DE8815485U1 - Device for disinfecting liquids with ultraviolet radiation - Google Patents

Description

Dr. K. Hönle GmbH Munich, December 2, 1988 Hartinsried, Germany be-ke 15

Device for disinfecting liquids with ultraviolet radiation

The present invention relates to a device for disinfecting liquids, in particular water, by ultraviolet rays.

The UV disinfection devices for liquids known from the current state of the art were designed according to the following construction methods:

For small outputs and small liquid throughputs, an internally centrally arranged radiator was usually used. This means that the UV burner was installed in the middle of the flow chamber through which the liquid to be disinfected flows. It had to be made of a material that was UV-permeable, water-resistant and able to withstand the extreme temperature gradient between the UV burner and the liquid. For larger devices, the so-called internally concentric radiator arrangement was chosen. In this case, several UV burners were arranged concentrically in the flow chamber and usually at the same distance from one another. Another design was the so-called externally concentric radiator arrangement. In this case, the UV burners were arranged outside the flow chamber. The flow chamber was formed by a UV-permeable tube. The last two arrangements have the disadvantage that a large number of burners are required and these systems can therefore only be used effectively in large systems. Finally, another embodiment was the radiator arranged transversely to the flow direction. However, in this case the radiation intensity is usually too low at higher flow velocities.

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However, all of these designs have the disadvantage that if the liquid contains solid particles that are impermeable to UV light, shadows are created that prevent the medium from being evenly disinfected. This creates the risk that pathogens will survive this disinfection process. In addition, all of these arrangements have the major disadvantage that the radiation intensity is extremely unevenly distributed across the cross-section of the flow chamber.

It is therefore an object of the present invention to provide a UV disinfection device which ensures a very uniform and absolutely shadow-free irradiation of the medium to be disinfected.

This object is achieved by the characterizing features of claim 1. According to the invention, the UV burner is arranged in one focal axis and the flow chamber for the water to be disinfected is arranged in the other focal axis of a hollow cylinder with an elliptical cross-section that is mirrored on the inside. According to a particularly preferred embodiment of the invention, a photocell can be arranged on the side of the flow chamber in the major axis of the ellipse defined by the two focal points, which allows an accurate measurement of the total absorption of the medium flowing through. If the illuminance of the photocell drops too much, for example, an alarm can be triggered, indicating that the medium has such a high absorption that reliable disinfection of the entire cross-section is no longer guaranteed.

Further preferred embodiments of the invention emerge from the above subclaims. Another great advantage of the present invention is that there is no direct contact between the outer wall of the UV burner and the wall of the flow chamber. Undesirable heating of the medium flowing through can thus be prevented. This makes the present invention particularly suitable for high-performance disinfection (large quantities of water or high disinfection levels) since high-pressure Hg lamps can also be used, which have very high UV radiation flux.

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The high thermal loads caused by high-pressure jets were State-of-the-art disinfection devices have not yet been

grown.

Advantageously, according to the invention, a high-pressure lamp Disinfection effects can be achieved that previously required 3, 5 or more lamps

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Furthermore, the spatial separation of lamp and object to be irradiated according to the invention allows for a considerably simpler replacement of the lamps. At the same time, the spatial separation of electrics and liquid/gas enables a simpler and more reliable device construction.

Further features and advantages of the invention will become apparent from the following description taken in conjunction with the drawings.

Show it:

Figure 1 shows a schematic diagram of the disinfection device according to the invention;

Figure 2 is a sectional view transverse to the flow direction of the medium γ through an embodiment of a j

Disinfection device; $ Figure 3 is a sectional view of the above inventive Disinfection device; [

Figure 4 Diagrams of the different radiation densities according to the prior art (central lamp arrangement) and the invention (elliptical radiation geometry).

Figure 1 shows a schematic diagram of a UV disinfection device according to the invention for liquids and gases, in particular for Uaccav· {Ja.!*· J" ^tOO-QV* \ZrtV»y«"i^h"hnnn $"jfjH 3&Idigr;&Pgr;"^ ^* ^nrt "l '«'&bull;ha*' lll/_C+ ^> v«ah"Igy· J UHC*

a quartz tube 2 through which the medium 3 to be sterilized can flow, arranged essentially parallel to one another at a certain distance.

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Emitter 1 and quartz tube 2 are surrounded by an elliptical reflector 4* This reflector 4 has the shape of an elliptical hollow cylinder. Ef is arranged so that the UV emitter �iacgr; is located in one ellipse focal axis, while the quartz tube is located in the other ellipse focal axis. The curve shape of the ellipse is described by the following mathematical function:

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Here, &khgr; runs along the major axis of the ellipse, y is the minor axis of the ellipse, a is the largest radius and b is the smallest radius of the ellipse.

Due to this inventive design of the UV disinfection device, the rays emanating from the radiator 1 are reflected by the elliptical reflector in such a way that they penetrate radially inwards from all sides through the quartz tube into the liquid to be disinfected.

Advantageously, an opening can be provided in the reflector in the plane of the main axis of the ellipse on the side on which the quartz tube is mounted, to which opening a photocell 5 is attached. In addition, a design can also be selected in which the opening has a certain opening angle α and the area of the reflector surrounding the photocell extends outwards from the ellipse at this angle.

Figures 2 and 3 show an advantageous embodiment of the invention. The reflector 4 consists of four identical circumferential sections 10 which, when arranged opposite one another in a mirror-symmetrical manner, produce the elliptical shape of the reflector 4. The division of the circumferential sections 10 runs in the area of the main and secondary axes of the ellipse, with the circumferential sections 10 abutting one another on the secondary axis, while in the area of the main axis there is an opening in the ends of the circumferential sections 10 facing one another or a slot between them, so that a photocell 5 can be attached here on the side of the quartz tube 2. On the

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On the opposite string, i.e. behind the radiator, this opening, which inevitably also results on this side due to the symmetry of the circumferential sections, can be used to attach or connect the UV radiator 1.

The great advantage of the present invention is clear in Figure 4. This figure shows a comparison between a central lamp arrangement, which has been the only economical solution up to now for smaller disinfection devices, and the arrangement according to the invention. The top line of Figure 4 shows the UV intensity for the case where the disinfection device is operated without a medium to be disinfected. It can be seen that in this case the distribution of the UV intensity is essentially the same for both arrangements. The next line shows the attenuation of the radiation due to the transmission attenuation of the medium for the example of water. This clearly shows the great advantage of the present invention:

With the central lamp arrangement, the radiation towards the outside is further reduced by the transmission attenuation of the medium, while with the arrangement according to the invention, in the ideal case, the attenuation of the medium exactly compensates for the increase in UV intensity towards the focal point of the ellipse. This is very clear from the diagrams in the third line of the figure. It can be seen that with the central lamp arrangement, which corresponds to the current state of the art, an extremely high radiation density is achieved directly near the UV lamp, while in the outer area the radiation is almost zero. This arrangement according to the state of the art therefore does not allow uniform irradiation of the medium to be disinfected. In contrast, line 3 on the right-hand side shows an approximately constant curve. From this curve it can be seen that the radiation density remains almost constant across the entire internal cross section of the quartz tube, thus enabling extremely uniform irradiation. In addition, it is ensured that any light-absorbing particles carried in the Merf-um, which in arrangements according to the state of the art always had a negative effect on UV radiation, are

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The solution according to the invention is irradiated evenly from all sides. The survival of any germs in the shadow area can thus be excluded.

The particularly advantageous embodiment of the invention with the UV radiation sensor in the main axis of the ellipse on the side of the quartz tube enables very good control of the disinfection effect. If a medium that is too cloudy flows through the quartz tube at home or if the quartz tube has become less permeable to UV radiation due to fogging, dirt or similar, this highly sensitive sensor can trigger an alarm that indicates to the user of the disinfection device that the disinfection effect has been reduced. The arrangement of the photocell according to this particularly advantageous embodiment of the invention allows the entire cross-section of the quartz tube to be monitored for possible clouding or dirt with a single photocell. The photocell 5 can also easily detect any reduction in the reflectivity of the reflector 4.

The disinfection device according to the invention is suitable for all liquid substances and gases. Depending on the transmission of the respective medium, the diameter of the quartz tube at most has to be adjusted if absolutely uniform irradiation over the entire cross-section is to be ensured.

Claims (6)

Dr. K. Hönle GmbH Munich, 2 December 1988 Martinsried, Germany be-ke 15 Device for disinfecting liquids with ultraviolet radiation Protection claims 1. UV disinfection device for liquids or gases, in particular for water, with a UV lamp and a reflector that collects the rays on the medium to be irradiated, characterized in that the reflector (4) has a hollow cylindrical shape with an elliptical cross-section, that the radiator (1) is arranged in one elliptical focal axis of the reflector (4) and that in the other elliptical focal axis of the reflector (4) a tube (2) permeable to UV rays is arranged, through which the medium to be disinfected (3) can flow. 2. UV disinfection device according to claim 1, characterized in that the tube (2) consists of quartz. 3. UV disinfection device according to one of claims 1 or 2, characterized in that the reflector (4) is composed of at least two circumferential sections (10) arranged mirror-symmetrically to one another. 4. UV disinfection device according to claim 3, characterized in that the dividing joints of the peripheral sections (10) run along the main and/or secondary axis of the ellipse, ■ «· # Help «I I I Il * · · I I I f * ff » ·· I III tt Il III * · I ■ »«··»( II
« t « « I III I I ·· 4«I III I Il Il · ■ * III ■ I » t 5. UV disinfection device according to one of the preceding claims, characterized in that an opening (6) is provided in the main axis of the ellipse on the side of the tube (2) in the reflector (4), in which opening a photocell (5) is mounted. 6. UV disinfection device according to one of the preceding claims?, characterized in that the peripheral sections (10) are extruded profiles. .» ' * * I I I I «I IMI