reformer

Abstract

The present invention relates to a reforming furnace for catalytic reforming of carbonaceous input materials using steam. The reforming furnace has a steel structure that serves as a framework for a refractory lining and is used to fix burners, reformer tubes, and supply and exhaust lines. The burners and reformer tubes are arranged in rows parallel to each other and in an alternating manner. The steel structure includes a plurality of main carrier units, wherein each main carrier unit has at least two vertically extending supports and a horizontally extending main carrier that connects these supports. According to the present invention, the main carriers in which these main carrier units are provided are arranged to extend parallel to the burner rows and the reformer tube rows. This type of steel structure enables uniform spacing of reformer tubes and burners throughout the reforming furnace. This produces advantages in terms of the maximum operating temperature of the reformer tubes, thereby extending the service life of the reformer tubes.

Description

Technical Field

[0001] The present invention relates to a reforming furnace for catalytically reforming carbonaceous input materials using steam, wherein the reforming furnace comprises a radiation space defined by a plurality of walls and delimited from the external environment, and the radiation space has a steel structure configured as a frame and intended to fix supply and exhaust lines, burners, and vertically arranged reformer tubes. Background Art

[0002] Reformers for catalytically reforming carbonaceous input materials using steam are known in many embodiments. A well-known example of a reformer for catalytically reforming carbonaceous input materials is a steam reformer for reforming natural gas and steam to produce synthesis gas, a mixture of carbon monoxide and hydrogen, and often undesirable concomitants such as carbon dioxide. This reforming process is endothermic and proceeds slowly, and therefore the conversion of carbonaceous input materials using steam requires an external combustion source to heat the reformer tubes (also reaction tubes) of the reformer that are filled with catalyst.

[0003] In the case of large industrial-scale plants, designs have been established that employ a generally box-shaped furnace with vertically arranged reformer tubes. The interior of the sum of these reformer tubes forms the reaction space of the reformer furnace. The reformer tubes are arranged in one or more rows positioned side by side with one another.

[0004] Each reformer tube row is typically fired by two burner rows, wherein a reaction tube row is centrally arranged between two burner rows extending parallel to the reformer tube rows to ensure uniform combustion of the reformer tubes. The burner row adjacent to the wall is different from the burner row not adjacent to the wall. For the burner row adjacent to the wall, the burners are arranged between the wall of the reformer furnace and the reformer tube row. For the burner row not adjacent to the wall, the burners are arranged between two reformer tube rows.

[0005] The burners are arranged in the so-called combustion space of the reformer furnace. The supply of reaction gases to the reformer tubes and the discharge of gaseous products from the reformer tubes necessarily take place outside the combustion space, and the walls of the reformer tubes thus define the spatial separation between the reaction space and the combustion space.

[0006] The whole consisting of the combustion space and the reformer tubes is also called the radiant zone of the reformer.

[0007] The burners in the burner row are supplied with air and combustion gas via supply lines and are arranged in the roof or floor of the reformer in the most common design, wherein the flames of the burners are directed vertically downwards towards the reformer floor or vertically upwards towards the reformer roof, respectively. Other arrangements of the burners (e.g. at the side walls of the reformer in a stepped arrangement for side firing, or for diagonal firing) are also known, but are not commonly used.

[0008] The radiant space of a reforming furnace having one or more reformer tube banks and a plurality of burner banks is usually configured as a steel structure, which serves as a frame for the refractory lining of the combustion space. In addition, supply and discharge line systems, burners and reformer tubes are fixed to and held by this steel structure.

[0009] Since vertically arranged supports (e.g. columns) for distributing the load cannot pass through the combustion space, the ceiling of the radiation space is in principle configured as a self-supporting or suspended steel structure. Therefore, the main carrier unit of the steel structure consisting of vertical supports and horizontal main carriers is arranged in such a way that these supports extend adjacent to the wall and to the outside of the combustion space.

[0010] The lateral length of the reformer is defined by the length of the reformer tube rows and the burner rows, i.e. by the number of reformer tubes per reformer tube row and the number of burners per burner row. If the lateral length of the reformer exceeds a certain size (e.g. 6 to 7 meters), static restrictions require that more than two main carrier units be arranged on the end sides of the reformer in order to distribute the load caused by the longer burner rows and reformer tube rows. In this case, a third main carrier unit or (where appropriate) further main carrier units must be arranged correspondingly between the main carrier units arranged on the end sides. The spacing between the main carrier units is approximately the same in each case, and the burner rows and reformer tube rows extend orthogonally to the main carriers of the main carrier units, which extend horizontally on the ceiling of the radiation space.

[0011] Reforming furnaces known in the prior art have been built with this steel construction design because it is the most economical way to configure the steel construction.

[0012] However, the above-mentioned method of arranging the main carrier unit also brings disadvantages. Since the additional main carrier unit is not arranged on the end side of the reformer, that is, since the number of main carrier units in a large reformer is extended to three or more, the main carrier of the main carrier unit extending horizontally on the top plate does not extend on the wall side, but extends centrally through the radiation space of the reformer. The centrally extended main carrier requires a larger axial spacing of the reformer tubes at this point. In other words, the spacing of one reformer tube in the reformer tube row from the adjacent reformer tube must be increased at the point where the main carrier of the main carrier unit extends along the top plate of the radiation space.

[0013] For example, the ideal reformer tube axial spacing in a standard reformer furnace is about 300 mm between reformer tubes. In the region of the centrally extending main carrier, this reformer tube axial spacing must be increased to more than 500 mm.

[0014] This structural limitation leads to the fact that the operating temperature of the reformer tubes in the region of the main carrier axis is higher, which generally leads to a shorter service life of the reformer tubes and to higher safety margins in the design of the reformer furnace. The higher temperature at these reformer tubes is caused by the fact that the view factor with respect to the burner flame is higher than the view factor of the other reformer tubes which are located in the reformer tube row and in which the axial spacing of the reformer tubes is smaller.

[0015] In this context, it is often mentioned that so-called bays are formed in the reformer furnace. The axial spacing of the reformer tubes is respectively the same (small) across the board within one bay, but is larger between adjacent reformer tubes of two adjacent bays. Summary of the invention

[0016] The object of the present invention is to at least partially overcome the aforementioned disadvantages of the prior art.

[0017] In particular, it is an object of the present invention to provide a reformer furnace in which the spacing between two adjacent reformer tubes within a reformer tube row is the same throughout the reformer furnace.

[0018] It is a further object of the present invention to provide a reforming furnace that does not include a spacer zone.

[0019] A further object of the present invention is to provide a reformer in which the operating temperature of the reformer tubes is more uniform than in known reformers.

[0020] The independent claims provide a contribution to at least partially achieving at least one of the aforementioned objects. The dependent claims provide preferred embodiments, which contribute to at least partially achieving at least one of the aforementioned objects. Where relevant, the preferred embodiments of the components of a class according to the invention are equally preferred for the same named or corresponding components of a corresponding other class according to the invention.

[0021] The terms "having", "comprising" or "including" etc. do not exclude the possible presence of additional elements, components etc. The indefinite article "a / an" does not exclude the possible presence of a plurality.

[0022] The objects of the invention are achieved at least in part by a reformer for catalytic reforming of carbonaceous input materials with steam, the reformer having a radiation space defined by a plurality of walls and delimited from the external environment, wherein the radiation space has a steel construction configured as a frame and intended to fix supply and exhaust lines, a burner, and vertically arranged reformer tubes, wherein

[0023] The burners are arranged to generate downward or upward flames to heat the reformer tubes, and wherein the burners and the reformer tubes are arranged in rows as burner rows and reformer tube rows within the radiation space, wherein the burner rows and the reformer tube rows are arranged in an alternating manner and parallel to each other, and the steel construction has a plurality of main carrier units, wherein each main carrier unit has two vertically extending supports arranged adjacent to the wall and a horizontally extending main carrier, the main carriers being connected via the supports, and the main carriers extending the entire length of the radiation space, and wherein the main carriers are configured to fix supply and exhaust lines, the burners, and the reformer tubes, and

[0024] The steel construction has a plurality of horizontally extending cross members which connect the supports of the main carrier units to each other. According to the invention, it is provided that the main carrier of the main carrier unit is arranged to extend parallel to the reformer tube row and the burner row, and

[0025] The cross member is arranged to extend at least partially orthogonally to the reformer tube bank and the burner bank.

[0026] According to the invention, the horizontally extending main carrier of the main carrier unit is arranged to extend parallel to the reformer tube row and the burner row, and the carrier extends in particular on the ceiling of the radiation space. Since the axial spacing of the reformer tubes does not need to be widened due to the main carrier extending orthogonally to the reformer tube row, this allows the reformer tubes to be arranged continuously over the entire length of the radiation space with the same spacing.

[0027] The main carrier of the main carrier unit supports the main load of supply and exhaust lines, burner and reformer tubes fixed to the main carrier of steel construction. Preferably, vertically arranged supports of the main carrier unit are connected to the ends of the main carrier.

[0028] The cross members connecting the vertically extending supports of the main carrier unit to each other are arranged at least partially orthogonally to the reformer tube rows and the burner rows, but also parallel to these reformer tube rows and these burner rows. The cross members serve to stabilize the steel construction and are not used to support the main loads of the supply and discharge lines, the burners and the reformer tubes. In one example, the cross members are arranged on the floor of the radiation space. Since the thickness of the cross members is significantly smaller than the thickness of the main carrier of the main carrier unit, these cross members can also be arranged in the space between the axis of the burner and the axis of the reformer tube without increasing the spacing between the individual reformer tubes. The cross members can in principle be fixed at any desired point between the lower end and the upper end of the vertically extending supports of the main carrier unit, or can be fixed to one of the two ends.

[0029] In the reforming furnaces known from the prior art, the cross members extend only parallel to the reformer tube banks and the burners. Since the cross members are not used to support the main loads of the supply and discharge lines, the burners and the reformer tubes, corresponding static limitations result and an orthogonal arrangement of the horizontally extending main carriers is accordingly required. This leads to the aforementioned disadvantages.

[0030] At least the horizontal main carrier of the main carrier unit, which is connected via vertically arranged supports, preferably extends along the ceiling of the radiation space. Here, the main carrier extends along the entire length of the radiation space. "Overall length" here means that the length of the main carrier is designed to correspond to the radiation space size requirements so that the heating of the reformer tubes can be as uniform as possible. The length of the radiation space is defined here by the spacing between the two end sides of the radiation space, i.e. the spacing between the front side and the rear side.

[0031] Arranging the main carrier parallel to the burner row and the reformer tube row produces the following advantages:

[0032] - The overall service life of the reformer tubes is extended because no load peaks occur at certain reformer tubes.

[0033] - the maximum temperature (T max ) is reduced. This allows the wall thickness of the reformer tubes to be reduced, saving material and therefore cost.

[0034] - Smaller wall thickness in turn leads to reduced thermally induced operating stresses in the reformer tubes, which in turn extends the service life of the reformer tubes.

[0035] - In addition, the smaller wall thickness leads to an improved heat convection from the radiation space to the interior of the reformer tubes. The temperature in the catalyst bed (cracked gas temperature) is thus increased, which makes it possible to configure a more efficient plant (increased reformer efficiency).

[0036] Depending on the size of the device, T max Here, a reduction of about 5 Kelvin to 10 Kelvin is expected. It is known from experience and many years of investigation that a reduction of 10 Kelvin (relative to T max ) corresponds here to a possible 10% reduction in wall thickness. If the aim is to maintain the wall thickness, then in turn it is conceivable that the theoretical service life of the reformer tubes would increase by 20,000 to 40,000 hours.

[0037] The reformer tube rows and the burner rows are arranged in an alternating manner and parallel to each other. Since each reformer tube row should be fired from both sides by two burner rows, it is preferred to start with the burner rows of the adjacent wall arranged along the lateral length of the radiation space. This is followed by a certain number of reformer tube rows of non-adjacent walls and burner rows of non-adjacent walls, which are present in an alternating manner and according to the size of the reformer, wherein the last burner row in the burner row on the side opposite to the "first" adjacent wall burner row in turn becomes the adjacent wall burner row. Thus, the following arrangement is preferably produced:

[0038] Side wall - burner row adjacent to the wall - (reformer tube row - burner row) n - Reformer tube row - Burner row adjacent to the wall - Side wall Here, n=0 or a natural number (n≥1).

[0039] The burners at the ends of the burner row and the reformer tubes at the ends of the reformer tube row are arranged at the end sides (front side and rear side) of the radiation space.

[0040] A preferred embodiment of the reformer furnace according to the invention is characterized in that the number of the main carrier units is a function of the number of the reformer tube rows and / or the number of the burner rows. Preferably, the number of main carrier units increases with the number of reformer tube rows and the number of burner rows, because the simplest solution in terms of construction is achieved if the number of main carriers for fixing the burners and reformer tubes is correspondingly increased while the number of burner rows and the number of reformer tube rows is increased.

[0041] A preferred embodiment of the reformer according to the invention is characterized in that the radiation space has a number h of main carrier units and a number r of reformer banks, wherein the relationship between h and r is h = r + 1. Preferably, the number of main carrier units is generated as a function of the number of reformer banks present, wherein preferably the radiation space contains one more main carrier unit than reformer banks arranged in the radiation space.

[0042] A preferred embodiment of the reformer according to the invention is characterized in that the radiation space has a number h of main carrier units and a number b of burner rows, wherein the relationship between h and b is h = b. Preferably, the number of main carrier units results from the number of burner rows present, wherein preferably the radiation space contains the same number of main carrier units as the number of burner rows arranged in the radiation space.

[0043] More preferably, for the reformer, the following equations hold: h=r+1, and h=b.

[0044] A preferred embodiment of the reformer furnace according to the invention is characterized in that the number of these main carrier units is not a function of the length of the reformer tube row and / or the number of these main carrier units is not a function of the length of the burner row. Due to the fact that the main carriers of the main carrier units are arranged parallel to and along the reformer tube row and the burner row, the number of main carrier units is not set by the length of the burner row and the length of the reformer tube row as in the orthogonal arrangement known from the prior art. Instead, the burner row and the reformer tube row in the radiation space can in principle be designed to have any desired length, wherein the number of main carrier units is determined only by the number of burner rows and the number of reformer tube rows.

[0045] A preferred embodiment of the reforming furnace according to the invention is characterized in that between two adjacent main carrier units

[0046] - separate burner banks are arranged, or

[0047] - A burner row and a reformer tube row adjacent to the burner row are arranged. Preferably, between two adjacent main carrier units there is either a burner row (because this is structurally simple and therefore preferred) or a burner row and a reformer tube row adjacent to the burner row.

[0048] Here, preferably, a separate burner row (since this can be realized in a structurally simple manner) is the burner row adjacent to the wall.

[0049] A preferred embodiment of the reformer according to the invention is characterized in that two of the plurality of main carrier units are arranged adjacent to a wall on two opposite walls of the radiation space in each case, wherein the main carriers of the main carrier units positioned adjacent to the wall extend parallel to the corresponding wall. In the case of a reformer having the smallest possible configuration, for example when only one reformer tube row and two burner rows are used (the burners in these two burner rows heat the reformer tubes in a single reformer tube row from both sides), the plurality of main carrier units include at least two main carrier units. In this case, the two main carrier units are each arranged adjacent to a wall, wherein the main carriers extend along the side wall from one end side of the radiation space to the opposite end side. In large reformers comprising more than only one reformer tube row, additional main carrier units are generally required. These additional main carrier units are arranged between the main carrier units arranged adjacent to the wall, wherein the main carriers of these additional main carrier units extend horizontally, spaced apart from the side wall, along the ceiling of the radiation space.

[0050] A preferred embodiment of the reformer according to the invention is characterized in that the main carrier units arranged adjacent to the wall have more than two vertically extending supports arranged adjacent to the wall. The main carrier units arranged adjacent to the wall may have more than two vertically extending supports (e.g. a third support) which are arranged centrally between the two end supports of the main carrier unit. This makes it possible to increase / improve the bearing capacity of the main carrier units arranged adjacent to the wall. Since no reformer tube row or burner row extends directly along the wall of the radiation space, additional vertical supports arranged at this point do not interfere.

[0051] A preferred embodiment of the reformer according to the invention is characterized in that all spacings between two adjacent reformer tubes within a reformer tube row and / or all spacings between two adjacent burners within a burner row are identical throughout the entire radiation space of the reformer. This regularity and symmetry of the arrangement of burners and reformer tubes is achieved for the first time by the arrangement according to the invention of the main carrier unit and is preferred since it allows equalization of the heating of the reformer tubes. Thus, temperature peaks of the walls of the reformer tubes and of the interior of the reformer tubes (catalyst bed) are optimally avoided. This also allows the flame pattern of the burners to be equalized to the greatest extent possible, for example by avoiding as much as possible undesirable bending of the flame in the direction of the center of the reformer.

[0052] A preferred embodiment of the reformer furnace according to the present invention is characterized in that all spacings between two adjacent reformer tubes measured by the horizontal extension between the two reformer tube axes of the adjacent reformer tubes are less than or equal to 500 mm, preferably in the range of 250 mm to 450 mm, and more preferably in the range of 280 mm to 320 mm.

[0053] A preferred embodiment of the reformer according to the invention is characterized in that the temperature of the gaseous products discharged via the discharge lines is on average up to 950°C, preferably in the range of 900-950°C, more preferably in the range of 925-950°C.

[0054] A preferred embodiment of the reformer according to the invention is characterized in that the steel construction serves as a framework for the refractory lining of the radiation space, wherein the space within the refractory lining defines a combustion space for firing the reformer tubes. The steel construction is arranged in the so-called radiation space. The wall or outer wall of the radiation space delimits the radiation space from the surroundings. The steel construction in turn forms a framework for the refractory lining of the reformer, wherein, viewed from the outer wall, this lining is arranged in the direction of the interior of the radiation space.

[0055] A preferred embodiment of the reformer according to the invention is characterized in that each main carrier unit has a truss construction which is arranged above the main carrier unit and is connected to the main carrier in a force-fit manner. Preferably, the truss construction is connected to the main carrier by means of a bolt connection (in a force-fit manner). Additionally, such a truss construction enables loads to be distributed via the main carriers of the main carrier units.

[0056] The object is also achieved at least in part by the use of a reformer according to the invention according to at least one of the aforementioned embodiments for steam reforming a carbonaceous input material, in particular natural gas. The carbonaceous input material may be any carbonaceous input material known to a person skilled in the art, which is suitable for reforming with steam to produce synthesis gas.

[0057] Example

[0058] The present invention is explained in more detail below by exemplary embodiments. In the following detailed description of exemplary embodiments, reference is made to the accompanying drawings that form a part thereof and contain the pictorial representations of specific embodiments of the present invention. In view of this, direction-specific terms such as "top", "bottom", "front", "rear" are used with reference to the orientation of the accompanying drawings described. Since the components of the embodiments can be positioned in multiple orientations, the direction-specific terms are used for illustration and are not limited in any way. Those skilled in the art will recognize that other embodiments can be used and structural or logical changes can be made without departing from the scope of protection of the present invention. Therefore, the following detailed description should not be understood in a restrictive sense, and the scope of protection of these embodiments is limited by the appended claims. Unless otherwise stated, the drawings are not to scale.

[0059] Further features, advantages and possible applications of the present invention will become apparent from the following description of exemplary embodiments in conjunction with the attached drawings.

[0060] In the attached picture:

[0061] Figure 1 shows a schematic highly simplified illustration of a reforming furnace 100 having a steel construction according to the prior art,

[0062] Figure 2 A schematically highly simplified illustration of a reforming furnace 200 of steel construction according to the invention is shown,

[0063] Figure 3a A schematic diagram showing heat flow distribution of a reformer tube bank 300a according to the prior art in which a spacer is formed, and

[0064] Figure 3bA schematic illustration of heat flow distribution according to a reformer tube bank 300b of a reformer furnace according to the present invention without a spacer zone is shown.

[0065] Figure 1 A schematic simplified perspective view of a reformer furnace 100 with a steel construction according to the prior art is shown. The radiation space of the reformer furnace 100 is roughly shown, which has the actual steel construction, refractory lining and multiple reformer tube rows and burner rows. The steel construction is used to fix the burners, reformer tubes, and supply and discharge lines to / from the burner / reformer tubes. For clarity, details about the fixings are not shown.

[0066] The reformer furnace 100 shown has four burner rows 101a, 101b and three reformer tube rows 102. Each of the burner rows 101a, 101b has six burners 103 arranged in a row. Each of the reformer tube rows 102 has eight reformer tubes 104 arranged in a row. The burner rows arranged at the respective left and right edges of the figure are burner rows 101a adjacent to the wall, which burn only one reformer tube row 102 arranged adjacent and in parallel. The burner rows arranged between the burner rows 101a adjacent to the wall are burner rows 101b of non-adjacent walls, which burn two reformer tube rows 102 arranged adjacent and in parallel in each case. The reformer tube rows 102 and the burner rows 101a, 101b each extend in the z direction shown in the figure. The burners 103 each generate a flame directed downward, i.e. the flame extends approximately in the y direction of the drawing and thereby heats the vertically arranged reformer tube 104 which also extends in the y direction. The burners 103 extend into the combustion space of the radiation space of the reforming furnace, which is defined by the refractory lining 105 as a boundary toward the outside. Here, the vertically extending reformer tube 103 passes through the top and bottom plates of the refractory lining 105 in such a way that the main length of the reformer tube 104 can be heated by means of the burners arranged adjacently. For the sake of clarity, the supply lines for supplying combustion gases and oxidants to the burners and the supply lines for supplying reaction gases to the reformer tubes are not shown. The same applies to the flue gas channels and exhaust lines for extracting the exhaust gases from the burners and the exhaust lines for exhausting gas products.

[0067] The steel structure of the reforming furnace shown has a total of three main carrier units. Each main carrier unit has two vertical supports 106a and 106b and a horizontal main carrier 107. The supports 106a, 106b each have a base 111. The horizontally extending main carrier 107 connects the two vertically extending supports by means of a press fit or an integral bonding connection (for example, by means of a bolt connection or a welding connection). Among the three main carrier units in total, two main carrier units are arranged on the end sides (front and rear sides, defined by the xy plane in each case) of the reforming furnace, and one main carrier unit is arranged between the main carrier units arranged on the end sides. Here, the vertical supports 106a, 106b of the main carrier units are arranged adjacent to the wall in each case, wherein the main carrier unit arranged between the main carrier units arranged on the end sides includes supports 106a, 106b extending along the side surface (defined by the yz plane) of the reforming furnace. The supports 106a, 106b of the main carrier unit arranged at the end side extend in the border region between the wall of the end side (xy plane) and the wall of the side surface (yz plane) of the reforming furnace 100. The wall of the reforming furnace encloses the radiation space together with the steel construction, the refractory lining 105 and the burners 103 and the reformer tubes 104. For the sake of clarity, the wall is not shown.

[0068] Additional vertically extending auxiliary supports 108 are arranged between the supports 106a, 106b of the main carrier unit, which are connected to the main carrier. The auxiliary supports 108 are used to stabilize the steel structure in addition. The auxiliary supports 108 pass through the top plate of the refractory lining 105 and are therefore partially arranged in the combustion space of the reforming furnace 100. In the example of the reforming furnace 100, three auxiliary supports 108 are provided for each main carrier unit. Here, the number of auxiliary supports 108 depends in principle on the width of the reforming furnace, i.e. on the number of reformer tube rows and burner rows. For additional static stability, above the main carrier 107, the steel structure has a truss structure 109, which is connected to the main carrier 107 in a press-fit manner and has interconnected struts arranged diagonally and vertically.

[0069] The horizontally extending main carrier 107 of the main carrier unit is arranged orthogonally to the burner rows 101a, 101b and the reformer tube row 102. In other words, the main carrier 107 extends in the illustrated x-direction, while the burner rows 101a, 101b and the reformer tube row 102 extend in the illustrated z-direction. Due to the length of the reformer tube row 102 (in each case with eight reformer tubes 104) and the burner rows 101a, 101b (in each case with six burners 103), two main carriers arranged on the end side are not sufficient in view of the static requirements. That is, the third main carrier unit arranged between the main carrier units arranged on the end side needs to meet the static requirements of the reformer tube row length and the burner row length shown. In principle, the number of main carrier units of a conventional reformer furnace increases with the increase of the length of the reformer tube row 102 and the length of the burner rows 101a, 101b.

[0070] The third main carrier unit occupies a certain amount of space, for example due to the vertically extending auxiliary supports, whereby the spacing between the third and fourth burners in the burner rows 101a, 101b must be increased compared to all other burner spacings. The same applies to the spacing between the fourth and fifth reformer tubes in the reformer tube row 102. This structural limitation leads to the fact that the operating temperature of the reformer tubes 104 in the area of ​​the central main carrier unit is higher, which can lead to a shorter service life and / or a higher safety margin in the design of the reformer tubes. The higher temperature of the fourth and fifth reformer tubes in the reformer tube row 102 in this case is caused by the fact that the viewing angle factor of these reformer tubes relative to the burner flame is higher than the viewing angle factor of the remaining tubes.

[0071] The centrally arranged main carrier unit subdivides the reformer into two so-called "compartments", wherein each compartment has three reformer tube rows with four reformer tubes in each case and four burner rows with three burners in each case. The formation of such compartments is in principle undesirable.

[0072] Figure 2 A schematic simplified perspective view of a reformer furnace 200 with a steel construction according to the present invention is shown. The radiation space of the reformer furnace 200 is roughly shown, which has the actual steel construction, refractory lining and multiple reformer tube rows and burner rows. The steel construction is used to fix the burners, reformer tubes, and supply and discharge lines to / from the burner / reformer tubes. For clarity, details about the fixings are not shown.

[0073] and Figure 1The reformer 200 shown has four burner rows 201a, 201b and three reformer tube rows 202. Each of the burner rows 201a, 201b has six burners 203 arranged in a row. Each of the reformer tube rows 202 has eight reformer tubes 204 arranged in a row. The burner rows arranged at the respective left and right edges of the figure are the burner rows 201a of the adjacent wall, which burn only one reformer tube row 202 arranged adjacent and in parallel. The burner rows arranged between the burner rows 201a of the adjacent wall are the burner rows 201b of the non-adjacent wall, which burn two reformer tube rows 202 arranged adjacent and in parallel in each case. The reformer tube rows 202 and the burner rows 201a, 201b each extend in the z direction shown in the figure. The burners 103 each generate a flame directed downward, i.e. the flame extends approximately in the y direction of the drawing and thereby heats the vertically arranged reformer tube 204 which also extends in the y direction. The burners 203 extend into the combustion space of the radiation space of the reforming furnace 200, which is defined by the refractory lining 205 as a boundary toward the outside. Here, the vertically extending reformer tube 203 passes through the top and bottom plates of the refractory lining 205 in such a way that the main length of the reformer tube 204 can be heated by means of the burners arranged adjacently. For the sake of clarity, the supply lines for supplying combustion gases and oxidants to the burners and the supply lines for supplying reaction gases to the reformer tubes are not shown. The same applies to the flue gas channels and exhaust lines for extracting the exhaust gases from the burners and the exhaust lines for exhausting gas products.

[0074] The steel structure of the reforming furnace shown has a total of four main carrier units. Each of the four main carrier units has two vertical supports 206a and 206b and a horizontal main carrier 207. The supports 206a, 206b each have a base 211. The horizontally extending main carrier 207 connects the two vertically extending supports by means of a press fit or an integral bonding connection (for example, by means of a bolt connection or a welding connection). Here, in these main carrier units, two main carrier units are arranged on the side surface (defined by the yz plane in each case) of the reforming furnace adjacent to the wall, and the two main carrier units are arranged between the aforementioned main carrier units. Here, all vertical supports 206a, 206b of the main carrier units are arranged adjacent to the wall. The supports 206a, 206b of the two main carrier units arranged between the main carrier units arranged on the side surface extend along the surface of the end side (defined by the xy plane) of the reforming furnace 200. The supports 206a, 206b of the main carrier unit arranged on the side surface adjacent to the wall extend in the region of the boundary between the wall of the end side (xy plane) and the wall of the side surface (yz plane) of the reforming furnace 200. The wall of the reforming furnace encloses a radiation space together with the steel construction, the refractory lining 205 as well as the burners 203 and the reformer tubes 204. For the sake of clarity, the wall of the reforming furnace 200 is not shown.

[0075] Additional vertically extending auxiliary supports 208 are arranged between the supports 206a, 206b of the main carrier unit, which are connected to the main carrier. The auxiliary supports 208 are used to stabilize the steel structure in addition. The auxiliary supports 208 pass through the top plate of the refractory lining 205 and are therefore partially arranged in the combustion space of the reforming furnace 200. In the example of the reforming furnace 200, an auxiliary support 208 is provided for each main carrier 207 that is not adjacent to the wall. Here, the number of auxiliary supports 208 depends in principle on the length of the reforming furnace, that is, on the number of reformer tubes 204 of each reformer tube row or the number of burners 203 of the burner row. For additional static stability, above the main carrier 207, the steel structure has a truss structure 209, which is connected to the main carrier 207 in a press-fit manner and has interconnected struts arranged diagonally and vertically. The supports of the main carrier unit are connected to each other by horizontally extending cross members 210. The cross members serve to stabilize the reformer furnace, but do not support the main load of the burners 203 and the reformer tubes 204 and the additionally present supply and exhaust lines.

[0076] According to the invention, the horizontally extending main carrier 207 of the main carrier unit is arranged parallel to the burner rows 201a, 201b and the reformer tube row 202. In other words, the main carrier 207 extends in the z-direction shown in the figure, which also applies to the burner rows 201a, 201b and the reformer tube row 202, which also extend in the z-direction. By means of the arrangement according to the invention of the main carrier unit, in particular in view of the main carrier 207 arranged parallel to the burner rows and the reformer tube rows, the burners 203 of each row and the reformer tubes 204 of each row can be arranged evenly spaced apart. In this case, the number of required main carrier units increases with the number of reformer tube rows and the number of burner rows. In the present case, one main carrier unit is required per burner row, and there is one more main carrier unit than reformer tube rows. Here, the number of reformer tubes per row and the number of burners per row are in principle unlimited, since between the supports 206a and 207a any desired number of auxiliary supports 208 can be arranged, which extend between the reformer tube row 202 and the burner rows 201a, 201b, whereby these auxiliary supports do not disturb the row symmetry. The steel construction according to the invention allows to build a reforming furnace which (in view of the uniform spacing of the reformer tubes) does not require "compartments".

[0077] The uniform spacing of the reformer tubes 202 in each reformer tube row allows the maximum temperature of each tube to be reduced by Figure 3a and Figure 3b The diagrams are schematically explained.

[0078] Figure 3a A detail of a reformer tube bank with six reformer tubes 301a and an associated heat profile 302a of a reformer furnace 100 is shown. Here, the main carrier 303a of the main carrier unit extends orthogonally to the reformer tube bank and therefore requires, as explained above, a larger spacing between those reformer tubes 301a extending in the region of the main carrier 303a. Thus, an unfavorable heat profile is produced in this region relative to the remaining region of the reformer tube bank. This is caused in particular by the higher view factor of the reformer tubes arranged in the region of the main carrier 303a relative to the adjacent burner flame.

[0079] Figure 3b A similar case of a reformer furnace 200 according to the invention is shown with reformer tubes 301b and associated heat profile 302b. The uniform spacing of the reformer tubes 301b also equalizes the heat profile 302b, as a result of which the maximum operating temperature of the reformer tubes 301b can be reduced. Advantageously, the reformer furnace 200 according to the invention does not have any "compartments".

[0080] List of Reference Numerals

[0081] 100 Reformer (Existing Technology)

[0082] 200 Reforming furnace (the present invention)

[0083] 101a, 201a Burner row (adjacent wall)

[0084] 101b, 201b Burner row (not adjacent to the wall)

[0085] 102, 202 Reformer tube row

[0086] 103, 203 Burner

[0087] 104, 204 Reformer tube

[0088] 105, 205 refractory lining

[0089] 106a, 106b, 206a, 206b Support member

[0090] 107, 207 Main carrier

[0091] 108, 208 Auxiliary support

[0092] 109, 209 Truss structure

[0093] 210 Transverse member

[0094] 111, 211 base

[0095] 301a, 301b Reformer tube

[0096] 302a, 302b Heat distribution

[0097] 303a Main carrier

Claims

1. A reforming furnace for catalytically reforming a carbonaceous input material using steam, the reforming furnace having A radiation space defined by a plurality of walls and separated from an external environment, wherein: The radiation space contains a steel construction configured as a frame and intended to fix supply and exhaust lines, burners and vertically arranged reformer tubes, wherein The burners are arranged to produce downward or upward flames to heat the reformer tubes, and wherein The burners and the reformer tubes are arranged in rows within the radiation space as burner rows and reformer tube rows, wherein the burner rows and the reformer tube rows are arranged in an alternating manner and parallel to each other, and The steel construction has a plurality of main carrier units, wherein each main carrier unit has two vertically extending supports arranged adjacent to the wall and a horizontally extending main carrier, the main carriers being connected via the supports and extending the entire length of the radiation space, and wherein, The main carriers are configured for fixing the supply and exhaust lines, the burners and the reformer tubes, and The steel construction has a plurality of horizontally extending cross members which connect the supports of the main carrier units to one another. It is characterized in that The main carriers of the main carrier units are arranged to extend parallel to the reformer tube rows and the burner rows, and The cross members are arranged to extend at least partially orthogonally to the reformer tube banks and the burner banks.

2. The reforming furnace according to claim 1, characterized in that: The number of the main carrier units is a function of the number of the reformer tube rows and / or the number of the burner rows.

3. The reforming furnace according to claim 1 or 2, characterized in that: The radiation space has a number h of main carrier units and a number r of reformer tube banks, wherein the relationship between h and r is h=r+1.

4. The reforming furnace according to claim 1 or 2, characterized in that: The radiation space has a number h of main carrier units and a number b of burner rows, wherein the relationship between h and b is h=b.

5. The reforming furnace according to claim 1 or 2, characterized in that: The number of these main carrier units is not a function of the length of the reformer tube row and / or the number of these main carrier units is not a function of the length of the burner row.

6. The reforming furnace according to claim 1 or 2, characterized in that: Between two adjacent main carrier units - separate burner banks are arranged, or - A burner row and a reformer tube row adjacent to the burner row are arranged.

7. The reforming furnace according to claim 6, characterized in that: That single burner row is the burner row adjacent to the wall.

8. The reforming furnace according to claim 1 or 2, characterized in that: Two main carrier units of the plurality of main carrier units are arranged in each case adjacent to a wall on two opposite walls of the radiation space, wherein the main carriers of the main carrier units located adjacent to the wall extend parallel to the respective wall.

9. The reforming furnace according to claim 8, characterized in that: The main carrier units arranged adjacent to the wall have more than two vertically extending supports arranged adjacent to the wall.

10. The reforming furnace according to claim 1 or 2, characterized in that: All spacings between two adjacent reformer tubes within a reformer tube row and / or all spacings between two adjacent burners within a burner row are the same throughout the entire radiant space of the reformer furnace.

11. The reforming furnace according to claim 1 or 2, characterized in that: All spacings between two adjacent reformer tubes measured by the horizontal extension between the two reformer tube axes of the adjacent reformer tubes are less than or equal to 500 mm.

12. The reforming furnace according to claim 11, characterized in that All spacings between two adjacent reformer tubes measured by the horizontal extension between the two reformer tube axes of adjacent reformer tubes are in the range of 250 mm to 450 mm.

13. The reforming furnace according to claim 12, characterized in that: All spacings between two adjacent reformer tubes measured by the horizontal extension between the two reformer tube axes of the adjacent reformer tubes are in the range of 280 mm to 320 mm.

14. The reforming furnace according to claim 1 or 2, characterized in that: The temperature of the gaseous products discharged via these discharge lines is on average up to 950°C.

15. The reforming furnace according to claim 14, characterized in that: The temperature of the gaseous products discharged via these discharge lines is in the range of 900°C to 950°C.

16. The reforming furnace according to claim 15, characterized in that The temperature of the gaseous products discharged via these discharge lines ranges from 925°C to 950°C.

17. The reforming furnace according to claim 1 or 2, characterized in that: The steel construction acts as a framework for the refractory lining of the radiation space, wherein the space within the refractory lining defines a combustion space for firing the reformer tubes.

18. The reforming furnace according to claim 1 or 2, characterized in that: Each main carrier unit has a truss construction which is arranged above the main carrier unit and connected to the main carrier in a press-fit manner.

19. Use of a reforming furnace according to any one of claims 1 to 18 for steam reforming a carbonaceous input material.

20. The use according to claim 19, characterized in that The carbonaceous input material is natural gas.

Images