Device for the Photochemical Treatment or Cleaning of a Liquid Medium

Abstract

The present invention concerns a device (10) for the photochemical treatment of a liquid medium, the device (10) having at least one flow channel (16a, 16b) for the liquid medium to pass through, said flow channel being delimited at least in sections by a UV-light-emitting surface (14) of at least one UV-light-producing body (12). The at least one UV-light-producing body (12) is designed such that the passing liquid medium can be electrically contacted and replaces at least one electrode for producing the UV light in the device (10).

Claims

1. Device (10) for the photochemical treatment of a liquid medium, wherein the device (10) comprises at least two flow channels (16, 16a, 16b) for the liquid medium to pass through, said at least two flow flow channels being delimited at least in sections by a UV-light-emitting surface (14) of at least one UV-light-producing body (12), characterized in that the liquid medium is contacted in each of the at least two flow channels (16a, 16b) directly or capacitively and that, during operation of the device, a potential difference is applied between the at least two flow channels, and the electrical energy is coupled into the plasma of the at least one UV-light-producing body by this voltage, whereby the plasma is ignited or maintained.

2. Device (10) for the photochemical treatment of a liquid medium, wherein the device (10) comprises at least one flow channel (16, 16a, 16b) for the liquid medium to pass through, said flow channel being delimited at least in sections by a UV-light-emitting surface (14) of at least one UV-light-producing body (12), characterized in that the flow channel (16) is delimited on a first side by a metallic wall (36a, 36b) and on a second, opposite side by the light-emitting surface (14) of the UV-light-producing body (12), and that the metallic wall (36a, 36b) is used as an electrode.

3. Device (10) according to claim 1, characterized in that a power supply for the contactable liquid medium is realized by a grid (24) arranged in the liquid medium in the region of the UV-light-producing body (12).

4. Device according to claim 1, characterized in that at least one circuit (30b, 30c, 30d) of the liquid medium is electrically insulated from ground during operation of the UV-light-producing body (12), said circuit being connected to an electrode (24, 26a, 36b).

5. Device (10) according to claim 1, characterized in that a power supply for the contactable liquid medium is realized by an electrically conducting wall of the at least one UV-light-producing body (12).

6. Device (10) according to claim 1, characterized in that a power supply for the contactable liquid medium is realized by an electrically conducting light-emitting surface (14) of the at least one UV light-producing body (12), said light-emitting surface being arranged towards the liquid medium.

7. Device (10) according to claim 1, characterized in that at least one connection line (30a, 30b) for the liquid medium flowing through the device (10) is electrically insulated from grounded system components or that the connection line (30) itself has a high electrical impedance.

8. Device (10) according to claim 7, characterized in that the high electrical impedance is realized by the use of sufficiently long connection lines (30) made of electrically insulating materials.

9. Device (10) according to claim 8, characterized in that the high electrical impedance is realized by at least one dielectric interruption (39) in the connection line (30).

10. Device (10) according to claim 7, characterized in that the electrical insulation or the high electrical impedance is realized by insulating materials of a gear pump, peristaltic pump (32), or piston pump, said insulating materials being arranged in the connection line (30).

11. Device (10) according to claim 7, characterized in that the high electrical impedance is realized by an inductance, wherein the inductance is realized by a connection line (30) wound around a magnet core.

12. Device (10) according to claim 1, characterized in that the at least one UV-light-producing body (12) is supplied by a bipolar electric voltage, so that only a portion of a total voltage relative to ground is respectively applied to each electrode.

13. Device (10) according to claim 12, characterized in that the bipolar voltage is produced by a transformer with a grounded center.

14. Device (10) according to claim 12, characterized in that the bipolar voltage is produced by a bridge circuitpreferably, by a full bridge.

15. Device (10) according to claim 1, characterized in that an end of the connection line (30a) comprises a grounding (34), said end facing away from the UV-light-producing body (12).

Description

[0037] Exemplary embodiments of the invention are illustrated in the figures and are explained in more detail in the following description. Illustrated, in each case in schematic form, are:

[0038] FIG. 1 a device according to the invention for the photochemical treatment of a liquid medium in a first embodiment;

[0039] FIG. 2 the device according to the invention in a second embodiment;

[0040] FIG. 3 the device according to the invention in a possible environment.

[0041] FIG. 1 shows a device 10 according to the invention for the treatment or cleaning of a liquid medium in a lateral view in a first embodiment. The liquid medium is preferably contaminated water.

[0042] The device 10 of FIG. 1 comprises two UV-light-producing bodies or lamps 12, which, with their UV-light-emitting surface 14, form a region of a flow channel 16 for contaminated water. Naturally, more than two UV-light-producing bodies 12 can also be arranged with their light-emitting surfaces 14 one after the other. The light emission of the UV light from the light-emitting surface 14 is illustrated by arrows 18. A flow direction of the contaminated water is indicated by an arrow 20.

[0043] The UV-light-producing body 12 can be flat, cubical, round, oval, or annular; preferably, the UV-light-producing body 12 is designed as a flat cuboid. What is important is that its UV-light-emitting surface 14 delimits the flow channel 16 and directly forms at least a region of a wall of the flow channel 16. Thereby, the contaminated water can directly pass the UV-light-emitting surface 14.

[0044] The UV-light-producing body 12 can comprise amplification supports (not shown) in the internal space. This serves for greater stability of the UV-light-producing body 12.

[0045] The UV-light-producing body 12 comprises, preferably, xenon as filling gas and functions according to the known principle of gas discharge, wherein a dielectric barrier discharge (DBD) preferably occurs as a result of an excitation of the xenon gas with a high-frequency and/or pulsed electrical voltage, and a UV light with a wavelength of approx. 172 nm is thereby produced.

[0046] In principle, other inert gases, such as helium, argon, krypton, or neon can also be used. Also possible in this case are mixtures of several inert gases and/or mixtures with appropriate halogens, such as fluorine, chlorine, bromine, or iodine. What is important is that light with a wavelength of less than 185 nm is produced, because this light is very high-energy and allows for a photolysis of the water. The contaminants contained in the water are thereby oxidized into harmless substances.

[0047] The flow channel 16 is preferably rectangular. It could, however, also have an arbitrarily different cross-section, wherein the shape of the lamp 12 must be adapted to the cross-section in sections, in order to avoid a loss of energy by circulating contaminated water.

[0048] The illustrations in the figures are, for better clarity, not drawn to scale. A preferred thickness D of the flow channel 16 is approx. 1 mm; the width is essentially arbitrary. 10 cm have proven to be the upper limit for the thickness D of the flow channel 16. Better cleaning results arise with thicknesses of less than 5 cm, and preferably less than 1 cm.

[0049] Inside the flow channel 16, a metallic grid 24 is arranged parallel to the light-emitting surfaces 14. The grid 24 can be a wire grid made of thin, stainless steel wires. The grid 24 is electrically contacted, and suitable electrical impulses are applied to it by a pulse generator 26.

[0050] The grid 24 is used to electrically contact the contaminated water flowing through the flow channel 16, so that the flowing water forms an electrode for operating the UV-light-producing body 12. In the process, the electrical signals that the UV-light-producing body 12 requires for its operation are applied to the grid 24 by the pulse generator 26. The counter electrode can be arranged inside or outside of the UV-light-producing body 12 and is not shown.

[0051] FIG. 1 shows a (first) electrical connection 35 of the grid. The housings of the UV-light-producing body 12 can be grounded (see reference symbol 34) and can form a second electrical connection.

[0052] A second electrode for operating the UV-light-producing body 12 can also be formed metallically and then be arranged in or on the UV-light-producing body 12 and electrically contacted there.

[0053] FIG. 2 shows the device 10 according to the invention for the treatment or cleaning of contaminated water in a lateral view in a second embodiment. In contrast to the first embodiment, the light-emitting surface 14 of the UV-light-producing body 12 is electrically contacted in the second embodiment. For this purpose, the light-emitting surface 14 is designed to be electrically conducting. In this case, the light-emitting surface 14 can be made, for example, of a material 28 that is semi-transparent to the produced UV radiation, wherein the material 28 is electrically contactable and electrically conducting. In the process, the electrical signals that the UV-light-producing body 12 requires for its operation are applied to the semi-transparent material 28 by the pulse generator 26.

[0054] FIG. 3 shows another embodiment of the device 10 according to the invention in a possible environment. On the UV-light-producing body 12 designed as a flat cuboid, flow channels 16a and 16b are formed on both sides directly on the respective light-emitting surfaces 14. Each flow channel 16a and 16b is delimited on a first side by a metallic wall 36a and 36b and on the second, opposite side by the light-emitting surface 14 of the UV-light-producing body 12. Each metallic wall 36a and 36b is used at the same time as an electrode as well. The electrode 36a is grounded (see reference symbol 34), whereas the operating voltage for the UV-light-producing body 12 is applied to the electrode 36b via the electrical connection 35.

[0055] The flow channel 16a is connected to a storage container 37 via a connection line 30a. The flow channel 16b is connected to a collecting container 38 via a connection line 30d. Furthermore, the flow channels 16a and 16b are connected to one another via additional connection lines 30b and 30c via a pump 32, such as a peristaltic pump. The water is thus first pumped from the storage container 37 via the grounded flow channel 16a. Subsequently, the water is pumped through the connection lines 30b and 30c into the flow channel 16b, to which the high operating voltage of the UV-light-producing body 12 is applied. Afterwards, the treated water is collected in the collecting container 38 via the connection line 30d. Both containers 37 and 38 are grounded (see, in each case, reference symbol 34).

[0056] In the operating state, an electrical insulation is ensured between the voltage-carrying connection line 30d and the grounded collecting container 38 via the air gap 39. An electrical insulation between the voltage-carrying connection line 30c and the grounded line 30b is ensured by the peristaltic pump 32, which comprises components that are dielectrically acting (electrically insulating) in the flow range.

[0057] The groundings 34 serve to safely operate the UV-light-producing body 12. Parasitic currents should be discharged safely and parasitic electrical couplings should be avoided.

[0058] The research work that led to these results was supported by the European Union.