Electrically heated reactor

Abstract

An electrically heated reactor is disclosed. The electrically heated reactor comprises: a reaction tube including an inlet formed at one end and an outlet formed at the other end, and having formed therein a passage through which a reactant passes; a power source configured to supply power to the reaction tube to heat the reactant passing through the passage; and a pair of conductive sockets connected to the power source through electric wires to allow a current to flow through the reaction tube, wherein the reaction tube includes a plurality of tube portions having resistivity and length, the resistivity of one tube is different from the resistivity of another neighboring tube, and the length of one tube may be the same as or different from the length of another tube.

Description

Electrically heated reactor

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0070385, filed May 29, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to an electric heating reactor, and more particularly, to an electric heating reactor capable of optimally controlling the temperature within the reactor by utilizing electric heating technology.

[0004] In the chemical industry, natural gas is used as fuel to maintain high temperatures in various equipment (e.g., crackers, reformers, reactors, boilers, etc.). However, heating through natural gas combustion is not only inefficient in terms of energy consumption but also a major contributor to carbon emissions. Therefore, efforts are being made to replace natural gas combustion heating with electric heating.

[0005] Furthermore, heating by combustion can result in local temperature variations due to heat transfer by radiation. Temperature gradients can also occur depending on the structure and location of the heating source and reactor, potentially affecting reaction products. Therefore, a technology is needed that can optimally control the temperature within the reactor using electric heating.

[0006] The information contained in this background section is intended to enhance understanding of the background of the invention and may include matters that are not prior art and are already known to those of ordinary skill in the art.

[0007] An embodiment of the present invention seeks to provide an electric heating reactor capable of optimally controlling the temperature within the reactor by utilizing electric heating technology.

[0008] An electric heating reactor according to an embodiment of the present invention comprises a reaction tube having an inlet formed at one end and an outlet formed at the other end, and a passage formed therein through which a reactant passes; a power source configured to supply electric power to the reaction tube to heat the reactant passing through the passage; and a pair of conductive sockets connected to the power source via wires to allow electric current to flow through the reaction tube, wherein the reaction tube comprises a plurality of tube sections having resistivities and lengths, and the resistivity of one tube is different from the resistivity of another adjacent tube, and the length of one tube may be the same as or different from the length of the other tube.

[0009] By controlling the resistivity and length of the plurality of tube sections, a temperature gradient within the reaction tube can be obtained.

[0010] The resistivity of one tube section relatively close to the inlet may be less than or equal to the resistivity of the tube section relatively close to the outlet so as to obtain a temperature gradient in which the temperature increases from the inlet to the outlet.

[0011] The lengths of the plurality of tube sections are equal so as to obtain a temperature gradient in which the temperature increases linearly from the inlet to the outlet, and the resistivity of the plurality of tube sections can increase proportionally from the tube section closest to the inlet to the tube section closest to the outlet.

[0012] The lengths of adjacent tube sections are different from each other so as to obtain a temperature gradient in which the temperature increases in a curve from the inlet to the outlet, and the resistivity of the plurality of tube sections can increase from the tube section closest to the inlet to the tube section closest to the outlet.

[0013] The resistivity of one tube section relatively close to the inlet may be greater than or equal to the resistivity of the tube section relatively close to the outlet so as to obtain a temperature gradient in which the temperature decreases from the inlet to the outlet.

[0014] The lengths of the plurality of tube sections are equal so as to obtain a temperature gradient in which the temperature decreases in a straight line from the inlet to the outlet, and the resistivity of the plurality of tube sections can be proportionally decreased from the tube section closest to the inlet to the tube section closest to the outlet.

[0015] The lengths of adjacent tube sections are different from each other so that a temperature gradient in which the temperature decreases in a curve from the inlet to the outlet can be obtained, and the resistivity of the plurality of tube sections can decrease from the tube section closest to the inlet to the tube section closest to the outlet.

[0016] To prevent cold spots, the resistivity of some of the multiple tube sections can be set relatively high and the length can be set relatively long.

[0017] To prevent hot spots, the resistivity of some of the multiple tube sections can be set relatively low and the length can be set relatively long.

[0018] The above electric heating reactor may further include a cooler for cooling the pair of conductive sockets.

[0019] By implementing a temperature gradient appropriate to the reaction mechanism in high-temperature catalytic / non-catalytic chemical reactions, product yields can be maximized, catalyst life improved, and process times improved.

[0020] By controlling the temperature by section according to the exothermic and endothermic reactions, the occurrence of local hot spots or cold spots can be prevented, thereby improving the efficiency of the process.

[0021] In addition, the effects that can be obtained or expected from embodiments of the present invention will be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. That is, the various effects expected according to embodiments of the present invention will be disclosed in the detailed description that follows.

[0022] Embodiments of the present disclosure may be better understood by reference to the following description taken in conjunction with the accompanying drawings in which like reference numerals designate identical or functionally similar elements.

[0023] FIG. 1 is a schematic diagram illustrating an electric heating reactor according to a first embodiment of the present invention.

[0024] Figure 2 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 1.

[0025] Figure 3 is a schematic diagram illustrating an electric heating reactor according to a second embodiment of the present invention.

[0026] Figure 4 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 3.

[0027] Figure 5 is a schematic diagram illustrating an electric heating reactor according to a third embodiment of the present invention.

[0028] Figure 6 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 5.

[0029] Figure 7 is a schematic diagram illustrating an electric heating reactor according to a fourth embodiment of the present invention.

[0030] Figure 8 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 7.

[0031] Figure 9 is a schematic diagram illustrating an electric heating reactor according to a fifth embodiment of the present invention.

[0032] Figure 10 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 9.

[0033] Figure 11 is a schematic diagram illustrating an electric heating reactor according to a sixth embodiment of the present invention.

[0034] Figure 12 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of Figure 11.

[0035] The drawings referenced above are not necessarily drawn to scale, but should be understood to present rather simplified representations of various preferred features that illustrate the fundamental principles of the present disclosure. For example, specific design features of the present disclosure, including specific dimensions, orientations, positions, and shapes, will be determined in part by the specific intended application and usage environment.

[0036] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will also be understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any one or all combinations of the associated listed items.

[0037] Additionally, it is understood that one or more of the methods or aspects thereof below may be implemented by at least one controller. The term "controller" may refer to a hardware device comprising a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute the program instructions to perform one or more processes described in more detail below. The controller may control the operation of units, modules, components, devices, or the like, as described herein. It is also understood that the methods below may be implemented by a device comprising the controller in conjunction with one or more other components, as will be appreciated by those skilled in the art.

[0038] Additionally, the controller of the present disclosure may be implemented as a non-transitory computer-readable recording medium containing executable program instructions executed by a processor. Examples of computer-readable recording media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), compact disc (CD) ROM, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable recording medium may also be distributed across a computer network so that the program instructions are stored and executed in a distributed manner, such as on a telematics server or a Controller Area Network (CAN).

[0039] According to the present invention, an electric heating reactor comprises an inlet formed on one side and an outlet formed on the other side, a reaction tube having a passage formed therein through which a reactant passes and configured to heat the reactant passing through the passage, a power source configured to supply electric power to the reaction tube, and a pair of conductive sockets electrically connecting the power source and the reaction tube. When electric power from the power source is supplied to the reaction tube through the conductive sockets, the reaction tube generates heat and heats the reactant inside. In this way, the present invention can efficiently heat the temperature inside the reactor by utilizing electric heating technology.

[0040] The above reaction tube includes a plurality of tube sections having resistivities and lengths. For example, the plurality of tube sections includes a first tube section having a first resistivity and a first length, and a second tube section having a second resistivity different from the first resistivity and a second length different from the first length and coupled to the first tube section. When power from a power source is supplied to the reaction tube, the first and second tube sections having different resistivities and lengths generate heat at different temperatures. Here, the number of tube sections is not limited to two. By arranging each of the plurality of tube sections in each of the plurality of sections, the temperature of the reactor can be controlled for each section. For example, in order to increase the temperature of the reactor in the direction in which the reactants flow, the resistivity of one tube section relatively close to the inlet is less than or equal to the resistivity of another tube section relatively far from the inlet. Conversely, in order to increase the temperature of the reactor in the direction in which the reactants flow, the resistivity of one tube section relatively close to the inlet is greater than or equal to the resistivity of another tube section relatively far from the inlet. In another example, a desired temperature gradient can be created within a reactor by adjusting the lengths of multiple tube sections with different resistivities. For example, tube sections with relatively high resistivity and relatively long lengths can be placed in regions where cold spots are likely to occur in endothermic reactions, or tube sections with relatively low resistivity and relatively long lengths can be placed in regions where hot spots are likely to occur in exothermic reactions.

[0041] In addition, the electric heating reactor further includes a cooler for cooling the conductive socket. This can improve operational stability by suppressing temperature rise of the conductive socket.

[0042]

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0044] FIG. 1 is a schematic diagram illustrating an electric heating reactor according to a first embodiment of the present invention, and FIG. 2 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 1.

[0045] As illustrated in Fig. 1, the electric heating reactor (10) according to the first embodiment of the present invention is configured to receive power, generate heat, and heat the reactants inside using the generated heat. The electric heating reactor (10) includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b).

[0046] The reaction tube (20) is made of an alloy material having high resistivity (e.g., Ni-Cr, Fe-Cr, Fe-Ni-Cr, Fe-Cr-Al, etc.), and a passage through which a reactant passes is formed longitudinally inside the tube. For example, the reaction tube (20) may be formed in an annular pipe shape, and a passage may be formed longitudinally inside the tube. When power is applied to the reaction tube (20), the reaction tube (20) generates heat due to the high resistivity, and the generated heat can be used to heat the reactant passing through the passage.

[0047] An inlet (21) is formed at one end of the reaction tube (20), and a supply line (12) is connected to the inlet (21). The reactant is supplied into the reaction tube (20) through the supply line (12) and the inlet (21). An outlet (22) is formed at the other end of the reaction tube (20), and a discharge line (14) is connected to the outlet (22). The product of the reaction that has completed the reaction and / or the unreacted product that has not completed the reaction while passing through the interior of the reaction tube (20) is discharged to the discharge line (14) through the outlet (22).

[0048] The above reaction tube (20) includes first, second, and third tube sections (24a, 24b, 24c) arranged in a row. The first tube section (24a) is provided at one end of the reaction tube (20) and has a first resistivity (ρ1) and a first length (L1). An inlet (21) is formed at one end of the first tube section (24a), and a reactant flows into the reaction tube (20), particularly the first tube section (24a), through the inlet (21). The second tube section (24b) is provided at the middle portion of the reaction tube (20), and one end of the second tube section (24b) is connected to the other end of the first tube section (24a). The second tube section (24b) has a second resistivity (ρ2) different from the first resistivity, and a second length (L2) equal to or different from the first length. A third tube portion (24c) is provided at the other end of the reaction tube (20), and one end of the third tube portion (24c) is connected to the other end of the second tube portion (24b). The third tube portion (24c) has a third resistivity (ρ3) that is equal to or different from the first resistivity and different from the second resistivity, and a third length (L3) that is equal to or different from the first and second lengths. An outlet (22) is formed at the other end of the third tube portion (24c), so that reactants that have completed the reaction and / or unreacted substances that have not completed the reaction are discharged from the reaction tube (20), particularly the third tube portion (24c), through the outlet (22).

[0049] The first passage formed inside the first tube portion (24a) is connected to the second passage formed inside the second tube portion (24b), and the second passage formed inside the second tube portion (24b) is connected to the third passage formed inside the third tube portion (24c). The diameters of the first, second, and third passages may be the same or substantially similar to each other. Accordingly, the reactant introduced into the first passage through the inlet (21) reacts while passing through the first, second, and third passages inside the reaction tube (20) in sequence and is discharged from the third passage through the outlet (22). In addition, since the diameters of the first, second, and third passages are the same or substantially similar to each other, the flow resistance of the reactant passing through the first, second, and third passages does not increase.

[0050] The first, second, and third resistivities and the first, second, and third lengths can be set according to a desired temperature gradient within the reaction tube (20). For example, as shown in FIG. 2, if a temperature gradient (see solid line in FIG. 2) in which the temperature within the reaction tube (20) increases linearly from the inlet (21) to the outlet (22) is required, the first, second, and third lengths are set to be equal to each other, the first resistivity is set to be the smallest, the third resistivity is set to be the largest, and the second resistivity is set to be larger than the first resistivity and smaller than the third resistivity. In addition, preferably, the difference between the second resistivity and the first resistivity can be set to be equal to the difference between the third resistivity and the second resistivity. In this case, the heat actually generated in the first, second, and third tube sections (24a, 24b, 24c) increases in a stepwise manner from the first tube section (24a) to the third tube section (24c) (see the dotted line in Fig. 2).

[0051] The power source (30) is configured to supply power to the reaction tube (20). The power source (30) may be an AC power source or a DC power source.

[0052] The first and second conductive sockets (32a, 32b) supply power from the power source (30) to the reaction tube (20) so that the reaction tube (20) generates heat. The first conductive socket (32a) is mounted on one end of the first tube section (24a) and electrically connects the power source (30) and the first tube section (24a) via a wire (34). In addition, the second conductive socket (32b) is mounted on the other end of the third tube section (24c) and electrically connects the power source (30) and the third tube section (24c) via a wire (34). Power from the same power source (30) is transmitted to the first, second, and third tube sections (24a, 24b, 24c) through the first and second conductive sockets (32a, 32b), but since the first, second, and third resistivities of the first, second, and third tube sections (24a, 24b, 24c) are different from each other, the first, second, and third tube sections (24a, 24b, 24c) generate heat at different temperatures. Therefore, the temperatures of the first, second, and third tube sections (24a, 24b, 24c) can be set differently through wiring with only one power source (30), thereby obtaining a desired temperature gradient.

[0053] Meanwhile, a cooler (not shown) is provided in or near the first and second conductive sockets (32a, 32b) to cool the first and second conductive sockets (32a, 32b).

[0054] FIG. 3 is a schematic diagram illustrating an electric heating reactor according to a second embodiment of the present invention, and FIG. 4 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 3.

[0055] As illustrated in FIG. 3, the electric heating reactor (10) according to the second embodiment of the present invention includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b). Here, the electric heating reactor (10) according to the second embodiment of the present invention is identical to the electric heating reactor (10) according to the first embodiment of the present invention, except for the number of tube sections included in the reaction tube (20). Therefore, only the reaction tube (20) will be described.

[0056] The above reaction tube (20) includes first, second, third, fourth, and fifth tube sections (24a, 24b, 24c, 24d, and 24e) arranged in a row. The first tube section (24a) is provided at one end of the reaction tube (20) and has a first resistivity (ρ1) and a first length (L1). An inlet (21) is formed at one end of the first tube section (24a), and a reactant flows into the reaction tube (20), particularly the first tube section (24a), through the inlet (21). The second tube section (24b) is provided adjacent to the first tube section (24a), and one end of the second tube section (24b) is connected to the other end of the first tube section (24a). The second tube portion (24b) has a second resistivity (ρ2) different from the first resistivity and a second length (L2) that is equal to or different from the first length. The third tube portion (24c) is provided adjacent to the second tube portion (24b), and one end of the third tube portion (24c) is connected to the other end of the second tube portion (24b). The third tube portion (24c) has a third resistivity (ρ3) that is equal to or different from the first resistivity and different from the second resistivity, and a third length (L3) that is equal to or different from the first and second lengths. The fourth tube portion (24d) is provided adjacent to the third tube portion (24c), and one end of the fourth tube portion (24d) is connected to the other end of the third tube portion (24c). The fourth tube portion (24d) has a fourth resistivity (ρ4) that is equal to or different from the first and second resistivities and different from the third resistivity, and a fourth length (L4) that is equal to or different from the first, second, and third lengths. The fifth tube portion (24e) is provided at the other end of the reaction tube (20), and one end of the fifth tube portion (24e) is connected to the other end of the fourth tube portion (24d). The fifth tube portion (24e) has a fifth resistivity (ρ5) that is equal to or different from the first, second, and third resistivities and different from the fourth resistivity, and a fifth length (L5) that is equal to or different from the first, second, third, and fourth lengths. An outlet (22) is formed at the other end of the fifth tube section (24e), and reactants that have completed the reaction and / or unreacted substances that have not completed the reaction are discharged from the reaction tube (20), particularly the fifth tube section (24e), through the outlet (22).

[0057] The first passage formed inside the first tube part (24a) is connected to the second passage formed inside the second tube part (24b), the second passage formed inside the second tube part (24b) is connected to the third passage formed inside the third tube part (24c), the third passage formed inside the third tube part (24c) is connected to the fourth passage formed inside the fourth tube part (24d), and the fourth passage formed inside the fourth tube part (24d) is connected to the fifth passage formed inside the fifth tube part (24e). The diameters of the first, second, third, fourth, and fifth passages may be the same or nearly similar. Accordingly, the reactant introduced into the first passage through the inlet (21) reacts while passing through the first, second, third, fourth, and fifth passages inside the reaction tube (20) in sequence and is discharged from the fifth passage through the outlet (22). In addition, since the diameters of the first, second, third, fourth, and fifth passages are the same or nearly the same, the flow resistance of the reactants passing through the first, second, third, fourth, and fifth passages does not increase.

[0058] The first, second, third, fourth, and fifth resistivities and the first, second, third, fourth, and fifth lengths can be set according to a desired temperature gradient within the reaction tube (20). For example, as shown in FIG. 4, if a temperature gradient (see solid line in FIG. 4) in which the temperature within the reaction tube (20) increases linearly from the inlet (21) to the outlet (22) is required, the first, second, third, fourth, and fifth lengths are set to be equal to each other, and the first, second, third, fourth, and fifth resistivities are set to gradually increase from the smallest first resistivity to the largest fifth resistivity. In addition, preferably, the difference between the second resistivity and the first resistivity, the difference between the third resistivity and the second resistivity, the difference between the fourth resistivity and the third resistivity, and the difference between the fifth resistivity and the fourth resistivity can be set to be equal to each other. In this case, the heat actually generated in the first, second, third, fourth, and fifth tube sections (24a, 24b, 24c, 24d, 24e) increases in a stepwise manner from the first tube section (24a) to the fifth tube section (24e) (see dotted line in Fig. 4).

[0059] FIG. 5 is a schematic diagram illustrating an electric heating reactor according to a third embodiment of the present invention, and FIG. 6 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 5.

[0060] As illustrated in FIG. 5, the electric heating reactor (10) according to the third embodiment of the present invention includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b). Here, the electric heating reactor (10) according to the third embodiment of the present invention is identical to the electric heating reactor (10) according to the first embodiment of the present invention, except for the number of tube sections included in the reaction tube (20). Therefore, only the reaction tube (20) will be described.

[0061] The above reaction tube (20) includes first and second tube sections (24a, 24b) arranged in a row. The first tube section (24a) is provided at one end of the reaction tube (20) and has a first resistivity (ρ1) and a first length (L1). An inlet (21) is formed at one end of the first tube section (24a), and a reactant flows into the reaction tube (20), particularly the first tube section (24a), through the inlet (21). A second tube section (24b) is provided at the other end of the reaction tube (20), and one end of the second tube section (24b) is connected to the other end of the first tube section (24a). The second tube section (24b) has a second resistivity (ρ2) different from the first resistivity, and a second length (L2) equal to or different from the first length. An outlet (22) is formed at the other end of the second tube section (24b), and reactants that have completed the reaction and / or unreacted substances that have not completed the reaction are discharged from the reaction tube (20), particularly the second tube section (24b), through the outlet (22).

[0062] The first passage formed inside the first tube section (24a) is connected to the second passage formed inside the second tube section (24b), and the diameters of the first and second passages may be the same or substantially similar to each other. Accordingly, the reactant introduced into the first passage through the inlet (21) reacts while passing through the first and second passages inside the reaction tube (20) in sequence and is discharged from the second passage through the outlet (22). In addition, since the diameters of the first and second passages are the same or substantially similar to each other, the flow resistance of the reactant passing through the first and second passages does not increase.

[0063] The first and second resistivities and the first and second lengths can be set according to the desired temperature gradient within the reaction tube (20). For example, as shown in FIG. 6, if a temperature gradient is required in which the temperature within the reaction tube (20) increases in a curve from the inlet (21) to the outlet (22), but increases gradually in the first tube section (24a) and increases rapidly in the second tube section (24b) (see the solid line in FIG. 6), the first length is set longer than the second length, and the first resistivity is set smaller than the second resistivity. In this case, the heat actually generated in the first and second tube sections (24a, 24b) increases in a stepwise manner from the first tube section (24a) to the second tube section (24b) (see the dotted line in FIG. 6).

[0064] FIG. 7 is a schematic diagram illustrating an electric heating reactor according to a fourth embodiment of the present invention, and FIG. 8 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 7.

[0065] As illustrated in FIG. 7, the electric heating reactor (10) according to the fourth embodiment of the present invention includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b). Here, the electric heating reactor (10) according to the fourth embodiment of the present invention is identical to the electric heating reactor (10) according to the third embodiment of the present invention, except for the first and second resistivities and the first and second lengths for creating a desired temperature gradient. Therefore, only the first and second resistivities and the first and second lengths for creating a desired temperature gradient will be described.

[0066] As illustrated in Fig. 8, if a temperature gradient (see solid line in Fig. 8) is required in which the temperature within the reaction tube (20) increases in a curve from the inlet (21) to the outlet (22), but increases rapidly in the first tube section (24a) and gradually in the second tube section (24b), the first length is set shorter than the second length, and the first resistivity is set smaller than the second resistivity. In this case, the heat actually generated in the first and second tube sections (24a, 24b) increases in a stepwise manner from the first tube section (24a) to the second tube section (24b) (see dotted line in Fig. 8).

[0067] FIG. 9 is a schematic diagram illustrating an electric heating reactor according to a fifth embodiment of the present invention, and FIG. 10 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 9.

[0068] As illustrated in FIG. 9, the electric heating reactor (10) according to the fifth embodiment of the present invention includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b). Here, the electric heating reactor (10) according to the fifth embodiment of the present invention is identical to the electric heating reactor (10) according to the first embodiment of the present invention, except for the first, second, and third resistivities and the first, second, and third lengths for creating a desired temperature gradient. Therefore, only the first, second, and third resistivities and the first, second, and third lengths for creating a desired temperature gradient will be described.

[0069] As shown in Fig. 10, if a temperature gradient (see solid lines in Fig. 10) is required in which the temperature decreases in a curved manner from the first tube section (24a) to the second tube section (24b) and increases in a curved manner from the second tube section (24b) to the third tube section (24c), the second resistivity is set to be smaller than the first and third resistivities. Here, the first, second, and third resistivities and the first, second, and third lengths can be set by those skilled in the art according to the shape of the desired temperature gradient. In this case, the heat actually generated in the first, second, and third tube sections (24a, 24b, and 24c) decreases in a stepwise manner from the first tube section (24a) to the second tube section (24b) and increases in a stepwise manner from the second tube section (24b) to the third tube section (24c) (see dotted lines in Fig. 10).

[0070] FIG. 11 is a schematic diagram illustrating an electric heating reactor according to a sixth embodiment of the present invention, and FIG. 12 illustrates one example of a strategy for controlling the temperature of the electric heating reactor of FIG. 11.

[0071] As illustrated in FIG. 11, the electric heating reactor (10) according to the sixth embodiment of the present invention includes a reaction tube (20), a power source (30), and first and second conductive sockets (32a, 32b). Here, the electric heating reactor (10) according to the sixth embodiment of the present invention is identical to the electric heating reactor (10) according to the first embodiment of the present invention, except for the first, second, and third resistivities and the first, second, and third lengths for creating a desired temperature gradient. Therefore, only the first, second, and third resistivities and the first, second, and third lengths for creating a desired temperature gradient will be described.

[0072] As shown in Fig. 12, if a temperature gradient (see solid line in Fig. 12) is required in which the temperature increases in a curved manner from the first tube portion (24a) to the second tube portion (24b) and decreases in a curved manner from the second tube portion (24b) to the third tube portion (24c), the second resistivity is set to be greater than the first and third resistivities. Here, the first, second, and third resistivities and the first, second, and third lengths can be set by those skilled in the art according to the shape of the desired temperature gradient. In this case, the heat actually generated in the first, second, and third tube portions (24a, 24b, and 24c) increases in a stepwise manner from the first tube portion (24a) to the second tube portion (24b) and decreases in a stepwise manner from the second tube portion (24b) to the third tube portion (24c) (see dotted line in Fig. 12).

[0073]

[0074] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and includes all changes that can be easily modified and deemed equivalent by a person having ordinary skill in the art to which the invention pertains from the embodiments of the present invention.

Claims

1. A reaction tube having an inlet formed at one end and an outlet formed at the other end, and a passage formed inside through which reactants pass; A power source configured to supply power to said reaction tube to heat the reactants passing through said passage; and A pair of conductive sockets connected to the power source via wires to allow current to flow through the reaction tube; Includes, The above reaction tube comprises a plurality of tube sections having a resistivity and a length, An electrical heating reactor in which the resistivity of one tube is different from that of another adjacent tube, and the length of one tube is equal to or different from that of the other tube.

2. In paragraph 1, An electrically heated reactor that obtains a temperature gradient within a reaction tube by controlling the resistivity and length of the plurality of tube sections.

3. In paragraph 2, An electrically heated reactor in which the resistivity of one tube section relatively close to the inlet is less than or equal to the resistivity of the tube section relatively close to the outlet so as to obtain a temperature gradient in which the temperature increases from the inlet to the outlet.

4. In paragraph 3, An electrically heated reactor in which the lengths of the plurality of tube sections are equal so as to obtain a temperature gradient in which the temperature increases linearly from the inlet to the outlet, and the resistivity of the plurality of tube sections increases proportionally from the tube section closest to the inlet to the tube section closest to the outlet.

5. In paragraph 3, An electrically heated reactor in which the lengths of adjacent tube sections are different from each other so as to obtain a temperature gradient in which the temperature increases in a curve from the inlet to the outlet, and the resistivity of the plurality of tube sections increases from the tube section closest to the inlet to the tube section closest to the outlet.

6. In paragraph 2, An electrically heated reactor in which the resistivity of one tube section relatively close to the inlet is greater than or equal to the resistivity of the tube section relatively close to the outlet so as to obtain a temperature gradient in which the temperature decreases from the inlet to the outlet.

7. In paragraph 6, An electrically heated reactor in which the lengths of the plurality of tube sections are equal so as to obtain a temperature gradient in which the temperature decreases linearly from the inlet to the outlet, and the resistivity of the plurality of tube sections decreases proportionally from the tube section closest to the inlet to the tube section closest to the outlet.

8. In paragraph 6, An electrically heated reactor in which the lengths of adjacent tube sections are different from each other so as to obtain a temperature gradient in which the temperature decreases in a curve from the inlet to the outlet, and the resistivity of the plurality of tube sections decreases from the tube section closest to the inlet to the tube section closest to the outlet.

9. In paragraph 2, An electric heating reactor in which the resistivity of some of the tube sections among the plurality of tube sections is set relatively high and the length is set relatively long.

10. In paragraph 2, An electric heating reactor in which the resistivity of some of the tube sections among the plurality of tube sections is set relatively low and the length is set relatively long.

11. In paragraph 1, An electric heating reactor further comprising a cooler for cooling the pair of conductive sockets.

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