalysis

[0001] The present relates to the field of water disinfection technologies, in particular UV reactor systems. State of the art

[0002] UV disinfection systems are commonly used to treat water. For example, document EP2394963A1 discloses an ultraviolet sterilization device for outdoor water. Summary of the invention

[0003] Water disinfection is a critical issue in many sectors, particularly for ensuring food safety. Traditional UV reactors generally use a UV lamp to disinfect water by passing it close to the light source. The water enters through an inlet, passes through the reactor where it is exposed to UV light, and then exits through an outlet. This method relies on the use of UV lamps to eliminate microorganisms present in the water.

[0004] Current solutions have several drawbacks. First, the effectiveness of UV disinfection depends on the transparency of the water. Non-transparent liquids, such as coffee, pose significant challenges because UV light cannot penetrate effectively. Furthermore, the quartz sleeves used to protect UV lamps are fragile and expensive, increasing maintenance costs. Another major drawback is the absence of residual disinfectant after UV treatment, unlike chlorine, meaning that the water can be recontaminated after treatment. Finally, cleaning UV lamps, which can become clogged over time, often requires manual or chemical intervention, complicating maintenance.

[0005] A first aspect of the invention relates to a water purifier comprising: • a first UV light source, • a static mixer comprising a photocatalyst and located around the first UV light source, • a second UV light source located around the static mixer; in which at least one of the first UV light source and the second UV light source emits light of a wavelength that triggers the production by the photocatalyst of hydroxyl radicals and / or ozone in the water.

[0006] By UV illumination of the first UV light source and / or the second UV light source, hydroxyl radicals and / or ozone are generated, enabling additional disinfection of the water. The wavelength of one of the two UV light sources may be less than 387 nm, for example, from 254 nm to 365 nm.

[0007] Advantageously, one of the first and second UV light sources is configured to emit UV-A, and the other of the first and second UV light sources is configured to emit UV-C. This configuration allows for complementary disinfection by two different wavelengths, in addition to the generation of hydroxyl radicals by the photocatalyst, increasing the overall efficiency of the system. Furthermore, UV-C illumination can generate ozone from the dissolved oxygen present in the water to be purified.

[0008] Advantageously, the first UV light source is configured to emit UV-C. This ensures rapid and effective disinfection of microorganisms while maintaining a high level of safety for personnel working around the water purifier. Preferably, the first UV source comprises LED strips or ribbons, for example arranged in the form of a cylinder or tube.

[0009] Advantageously, the second light source is configured to emit UV-A. This can promote the generation of hydroxyl radicals by the photocatalyst while ensuring a high level of safety for personnel working around the water purifier. Preferably, the second UV light source comprises LED strips or ribbons.

[0010] Advantageously, the water purifier comprises a first transparent body and a second transparent body containing the first transparent body and the static mixer. The first UV light source is received in the first transparent body, and the second UV light source is placed outside the second transparent body. This structure allows for maximum protection and efficiency of the light sources. For example, the first transparent body can be part of the first UV light source, for example, in the case of an LED tube.

[0011] Advantageously, the water purifier includes a motor arranged to drive the static mixer, the static mixer being in contact with a wall of the first transparent body and / or the second transparent body, the static mixer being configured so that its movement cleans the wall with which it is in contact. This ensures automatic maintenance and reduces surface fouling. For example, the static mixer may include a plurality of wires, foams, elastomer lips, and / or scrapers for cleaning the wall with which it is in contact.

[0012] Advantageously, the static mixer includes at least one cleaning product distribution conduit arranged to distribute the cleaning product within the water purifier and connected to a cleaning product inlet. This allows for uniform distribution of the cleaning product, improving cleaning efficiency. For example, the static mixer may be partially or substantially hollow and include a plurality of small holes to allow the distribution of the cleaning product within the water purifier.

[0013] Advantageously, the water purifier comprises a longitudinal axis, an inlet for the water to be treated, and an opposite treated water outlet, wherein at least one of the inlet and outlet is offset from the longitudinal axis. This arrangement promotes turbulent flow, improving contact time and fluid mixing.

[0014] Advantageously, the static mixer comprises a plurality of surfaces arranged obliquely with respect to the longitudinal axis of the water purifier. This optimizes mixing and contact time inside the reactor while providing an increased surface area for the photocatalyst. The static mixer may comprise a single element with several surfaces or a plurality of elements, each with one or more surfaces.

[0015] Advantageously, the water purifier includes a disinfectant inlet located on the side of the effluent inlet to be treated. This allows for the efficient introduction of disinfectant, increasing treatment efficiency, for example in the case of highly contaminated water.

[0016] A second aspect of the invention relates to a water purification process with a water purifier according to the first aspect of the invention comprising the following steps: • Circulate the water to be purified through the water purifier • Illuminate the water to be purified with the first UV light source and the second UV light source.

[0017] A third aspect of the invention relates to the use of a water purifier according to the first aspect of the invention to purify water. Description of the figures

[0018] [Fig. 1] illustrates an exploded view diagram of the water purifier with a static mixer and UV light sources.

[0019] [Fig.2] shows a diagram of the water purifier reactor with the static mixer and UV light sources assembled. Detailed description

[0020] The present invention relates to the purification of water, for example, water intended for human or animal consumption, for an industrial installation, an agricultural installation, or water intended for discharge into the natural environment. The water to be purified is not necessarily pure water but may contain suspended matter, dissolved salts, food additives, fertilizers, or industrial additives.

[0021] In a general embodiment, the water purifier comprises a first UV light source, for example in the central part of the water purifier, surrounded by a static stirring element coated with a photocatalyst such as TiO2 or ZnO. This static stirring element is designed to maximize the surface area and contact between the water and the UV light, thereby improving disinfection efficiency. Furthermore, the photocatalyst is designed to generate hydroxyl radicals through UV illumination. A second UV light source can enhance the photocatalysis process around this element.

[0022] Ultraviolet (UV) radiation is electromagnetic radiation located between visible light and X-rays in the electromagnetic spectrum. It is classified into three main categories: UV-A, UV-B and UV-C, according to its wavelength.

[0023] UV-A radiation, with wavelengths between 320 and 400 nanometers, represents approximately 95% of the UV radiation that reaches the Earth's surface. It penetrates deeply into the skin and is primarily responsible for skin aging and wrinkles. UV-A radiation can be artificially produced using mercury vapor lamps, special fluorescent lamps, or UV-A LEDs.

[0024] UV-C, with wavelengths between 100 and 280 nanometers, is the most energetic and most dangerous of the UV range. UV-C is used primarily for its germicidal properties, as it can destroy microorganisms by damaging their DNA. It is produced artificially using low-pressure mercury lamps or UV-C LEDs but is dangerous to animals and humans, particularly in cases of direct exposure.

[0025] A static mixer is a device commonly used in water treatment to efficiently mix fluids or substances without using moving parts. It consists of one or more fixed elements that create controlled turbulence as water passes through the device.

[0026] For example, surfaces having profiles oblique to the flow of water to be purified are arranged in the water purifier between the first UV source and the second UV source, without leaving a preferred path for the flow of water to be purified, thus imposing tortuous paths and continuously dividing and recombining the water. the water flow. The static mixer can be made of polymer, ceramic, composite materials or stainless metal.

[0027] In the present invention, the static mixer is coated with or incorporates a photocatalyst, the photocatalyst being adapted to generate hydroxyl radicals and / or ozone in water under UV illumination. This photocatalyst is, for example, titanium dioxide (TiO2) or zinc oxide (ZnO). This photocatalyst may be in the form of a coating, plates fixed to the static mixer, or integrated into the body of the static mixer, for example, in the case of a composite.

[0028] The static mixer can thus both increase the contact time of the water to be purified within the purifier, contribute to disinfection by the generation of hydroxyl radicals and / or ozone and also ensure good homogenization of these radicals or ozone in the flow of water to be purified.

[0029] In the example of [Fig. 1], the water purifier 100 comprises, from the inside out, the first transparent body 110 housing or incorporating the first UV light source 118, the static mixer 120, the second transparent body 130, and the second UV light source 138. The second transparent body 130 can serve as the body of the water purifier 100. In addition, an opaque casing (not shown) can cover all or at least the second UV light sources 138.

[0030] At the ends of the second transparent body is an inlet hood 131 provided with a water inlet 132 and optionally a disinfectant product inlet 133 and opposite an outlet hood 134 including a water outlet 135. The first transparent body 110 and / or the first UV light source 118 can protrude from the outlet hood so as to allow the connection of the first UV light source 118 with a power supply.

[0031] In addition, a motor 140 can be connected to the static mixer 120 so as to allow movement within the second transparent body 130, for example a rotational movement.

[0032] The first UV light source preferentially emits UV-C and the second UV light source preferentially emits UV-A. Thus, UV-A can generate hydroxyl radicals and / or ozone by photocatalysis while UV-C can contribute to water disinfection.

[0033] Figure 2 shows the water purifier 100 in an assembled configuration. In operation, the water to be purified enters through the water inlet 132 and flows between the first transparent body 110 and the second transparent body 130, the flow being impeded by the static mixer 120, which imposes a multitude of flows between its surfaces. The double UV illumination by the two UV light sources allows for both a disinfection of water, even in the case of suspended matter, and the generation of hydroxyl radicals and / or ozone, thus allowing double disinfection.

[0034] At the outlet of the water purifier, that is to say when it passes through the water outlet 135, the water is thus suitably purified, without requiring too large a water purifier volume or expensive electrical power.

[0035] In the case of highly contaminated water, a disinfectant product, for example based on chlorine, can be introduced through the disinfectant inlet 133, thus carrying out a triple disinfection of the water in the water purifier.

[0036] Preferably, the water purifier 100 can be configured with a water inlet 132 and / or a water outlet 135 offset from a longitudinal axis of the water purifier 100, creating a swirling effect that optimizes the mixing and contact time of the water to be purified. Along a longitudinal median plane of the water purifier, the water inlet 132 and / or the water outlet 135 may not be aligned with this median plane.

[0037] During a maintenance operation, the static mixer, which is stationary in operation, can be rotated to clean the wall of the first transparent body 110 and / or the second transparent body 130 by means of the motor 140. Thus, a mechanical cleaning of at least one of the internal walls of the water purifier can be carried out simply or even automatically.

[0038] Preferably, the water purifier may allow the addition of a cleaning agent, for example, a surfactant. At least some of the static mixer elements may thus be hollow and have holes, or comprise a plurality of channels (not shown) allowing the disinfectant to be distributed directly onto the surfaces of the static mixer, for example, near or in the areas of contact with the wall(s) to be cleaned. This improvement thus allows for dual chemical and mechanical cleaning of the water purifier, without requiring complex and time-consuming disassembly.

[0039] Finally, a cleaning product can also be introduced through the disinfectant product inlet 133 or another inlet, preferably located in the axis of the second transparent body and / or of material orthogonal to the water inlet 132, further enhancing the chemical cleaning of the water purifier.

[0040] The static mixer can extend over the entire length or at least most of the length of the second transparent body. The first transparent body can extend over the entire length or at least 80% of the length of the second transparent body.

[0041] The water inlets and outlets are shown in the figures orthogonally with respect to a longitudinal axis of the water purifier, but they can also be aligned with this axis. The water inlet and outlet can be reversed, so that water can enter the water purifier from the top and exit from the bottom. Alternatively, The water purifier can be used lying down, that is, with its longitudinal axis oriented horizontally.

[0042] The water purifier can be equipped with any type of valve and sensor commonly used for a water purifier and for example a flow, temperature, pressure, pH, transmittance and light sensor.

[0043] It will be understood that various modifications and / or improvements obvious to a person skilled in the art can be made to the different embodiments of the invention described in this description without departing from the scope of the invention as defined by the attached claims.

Claims

Demands

1. Water purifier (100) comprising: • a first UV light source (118), • a static mixer (120) comprising a photocatalyst and situated around the first UV light source (110), • a second UV light source (138) situated around the static mixer (120); wherein at least one of the first UV light source (118) and the second UV light source (138) emits light of a wavelength triggering the production by the photocatalyst of hydroxyl radicals and / or ozone in the water.

2. Water purifier (100) according to the preceding claim, wherein one of the first UV light source (118) and the second UV light source (138) is configured to emit UV-A and the other of the first UV light source (118) and the second UV light source (138) is configured to emit UV-C.

3. Water purifier (100) according to any one of the preceding claims, wherein the first UV light source (118) is configured to emit UV-C and wherein the second UV light source (138) is configured to emit UV-A.

4. Water purifier (100) according to any one of the preceding claims, comprising a first transparent body (110) and a second transparent body (130) containing the first transparent body (110) and the static mixer (120), the first UV light source (118) being received in the first transparent body (110), the second UV light source (138) being placed outside the second transparent body (130).

5. A water purifier (100) according to the preceding claim, comprising a motor (140) arranged to move the static mixer (120), the static mixer (120) being in contact with a wall of the first transparent body (110) and / or the second transparent body (130), the static mixer (120) being configured to allow, by its movement, cleaning of the wall of the first transparent body (110) and / or of the second transparent body (130) with which it is in contact.

6. Water purifier (100) according to any one of the preceding claims, wherein the static mixer (120) includes at least one cleaning product distribution conduit arranged to distribute a cleaning product into the water purifier (100) and connected to a cleaning product inlet.

7. Water purifier (100) according to any one of the preceding claims, comprising a longitudinal axis, a water inlet (132) to be treated and an opposite treated water outlet (135), wherein at least one of the water inlet (132) and the water outlet (135) is offset from the longitudinal axis.

8. Water purifier (100) according to the preceding claim, the static mixer (120) comprising a plurality of surfaces arranged obliquely with respect to the longitudinal axis.

9. Water purifier (100) according to any one of claims 7 and 8, further comprising a disinfectant inlet located on the side of the water inlet (132).

10. A method for purifying water with a water purifier (100) according to any one of the preceding claims, comprising the following steps: a. Circulating water to be purified in the water purifier (100), b. Illuminating the water to be purified with the first UV light source (118) and the second UV light source (138).

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