DE102017104426A1 - Liquid-cooled LED immersion light for activating reactions in fluids - Google Patents

Abstract

The invention relates to an LED immersion light with a rod-shaped lamp body, which carries LEDs on at least one side and is arranged over a longitudinal section for permanent immersion in a liquid, wherein along the lamp body, a closed piping system for liquid cooling is integrated, to which the LEDs thermally coupled. In addition, the invention relates to a system and method for controlling a reaction process with the LED immersion light.

Description

The present invention relates to an LED immersion light which is adapted to provide light for a reaction process in a liquid, and to a corresponding system and a method for carrying out the reaction process.

In the chemical industry, reaction processes in fluids are initiated or controlled by light for various applications. There are also LED light sources with a spectral range depending on the application used. Furthermore, it is also known that light sources are immersed in the process fluid in order to come into the most direct contact with them. Partly also high radiation powers are required, e.g. in BioReactors with bacteria or similar organisms to trigger or keep the reaction process.

In some of the lights, however, it is a disadvantage that not only the desired light is generated by the lights, but also power is converted into heat. In principle, LEDs are already preferred because they have only a lower power loss compared to conventional light sources. This can still be about 50%, i. About half of the electrical energy is not converted into light of the desired wavelength but into heat.

Object of the present invention is to eliminate the negative effects that a heat input in a luminaire of the type mentioned above exerts on the reaction process, as possible, and also to simplify the thermal management of the reaction process.

The object is achieved by an LED immersion luminaire according to claim 1 and by a system according to claim 12 and a method according to claim 14.

A particularity of the LED immersion luminaire of the present invention is liquid cooling. The immersion luminaire comprises a luminaire body which carries LEDs as light sources on at least one side. This section of the lamp body is specially designed to be permanently immersed in a liquid. On the lamp body, a piping system is further provided, which is integrated in a closed circuit of liquid cooling. The part of the lamp body which is introduced into the reaction vessel is sealed in such a way that it is suitable for a permanent immersion in the liquid of the reaction components. In that regard, the lamp differs from a simple moisture or splash-proof light, or a lamp that is only suitable for temporary submersion. On the other hand, in the case of the LED immersion luminaire according to the invention, the entire luminaire does not have to be permanently immersed in the liquid, but it is sufficient for that portion of the luminaire body which carries the LEDs and which is cooled via the closed piping system to be permanently immersed in the liquid Liquid is set up.

According to a preferred embodiment, connections for a supply and return line of the pipeline system and / or electrical connections for the electrical supply of the LEDs are provided in a not intended for immersion portion of the lamp body on a the immersion adapted adapted section opposite end of the lamp. The connections therefore do not need to meet the same high demands on the liquid-tightness which is necessary for the luminaire in the region of the section to be immersed. Instead, the terminals are arranged on the immersion light above the level of the liquid in which the reaction components are located.

According to a preferred embodiment, the piping system has an inner diameter of at least 1.5 mm, preferably at least 2 mm, and the LEDs have an electrical power between 40 W and 200 W, preferably between 100 W and 160 W, on. As described above, the thermal power dissipation of LEDs is about 50% of the total power. The immersion light will therefore bring a thermal power of about 20 W to 100 W, in particular 50 W to 80 W, in the reaction liquid. The piping system having an inner diameter of 1.5 mm or more, when e.g. is traversed with water as the cooling liquid at a flow temperature of 20 ° C, oversized to compensate for the thermal power loss of the LEDs. However, according to the invention it is provided that the cooling system of the immersion light can extract more heat from the overall system than is introduced into the system by the electrical power dissipation of the LEDs. As a result, additional heat released into the system by converting the light during the reaction process can also be dissipated by the dipping light cooling system. Separate cooling of the reaction fluid is therefore no longer necessary. The entire thermal control can be carried out solely by the cooling system of one or possibly several immersion lights.

According to a preferred embodiment, the dipping section of the lamp body has a length of at least 1 m, preferably 1.5 m, on. The length of the submerged section is thereby optimized for the cooling system. For much longer sections to be immersed, the cooling capacity over the length of the lamp body would no longer be uniform. Shorter dipping sections, however, would have the disadvantage of no longer being suitable for reaction vessels common in the chemical industry.

According to a preferred embodiment, the section set up for immersion is designed according to protection class IP68 or higher and / or a non-immersion section with a protection class below IP68, in particular according to protection class IP65, is set up. In particular, the portion not intended for immersion is formed with a lower protection class than the portion intended for immersion. As a result, for example, the connections for the electrical supply and for the supply of cooling fluid according to a lower protection class can be formed inexpensively, while only the immersed area of the luminaire of high protection class must be set up for permanent immersion in liquid.

According to a preferred embodiment, the closed pipeline system comprises two lines routed parallel to one another, which are connected continuously to a 180 ° arc segment. One of the two lines includes the flow, while the parallel pipe forms the return line. The arcuate segment is preferably arranged at the lower end of the dipping section of the luminaire. This design allows the cooling liquid of the supply and return flows countercurrently. As a result, the portion of the luminaire set up for immersion can be uniformly cooled over its entire length. In contrast, an asymmetry in the piping system would cause a different cooling capacity over the length of the section to be immersed. The 180 ° arc segment can be formed for example by a flexible hose. The pipes for the flow and return are preferably made of rigid tubes, e.g. made of metal tubes, designed to form a good thermal contact with the LEDs.

According to a preferred embodiment, the piping system is formed by individual pipe and / or hose segments. As stated above, in particular, the 180 ° arc segment can be formed by a hose. The remaining pipes are preferably made of metal. It is quite possible to assemble the luminaire from several modules, so that the pipelines of the flow and the return respectively consist of several pipe sections. As a result, the luminaire can also be constructed in a modular manner in order, for. to be set up for different immersion depths.

According to a preferred embodiment, the lamp body is formed from an extruded aluminum profile with two longitudinal joints, in each of which a pipe of the closed piping system is provided. An aluminum profile has the advantage that it conducts the heat from the LEDs to the pipes well. The arrangement of the pipes in longitudinal joints of the extruded aluminum profile also has the advantage that the pipe itself is well thermally coupled to the lamp body.

According to a preferred embodiment, the luminaire body carries only one or more LED modules on one or two opposite sides, which are thermally coupled to the luminaire body. For lights, which are arranged on a side wall of the reaction container, it is sufficient that only one side of the lamp body is occupied by LEDs. In contrast, immersion lights, which are arranged centrally in the reaction vessel, preferably occupied on several sides with LEDs. The LEDs can be provided in modules, in particular on sections of a PCB (Printed Circuit Board), and can be applied flat on the sides of the luminaire body, in particular the aluminum profile. Due to the flat support of the thermal contact between the LEDs and the lamp body is improved. It would also be conceivable that more than two sides of the lamp body are occupied by LEDs. In this case, however, the pipes of the cooling system would have to be mounted inside the lamp body. With only two sides of the luminaire body occupied by LEDs, at least two further narrow sides remain, along which the piping system can be guided.

According to a preferred embodiment, the longitudinal section of the luminaire body set up for immersion is covered with glass, in particular borosilicate glass, and / or with plastic, in particular PMMA, PC or PET. As a result, the lamp body can be easily sealed, so that it is suitable for permanent immersion in the liquid. Furthermore, these sheaths have the advantage that they are permeable to a wide wave spectrum. Optionally, the glass or plastic material can be tailored to the wavelength of the LEDs used.

According to a preferred embodiment, the LEDs have the light colors white, in particular more than 6,500 K, blue, red and / or ultraviolet. White light and especially blue and red Light is suitable for photosynthesis. The green color range, however, can be omitted for the photosynthesis. Ultraviolet light is suitable for other types of reactions, for example, for various types of polymerization or even sterilization.

The present invention further relates to a system for carrying out a chemical or biological reaction process in a liquid, which comprises a reaction container for receiving the liquid and at least one LED immersion lamp according to one of the embodiments described above, and a heat exchanger and a pump, which with the at least an LED immersion lamp are connected to a cooling liquid, in particular water, to pass through the closed pipe system of the LED immersion light.

According to a preferred embodiment, the system comprises a plurality of LED immersion lights. Further, a first distributor is provided between the plurality of leads of the LED immersion lights and a second distributor between the plurality of returns of the LED immersion lights, and the first and second distributors are connected to the heat exchanger and the pump for passing the cooling liquid through all the LEDs - to let inlets to circulate. According to this embodiment, a refrigeration cycle can be used for all LED immersion lights. Furthermore, the distributors ensure that all LED immersion lights are cooled evenly. If one were to switch the cooling circuits of the luminaires in series in series, the cooling capacity would gradually decrease from one luminaire to the next luminaire.

According to another aspect of the invention, there is provided a method of operating one of the foregoing systems with the one or more LED immersion lights, wherein the flow rate of the cooling fluid through one or more of the LED immersion lights and a flow temperature of the cooling fluid through one or more a plurality of LED immersion lights is controlled such that the heat extracted from the system by the heat exchanger is different from the heat generated by the thermal power dissipation of the LEDs of the one or more LED immersion lights. In particular, by cooling the one or more LED immersion lights, more heat can be extracted from the system than is added to the system by the power dissipation of the LEDs. For example, the flow rate may be between 0.001 and 0.01 kg / s in each light, i. in the case of several lamps after the first distributor or before the second distributor. As a result, more heat can be withdrawn from the system as a whole, as is introduced by the thermal power loss of the LEDs in the system. Thus, the temperature can be controlled in the reaction liquid and optionally dissipate heat during the reaction process through the lights. A separate cooling of the reaction liquid is no longer necessary in this embodiment. For other reaction processes, it may also be preferred that the heat extracted via the cooling of the LED immersion lights is lower than the heat loss of the LEDs. In this case, the LED immersion lights can be used as heating elements. In general, with the regulation of the cooling circuit for the LED immersion lights, the thermal management for the reaction process can be completely controlled.

• 1 zeigt eine schematische Ansicht eines Systems zur Durchführung einer Reaktion in einer Flüssigkeit gemäß dem Stand der Technik.
• 2 zeigt eine schematische Ansicht eines Systems zur Durchführung einer Reaktion in einer Flüssigkeit gemäß einer Ausführungsform der Erfindung.
• 3 zeigt eine Seitenansicht einer LED-Eintauchleuchte einer Ausführungsform der Erfindung.
• 4 zeigt einen Querschnitt der LED-Eintauchleuchte entlang der Ebene A-A der 3.
• 5 zeigt einen Querschnitt durch die LED-Eintauchleuchte entlang der Ebene B-B der 3.
• 6 zeigt einen Querschnitt der LED-Eintauchleuchte im Bereich C der 4.
• 7 zeigt eine perspektivische Ansicht der Eintauchleuchte nach 3 in einem unteren Bereich.
• 8 zeigt Querschnitte verschiedener Ausführungsformen von LED-Eintauchleuchten.

Further advantages and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings. The figures show the following:

• 1 shows a schematic view of a system for carrying out a reaction in a liquid according to the prior art.
• 2 shows a schematic view of a system for carrying out a reaction in a liquid according to an embodiment of the invention.
• 3 shows a side view of an LED immersion lamp of an embodiment of the invention.
• 4 shows a cross section of the LED immersion light along the plane AA of 3 ,
• 5 shows a cross section through the LED immersion light along the plane BB of 3 ,
• 6 shows a cross section of the LED immersion light in area C of 4 ,
• 7 shows a perspective view of the dipping light after 3 in a lower area.
• 8th shows cross sections of various embodiments of LED immersion lights.

In the 1 For example, a system for performing a light initiated reaction process in a prior art fluid is shown. Several rod-shaped lights are in the liquid 2 immersed with the reaction components to initialize or control the reaction process. To the heat input through the lights in the liquid 2 To compensate, an external cooling is also provided, which is the liquid 2 through a heat exchanger to control the temperature.

Referring to the 2 a comparable system according to an embodiment of the invention is shown. In the liquid 2 are LED immersion lights 6 dipped, which are self-cooled. Each of the lights 6 has a liquid cooling as described below. The flow and return of the liquid cooling of the several lights 6 are in a first or second distributor 10 and 12 summarized and connected to a heat exchanger and an external cooling. Thereby it is no longer necessary to cool the liquid in which the reaction process takes place, as in 1 shown. The thermal management can alone on the tempered lights 6 respectively. It should be noted that the cooling for the lights 6 designed so that also more heat of the liquid 2 can be withdrawn, as by the thermal power dissipation of the lights 6 is introduced into the system. As a result, in particular heat which is released by the reaction process itself can be dissipated by the cooling of the lights.

Referring to the 3 to 7 is an embodiment of the lamp 6 described.

The lamp 6 is designed in the form of an LED immersion light. A lower rod-shaped longitudinal section 20 the lamp is for permanent immersion in the liquid 2 of the reaction vessel 4 set up. Above the rod-shaped sections 20 there is a section 22 which is not suitable for permanent immersion in the liquid. In particular, the section 20 according to protection class IP68, while the upper section 22 only fulfills the protection class IP65.

Around the section designed for permanent immersion 20 is an outer coat 24 provided in the embodiment according to the 3 to 7 is cylindrical. The cylinder 24 must be resistant to the liquid 2 or the reaction components contained therein. Furthermore, it must be translucent for the corresponding wavelengths of the luminaire. Preferably, glass or a transparent plastic is used.

Inside the casing 24 there is a lamp body 26 , which is made in the illustrated embodiment of an aluminum extruded profile. As in cross section 5 can be seen, owns the lamp body 26 two opposite contact surfaces on each of which a PCB 28 with LED 30 is arranged. The PCB 28 are in good thermal contact with the lamp body 26 educated. Furthermore, on two narrow sides of the filament 26 each provided a longitudinal joint, in which a tube 32 is inserted. The tubes 32 are part of a closed piping system of the luminaire and form in the upper section not intended for immersion 22 one connection each for the flow and return of the luminaire. In the lower part of the lamp, ie at the end of the section to be dipped 20 , which is the section not intended for immersion 22 Opposite, are the tubes 32 with an arcuate section 34 connected, so that a closed piping system arises within the lamp. The two tubes 32 can be used as either forward or reverse because they are symmetrical. By the arrangement of the tubes 32 in the longitudinal joints of the lamp body 26 and by the surface connection of the PCB 28 on the lamp body 26 stand the tubes 32 in good thermal contact with the LED 30 , This can efficiently reduce the heat caused by power dissipation in the LEDs 30 arises, be dissipated. As previously described, more heat may be dissipated to the liquid 2 continue to cool.

The flow rate may for example be 0.005 kg / s at a pressure of about 436 mbar. As a result, when using water as a coolant with a flow temperature of about 20 °, the power loss of the LED, which makes up about 50% of the total electrical power of the LED modules of a lamp, in the present case about 130 W, be discharged and beyond the liquid 2 be cooled even further with the reaction components. The section 20 the lamp is about 1.5 m. Over this length can be the lamp body 26 with the tubes 32 Cool an inner diameter of about 2.6 mm over the entire length. Shorter embodiments are also possible. Longer embodiments, however, are less preferred because then the cooling performance can not be provided uniformly over the entire length of the lamp. It should be noted that the values for the length of the section to be dipped 20 the lamp, the material selection for the lamp body 26 as well as the total power of the LEDs 30 on the pipe inside diameter of the pipe system 32 . 34 must be adjusted to the desired temperature distribution within the luminaire and in the liquid 2 adjusting the reaction components.

In the 8th Several cross-sections are shown according to the figure 5 for various embodiments of the lamp. The illustrated embodiments always include the same lamp body 26 each with two symmetrical tubes 32 , Depending on the embodiment, LED modules (ie, PCB 28 and LEDs 30 ) may be provided on only one or two opposite sides of the lamp body. Furthermore, it is also possible that within a lamp several lamp body, eg five pieces, as in the 8th shown below, are provided. The one or more lamp bodies are provided in a casing 24. This may be cylindrical, square or rectangular, as in the various embodiments of 8th shown.

For the multiple lamp body embodiment, separate terminals may be provided for each of the piping systems of the individual lamp bodies 26 be provided. However, all luminaire bodies are preferably mechanically connected to each other in a non-immersion section of the luminaire.

Numerous modifications of the above-described embodiments can be made without departing from the scope of the invention, which is defined by the claims. In particular, other forms of lamp bodies are possible. It is also conceivable that the lamp body has more than just two contact surfaces for LED PCB. The lights may be constructed in a modular manner, for example, both the piping system for cooling and the PCB for the LED each extend only over a portion of the lamp body and are connected together. Preferably, however, the lamp body itself is formed by a continuous metal profile in order to achieve a better heat conduction over the lamp body.

LIST OF REFERENCE NUMBERS

2

Liquid with reaction components

4

container

6

LED immersion lamp

10

Distributor for flow

12

Distributor for return

20

Submerged section

22

For immersion unintended section

24

jacket

26

Luminaire body, in particular extruded aluminum profile

28

PCB (Printed Circuit Board)

30

LED

32

tube

34

180 ° -Bogensegment

Claims (15)

LED immersion light (6) with a rod-shaped lamp body (26) carrying on at least one side LEDs (30) and which is arranged over a longitudinal portion (20) for permanent immersion in a liquid, wherein along the lamp body (26) is a closed Piping system (32, 34) is integrated for a liquid cooling, to which the LEDs (30) are thermally coupled. LED immersion light (6) after Claim 1 in which connections for a supply and return of the piping system (32, 34) and / or electrical connections for supplying the LEDs (30) in a non-immersion section (22) of the lamp (6) at one set up for permanent immersion Section (20) opposite end of the lamp body are provided. LED immersion light (6) according to any one of the preceding claims, wherein the piping system (32, 34) has an inner diameter of at least 1.5 mm, preferably at least 2 mm, and the LEDs an electrical power between 40 W and 200 W, preferably between 100 W and 160 W, exhibit. LED immersion light (6) according to one of the preceding claims, wherein the dipping section (20) has a length of at least 1 m, preferably 1.5 m. LED immersion light (6) according to any one of the preceding claims, wherein the dipping set-up portion (20) according to the protection class IP68 or higher is set and / or a non-immersion section below the protection class IP68, in particular according to the protection class IP65 is set , LED immersion light (6) according to one of the preceding claims, wherein the closed pipe system (32, 34) comprises two parallel lines (32), which are connected to a 180 ° arc segment (34) continuously. LED immersion light (6) according to one of the preceding claims, wherein the piping system (32, 34) is formed by individual tube and / or tube segments. LED immersion light (6) according to one of the preceding claims, wherein the lamp body (26) is formed from an extruded aluminum profile with two longitudinal grooves, in each of which a pipe (32) of the closed pipe system (32, 34) is provided. LED immersion light (6), wherein the lamp body (26) carries on one or on two opposite sides each one or more LED modules (28) which are thermally coupled to the lamp body (26). LED immersion light (6) according to one of the preceding claims, wherein the longitudinal section (20) set up for immersion is coated with glass, in particular borosilicate glass, and / or with plastic, in particular PMMA, PC or PET. LED immersion luminaire according to one of the preceding claims, wherein the LEDs (30) have the light color white, in particular more than 6500 K, blue, red, and / or ultraviolet. System for carrying out a chemical or biological reaction process in a liquid (2), which comprises a reaction vessel (4) for receiving the liquid and at least one LED immersion light (6) according to one of the preceding claims, and a heat exchanger and a pump, which with the at least one LED immersion light are connected to guide a cooling liquid, in particular water, through the closed piping system (32, 34) of the LED immersion light (6). System after Claim 12 , which several LED immersion lights (6) after each of the Claims 1 to 11 and a first distributor (10) is provided between a plurality of leads of the LED immersion lights and a second distributor (12) between a plurality of returns of the LED immersion lights, and the first and the second distributor (10, 12) with the Heat exchanger and the pump are connected to circulate the cooling liquid through the LED immersion lights (6). Method for operating a system according to one of Claims 12 or 13 wherein the flow rate of a cooling liquid through one or more of the LED immersion lights (6) and a flow temperature of the cooling liquid through the one or more LED immersion lights (6) is controlled so that the heat extracted from the system by the heat exchanger is different from the one Heat that is added to the system by the thermal power dissipation of the LEDs (30) of the one or more LED immersion lights (6) is different. Method according to Claim 14 wherein the heat extracted from the system by the heat exchanger is higher than the thermal power dissipation of the LEDs (30) of the one or more LED immersion lights (6).

Images