Patent ID: 12201957

DETAILED DESCRIPTION

The device according to the disclosure is a photochemical helical photoreactor for the continuous production of a photochemical reaction product at the large or industrial scale, respectively, which can be scaled from the laboratory or pilot scale.

The helical photoreactor1for the continuous production of a product fluid P from a reactant fluid E illustrated inFIGS.1and2has a lamp module10, a tube coil20, a carrier device30and a protective housing40as reactor components, which can also be seen inFIG.3.FIGS.4and5show a further example of a helical photoreactor1, which differs in several details from the helical photoreactor1fromFIG.1-3, but which also consists of a lamp module10, a carrier device30comprising a tube coil20and a protective housing40.

The protective housing40surrounds a receiving space38′, which is sealed in a pressure-tight manner, in which the lamp module10and the tube coil20held by the carrier device30are arranged. The protective housing40consists of a receiving section38, which is circular cylindrical here, which is sealingly connected to a head plate39on one end (on the head-side), to which the lamp module10is releasably fastened. It goes without saying that designs of a receiving section, which deviate from the circular cylindrical shape, are also possible. On the other end (on the bottom side), the receiving section38is sealingly connected or can be sealingly connected, respectively, via a base flange34to a housing bottom37(FIG.1-3), which has a bottom flange35for this purpose, or to a bottom plate36(FIG.5), respectively, by means of a suitable seal.

It is noted that the terms “head” and “bottom” refer to a vertical arrangement of the protective housing40with the reactor components lamp module10, tube coil20and carrier device30arranged therein, wherein the head plate39is located on the top and the housing bottom37or the bottom plate36, respectively, on the bottom. This does not mean, however, that a vertical arrangement is absolutely required for the operation, but only that this can be a preferred, advantageous arrangement. A helical photoreactor1can likewise be operated in horizontal or other orientation of the protective housing40with the reactor components lamp module10, tube coil20and carrier device30located therein, if this is desirable.

As can be seen in the example ofFIGS.4and6, the helical photoreactor1can thereby have a pivot axis S, about which the protective housing40with the reactor components lamp module10, tube coil20and carrier device30arranged therein can be pivoted between at least a vertical arrangement and at least a horizontal arrangement by 90° or 180°, respectively, optionally by 360°. The pivot axis S accordingly runs at a right angle to a longitudinal axis of the protective housing40or of the lamp module10, respectively, or of the tube coil20. The protective housing40with the reactor components lamp module10, tube coil20and carrier device30arranged therein can thus be arranged in an orientation, which is desired for the operation and which can deviate from an alignment of the protective housing40for maintenance or assembly purposes, respectively. The example inFIG.6shows a helical photoreactor1, the protective housing40of which with the reactor components lamp module, tube coil and carrier device arranged therein can be transferred from a vertical arrangement inFIG.6aby pivoting about the pivot axis S (FIG.6b) into a horizontal arrangement inFIG.6c.

If the helical photoreactor1is operated, for example, in the vertical arrangement (FIG.6a), the horizontal arrangement (FIG.6c) can be used for assembly or maintenance purposes, respectively, in the case of which the protective housing40can be accessed well from the head side as well as from the bottom side, so that the carrier device with the tube coil and/or the lamp module can be removed and replaced easily. It goes without saying that deviating orientations of the protective housing40are conceivable for the operation and for the maintenance/assembly.

As can be seen inFIG.6, the helical photoreactor1can comprise a rack50, which surrounds the protective housing40in the vertical arrangement (FIG.6a) in the illustrated example. The rack50is connected to a frame51, which can be pivoted about the pivot axis S and to which the protective housing40is fastened. For this purpose, the frame51has three fastening sections52here, which are connected to the head plate39, the bottom plate36and a fastening ring45, which is arranged therebetween around the receiving section38and which is connected via fastening bars46to the head plate39and the bottom plate36. In this example, the pivot axis S is located on the lower end of the frame51, i.e., in the region of the bottom plate36. It goes without saying that a pivoting device for pivoting the protective housing can be embodied differently than the rack50comprising frame51, which is only illustrated in an exemplary manner. Instead of a rack, a container comprising closed walls can also be used, the arrangement of the pivot axis and fastening of the protective housing can vary.

Alternatively, to the example fromFIG.6, the pivot axis S, as illustrated inFIG.4, can be provided in a central region of the protective housing40, so that fewer acceleration forces develop in an advantageous manner when the protective housing40is pivoted with the components arranged therein. In the case of the arrangement of alignment elements44on the central fastening ring45, a holding frame51can optionally be forgone and the protective housing40can be mounted directly in a corresponding rack or outer container, respectively, Both pivoting variations have advantages and disadvantages with regard to accessibility, space requirement and acceleration forces during the pivoting, but both ensure a simplification during the assembly/disassembly of lamp module and/or carrier device with tube coil into or out of the protective housing, respectively.

The tube coil20of the helical photoreactor1fromFIG.1-3has a plurality of tube coils23and an input section21for supplying a reactant fluid E on the head-side end. The input section21extends parallel to the longitudinal axis of the tube coil20, which corresponds to the axis of rotation of an imaginary circular cylinder, around the jacket of which the windings23are wound. On the bottom-side end, the tube windings23are connected to a return line24, which extends on the outer side along the windings23parallel to the longitudinal axis all the way to an output section22for removal of the product fluid P with the reaction product. The output section22is thus arranged on the same side of the tube coil20as the input section21and parallel thereto, so that input and output section21,22can be connected on the same side to a corresponding reactant and product line (not illustrated) in each case. The input section21as well as the output section22extend through the head plate39here. Corresponding openings for arranging the input section21and the output section22are provided there, which are sealed by means of suitable seals (not illustrated).

The tube coil20illustrated inFIG.5is embodied as double-threaded tube coil20with ascending windings23a, which form a first winding pitch, and descending windings23b, which form a second winding pitch, wherein the two winding pitches are connected on the head side by means of a return winding23c. The input section21, which is connected to the first ascending winding23a, as well as the output section22, which is connected to the last descending winding23b, are thus located on the same side of the tube coil20. Input and output section21,22also run parallel to the longitudinal axis of the tube coil20here and run through the bottom plate36or openings provided therein, respectively, which are sealed accordingly, in this example.

Due to the fastening of the lamp module10to the head plate39, the arrangement of the tube coil20with the input and output section21,22on the bottom plate36is particularly advantageous because the connections of the tube coil20and the connections of the lamp module10are then located on opposite sides of the protective housing40, and the assembly and disassembly is simplified. This arrangement of the input and output section21,22of the tube coil20is thereby not limited to the double-threaded embodiment fromFIG.5but can also be implemented accordingly for a tube coil20comprising return line24, as inFIG.1-3. Vice versa, a double-threaded tube coil without return section can also be used in a helical photoreactor1according toFIG.1-3, in the case of which input and output section run through the head plate. Without pivotability, a corresponding assembly space would need to be kept free in each case above and below the protective housing40in the case of a vertically oriented protective housing40, in order to provide for an assembly or disassembly, respectively, of the lamp module from the top and for an assembly or disassembly, respectively, of the carrier device with the tube coil from the bottom.

The pivotability can thereby be used expediently in that assembly or disassembly, respectively, only takes place from the top, even if only the carrier device30comprising the tube coil20is to be replaced. The protective housing40can then quasi be turned upside down in vertical orientation, so that the head plate39, to which the lamp module10is fastened, points downwards, and the bottom plate36, which is connected to the carrier device30and the tube coil20, points upwards. With the bottom plate36, the carrier device30with the tube coil20can then be removed upwards from the receiving space38′, while the lamp module10remains in the protective housing40. After changing the tube coil20on the carrier device30, it can be inserted again around the lamp module10, before the helical photoreactor1is transferred into its operating arrangement after fastening the bottom plate36to the receiving section38. The carrier device30can be firmly connected to the bottom plate36thereby, so that the insertion and removal of the carrier device30with the tube coil20takes place together with the bottom plate36. Alternatively, the carrier device30with the tube coil20can be releasably connected to the bottom plate36when this appears to be more advantageous for weight reasons. During the assembly, the carrier device30with the tube coil20can then be inserted first, and the bottom plate36is then assembled or the bottom plate36is initially removed during the disassembly and the carrier device30with the tube coil20is then removed, respectively.

As can be seen inFIG.1, the tube coil20surrounds the lamp module10in the helical photoreactor1, wherein the tube coils23cover the radiation region of the lamp module10. InFIG.5, the tube coil20is formed with tube windings23a,23b, which cover the radiation region of the lamp module10when the tube coil20is arranged in the protective housing40around the lamp module10, as suggested by the block arrow inFIG.4. The supplied reactant fluid E is subjected to the operating radiation as reaction medium in response to the passage of the windings23,23a,23b, whereby the photochemical reaction for the production of the reaction product is triggered, so that product fluid P is discharged from the tube coil. Different dwell times can be realized as a function of the pitch or number of the windings23,23a,23b, respectively, the diameter of the windings and of the tube as well as the length of the wound tube section and the volume flow of the reactant fluid E. The diameter of the tube or of the windings, respectively, is selected on the basis of the hydrodynamic properties as well as of the absorption.

The tube windings23,23a,23bare thus made of a material, which is transparent for the operating radiation of the lamp module10, which can be a flexible plastic material or a rigid plastic or glass material. In the illustrated examples, the tube coils20are formed in one piece, so that the respective input and output sections21,22or the return line24, respectively, also consist of the same transparent material as the tube windings23,23a,23b. Deviating therefrom, however, it can also be provided that the windings23,23a,23band the input and output sections21,22or the return line24, respectively, are manufactured separately and are connected to one another for forming a tube coil20. In such a case, the input and output sections21,22or the return line24, respectively, can also consist of a different material, which is not transparent for the operating radiation, in order to ensure a good process control. To also ensure this in the case of one-piece tube coils20, the return line24and optionally also the input and/or output section21,22can be shaded. This can take place, e.g., by applying a coating, which absorbs the operating radiation, or by the arrangement of corresponding shielding elements.

The mechanical integrity of the tube coil can be problematic, depending on the material, so that the tube coil cannot be classified as pressure equipment under the PED (Pressure Equipment Directive) in accordance with AD2000, optionally due to the material and due to aging, which may optionally be required for performing a photochemical reaction. In this case, the protective housing represents a safe containment system for protecting persons and the environment in the event of a leakage or the bursting of a tube coil made of plastic or glass.

A simple assembly and disassembly of the helical photoreactor1is made possible by means of a carrier device30, which, as can be gathered fromFIGS.1to3and5, has various holding elements32, which are releasably fastened to the windings23,23a,23b, to the input and output sections21,22or the return line24, respectively. The holding elements32are connected with engagement elements31, whereby the exemplary carrier device30, asFIG.2shows, has three engagement elements31formed as elongated profile elements, which are arranged on an imaginary circular line around the tube coil20and extend parallel to the axis of rotation of the tube coil20, which corresponds to the longitudinal axis of the lamp module10in the case of arrangement in the helical photoreactor1. In order to ensure the correct positioning of the carrier device30with the tube coil20in the protective housing40with respect to the lamp module10, the helical photoreactor1has, corresponding to the three elongated engagement elements31, three elongated guide elements33, which are present in the protective housing40parallel to a longitudinal axis defined by the lamp module10. With the engagement elements31, the carrier device30with the tube coil20can be inserted into the protective housing40in correct position with respect to the lamp module10on the elongated guide elements33.

In the advantageous embodiment, which is shown inFIGS.4and5and which clarifies that the connection of the tube coil20takes place by means of the bottom plate36, the rotational position of the tube coil20plays no role, so that the elongated guide elements33can be arranged in the protective housing40, and the engagement elements31of the carrier device30so as to be distributed evenly on the imaginary circular line around the tube coil20. In the event that the tube coil20can be assembled in the protective housing40only in a certain rotational position around the lamp module10, so that, as in the example ofFIGS.1to3, the position of the input and output section21,22of the tube coil20corresponds to the openings in the head plate39provided for this purpose, the arrangement of the elongated guide elements33in the protective housing40can deviate from a rotationally symmetrical arrangement. With corresponding asymmetrical arrangement of the engagement elements31, the carrier device30can only be inserted in a single rotational position, in which the elongated guide elements33are aligned with the engagement elements31.

The carrier device formed as rack in this way can receive different tube coils made of flexible or rigid plastic or of glass. The windings of a tube coil made of flexible plastic material can accordingly be wound onto the carrier device in different diameters and lengths, while tube coils made of rigid plastic or glass can be inserted into the carrier device. By means of the simple insertion and removal into the and out of the protective housing, fitting and replacement of the carrier device can be performed comfortably outside of the protective housing and independently of the lamp module. If the carrier device is fitted with the tube coil, the carrier device is inserted with the engagement elements into the protective housing on the elongated guide elements and is thereby automatically pushed over the lamp module, so that the windings of the tube coil are irradiated from the inside by means of the lamp module during operation of the helical photoreactor.

Modifications to the guide elements and the engagement elements, which deviate from the illustrated examples with respect to number and embodiment, are readily possible and fall under the scope of protection. A helical photoreactor can thus have more or fewer than three guide elements and three engagement elements, which can be present in different arrangement in the protective housing. Differently than shown, it is also possible that the holding elements are not connected to an elongated engagement element but that individual or all holding elements are formed with separate engagement elements, which can be engaged with one of the elongated guide elements in the protective housing. With respect to the elongated guide elements, it is further conceivable that they are not present as separate components, as illustrated, but can be formed, for example, on the inner wall of the protective housing. And alternatively to the illustrated rail guide, the elongated guide element can be formed, for example, similar to a guide spindle, on which, for example, slide bushing elements made of plastic, e.g., PTFE, can be guided as engagement elements of the carrier device.

The protective housing40sealed for the operation of the helical photoreactor1does not only serve as safety enclosure but also for controlling the temperature of the tube coil20or of the reaction medium guided therein, respectively, from the outside, in order to set an optimal temperature during the photochemical reaction. After closing the protective housing40, the receiving space38′ is filled with a liquid temperature control medium Ks, which is transparent for the operating radiation of the lamp module10. For this purpose, the protective housing40has a housing inlet connection41, which, in the example ofFIGS.1to3, is arranged on the housing bottom37and, in the example ofFIGS.4and5, on the cylindrical receiving section38adjacent to the bottom plate36. In order to circulate the temperature control medium Ksfor a better temperature control, the protective housing40further has a housing outlet connection41′, which is arranged adjacent to the head plate39on the cylindrical receiving section38and diametrically to the housing inlet connection41. For the circulation, corresponding circulation lines (not illustrated), which are connected in the known way to a pump and optionally a heat exchanger, then connect to the housing inlet connection41and the housing outlet connection41′.

Exemplary temperature control media Kscomprise electrically non-conductive cooling liquids, such as, e.g., silicon oils, but also simple cooling liquids, such as water and ethylene glycol. Filter liquids can optionally further be used as temperature control medium Ks, in order to briefly absorb radiation of the lamp module below a certain wavelength as cut-off filter liquid or to only allow (UV) radiation of the lamp module within a certain wavelength range as bandwidth filter liquid. Aqueous compositions for filter solutions of this type are known from the prior art, whereby different filter wavelengths can be set by variation of the concentration and mixing of dissolved salts (e.g., Cu—SO4, Fe2(SO4)3, FeSO4, FeCl3, Na2WO4, SnCl2, Na3VO4, BiCl3, KVO3, KNO2, K2CrO4, NiSO4, CoSO4, . . . ).

The lamp module10illustrated in the helical photoreactor1inFIGS.1to5has a immersion tube11, which is arranged coaxially in the tube coil20. On the head-side end, the immersion tube11, which is closed on the bottom side, is received by the head plate39, so that a immersion tube interior space11′ enclosed by the immersion tube11is separated from the receiving space38′ in the protective housing40, which is optionally filled with the temperature control medium Ks. The closed end of the immersion tube11is mounted in the bottom region of the protective housing40, in order to hold the immersion tube11in a stable manner. For this purpose, corresponding coaxially formed passage openings34′,35′ can be seen inFIGS.1to3in the base flange34and the bottom flange35, which, in contrast to the illustration, could have further passage openings, so that the temperature control medium Kssupplied through the housing inlet connection41on the bottom section37can flow out of the bottom space37′ into the receiving space38′. The lamp module10, which is shown inFIG.4, is mounted to the closed end of the immersion tube11in a holder47, which is spring-loaded by means of spring element48and which comes to rest on the bottom plate36after insertion of the carrier device30with the tube coil20fromFIG.5and the connection of the base plate36to the base flange34.

A lamp12, which emits the operating radiation and optionally also radiation with wavelengths, which deviate from the operating radiation, is arranged in the immersion tube11. For the cooling of the lamp12and for the thermal decoupling from the receiving space38′, the lamp module10has a immersion tube inlet connection15, via which the immersion tube interior space11′ can be filled with a further liquid temperature control medium KL, which, like the immersion tube11, is selected to be transparent at least for the operating radiation. For the circulation of the second temperature control medium KL, the lamp module10further has a immersion tube outlet connection16, by means of which the heated temperature control medium KL, is discharged from the immersion tube interior space11′ via non-illustrated circulation lines and is supplied again via the immersion tube inlet connection15after dissipation of the absorbed heat outside of the protective housing40.

For the connection of the cooling circuit and for the electrical connection of the lamp12, the lamp module10has a head part42, which sealingly closes the immersion tube11on the head-side end. The head part42fromFIGS.1to3is not connected directly to the head plate39, which may well be the case, however, asFIGS.4to5shows: the head part42is connected to the head plate39there. Deviating therefrom, head plate and head part can also be present so as to be integrated in a component (not illustrated).FIGS.1to3show that the immersion tube inlet connection15and the immersion tube outlet connection16extend through the head part42for the connection of the immersion tube interior11′ to a cooling circuit, while the head part42inFIG.4shows an electrical connecting element43, which is connected to the lamp12and which is connected to a further electrical connecting element43′ for the connection to an external power source. The separate illustration of the coolant and power connections of the head parts42inFIGS.1to3and4thereby only serves for the better overview and does not represent any limitation whatsoever. On the contrary, it goes without saying that the lamp module10fromFIGS.1to3also has corresponding electrical connecting elements for the power supply of the lamp12, and the lamp module10fromFIG.4can have corresponding immersion tube inlet and immersion tube outlet connections for a coolant KL.

Control cabinets and control gear, which a helical photoreactor can comprise for controlling the lamp by means of power setting (optionally also by pulsing the lamp) and which can be formed, for example, for the secure switch-off according to the ATEX guidelines, are not illustrated.

As radiation source, the lamp modules10in the shown helical photoreactors1have an LED lamp12comprising several LEDs13, which are arranged on a carrier body14so as to be distributed over the jacket surface thereof. Compared to conventional radiation sources, an LED lamp can preferably be used in the case of spontaneously full luminous flux, due to its comparatively low power consumption, long service life and the high switching capacity. The operating radiation of the LED lamp13can be set systematically by means of suitable selection of the LED13because the wavelength of the radiation emitted by LEDs is a function of the doping of the semiconductor component. Even though LEDs are not radiant heaters, high temperatures, which do in fact develop during the operation as a function of the arrangement and the performance of the LEDs, significantly shorten the service life of the LEDs. In order to operate the dimmable LEDs for a high light yield or radiation intensity, respectively, with high currents, an effective heat dissipation is required in order to maintain the service life of the LEDs.

For the heat dissipation, the carrier body14can thus consist of a metal, in particular aluminum. Due to the fact that this heat dissipation is often not sufficient when using photoreactors for chemical syntheses, which can run strongly exothermally, a fluid duct14′ extends through the carrier body14, which simultaneously acts as cooling body, in order to at least partially transmit heat, which the carrier body14absorbed from the LEDs13, to the cooling fluid KL, which flows through the fluid duct14′ in the case of the illustrated LED lamp12. For this purpose, the fluid duct14′ is connected on a head-side end of the carrier body14to the immersion tube inlet connection15, which extends through the head part42. In a non-illustrated variation, it is conceivable that the course of the fluid duct within the carrier body has a return on the bottom-side end, so that the fluid duct can also be connected to the immersion tube outlet connection on the head-side end of the carrier body.

It is shown figuratively that the fluid duct14′ leads to the bottom-side end of the carrier body14through an inlet opening14″ in the immersion tube interior space11, so that the cooling fluid KL, which is supplied on the head-side end through the immersion tube inlet connection15, escapes on the bottom-side end of the carrier body14and flows along the surface of the LED lamp12to the head-side end of the lamp module10, where it reaches through an outlet opening16′ on a side of the head part42facing the immersion tube interior space11into the immersion tube outlet connection16, which extends parallel to the immersion tube inlet connection15through the head part42. Connecting lines, which are connected to the immersion tube inlet and immersion tube outlet connection15,15for forming a cooling circuit with pump and optionally heat exchanger, are not illustrated. Heat, which the cooling fluid KL, has absorbed by means of the direct contact with the LEDs13, can thus be dissipated outside of the lamp module12. By circulating the cooling fluid KL, the temperature control of the lamp12can take place independently of a temperature control of the reaction medium in the tube coil20.

Due to the fact that the cooling fluid KL, directly contacts the LEDs13and the electrical connections thereof and is located in the radiation region of the lamp12, an electrically non-conductive, i.e., electrically insulating liquid, is selected as cooling fluid KL, which is transparent for the operating radiation. With respect to the cooling of the LEDs13and the thermal decoupling from the receiving space38′, the lamp module10is thus improved and furthermore provides an increased total light or radiant power, respectively, i.e., an increased radiation quantity and density on the outer surface of the immersion tube, with respect to the lamps according to the prior art because, due to a refractive index, which is significantly larger than the refractive index of air or inert gas and which lies in the range of approximately 1.35 to approximately 1.55 (at 20° C.) in the case of suitable non-conductive liquids, the non-conductive liquid provides an increased photon decoupling efficiency on the phase boundary diode surface-immersion tube interior space and a decreased reflection on the phase boundary immersion tube interior space-immersion tube wall and thus avoids near field reflections.

It is further advantageous that an accelerated aging of the primary optics of the LEDs is avoided, which are present in particular in chemical plants, in which VOCs (“volatile organic compounds”) are present, which can develop even when using an inert gas, such as nitrogen because VOCs penetrate into the primary optics, which are usually embodied as silicon lens, cloud the latter and thus lower the light yield. Due to the fact that the primary optics are shielded from VOCs by means of the non-conductive liquid, the aging process is significantly slowed down.

For example, low-viscosity silicon oils, which are transparent and non-flammable all the way into the medium UV-C range, can be used as liquid coolant KL. Depending on the wavelength of the operating radiation, fluorinated hydrocarbons, such as perfluorocarbons and hydrofluoroethers can optionally also be used as coolant KL, which are advantageously non-flammable, but have absorption bands within certain wavelength ranges: if the operating radiation lies outside of the absorption bands, fluorinated hydrocarbons, such as, for example, 3M fluorinated electronic liquid or 3M Novec high-tech liquid by 3M™ (3M electronics, St. Paul, USA) can be used.

Highly refined mineral oils can further be resorted to as coolant KL, in particular within the spectral range of below 250 nm, which mainly comprise saturated hydrocarbons. Alkanes and cycloalkanes are advantageously transparent from the visible wavelength range all the way into the wide UV-C range and in the case of sufficiently low distance between LED and immersion tube of up to 195 nm. When using highly refined mineral oils as coolant, however, attention has to be paid to a careful and sealed exclusion of air, in order to avoid the formation of flammable steam-air mixtures. Further alternative examples for a coolant KL, comprise synthetic ester and ether compounds. Compared to mineral oils, synthetic organic ester oils, which are transparent all the way into the medium UV-C range, have the advantage, for example, of a higher temperature resistance and higher burning and ignition temperature and are more environmentally friendly, but have a lower resistance to aging. In the case of ether compounds, such as, for example, 1,4-dioxane, the transmission all the way into the medium UV-range is also sufficient, but attention is to also be paid here to a careful exclusion of air during the construction of the lamp module, in order to avoid easily flammable steam-air mixtures.

Unless already mentioned, the temperature media KL, listed for the lamp module10can also be selected as temperature control medium Ksfor cooling the tube coil20. The same coolant as the temperature medium KL, for cooling the lamp12, can be used as temperature control medium Ksfor cooling the tube coil20, or different temperature control media can be used. The two cooling circuits are preferably separated from one another, but both cooling circuits can optionally also be connected to one another, depending on developing temperature levels.

It goes without saying that further liquids can possibly also be used as coolant KL, as long as they are electrically insulating and transparent for the wavelength of the operating radiation. In order to provide a transmission of at least 75%, which is required for the desired transparency, in particular at wavelengths of below 250 nm, the inner diameter of the immersion tube with respect to the outer diameter of the carrier body, which is fitted with the LEDs, can be selected so that the distance between the LED surface and the immersion tube inner wall, and thus the absorption by means of the coolant, is as small as possible. In the case of the design with respect to the distance between immersion tube and carrier body, it is to further be considered that the coolant is provided with a volume flow, which is sufficient for an optimal heat dissipation and suitable flow control.

Each helical photoreactor thus advantageously provides for a thermal decoupling and temperature control of the lamp, independently of the temperature control of the tube coil, i.e., of the reaction medium or product fluid, respectively, with the reaction product. It is thus possible to not only perform strongly exothermic reactions with large heat development, but, for example, also low temperature reactions without the formation of condensed water in the immersion tube. The helical photoreactor can further be flexibly adapted by means of the carrier device. The carrier device allows for the use of different tube coils, which can have different diameters, which are adapted to the spectral absorption and hydrodynamics (plug-flow) and/or different lengths for adapting the dwell time in correlation with the pressure loss as a function of the viscosity of the reaction or product medium, respectively. Tube coils, which can be used with the carrier device, can further differ with regard to the materials, which can have transmission values and pressure resistances, which are adapted depending on the reaction conditions. Tube coils made of solid plastic and glass materials also provide for smaller bending radii than can be achieved by forming a flexible plastic hose. Functionalized tube coils comprising immobilized catalysts can moreover be used, which can be fixed, for example, in a sol-gel process. For this purpose, a catalyst-containing coating solution (sol) can be applied to the inner surface, in order to reach the desired coating as gel film with preferably homogenous, amorphous structure and even, thin layer thickness, if possible without defects, after drying, in order to avoid radiation losses due to reflection or scattering, respectively, on the boundary surfaces. Tube coils made of quartz glass can be provided, for example, with an inorganic gel film based on SiO2, which remains amorphous even after a solidification treatment at temperatures of above 400° C. The coating solution thereby contains at least a photocatalytic material and optionally further metal oxides (e.g., aluminum, titanium or yttrium oxide, . . . ), which can influence the optical properties of the tube coil surface, but which can optionally also act photocatalytically.

The separate arrangement of lamp module on one side and carrier device comprising tube coil on the other side in the protective housing further also provides for a simple replacement of the entire lamp module, in order to operate with operating radiations of different wavelengths. If the immersion tube is transparent in all wavelengths of the operating radiations, it is possible to leave the immersion tube in the protective housing and to only replace the lamp, in order to provide the desired operating radiation.

In contrast to conventional chemical photoreactors, which are mostly equipped for a batch operation with immersion lamps, the operational safety of the continuously operated helical photoreactor is increased because only comparatively small quantities of the reaction medium are located in the tube coil within the protective housing, which is designed as pressure container according to pressure equipment directives. The helical photoreactor, which allows for a simplified scaling from laboratory to industrial scale, is further not only suitable for performing photochemical reactions in the liquid phase, during which a liquid reactant fluid is supplied into the tube coil, the windings of which passes as liquid reaction medium and leaves the tube coil as liquid product fluid with the reaction product, but also for performing photochemical reactions in the gas phase.

The illustrated examples refer to a helical photoreactor, which has a tube coil, which is arranged around a lamp module and which is held by a carrier device, which, together, are arranged in a protective housing. The longitudinal axis of the lamp module is thereby identical with the longitudinal axis of the tube coil. In a non-illustrated modification, a helical photoreactor can also have several tube coils, which each surround a lamp module and are arranged in parallel in a protective housing, wherein a separate carrier device for each tube coil or a common carrier device for all tube coils can be provided. Modifications are likewise conceivable, in the case of which a helical photoreactor has two (or more) tube coils, which are arranged around a lamp module, wherein the windings of the tube coils have the same pitch and can be arranged offset according to a double-(or multi-) threaded thread. Two or more lamp modules can further be arranged parallel to the longitudinal axis of a tube coil next to one another or one behind the other along the longitudinal axis in a tube coil, in order to increase the radiant power or to realize different photochemical reactions by means of different wavelengths of the operating radiation. In a further embodiment, a helical photoreactor can further have additional lamp modules, which are arranged in the protective housing outside of the tube coil, so that the tube coil cannot only be irradiated from the inside, but also from the outside. A correct positioning of the tube coil with respect to the additional lamp module is also secured here by means of the carrier device.

LIST OF REFERENCE NUMERALS

1helical photoreactor10lamp module11,11′ immersion tube, immersion tube interior space12LED module13LED14,14′,14″ carrier/cooling body, fluid duct, inlet opening15immersion tube inlet connection16,16′ immersion tube outlet connection, outlet opening20tube coil21input section22output section23,23a,23btube winding24return line30carrier device31guided engagement element32holding element33elongated guide element34,34′ base flange, passage opening35,35′ bottom flange, passage opening36base plate37,37′ protective housing bottom section, bottom space38,38′ protective housing receiving section, receiving space39head plate40protective housing41,41′ housing inlet connection, housing outlet connection42head part43,43′ connecting element44alignment element45fastening ring46fastening bar47holder48spring element50rack51frame52fastening sectionKLtemperature control or coolant, respectively (lamp module)Kstemperature control or coolant, respectively (protectivehousing)E reactant fluidP product fluidS pivot axis