DE102006022970B3 - UV-light source - Google Patents

Abstract

It is proposed a device for generating UV light and / or VUV light, which is simple and allows a broad-area radiation of UV light.

Description

The generation of UV light and VUV light by the excitation of gases or gas mixtures with high-frequency electrical waves, in particular with microwaves, is, for example, from the DE 41 36 297 A1 known. In this UV emitter, as with many other known from the prior art UV lamps, the energy density of the microwaves and the plasma generated by the microwaves is highly location-dependent. As a result, the energy density of the emitted UV or VUV light is highly location-dependent. In addition, many of the known from the prior art UV emitters represent a point or line-shaped radiation source and already for this reason, the energy density of the emitted UV light decreases at least with the square of the distance to the radiation source.

to execution of photochemical or photophysical processes, preferably in gaseous, liquid or solid phase, however, it is necessary to that the energy density of the light emitted by the UV light source as possible evenly and anywhere is to achieve optimum process quality and speed.

From the GB 2 413 005 A For example, a UV light source is known in which three elongate plasma pistons are arranged parallel to one another in a chamber which is at least partially permeable to UV light. This UV light source is a line source, so that the intensity of the emitted UV light is highly location-dependent.

From the DE 199 55 671 A1 For example, there is known a plasma generating apparatus which attempts to provide plasma with a very homogeneous energy density within a processing chamber.

From the DE 41 09 895 C2 For example, a device for generating UV light with a chamber is known. The chamber contains a gas-filled plasma bulb. Outside this chamber there is a magnetron which generates microwave radiation which is directed into the chamber via a waveguide and openings in the chamber. There, the microwaves excite the gas or gas mixture in the plasma bulb so that it emits UV rays.

adversely in this device is the complicated structure. At this Two magnetrons are needed to do this in a plasma flask with a length of about 15 cm in length to excite gas to emit UV light. Furthermore is for every magnetron needs a waveguide.

Of the Invention is based on the object, a device for generating of ultraviolet light, in particular vacuum ultraviolet light, to provide is simple and which a flat and homogeneous emission of UV light allowed.

These Task is in a device for generating UV light according to the preamble of claim 1 solved thereby that several plasma bulbs are present in the chamber.

The Presence of multiple plasma bulbs in the chamber leads to a Increasing the efficiency of the device, as the microwave radiation completely from the gas in the plasma bulb is absorbed. Furthermore naturally take several Plasma pistons a certain volume of space, so that a surface radiation of UV light is ensured by several plasma bulbs.

Surprisingly It has been found in experiments that by the variety juxtaposed plasma pistons leveling each other, the area-specific Power emitted by the device according to the invention UV light over the entire light exit area is very constant, although in the chamber homogeneously diffuse microwaves be initiated.

Finally is it is possible in the several plasma flasks different gases or gas mixtures provide, so that easily the wavelength spectrum of the emitted light can be adjusted.

Finally is also as an added benefit to emphasize that reliability the device according to the invention greatly increases due to the presence of several plasma bulbs. A Leakage in one of the plasma pistons merely leads to failure of this Plasmacolbens, so that the inventive device still is ready for use, albeit with reduced light output.

The Production and filling the plasma bulb with a gas or gas mixture is manufacturing technology good control, since the plasma pistons of quartz glass tubes with can be made round or oval cross-section. By Melting off the ends of these. Glass tubes can simplify the plasma pistons Be hermetically sealed.

By the surface emitted UV light of the device according to the invention a variety of photochemical and photophysical processes can be excited so that these processes proceed smoothly and at high reaction rates. For example, the disinfection of drinking and waste water, exhaust gases and solids, such as For example, foods, wet oxidation processes, syntheses, in particular of vitamins, UV polymerization reactions, curing processes and / or biochemical processes with the UV light emitted from the vacuum container according to the invention or VUV light are initiated.

The inventive device can in principle UVA, UVB, UVC and vacuum UV light in one wavelength range from 200 to 400 nm (UV light) and from 100 nm to 200 nm (VUV light). The from the vacuum tank emitted wavelengths of UV light u. a. on which gas or gas mixture the plasma bulbs filled are what pressure prevails in the plasma bulb and how the in the plasma piston located gas, or plasma is excited. The

stimulation of the gas in the vacuum tank can For example, by microwave energy.

Further, advantageous embodiments of the invention are the dependent claims.

to filling the plasma bulb can Noble gases, halides, inert gases, hydrocarbons, oxygen, Nitrogen or mixtures or chemical compounds of these gases be used.

Preferably, a pressure between 10 ^-9 mbar and 1 bar prevails in the plasma piston.

By the choice of materials for the plasma pistons and the discs, the use of different Materials or combinations of materials, such as quartz glass or sapphire crystal, can the durability across from the gas filling and the transmission of UV or VUV light can be influenced.

By the choice of gas or gas mixture, which in the plasma piston filled as well as the pressure in the plasma flask or by use of plasma flasks containing different gases or gas mixtures filled are, in a device, the emission behavior of the vacuum vessel in wide ranges are varied and controlled so that the emitted UV light optimally to the photochemical or physical process, the with the device according to the invention be initiated, can be adjusted.

The inventive device can for the be used in a variety of applications. In particular this device according to the invention for any photochemical or photophysical processes, preferably in gaseous, liquid or solid phase (also gels) can be initiated suitable. The possible Applications of the device according to the invention includes, for example, the UV disinfection of drinking and waste water, Exhaust gases and solid materials (for example, plastic films, the for Packaging purposes in the food industry are disinfected have to), Oxidation processes, syntheses, for example of vitamin D and others, UV polymerization reactions, curing processes and biochemical Processes using ultraviolet light can be initiated.

The inventive device Can also be installed in a channel, so that through the Channel pouring Medium, such as drinking or waste water, irradiated with UV light and can be disinfected.

Further Advantages and advantageous embodiments of the invention are the subsequent drawing, the description and the claims can be removed.

drawing

It demonstrate

1 an isometric view of a chamber according to the invention partially cut;

2 an isometric view of a chamber according to the invention;

3 a cross section through a chamber according to the invention;

4 an isometric view of a device according to the invention with chamber, waveguide and multiple magnetrons;

5 a cross section through a mounting situation and

6 a longitudinal section through a mounting situation.

description the embodiments

In 1 is a chamber 1 a device according to the invention shown in an isometric cut.

The chamber consists of a surrounding frame 3 , At a front of the frame 3 is a blind 5 screwed. The screw holes of this screw connection are denoted by the reference numeral 7 Mistake. The aperture 5 serves to accommodate a disc 9 , This disc 9 is made of a material which is transparent to UV light and / or VUV light. On the disc 9 For example, a grid (not shown) which is impermeable to microwave radiation may be applied but lets pass UV light.

By the retention the microwaves increase efficiency and a closed cage after Faraday formed.

The grid may for example consist of a metallic material and by vapor deposition or a printing process directly on the disc 9 be applied. Alternatively, it is also possible to make the grid as a braid of metal wires and together with the disc 9 in the aperture 5 to fix.

Inside the chamber 1 are two rows of plasma pistons 11 arranged with preferably oval cross-section.

On the back of the frame 3 are also a panel 5 and a slice 9 available. The structure corresponds to the front, so that can be dispensed with a detailed description.

In 2 is the chamber 1 not shown cut. The same components have the same reference numerals and it applies the respect 1 Said accordingly. In the frame 3 are one or more openings 10 provided by the microwave radiation in the interior of the chamber 1 can be coupled.

Through the opening 10 at the top of the chamber 1 Microwave radiation reaches the interior of the chamber 1 ,

There, the microwaves excite the plasma bulb 11 located gas or in the plasma bulb 11 located gas mixture for the emission of UV light and / or VUV light. By choosing the gas and the inside of the plasma bulb 11 prevailing pressure may be the wavelength of the plasma bulb 11 emitted light can be adjusted in wide ranges.

Of course, not in all plasma bulbs 11 a chamber 1 the same gas or the same gas mixture may be present. This makes it possible for that through the disc 9 the chamber 1 UV light or VUV light with different wavelengths is emitted.

In 3 is a cross section through a device according to the invention shown. How out 3 seen, the disc is 9 at the aperture 5 with the help of a terminal strip 13 attached. The terminal block 13 is with the aperture 5 bolted (not shown), leaving the disc 9 between the terminal block 13 and the aperture 5 is clamped.

If necessary, a seal - for example made of silicone - between disc 9 and aperture 5 as well as aperture 5 and frame 3 be provided. On the opening 10 in the frame 3 is a waveguide 15 placed.

The waveguide 15 serves the purpose of one or more magnetrons 17 emitted microwaves through the opening 10 inside the chamber 1 to lead. In many applications of the device according to the invention, the magnetron or the 17 directly on the frame 3 be put on. The waveguide 15 is then dispensable.

In 4 is an isometric view of a device according to the invention, consisting essentially of the chamber 1 , Waveguides 15 and magnetrons 17 shown.

By using one or more magnetrons 17 be over the entire length of the chamber 1 Microwaves in the chamber 1 coupled, so that all plasma pistons 11 be excited by the microwaves with about the same intensity. Further advantages of using several magnetrons 17 are the utility of low cost standard magnetrons and reliability due to multiple redundancy.

It has surprisingly been found in practical experiments that by the reflection of the microwaves in the interior of the chamber 1 the plasma pistons 11 be excited with almost the same intensity to illuminate or to emit UV light. Therefore, reflectors or other devices can be used to direct the microwaves within the chamber 1 be waived. It is definitely beneficial if the interior walls of the chamber 1 consist of a material and / or have a grid which reflects microwaves, or are provided with a corresponding microwave reflective coating.

In 5 a device according to the invention is shown cut, which is installed in a sewer and used for disinfection of the water flowing through the sewer.

The channel is in 5 with the reference number 19 designated. The entire channel cross-section is filled with water (not shown).

In the channel 19 there is a chamber 1 a device according to the invention for generating UV light.

The chamber 1 is so in the channel 19 arranged that the longitudinal direction of the chamber 1 parallel to the flow direction of the water in the channel 19 runs. In the cross section according to 5 the water flows through the channel perpendicular to the plane of the drawing 19 , The ones from the magnetrons 17 generated microwaves pass through the waveguide 15 in the interior of the chamber 1 , These microwaves are in 5 through arrows 21 indicated. Inside the chamber 1 the microwaves hit the plasma pistons 11 and excite the gas or gas mixture in the plasma bulb, so that this gas emits UV light or vacuum UV light (excimer emitter).

This emitted UV light is in 5 through arrows 23 indicated. UV light, as has long been known, has the property of being disinfecting. As a result, this will happen in the channel 19 water by the plasma bulb 11 emitted UV light disinfected.

On the side walls of the channel may be a UV-reflective coating 25 be provided. This will ensure that UV light is applied to the side walls of the canal 19 is not absorbed by the side walls, but by the coating 25 is reflected and can serve to disinfect the water again. As a result, the efficiency of the device according to the invention is improved in a simple manner.

To ensure that the whole through the channel 19 flowing water is disinfected, are in the channel 19 conducting body 27 intended. This guide body 27 narrow in the area of the light source 1 the free flow cross-section to a degree based on the dimensions of the disc 9 is tuned. As a result, the entire flows in the channel 19 water at the glass 9 over and gets into the arrows 23 indicated radiation range of the UV light source according to the invention. The guide body 27 are in the longitudinal section through the channel 19 according to 6 also clearly visible.

Alternatively to the installation of the guide body 27 in the channel 19 It is also possible in the bottom of the canal 19 to provide a recess (not shown). This recess can be the lower part of frame 3 and aperture 5 the chamber 1 pick up, so that the disc 9 to the bottom of the canal 9 way down. This solution can also be on the ceiling of the canal 19 be applied.

Of course, at Also requires several light sources according to the invention in series and / or be connected in series.

Claims (14)

Device for generating UV light and / or vacuum UV light with a chamber ( 1 ), with a gas-filled plasma flask ( 11 ) and with a magnetron ( 17 ) for generating microwaves, the plasma bulb ( 11 ) within and the magnetron ( 17 ) outside the chamber ( 1 ) are arranged, wherein the chamber ( 1 ) at least one area permeable to UV light and / or VUV light ( 9 ) and at least one opening ( 10 ) through which microwaves into the chamber ( 1 ), characterized in that in the chamber ( 1 ) several plasma bulbs ( 11 ) available. Device according to claim 1, characterized in that the chamber ( 1 ) a first disc ( 9.1 ) and a second disc ( 9.2 ) includes that the first disc ( 9.1 ) and the second disc ( 9.2 ') are substantially parallel to each other, and that the first disc ( 9.1 ) and / or the second disc ( 9.2 ) is at least partially permeable to UV light and / or vacuum UV light. Apparatus according to claim 1 or 2, characterized in that at least the first disc ( 9.1 ) and / or the second disc ( 9.2 ) made of quartz glass or other material permeable to UV light and / or VUV light. Device according to one of the preceding claims, characterized in that the chamber ( 1 ) is impermeable to microwaves. Device according to one of the preceding claims, characterized in that the insides of the chamber ( 1 ) Reflect microwaves. Apparatus according to claim 4 or 5, characterized in that on the first disc ( 9.1 ) and / or the second disc ( 9.2 ) a microwave shielding grid ( 26 ) is provided of a metallic material. Device according to one of the preceding claims, characterized in that a first row of plasma pistons ( 11 ) parallel to the first disc ( 9.1 ) is arranged. Device according to one of the preceding claims, characterized in that a second row of plasma pistons ( 11 ) parallel to the second disc ( 9.2 ) is arranged. Device according to one of the preceding claims, characterized in that the plasma pistons ( 11 ) across a width (B) of the chamber ( 1 ). Device according to one of the preceding claims, characterized in that through the at least one opening ( 10 ) of the at least one magnetron ( 17 ) generated microwaves in the chamber ( 1 ) are coupled. Device according to one of the preceding claims, characterized in that between the at least one magnetron ( 17 ) and the chamber ( 1 ) one or more waveguides ( 15 ) are provided. Device according to one of the preceding claims, characterized in that the plasma pistons ( 11 ) are filled with noble gases, halides, inert gases, hydrocarbons, oxygen, nitrogen or mixtures or chemical compounds of these gases. Device according to one of the preceding claims, characterized in that in the plasma piston ( 11 ) a pressure between 10 ^-9 mbar and 1 bar prevails. Device according to one of the preceding claims, characterized in that outside the chamber ( 1 ) and substantially parallel to the discs ( 9.1 . 9.2 ) a UV light and / or VUV light reflecting layer ( 25 ) is available.