Equipment for carrying out chemical reactions in process fluids at production facilities

Abstract

An apparatus for conducting a chemical reaction in a process fluid in a production system having at least one ground connection connected to earth is provided, the apparatus comprising: a reactor having one or more reaction tubes, each having several electrically heatable tube segments led into and out of the reactor via at least one feed section and at least one discharge section, and connected to each other in a current output region by an electrically conductive star bridge; and a power supply configured to provide a polyphase alternating current having N phases at a predetermined voltage to N phase wires, where N is an integer greater than or equal to 2, and for each two phases, the phase shift between the two phases is 2π·k / N, where k is an integer in the range of 1 to N−1. For each of the at least one power supply, N power supply connections are provided, each connected to at least one of the tube segments in the current input region, each of the power supply connections being connected to one of the phase wires of the power supply, and at least one power supply forming a neutral point to which the phase wires of the power supply are connected, the neutral point not being connected to earth.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to apparatus for conducting chemical reactions in process fluids in production systems, and in particular to grounding the apparatus. [Background technology]

[0002] Chemical industrial processes use reactors in which one or more reactants are conveyed through heated reaction tubes and converted catalytically or non-catalytically within the reactor. Heating specifically serves to overcome the activation energy requirement to carry out a chemical reaction. The reaction may proceed entirely endothermically or exothermically after the activation energy requirement has been overcome. The present invention specifically relates to strongly endothermic reactions.

[0003] Examples of such processes are steam cracking, different reforming processes, in particular steam reforming, dry reforming (carbon dioxide reforming), mixed reforming processes, processes for dehydrogenating alkanes, etc. In steam cracking, the reaction tubes are led through the reactor in the form of a tube coil with at least one U-bend within the reactor, whereas steam reforming typically uses tubes extending through the reactor without a U-bend.

[0004] The present invention is suitable for all such processes and reactor tube embodiments. By way of example only, see the entries "Ethylene," "Gas Production," and "Propene" in Ullmann's Encyclopedia of Industrial Chemistry, e.g., DOI: 10.1002 / 14356007.a10_045.pub2, published April 5, 2009; DOI: 10.1002 / 14356007.a12_169.pub2, published December 15, 2006; and DOI: 10.1002 / 14356007.a22_211, published June 15, 2000.

[0005] The reaction tubes of the corresponding reactor are conventionally heated by using burners, which are in turn led through a combustion chamber in which the burners are arranged.

[0006] However, as described, for example, in DE 102015004121 A1 (as well as EP 3075704 A1), there is currently a growing demand for synthesis gas and hydrogen produced without or with reduced local carbon dioxide emissions. However, processes using fired reactors, which are typically based on burning fossil energy carriers, cannot meet this demand. Other processes are precluded, for example, by high costs. The same also applies to the production of olefins and / or other hydrocarbons by steam cracking or dehydrogenating alkanes. In such cases, too, processes that emit at least a smaller amount of carbon dioxide on-site are desirable.

[0007] Against this background, the cited German Patent Application Publication No. 102015004121 (A1) proposes electrically heating a reactor for steam cracking in addition to ignition. In this case, one or more voltage sources are used that provide three-phase AC voltage to three external conductors. Each external conductor is connected to a reactor tube. A star connection is formed in which the neutral point is realized by a collector, the tubes of which are open and conductively connected. In this way, the collector ideally remains without potential. International Patent Application Publication No. 2015 / 197181 (A1) similarly discloses a reactor in which the reactor tubes are arranged with a neutral point connected thereto. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] German Patent Application Publication No. 102015004121(A1) [Patent Document 2] European Patent Application Publication No. 3075704(A1) [Patent Document 3] International Publication No. 2015 / 197181(A1) [Non-patent literature]

[0009] [Non-Patent Document 1] Ullman, "Encyclopedia of Industrial Chemistry," April 5, 2009, DOI: 10.1002 / 14356007.a10_045.pub2, December 15, 2006, DOI: 10.1002 / 14356007.a12_169.pub2, and June 15, 2000, DOI: 10.1002 / 14356007.a22_211 [Non-patent document 2] DIN EN 10027, Part 1, "Materials" Summary of the Invention [Problem to be solved by the invention]

[0010] The process medium is fed into the reactor through the feed section or discharged from the reactor through the discharge section, which are sections of the reactor tubes. The feed section and the discharge section are connected to tube sections (tube segments) that are suitable for heating by electric current. Due to the process medium used and the high process temperatures, it is not possible or only possible to use electrically insulating materials such as plastics or ceramics for the feed and discharge sections. Therefore, the electric current is conducted through these sections to the outside of the reactor and into the production system that uses the reactor. In particular, since the above-mentioned ideal case of no electric potential on the collector is not always achieved, there is a problem that it may cause damage to other parts of the production system and danger to people. [Means for solving the problem]

[0011] This object is achieved by a device having the features of the independent claim 1, while the dependent claims relate to preferred embodiments of the invention.

[0012] According to the invention, the neutral of the power supply is not earthed, so that if a potential difference exists between the neutral and the supply or discharge area, this cannot cause current flow from the supply or discharge area through the production system to earth and from earth to the neutral, which could be dangerous (electrical safety / explosion protection) or damaging (corrosion / equipment defects) to the production system.

[0013] An apparatus for conducting a chemical reaction in a process fluid in a production system having at least one ground connection connected to ground for grounding a production system component includes a reactor and at least one power source. The reactor has one or more reaction tubes with several electrically heatable tube segments routed into the reactor through at least one supply section, out of the reactor through at least one discharge section, and connected to each other in a current output region by a conductive star bridge. Specifically, the process fluid is supplied to the reactor or reaction tubes through the supply section and discharged from the reactor or reaction tubes through the discharge section. The at least one power source is configured to provide a polyphase alternating current having N phases at a predetermined voltage to N phase lines, where N is an integer greater than or equal to 2, and the phase-to-phase phase shift for each of the two phases is 2π·k / N, where k is an integer in the range of 1 to N-1 in each case. For at least one power source, a number N of power source connections are provided, each of which is connected to at least one of the pipe segments within the current input area, and each of the power source connections is connected to one of the phase wires of the power source. At least one power source has a neutral point to which the phase wires of the power source are connected, and the neutral point is not connected to a ground connection (i.e., the neutral point is not grounded).

[0014] The chemical reaction may be a chemical reaction that at least partially proceeds at a temperature in the range of 200°C to 1700°C, particularly 300°C to 1400°C, or 400°C to 1100°C. The chemical reaction is preferably a chemical reaction that at least partially proceeds at a temperature of at least 500°C, more preferably at least 700°C, and particularly at least partially in a temperature range of 500°C or 700°C to 1100°C. The voltage / current provided accordingly is suitable for providing a corresponding heating power. The reactor and the power supply are similarly configured to perform the chemical reaction at these temperatures and provide a corresponding heating power. Preferably, the chemical reaction is one of steam cracking, steam reforming, dry reforming (carbon dioxide reforming), propane dehydrogenation, or a reaction using a hydrocarbon that is generally at least partially performed above 500°C.

[0015] In this case, a production system is understood to mean in particular an industrial system in which a process medium or process fluid undergoes a chemical reaction. This system may be located, for example, in a production building. In addition to the apparatus according to the invention for carrying out the chemical reaction, the production system generally comprises further system parts (or other system parts, i.e., system parts different from the apparatus), in particular a system part in which the process fluid is pre-treated and fed to the reactor or reaction tube via a feed section, i.e., conveyed into the reactor or reaction tube, and a system part in which the process fluid is post-treated and discharged from the reactor or reaction tube via a discharge section, i.e., conveyed away from the reactor or reaction tube.

[0016] The production system comprises a ground connection which serves to ground parts of the system (i.e. the device according to the invention and further system parts) by connecting the parts of the system to the ground connection via an electrical wire.

[0017] Preferably, N=3, i.e. a three-phase alternating current, or so-called three-phase current, is used. In this case, successive phases are shifted in each case by 2π / 3 (corresponding to 120°). The use of three-phase alternating current allows in particular connection to a public supply network.

[0018] Preferably, a neutral conductor is provided connecting the star bridge to the ungrounded neutral of the power supply, so that potential differences between the star bridge and the neutral of the power supply, which may appear due to asymmetrical loading on the phases, can be partially compensated (taking into account the resistance of the neutral conductor).

[0019] Preferably, the star bridge is not connected to an earth connection, so that dangerous (electrical safety / explosion protection) or damaging (corrosion / equipment defect) currents cannot also be generated through the further system parts from the location of the star bridge with wires attached to the earth connection via earth, the earth connections of the further system parts, and supply or discharge areas conductively connected to the further system parts.

[0020] Furthermore, a main earth rail is preferably provided, to which the supply and discharge areas are conductively connected. This is advantageous, since potential equalization between the supply and discharge areas can be achieved via the main earth rail, so that possible current flows through further system parts are at least reduced. A main earth rail conductively connected to ground is provided in particular in the production system, with one or more of the ground connections being provided on the main earth rail (so that these ground connections are indirectly connected to ground via the main earth rail).

[0021] Preferably, the supply and discharge areas are arranged spatially adjacent to one another and are conductively connected to one another by (conductive) connecting elements. Due to the spatial extent of the reactor, and in particular of the star bridge (which can be several meters in each case), potential differences can occur on different sides of the reactor or of the star bridge. Arranging the supply and discharge areas adjacently prevents these potential differences from appearing as different potentials in the supply and discharge areas, which could, for example, cause an undesired current flow from the supply area through the production system to the discharge area. The additional conductive connection via the connecting elements achieves direct equalization of the supply and discharge areas without indirect equalization due to current flow through the production system.

[0022] When speaking of potential equalization here, it should be pointed out that this may not be perfect, naturally due to the fact that the resistance of electrical conductors is not zero. From the perspective of circuit configuration, the elements where potential equalization is performed (e.g., connection elements) form a resistance, as do further system parts, and ground also forms a resistance. However, the resistance of the elements where potential equalization may be performed is very low in contrast to the current path through the further system part, so that practically no current flow occurs through the further system part.

[0023] More preferably, the distance between adjacent supply and discharge sections is less than one-tenth of the dimension of the star bridge. Possible dimensions are preferably as follows: the distance between adjacent supply and discharge sections is less than 10 cm, preferably less than 5 cm. Due to these short dimensions, only relatively small potential differences can generally exist (compared to the maximum potential difference across the entire extent of the star bridge). The dimension of the star bridge may, for example, be the diameter of the smallest sphere (i.e., the sphere with the smallest diameter) that completely surrounds the star bridge.

[0024] The connecting element is preferably connected to ground via a ground connection. In particular, when the star bridge is not grounded, the conductive connection of the connecting element to the ground connection results in a "single-point" grounding of the device from the viewpoint of the circuit configuration, as seen by further system parts. In practice, the device is grounded exactly at a single point, where the further system parts are conductively connected to the device via the supply and discharge sections. Neither the power source nor the consumer (reactor, reaction tube) is (directly) grounded. That is, as seen by further system parts, the device according to the invention is connected only at a single point, which is grounded from the viewpoint of the circuit configuration (in the sense of an electrical circuit), with no other direct or indirect electrical connections. In this case, "point" should be clearly understood not in the sense of a geometric point of zero dimensions, but rather in the electrical engineering sense of an electrical connection point (with as small a geometric extent as possible).

[0025] Preferably, the electrically conductive connecting element is manufactured integrally, in particular as a cast component, and more preferably the connecting element is manufactured integrally with the tube inlet section and the tube outlet section. If the connecting element is manufactured as a cast component, one end of the ground connecting line is preferably cast into the cast component. These measures advantageously result in low resistance between the individual elements, in particular no contact resistance at all occurring between the elements.

[0026] Other advantages and embodiments of the invention arise from the present specification and the accompanying drawings.

[0027] The invention is represented diagrammatically in the drawings using exemplary embodiments and will be described below with reference to the drawings. [Brief explanation of the drawings]

[0028] [Figure 1] 1 shows an apparatus according to a preferred embodiment of the present invention; [Figure 2] 2 shows an apparatus according to another preferred embodiment of the present invention; [Figure 3] 3 shows a cross-sectional view of a connecting element that may be used in the embodiment of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0029] In the figures, elements that structurally or functionally correspond to one another are denoted by the same or similar reference symbols and, for the sake of clarity, will not be described repeatedly.

[0030] 1 shows an apparatus 100 according to a preferred embodiment of the present invention installed in a production system 2. The apparatus 100 comprises a reactor 110 for carrying out a chemical reaction in a reaction medium or process fluid flowing through an electrically heated reaction tube 12, and a power supply 30 providing the current required for the electrical heating at an appropriate voltage.

[0031] For clarity, elements that appear multiple times in a figure will only be provided with a reference symbol once or twice.

[0032] Within the production system 2, one or more grounding points or grounding connections 4 are provided, which are electrically conductively connected to the ground 5. Parts of the production system (the device according to the invention, further system parts) are grounded via these grounding connections. Typically, the production system has a concrete base plate on which the production system parts are mounted. The grounding connections are then provided on this base plate, where electrical conductors (e.g., conductive metal strips or cables) are routed from the grounding connections through the base plate into the ground or even into the water (river water). One or more of these grounding connections can be connected together via a grounding rail, i.e., a so-called main grounding rail (not shown), which is connected to the ground, resulting in a sort of indirect grounding via the main grounding rail. Furthermore, in addition to the reactor 110, the production system 2 also has further system parts 6 (symbolically indicated simply by rectangles) in which, in particular, pre- and post-treatment of the process fluids takes place. The further system parts are connected to the grounding connection via a grounding wire 7.

[0033] The reactor 110 comprises one or more reactor tubes 12 (only one shown here) in which a chemical reaction of a process fluid is carried out by heating the process fluid. The reactor 110 preferably has thermal insulation, e.g., in the form of an insulating reactor wall. The illustrated reactor tube 12 has the shape of a tube coil, which is led from a feed section 152, which supplies the process fluid to the reactor tube or reactor via tube segments 14 and tube bends 16, 17 that together form the tube coil, to a discharge section 154, where the process fluid is discharged (conveyed away) from the reactor tube or reactor. The feed section 152 and the discharge section 154 thus electrically connect the reactor 110 to further system parts 6, in particular, where the process fluid is provided and pumped through the reactor tubes or further processed after chemical reaction. If a reactor wall is provided, the feed section 152 and the discharge section 154 extend substantially through the reactor wall.

[0034] The material used for the reactor tube(s) is a material with a conductivity suitable for electrically heating the reactor tube(s), such as a heat-resistant alloy steel, particularly a heat-resistant chromium-nickel alloy steel. As a result, the supply and discharge sections are electrically conductive as part of the reactor tube(s). Such alloy steel can also be used for the power connections (through which current is conducted into the reactor vessel) and for the connecting bridges (at least partially arranged within the reactor vessel). For example, materials with the standard designations GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCrW, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, or GX55NiCrWZr33-30-04 according to DIN EN 10027, Part 1, "Materials" can be used.

[0035] For example, in the case of a plurality of reactor tubes in the form of a package comprising a plurality of reactor tubes or tube coils arranged at a distance from one another, in each case parallel to one another and perpendicular to the drawing plane, as shown in the figures, a separate inlet and outlet zone can be provided for each reactor tube. However, it is preferred to lead at least some (in particular even all) of the plurality of reactor tubes into the reactor via a common inlet zone and / or out of the reactor via a common outlet zone. These several (or all) reactor tubes are then connected in the reactor to the common inlet zone and / or to the common outlet zone via a distributor tube arrangement. In the case of the above-mentioned arrangements in the form of a package, the tubes of the distributor tube arrangement extend accordingly perpendicular to the drawing plane. These distributor tube arrangements are also called headers.

[0036] In addition to tube coils, the reaction tubes can of course also be led through the reactor in other ways, for example, each reaction tube can have a U-shape within the reactor, or only straight reaction tubes can be provided, these tubes being in each case connected to one or more feed zones and one or more discharge zones via distributor tube arrangements. Different power connections (and accordingly different phase wires) are then connected to the different reaction tubes.

[0037] Electrical heating of the reactor tube 12 is effected via the tube segments 14 through which an electric current (more precisely, an alternating current) flows, the current being fed into the tube segments 14 in a current input region and being discharged from the tube segments 14 in a current output region. For this purpose, the tube segments 14 are conductively connected to power connections 20 in the current input region and to an (electrically conductive) star bridge 22 in the current output region. Each of the power connections 20 is connected to one or more of the tube segments 14 (obviously, a single tube segment should not be connected to more than one power connection at the same time). The current is provided as an alternating current, with the different power connections being connected to different phases; see further below for a description of the power supply 30.

[0038] The current input area is formed in the figure by a lower tube bend 16, which is conductively connected to a corresponding power connection 20 (e.g., a bus bar leading into the reactor), i.e., is in conductive contact with the corresponding power connection 20 (so that the current starts from the power connection and is fed into the tube segment indirectly via the lower tube bend). The current output area is formed in the figure by an upper tube bend 17, which is conductively connected to a star bridge 22 (so that the current is emitted indirectly via the upper tube bend). In this respect, lower / upper only relates to the arrangement in the figure; the actual arrangement may differ. Deviating therefrom, the power connection and / or the star bridge can also be conductively connected directly to the tube segment, for example via a corresponding sleeve surrounding the tube segment.

[0039] Furthermore, the reactor 110 or the reaction tubes 12 are supported by means of suspensions 18, for example by support equipment of the production system (not shown in further detail in the figures). The suspensions 18 are in this case connected via electrical (and thermal) insulators to star bridges 22, which are in turn connected to the reaction tubes 12 and thus support the reaction tubes 12. In this case, different support arrangements are also conceivable, and in each case, adequate electrical and thermal insulation must be ensured.

[0040] The power supply 30 is designed as an AC power supply that provides a polyphase, in this case three-phase, AC current at a given AC voltage. More generally, a different number of phases, N, is also possible. The phase shift between the phases is selected so that the voltages or currents cancel at the neutral point; that is, the phase shift between any two phases can be expressed in radians as 2π·k / N or in degrees as 360°·k / N, where k is an integer ranging from 1 to N-1. Thus, for three phases, it is 2π / 3 or 4π / 3, corresponding to 120° or 240°. The phase difference between two consecutive phases is obtained with k=1, i.e., 2π / N.

[0041] The power supply 30 is designed as an AC transformer, specifically as a high-current transformer. The primary side, i.e., the AC supply from, for example, a public supply network or a generator to the power supply 30, is shown here simply as a shaded box symbolizing the primary transformer coil 32. The primary power supply lines are not shown. The primary AC voltage can typically be several hundred to several thousand volts, e.g., 400 V, 690 V, or 1.2 kV. Between the public supply network or the generator, considered the primary side of the power supply 30, at least one additional transformer (not shown) (possibly at least one regulating transformer) may be placed to obtain an input voltage suitable for the high-current transformer. Instead of or in addition to this at least one intermediate transformer, the input voltage can also be set using one or more thyristor power control devices.

[0042] The secondary side is provided with phase wires U, V, W, through which the phases of the AC current are provided. The phase wires U, V, W are supplied with electrical energy via secondary transformer coils, not shown in detail (the phase wires are only shown extending through the primary transformer coils 32 to illustrate their electromagnetic interaction with one another). The secondary AC voltage can conveniently range up to 300 V, for example, below 150 V or below 100 V, or even below 50 V. The secondary side is galvanically isolated from the primary side.

[0043] The phase wires U, V, W are connected together within the power supply 30 to form a neutral point 34 of the power supply 30. Grounding of this neutral point 34 is no longer necessary, i.e., the neutral point 34 of the power supply is electrically isolated from the ground connection 4 of the production system 2, so that there is no connection to the ground connection via any conductor (and no other connection to ground is provided via any conductor).

[0044] The phase wires U, V, and W are connected to different associated power supply connections 20. As a result, a polyphase AC current is supplied to the tube segments connected to the power supply connections, with different phases of the AC current being supplied to the tube segments connected to different phase wires via corresponding power connections. For this polyphase AC current flowing through the tube segments 14, a star bridge 22 forms a neutral in this case so that, ideally from a circuit configuration standpoint, the currents or voltages cancel each other in the case of a symmetrical load.

[0045] Furthermore, a neutral conductor N is provided, which conductively connects the two neutral points to each other, i.e., on the one hand, to the neutral point 34 of the power supply 30 and on the other hand to the star bridge 22 (neutral point of the reactor).

[0046] Although only one power supply is shown, more generally, more than one power supply can be provided, particularly when multiple reaction tubes are provided, with different power supplies in this case being connected, for example, to different reaction tubes or to different subsets of reaction tubes.

[0047] Because different phases of the power supply are generally loaded asynchronously (e.g., pipe segments connected to different phase wires may have different electrical resistances due to different temperatures), a potential difference may develop between the star bridge 22 and the power supply neutral 34. This potential difference is partially compensated for by the neutral wire N; however, because the neutral wire has a finite (i.e., non-zero) resistance, a constant potential difference generally remains.

[0048] From the point of view of the circuit configuration, the reactor tubes are conductively connected with a certain resistance to further system parts or other system parts 6 of the production system 2 via the supply section 152 and the discharge section 154. The further system parts 6 are then connected via the ground wire 7 to the ground connection 4 and consequently to the ground 5. However, since the neutral point 34 of the power supply is not grounded (and is galvanically isolated from the primary side), there is no possibility of any current flow from the star bridge 22 through the further system parts 6 to the ground 5 and from there to the neutral point 34 of the power supply. This means that current flows through the further system parts 6 that could result in potential differences and thus cause damage or danger are avoided or at least reduced.

[0049] Figure 2 shows an apparatus 200 according to another embodiment of the invention, which is again shown together with the production system 2 in which it is installed. In essence, the apparatus 200 shown in Figure 2 is similar to the apparatus 100 shown in Figure 1. For the sake of brevity, the description of the elements already described (in particular of the power supply and of the electrical heating of the pipe segments) will not be repeated, but in this respect reference will be made to Figure 1, and the same reference symbols as in Figure 1 will be used for these elements. The apparatus 200 comprises a reactor 210 and a power supply 30.

[0050] In reactor 210 of apparatus 200, the supply section 252 and the discharge section 254 are arranged in parallel, spatially close to each other (in contrast to apparatus 100 of FIG. 1 ), and are conductively connected to each other. As a result, the difference between the potential at supply section 252 and the potential at discharge section 254 is reduced, and this difference can induce currents in further system parts 6, which flow between supply section 252 and discharge section 254 via these further system parts. Such different potentials can exist between different regions of the star bridge, whose materials have non-zero electrical resistances due to the spatial extent of the star bridge (which can be, for example, several meters; in this sense, the star bridge does not form a neutral “point”), and are transmitted to the supply section and discharge section when they are not arranged spatially close to each other.

[0051] "Spatially close" in this case may be specified in terms of extent relative to the spatial extent (e.g., average dimension or largest dimension) of the star bridge, e.g., the distance between adjacent supply and discharge areas should be at most one-tenth of the spatial extent of the star bridge. Similarly, an absolute distance may be specified, e.g., the distance between adjacent supply and discharge areas should be less than 10 cm, preferably less than 5 cm.

[0052] 2, the supply area 252 and the discharge area 254 are connected to one another by a conductive element 256 so that any potential difference between the supply area and the discharge area is compensated for and therefore reduced against the risk of current flow through the further system part 6. This connection element 256 is connected to the earth connection of the production system 2 via a grounding wire 257. Since no other earthing of the reactor is provided, in particular the neutral point 34 of the power supply, this earthing represents the only earthing via the earthing element 256, so that from the point of view of the circuit configuration a single-point earthing is realized.

[0053] In FIG. 2, the connecting elements 256 are positioned substantially relative to or at the height of the reactor wall, but it is also possible to arrange the connecting elements outside the reactor, for example outside the possible reactor wall, or inside the reactor.

[0054] A preferred embodiment of the connection element 256 is shown in FIG. 3. According to this embodiment, the connection element 256 is produced, specifically cast, integrally with the supply section 252 and the discharge section 254, and the connecting piece is electrically conductively connected to the ground connection wire 257. More specifically, as shown, one end of the ground connection wire (e.g., a conductive metal strip) is cast into the connection element. Alternatively, the supply section and the discharge section can be guided as tubing sections passing through openings 262, 264 in the connection element 256; for this purpose, for example, the connection element can first be heated and then shrunk onto the supply section and the discharge section to achieve good electrical contact during cooling. It is noted that the geometric arrangement of the elements as shown in FIG. 3 is for illustrative purposes only and does not limit the scope of protection, i.e., in actual embodiments, the geometric arrangement may differ from that shown in FIG. 3. Similarly, the relative dimensions shown for the individual elements are only examples and may generally differ in actual embodiments.

Claims

1. 1. An apparatus (100, 200) for carrying out chemical reactions in a process fluid in a production system (2) having at least one ground connection (4) connected to earth for grounding production system components, comprising: a reactor (110, 210) comprising one or more reaction tubes (12) each having several electrically heatable tube segments (14) led into and out of said reactor via at least one feed section (152, 252) and at least one discharge section (154, 254) and connected to one another in the current output area by an electrically conductive star bridge (22); at least one power source (30) configured to provide a polyphase alternating current having N phases at a predetermined voltage to N phase wires (U, V, W), where N is an integer greater than or equal to 2, and where for each two of said phases, the phase-to-phase phase shift of said two phases is 2π·k / N, where k is an integer in the range of 1 to N−1 in each case; Equipped with For each of the at least one power source, N power source connections (20) are provided, each connected to at least one of the pipe segments within a current input area, each of the power source connections being connected to one of the phase wires of the power source; In an apparatus (100, 200) in which a neutral point (34) to which the phase wires of the power source are connected is formed in the at least one power source, the neutral point is not connected to the ground connection.

2. 2. The apparatus (100, 200) of claim 1, wherein the chemical reaction is a chemical reaction that proceeds at least partially at a temperature of at least 500°C and is one of steam cracking, steam reforming, dry reforming, propane dehydrogenation, and reactions using hydrocarbons that occur at least partially above 500°C.

3. 3. The apparatus (100, 200) of claim 1 or 2, further comprising a neutral conductor (N) connecting the conductive star bridge (22) to the neutral point (34).

4. The device (100, 200) according to any one of claims 1 to 3, wherein the conductive star bridge (22) is not connected to a ground line (4).

5. The apparatus (100, 200) of any one of claims 1 to 4, wherein a main ground rail is provided, and the supply section (152, 252) and the discharge section (154, 254) are conductively connected to the main ground rail.

6. The apparatus (200) of any one of claims 1 to 5, wherein the supply section (252) and the discharge section (254) are arranged spatially adjacent to each other and are electrically conductively connected to each other by a connecting element (256).

7. 7. The apparatus (200) of claim 6, wherein the distance between adjacent supply sections (252) and discharge sections (254) is less than one-tenth the diameter of the conductive star bridge (22).

8. 8. The apparatus (200) of claim 6 or 7, wherein the distance between adjacent supply zones (252) and discharge zones (254) is less than 10 cm.

9. 9. The device (200) of claim 8, wherein the connection element (256) is conductively connected to the ground connection (4) via a ground connection line (257).

10. 7. The device (200) of claim 6, wherein said connecting element (256) is integrally manufactured, in particular as a cast component.

11. The apparatus (200) of claim 10, wherein the connecting element (256) is fabricated integrally with the tube inlet section (252) and the tube outlet section (254).

12. 12. The apparatus (200) of claim 11, wherein the connection element (256) is fabricated as the cast component, and one end of a ground connection wire (257) is cast into the cast component.

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