DE102021121861A1 - Device for killing organisms in water with light - Google Patents

Abstract

A device (1) for killing organisms with which water (2) is polluted by allowing light (5) to act on the water (2) has a line (3) for conducting the water (2), one for the light (5) providing light source (4) and a light distributor (6), which directs the light (5) through a light exit window (7) onto the water (2) in the pipe (3). The light distributor (6) is arranged within the line (3) such that an annular free line cross section (14) remains between an outer peripheral surface (15) of the light distributor (6) and an inner peripheral surface (16) of the line (3). The light exit window (7) is arranged in the outer peripheral surface (15) of the light distributor (6) and extends in the peripheral direction in the form of a ring along the entire ring-shaped free line cross section (14). The light distributor (6) distributes the light (5) from the light source (4) through the light exit window (7) over the entire annular free line cross section (14).

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a device for killing organisms with which water is polluted by exposing the water to light. Precisely, the present invention relates to a device having the features of the preamble of independent claim 1.

The term "water" here includes all liquids essentially consisting of water, in particular water in and from open waters, such as salty seawater, but also waste water and water purposefully mixed with additives, such as cooling water mixed with antifreeze.

The organisms with which the water is polluted can, in particular, be potential pathogens on the one hand and organisms on the other hand that tend to multiply in the water so that it becomes cloudy and/or on the water-wetted surfaces to grow.

STATE OF THE ART

From the WO 2016/107829 A1 a system for preventing the growth of biofilms on surfaces wetted by water, in particular outer surfaces of a ship, is known, in which the surfaces are irradiated with light, the surfaces moving relative to a light source providing the light. The light is UV-A light or UV-C light provided by a laser.

Preventing biofilm growth from marine organisms by irradiating surfaces or water adjacent to them with ultraviolet light to kill the marine organisms or prevent them from attaching to submerged surfaces is known US 5,322,569A known.

In the WO 1983/001400 A1 a method for removing material from an outer surface of a ship is known, in which a laser beam is directed onto the material.

From the US 6,407,385 B1 a method for removing foreign matter particles from a sample surface by pulsed laser light is known. The surface with the foreign particle to be removed is wetted with water. Otherwise, the path of the laser light to the sample surface is kept free of water. The wavelength of the laser light is chosen so that it is absorbed by the water.

From the US 2020/0369352 A1 a method is known for preventing the growth of surfaces and ships with the aid of UV-C light, which is supplied via a light-conducting optical medium adjacent to the respective surface.

From the WO 2019/178624 A1 a device for disinfecting pipelines using electromagnetic radiation, in particular UV light, is known, in which a source for the electromagnetic radiation is arranged on a spray chain, which is kept at a distance from the floor and lateral wall areas by means of spacers. A wavelength range of electromagnetic radiation is between 200 and 300 nm.

From the DE 10 2015 115 988 A1 a device for the treatment of liquids with at least one UV light element directed onto the liquid is known, which has a measuring device for measuring a flow rate and/or contamination of the liquid. The measuring device is coupled to a control device that controls the power of the UV light-emitting element. The UV light element is arranged in a hollow body through which the liquid flows so that it is in direct contact with the liquid.

From the EP 2 829 519 B1 a device for water disinfection and sterilization of water by treatment with ultraviolet radiation is known, which has at least one emitter with wavelengths in the UV-C range. The radiator is arranged in a sterilization reactor that can be lowered into a water storage tank. The sterilization reactor is formed from an elongated reactor chamber, which is open on both sides, with a system inlet and a system outlet, in which a pump for generating a volume flow through the reactor chamber is arranged in addition to the UV-C emitter. The housing of the sterilization reactor in the area of the radiator consists of UV-C transparent quartz glass.

OBJECT OF THE INVENTION

The invention is based on the object of demonstrating a device for killing organisms with which water is polluted by exposing the water to light, in which it is ensured that the light acts evenly on all of the water conducted through a pipe.

SOLUTION

The object of the invention is achieved by a device having the features of independent patent claim 1 . Preferred embodiments of the device according to the invention are defined in the dependent patent claims.

DESCRIPTION OF THE INVENTION

A device according to the invention for killing organisms with which water is polluted by allowing light to act on the water has a line for conducting the water, a light source providing the light and a light distributor which directs the light through a light emission window onto the water directed in the line.

As was already stated at the beginning, the term "water" here includes all liquids essentially consisting of water, in particular water in and from open waters, such as salty seawater, but also waste water and water purposefully mixed with additives, such as cooling water mixed with antifreeze , a.

The light directed onto the water can in principle be any light of sufficient intensity to kill the organisms with which a water is polluted. Laser light is preferred because it can not only be provided with sufficient intensity, but also has advantages when aimed at the water because of its monochromy and collimation.

In the device according to the invention, the light distributor is arranged within the line in such a way that an annular free line cross section remains between an outer peripheral surface of the light distributor and an inner peripheral surface of the line. The light exit window is arranged in the outer peripheral surface of the light distributor and extends in the peripheral direction along the entire ring-shaped free line cross section. The light distributor distributes the light from the light source through the light exit window evenly over the entire ring-shaped free line cross-section. This implies, in particular, that light enters the free line cross section from each peripheral area of the light exit window that is extended along the entire ring-shaped free line cross section.

This uninterrupted distribution of the light from the light source over the entire annular extent of the light exit window is achieved in the device according to the invention in that the light distributor fans out the light coming from the light source with a conical mirror towards the light exit window. It goes without saying that the light coming from the light source strikes the conical mirror along a conical axis of the conical mirror, with a light intensity distribution of the light being as rotationally symmetrical as possible to the conical axis. The conical mirror preferably fans out the light radially to a conical axis of the conical mirror. The cone mirror may have a polished mirror surface. A cone of the conical mirror is preferably provided with a highly reflective coating that is matched to the wavelength of the light in order to deflect the light to the light exit window with as little loss as possible. Monochrome laser light is advantageous in this regard, for example.

In concrete terms, the conical mirror of the device according to the invention can have a full angle of approximately 70° to 90° and can be arranged coaxially to the light exit window within the outer peripheral surface of the light distributor. When the light from the light source is collimated and incident parallel to the cone axis of the cone mirror, it is redirected by a cone mirror with a full angle of 90° radially to its cone axis. The light thus spans the distance between the light emission window and the inner surface of the cable using the shortest possible route. However, if the light distributor focuses the light coming from the light source with lens optics into a focal line in the free line cross section, which runs in a ring around the light distributor at preferably equal distances from the light exit window and the inner peripheral surface of the line, the light rays of the light do not strike parallel to it Cone axis on the cone mirror. In order to fan out the light with the conical mirror radially to the cone axis, a smaller full angle of the conical mirror than 90° is required. The exact value of the full angle depends on the focal length of the lens optics of the diffuser.

The lens optics have at least one lens for shaping, in particular for expanding, collimating and/or focusing the light coming from the light source. The widening of the light with the lens optics has the advantage that it facilitates a uniform distribution of the light over the entire ring-shaped free line cross-section with the help of the conical mirror. A small offset of the cone axis of the cone mirror in relation to a central axis of the incident light results in a much smaller error in the desired uniformity of the distribution of the light over the free line cross section with a large cross section of the incident light than with a small cross section of the incident light. Focusing the light coming from the light source into the annular focal line within the free line cross section maximizes the intensity with which the light affects the organisms in the water. The lens optics of the light distributor preferably have a long focal length of at least five times the maximum diameter of the expanded light from the light source, so that the light from the light source is spatially concentrated to a high intensity over the entire free line cross section between the light exit window and the inner peripheral surface of the line is.

In concrete terms, the outer peripheral surface of the light distributor and the inner peripheral surface of the line in the device according to the invention can be arranged in the shape of a cylinder jacket section and coaxially with one another. This creates ideal conditions for an even distribution of the light from the light source over the entire ring-shaped free cable cross-section.

The conduit of the device according to the invention may have a T-piece, the light distributor being mounted on a flange which closes an opening at one end of the cross tube of the T-piece, and the light distributor terminating freely in the cross tube. The water then flows between the other two openings of the T-piece through a 90° bend.

The light source of the device according to the invention can be arranged outside the line. The light source can be coupled to the light distributor via a light guide or directly. In the latter case, the light source can be mounted on the same flange as the light distributor. An arrangement of the light source within the line so that it is cooled by the water is also possible. In any case, the light source preferably comprises a laser.

The outer peripheral surface of the light distributor including the light exit window may be formed with a transparent tube. In particular, the transparent tube is a glass tube, preferably a quartz glass tube, which allows the light from the light source to pass through as unhindered as possible.

In the device according to the invention, the light source typically provides the light with a wavelength of visible light or of the UV range adjacent thereto. Light with a wavelength between 300 nm and 700 nm is preferred, even more preferably between 400 nm and 550 nm. In this wavelength range of blue light, the absorption of light by pure water is only low. The light can therefore propagate in the water until it encounters organisms to be killed. In other words, light of the preferred wavelength range is selectively absorbed by the organisms to be killed and therefore has a particularly high efficiency in killing the organisms. The blue light is preferably provided in a narrow wavelength band by a laser of the light source.

In particular, the light source of the device according to the invention provides the light with such a light output and the light distributor of the device according to the invention distributes the light from the light source over the ring-shaped free line cross-section in such a way that in all areas of the ring-shaped free line cross-section a surface power density or intensity of the light transverse to its Direction of propagation of at least 1 W/mm ² is achieved. As a result, every part of the water flowing through the ring-shaped free line cross-section is exposed to the light with at least this intensity. Preferably, the surface power density achieved everywhere, ie the intensity with which each part of the water flowing through the ring-shaped free line cross-section is exposed to the light, is at least 2 W/mm ² or even more. The areal power density or intensity of the light is increased by the focusing or spatial concentration of the light from the light source within the free flow cross-section. With a high intensity of the light, damage to the organisms can be achieved much more reliably than with the distribution of the same power of light over a larger area perpendicular to its direction of propagation.

At the same time, a specific light output of the light per 1 mm circumferential length of the inner circumferential surface of the line opposite the light exit window can be at least 10 W, preferably at least 20 W. This means that the light is provided with such a light output and is distributed over the ring-shaped free line cross-section in such a way that at least 5W, preferably at least 10W, light output per 1 mm of peripheral length arrives everywhere on the inner peripheral surface of the line opposite the light exit window. This ensures that every part of the water flowing through the free cross-section of the pipe is exposed to a minimum light dose, which depends on a flow rate at which the water flows through the free cross-section of the pipe, but which can easily be adjusted in such a way that it causes significant damage of the contained organisms is sufficient.

In the device according to the invention, it is advantageous if the inner peripheral surface of the line opposite the light exit window is mirrored. It is particularly advantageous if the light incident through the light exit window onto the inner peripheral surface of the line from the mirrored inner peripheral surface in entge is reflected back in the opposite direction, so that it increases the intensity of the light acting on the water flowing through the free flow cross-section. This is achieved in that the light impinges radially on the inner peripheral surface in the form of a section of the cylinder casing or the inner peripheral surface is shaped in the manner of a concave mirror, which focuses the incident light back onto its annular focal line.

Specifically, a distance between the light exit window and the opposite surface of the line can be between 20 mm and 150 mm. Typically, this distance is between 50 mm and 100 mm in the device according to the invention.

If the water is not pumped by another, external pump through the ring-shaped free line cross-section of the device according to the invention, the device according to the invention can have its own pump that pumps the water through the ring-shaped free line cross-section.

In a further development of the device according to the invention, a turbidity sensor is arranged in front of the light exit window and/or a fluorescence sensor behind the light exit window in a flow direction of the ring-shaped free line cross section, and a controller of the device controls the light source depending on signals from the turbidity sensor and/or the fluorescence sensor. The turbidity of the water detected by the turbidity sensor affects the range of the light in the water. In the event of greater turbidity, a greater light output must be provided so that every portion of the water flowing through the ring-shaped free cross-section of the pipe is exposed to the light with a certain minimum intensity or minimum dose, whereby the flow rate of the water can also be reduced to ensure a certain minimum dose. The fluorescence sensor can be designed to detect autofluorescence of living organisms. With the fluorescent light sensor arranged downstream of the light exit window, it can thus be checked whether the organisms contained in the water have actually been killed by the light or have at least been damaged to such an extent that they will die. With additional sensors, other parameters such as the flow rate of the water through the free pipe cross-section, the temperature of the water, the salinity of the water and the pressure of the water can be recorded, which can have an influence on the necessary light output of the light source to detect a registered load on the Eliminate water with organisms by exposure to light.

The line of the device according to the invention can be connected to a ballast water tank, in particular on board a ship, to a cooling water system, for example an open cooling water system on board a ship, but also to a closed cooling water system, to a drinking water tank or to a waste water tank, in order to at least increase and/or to prevent the growth of organisms in the respective tank or system, or to completely sterilize the water in the respective tank, so that it is suitable, for example, for irrigation of food plants or even as drinking water.

Advantageous developments of the invention result from the patent claims, the description and the drawings.

The advantages of features and combinations of several features mentioned in the description are merely exemplary and can have an effect alternatively or cumulatively without the advantages necessarily having to be achieved by embodiments according to the invention.

The following applies to the disclosure content - not the scope of protection - of the original application documents and the patent: Further features can be found in the drawings - in particular the illustrated geometries and the relative dimensions of several components to one another as well as their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different patent claims is also possible, deviating from the selected dependencies of the patent claims and is hereby suggested. This also applies to those features that are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different patent claims. Likewise, features listed in the patent claims can be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

The features mentioned in the patent claims and the description are to be understood with regard to their number in such a way that exactly this number or a larger number than the number mentioned is present without the need for an explicit use of the adverb “at least”. If, for example, a sensor is mentioned, this is to be understood in such a way that exactly one sensor, two sensors or more sensors are present. The features listed in the claims may be supplemented by other features or may be the only features that the Subject matter of the respective patent claim.

The reference signs contained in the claims do not limit the scope of the subject-matter protected by the claims. They only serve the purpose of making the claims easier to understand.

character list

• 1 zeigt eine erfindungsgemäße Vorrichtung im Längsschnitt und
• 2 zeigt ein schematisches Lichtabsorptionsspektrum von Wasser.

The invention is further explained and described below with reference to preferred exemplary embodiments illustrated in the figures.

• 1 shows a device according to the invention in longitudinal section and
• 2 shows a schematic light absorption spectrum of water.

FIGURE DESCRIPTION

In the 1 Device 1 shown serves to kill organisms with which water 2 is polluted. The device 1 has a line 3 which conducts the water 2 . A light source 4 of the device 1 provides light 5 with which the device 1 acts on the water 2 in order to kill the organisms in the water 2 . The light 5 is directed with a light distributor 6 through an exit window 7 onto the water 2 in the pipe 3 . In concrete terms, the light distributor 6 is cylindrical in shape with a rounded tip 8 which is directed counter to a flow direction 9 of the water 2 through the line 3, indicated by arrows. The cylindrical light distributor 6 protrudes coaxially into a transverse tube 10 of a T-piece 11 of the line 3 . The transverse tube 10 has tube flanges 12 at both of its ends. An opening at one of the two ends of the cross tube 10 is closed by a flange 13 attached to the tube flange 12 there, on which the light distributor 6 is mounted and from which the light distributor 6 protrudes into the cross tube 10, where its rounded tip 8 free ends. The water 2 flowing into the transverse tube 10 passes the light distributor 6 through an annular free line cross-section 14, which extends inwards through an outer peripheral surface 15 of the light distributor 6 in the shape of a cylindrical jacket, in which the light exit window 7 is arranged, and outwards through an inner peripheral surface that is also in the shape of a section of a cylinder jacket 16 of line 3 is limited. Then the water 2 is diverted by a baffle 17 into a connecting pipe 18 of the T-piece 10 with a further pipe flange 19 at the third opening of the T-piece 10 .

According to 1 the light 5 is fed from the light source 4 to the light distributor 6 via a light guide 21 . The light source 4 can also couple the light 5, which it usually generates with a laser, for example a diode laser, directly and thus without loss into the light distributor 6 and can also be mounted on the flange 13 for this purpose. The light distributor 6 distributes the light 5 from the light source 4 through the light exit window 7 evenly over the entire annular free line cross section 14. For this purpose, the light distributor 6 has a 1 Lens optics 20 (not shown in full), which expands the light 5 and focuses it via a conical mirror 22 into a focal line 23 running annularly around the light exit window 7 . The cone mirror 22 is arranged with its cone axis 24 coaxially to the outer peripheral surface 7, and the light 5 coming from the light source 4 falls on the cone mirror 22 with an intensity distribution that is rotationally symmetrical to the cone axis 24. The cone mirror 22 fans out the light 5 radially to its cone axis 24 on, so that it spans the entire ring-shaped free line cross-section 14 . The inner surface 16 is preferably mirrored in its area opposite the light exit window 7 in order to reflect the light 5 impinging here radially back to the cone axis 24 . A turbidity sensor 25 is arranged upstream of the light exit window 7 and is formed with an LED 27 in a transmission configuration opposite a detector 26 . The turbidity of the water 2 as a result of the sediments and organisms it contains is detected by the turbidity sensor 25 . A further fluorescence sensor 29 , likewise in a transmission configuration, is arranged downstream of the light exit window 7 with an LED 31 lying opposite a detector 30 , which emits monochromatic, for example blue, light 32 . The light 32 excites living organisms to fluoresce. The detector 30 registers the intensity of fluorescent light from such living organisms at different wavelengths than that of the light 32. The fluorescence sensor 29 thus detects the residual contamination of the water 2 with living organisms. In other words, the killing off of the organisms in the water 2 is checked based on fluorescence no longer occurring. A controller 33 controls or regulates a light output of the light emitted by the light source 4 depending on the signals from the fluorescence sensors 25 and 29. The controller 33 can take the signals from other sensors 34 into account.

The line 3 of the device 1 can be connected, for example, to a ballast water tank on board a ship, a cooling water system on board a ship, a drinking water tank or a waste water tank. The water 2 can be circulated through the device 1 with the aid of a pump, not shown here, or only when it flows into the respective The light 5 is applied to the tank or when it flows out of the respective tank.

The light 5 from the light source 4 is preferably blue laser radiation with a wavelength between 400 and 550 nm. As in 2 shows the schematic light absorption spectrum of water shown, the absorption coefficient of water is particularly low in this wavelength range. This means that pure water 2 allows the light 5 with this wavelength to pass through essentially unhindered. The light 5 thus reaches all areas of the free flow cross section 14 with high intensity. However, organisms in the water 2 hit by the light 5 absorb the light 5 and are thereby killed.

Reference List

1

contraption

2

Water

3

Management

4

light source

5

Light

6

light diffuser

7

light emission window

8th

rounded tip

9

Direction of water flow 2

10

cross tube

11

tee

12

pipe flange

13

flange

14

ring-shaped free line cross-section

15

outer peripheral surface

16

inner peripheral surface

17

baffle

18

pipe section

19

pipe flange

20

lens optics

21

light guide

22

conical mirror

23

focal line

24

cone axis

25

fluorescence sensor

26

detector

27

LEDs

28

Light

29

fluorescence sensor

30

detector

31

LEDs

32

Light

33

steering

34

sensor

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2016107829 A1 [0004]
• US5322569A [0005]
• WO 1983001400 A1 [0006]
• US 6407385 B1 [0007]
• US 20200369352 A1 [0008]
• WO 2019178624 A1 [0009]
• DE 102015115988 A1 [0010]
• EP 2829519 B1 [0011]

Claims (15)

Device (1) for killing organisms with which water (2) is polluted, by allowing light (5) to act on the water (2), with - a line (3) for conducting the water (2), - a the light (5) providing light source (4) and - a light distributor (6), which directs the light (5) through a light exit window (7) onto the water (2) in the pipe (3), - wherein the light distributor ( 6) is arranged within the line (3) in such a way that an annular free line cross section (14) remains between an outer peripheral surface (15) of the light distributor (6) and an inner peripheral surface (16) of the line (3), and - the light exit window ( 7) is arranged in the outer peripheral surface (15) of the light distributor (6) and extends in the circumferential direction in the form of a ring along the entire annular free line cross section (14), characterized in that - the light distributor (6) transmits the light (5) from the light source (4 ) through the light exit window (7). ch evenly distributed over the entire ring-shaped free line cross-section (14). Device (1) after claim 1 , characterized in that the light distributor (6) directs the light (5) coming from the light source (4) with a conical mirror (22), preferably radially to a conical axis (24) of the conical mirror (22), towards the light exit window (7). fans out. Device (1) after claim 2 , characterized in that the conical mirror (22) has a full angle of 60° to 90° and is arranged coaxially to the light exit window (7) within the outer peripheral surface (15) of the light distributor (6). Device (1) according to one of the preceding claims, characterized in that the light distributor (6) expands the light (5) coming from the light source (4) with lens optics (20) and then focuses it into an annular focal line (23) which with preferably equal distances to the light exit window (7) and the inner peripheral surface (16) of the line (3). Device (1) according to one of the preceding claims, characterized in that the outer peripheral surface (15) of the light distributor (6) and the inner peripheral surface (16) of the line (3) are arranged in the shape of a cylinder jacket section and coaxial to one another. Device (1) according to one of the preceding claims, characterized in that the line (3) has a T-piece (11), the light distributor (6) being mounted on a flange (13) which has an opening at one end of the Cross tube (10) of the T-piece closes, and ends freely in the cross tube (10). Device (1) according to one of the preceding claims, characterized in that the light source (4) has a laser and is preferably arranged outside the line (3). Device (1) according to one of the preceding claims, characterized in that the outer peripheral surface (15) of the light distributor (6) including the light exit window (7) is formed with a transparent glass tube, preferably a quartz glass tube. Device (1) according to one of the preceding claims, characterized in that the light source (4) provides the light (5) with a wavelength between 300 nm and 700 nm, preferably between 400 nm and 550 nm. Device (1) according to one of the preceding claims, characterized in that the light source (4) provides the light (5) with such a light output and the light distributor (6) distributes the light (5) so - that in all areas of the annular free line cross-section (14) a surface power density of the light (5) transverse to its direction of propagation of at least 1 W/mm ² , preferably at least 2 W/mm ² , is achieved and/or - that a specific light output of the light (5) is at least W , preferably at least 0.75 W, per 1 mm circumferential length of the inner circumferential surface (16) of the line (3) opposite the light exit window (7). Device (1) according to one of the preceding claims, characterized in that the inner peripheral surface (16) of the line (3) opposite the light exit window (7) is mirrored. Device (1) according to one of the preceding claims, characterized in that a distance between the light exit window (7) and the opposite inner peripheral surface (16) of the line (3) is between 20 mm and 150 mm, preferably between 50 mm and 100 mm. Device (1) according to one of the preceding claims, characterized in that a pump of the device (1) pumps the water (2) through the annular free line cross-section (14). Device (1) according to one of the preceding claims, characterized in that in A fluorescence sensor (25, 29) is arranged in a flow direction of the ring-shaped free line cross-section (14) in front of and behind the light exit window (7), and that a controller (33) of the device (1) controls the light source (4) as a function of signals from the Fluorescence sensors (25, 29) controls. Device (1) according to one of the preceding claims, characterized in that the line (3) is connected to - a ballast water tank, in particular on board a ship, - a cooling water system, in particular on board a ship, - a drinking water tank or - a waste water tank .

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