Recuperator burner base unit and recuperator burner

Abstract

A recuperator burner base unit comprising a burner base having a burner air port for supplying burner air, an exhaust gas port for suctioning exhaust gas and a combustion gas port, a recuperator connected to the burner base. A heat transfer body has separate throughflow channels provided for guiding counterflowing fluids and has an inner cavity for forming or guiding through a combustion gas line. The burner base is designed as a flat burner base element and comprises at least one gas guide-through opening for connecting the burner air port to one of the throughflow channels in the recuperator and / or at least one gas guide-through opening for connecting to the exhaust gas port to one of the throughflow channels and / or at least one opening for connection to the combustion gas port. At a front side of the burner base element a planar support surface is provided.

Description

[0001] This nonprovisional application is a continuation of International Application No. PCT / DE2024 / 100851, which was filed on Sep. 27, 2024, and which claims priority to German Patent Application No. 20 2023 105 645.8, which was filed in Germany on Sep. 27, 2023, and which are both herein incorporated by reference.BACKGROUND OF THE INVENTIONField of the Invention

[0002] The invention relates to a recuperator burner base unit.Description of the Background Art

[0003] Such a recuperator burner base unit forms the basic building block of a recuperator burner, which must then be supplemented in particular with a burner tube and a burner nozzle located in it.

[0004] EP 4 105 552 A1, which corresponds to US 2024 / 0263779, is a recuperator burner base unit with a recuperator that has a heat transfer body with a complex geometric structure in which the heat exchange surfaces between two internal air and exhaust gas throughflow channels are maximized. This geometric structure can only be produced with additive manufacturing processes. The heat transfer body results in a considerably improved heat exchange performance. However, the pot-like burner base with the connections and flow paths formed therein for at least two media, namely for burner air and exhaust gas, is designed to be very large-volume, so that one-piece production in an additive manufacturing process is correspondingly time-consuming and cost-intensive.SUMMARY OF THE INVENTION

[0005] It is therefore an object of the invention to provide a more cost-effective production of a recuperator burner base unit.

[0006] An essential element of the recuperator burner base unit according to the invention is a flat burner base element as part of the burner base, which comprises at least one air guide-through opening for the connection of the burner air port with one of the throughflow channels in the recuperator, at least one exhaust gas guide-through opening for connection with the exhaust gas port and at least one opening for the connection with the combustion gas port. The recuperator is integrally connected to the burner base element to form a single unit, with the flow paths in or on the recuperator merging directly into the openings of the burner base element. Broadly speaking, the invention provides for the recuperator to be printed on a support surface on the burner base element, i.e., an additive manufacturing process such as selective laser melting (SLM) in particular is used.

[0007] The flat burner base element, which can be produced in a simple and cost-effective way with the necessary openings, replaces the printer base in a 3D printer or is placed on top of it with a seating plane. In order for the recuperator to be able to be built up in layers on the burner base element, at least one support surface is formed at the front, and at the back a seating plane parallel to the support surface is provided or can be created.

[0008] The support surface consists, at most, of the entire front side and, at least, of a narrow strip of the surface on which the application is to be made, while the rest of the front side remains untreated. Several support surfaces can also be provided, which are either in one plane or arranged parallel to each other with an offset in the direction of the Z-coordinate.

[0009] A seating plane parallel to the support surface is formed at the rear side of the burner base element. This can be achieved, for example, by milling or sanding the rear side completely parallel to the support surface. However, three support points at the rear side are also sufficient, which are located in a seating plane parallel to the support surface.

[0010] Finally, it may also be provided to combine the burner base element with at least one adapter element and thereby make it placeable in an additive manufacturing machine in such a way that the support surface is parallel to the machine bed or another base plane of the manufacturing machine.

[0011] The burner base is the part that is arranged outside a furnace wall when installed, while the recuperator and burner tube are routed through the furnace wall and protrude into the furnace.

[0012] In a preferred embodiment of the invention, the burner base is formed solely by the burner base element and connectors attached to it for combustion gas, exhaust gas and burner air lines. The omission of any other housing components on the burner base enables particularly cost-effective production of a recuperator burner base unit.

[0013] However, it is also possible to use the flat burner base element only as an intermediate part to be arranged close to the furnace wall, to which further modules for combustion gas, exhaust gas and airflow are connected.

[0014] Special advantages in terms of production costs result from the fact that the dimensions of the burner base element are optimized in such a way that several recuperator burner base units can be produced side by side in a single operation in an additive manufacturing machine. For this purpose, it is provided that the burner base element is rectangular or, in particular, square, with the distances between the edges being approximately the same as the expansion of the heat transfer body element in this direction.

[0015] For example, if the heat transfer body has a cylindrical envelope, then the incircle of a square burner base element is essentially the same as the diameter of the envelope, possibly with a small allowance. This allows for several burner base elements to be placed close together and the recuperators to be built close together using 3D printing.

[0016] Furthermore, hexagonal burner base elements are possible, allowing for multiple rows of base units to be manufactured with an offset to each other, in order to make even better use of the floor area in the additive manufacturing machine.

[0017] In terms of space optimization, it is particularly advantageous if: there is a material bond between the support surface and the inner tube of the recuperator along a closed inner line within which at least one recess is formed on the burner base element for the passage or connection of at least one combustion gas line; there is a material bond between the support surface and the recuperator along a first closed center line, and the at least one exhaust gas guide-through opening is arranged between the inner line and the first center line and at least one air guide-through opening is located between the first and second center line.

[0018] The closed lines along which additive manufacturing takes place automatically form sealed channels that lead to the recuperator, eliminating the need for additional seals.

[0019] Alternatively, the air guide-through opening can be located outside the centerline and the exhaust gas guide-through opening between the inner and center lines.

[0020] It can also be advantageous if the inner line runs parallel to the center line. This creates a throughflow channel in between, e.g., for the guide-through of the burner air, which has a constant cross-section over the circumference.

[0021] In another advantageous embodiment of the invention, the inner line and the center line are circular. This results in a simple and space-saving configuration.

[0022] In order to minimize the floor area of the burner base element and still be able to provide larger flow cross-sections for burner air and exhaust gas, a preferred embodiment of the recuperator burner base unit provides: that the inner line is circular; that the distance between the inner line and the center line in at least one section is less than the diameter of the gas guide-through opening provided there; that the distance between the inner line and a section of the center line at the gas guide-through opening is at least equal to the diameter of the gas guide-through opening, and that the center line in the section is arc-shaped around a peripheral area of the gas guide-through opening and connects to the arc-shaped section with further tangential sections.

[0023] In particular, it may be provided that the center line at the other gas guide-through opening in the burner base element runs in an arc-shaped section parallel to the circumference of the opening and converges towards the inner line.

[0024] The approximation of the inner and middle lines can even go so far that the center line in one section at the gas guide-through opening is led to the inner line and connected to it, so that the throughflow channel is interrupted there and a ring flow is prevented. This reduces crossflows in the recuperator and forces the flow in the longitudinal direction of the throughflow channel leading through the recuperator.

[0025] A further simplification of the space-optimized layout on the burner base element is achieved by the fact that both gas guide-through openings, i.e., the exhaust gas guide-through opening and the air guide-through opening, are arranged on the same pitch circle, with the center of the pitch circle lying in the center of the circular inner line.

[0026] The central area within the inner line is preferably used for the guide-through of at least one combustion gas line, in particular two combustion gas lines, e.g., for methane and hydrogen, in order to be able to operate the burner with different energy sources or in mixed operation.

[0027] In addition, further guide-throughs may be provided in this area, for example an opening each for a bypass line and / or for an ignition electrode and / or for a sensor element for flame monitoring.

[0028] It is particularly advantageous to form the area within the inner line in an insert element that can be removed from the burner base element, so that cables attached to it can be pulled out of the burner from outside the furnace.

[0029] In addition to the two self-contained walls, which are provided in a preferred embodiment, additional peripheral walls may be formed, which are formed along other peripheral lines.

[0030] For example, the heat transfer body of the recuperator can be provided with a material bonded outer jacket, and an additional peripheral line can be provided outside the center line, where the outer jacket connects to the burner base element in a material-bonded manner.

[0031] The outer jacket on the peripheral line can form an intermediate tube through which the burner base element together with an end section of the recuperator is moved from the furnace wall to the outside. In this case, the exhaust gas is not sucked in directly at the exhaust intake opening, but instead through an additional exhaust duct that is formed between the centerline and the peripheral line.

[0032] In order to reduce flow obstacles, it can be advantageous to design the transition of the exhaust duct as well as the air duct into the burner base element with ring segment-shaped, almost trapezoidal recesses in the burner base element, which then merge into a round connection in a gas connection flange attached at the rear, to which fittings for connecting external lines can be easily attached.

[0033] It may be advantageous if a pair of peripheral lines is provided outside the center line, where the recuperator is additionally bonded with the burner base element and at least one media guide-through opening is provided between the peripheral lines in the burner base element. Another throughflow channel is formed between the pair of peripheral lines, through which, for example, a thermal oil can be fed into the recuperator.

[0034] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0036] FIG. 1 shows a recuperator burner base unit in perspective view;

[0037] FIG. 2 shows a burner base element in perspective view with a view of the front side;

[0038] FIG. 3 shows a recuperator in a cross-sectional view through the connection area with the burner base element;

[0039] FIG. 4 shows the recuperator burner base unit in perspective view from behind;

[0040] FIG. 5 shows the burner base element in perspective view of the rear side;

[0041] FIG. 6 shows the recuperator burner in perspective view of the rear side from diagonally behind;

[0042] FIG. 7 shows a cut through the rear part of the recuperator burner;

[0043] FIG. 8 shows an example of a grid-shaped production arrangement in a top view;

[0044] FIG. 9 shows an example of a grid-shaped production arrangement in a top view;

[0045] FIG. 10 shows an example of a recuperator burner base unit in a perspective exploded view;

[0046] FIG. 11 shows the burner base element according to FIG. 10 in perspective view with a view of a front side;

[0047] FIG. 12 shows the front side of the burner base element in accordance with

[0048] FIGS. 10 and 11 in a top view;

[0049] FIG. 13 shows an example of a burner base element in a rear perspective view;

[0050] FIG. 14 shows the front side of the burner base element according to FIG. 13 in a top view; and

[0051] FIGS. 15 and 16 show a cross-sectional representation by the recuperator burner base unit according to FIGS. 13 and 14 in offset sectional planes.DETAILED DESCRIPTION

[0052] FIG. 1 shows a recuperator burner base unit 100 in a perspective view. This comprises, as a single unit, a burner base 1—of which only a flat burner base element 10 is visible—and an adjacent recuperator 20, which is integrally connected to the burner base element 10. The connection is made by a transition body 22 on the recuperator 20, which is adapted to the geometry of the burner base element 10 and the connections, holes and channels contained therein, so that the transition body 22 and the other parts of the recuperator 20 can be printed directly on a flat support surface 10.3 on the front side 10.1 of the burner base element 10 in an additive manufacturing process. For this purpose, the contour of the transition body 22 at the connection to the support surface 10.3 at the burner base element 10 is designed in a special way.

[0053] As also can be seen in FIG. 1, a first gas guide-through opening 13 is recessed on the transition body 22, i.e., the outer wall of the transition body 22 is concave there in order to leave the entire cross-section of the gas guide-through opening 13 exposed. Preferably, an exhaust line is connected to the first gas guide-through opening. This allows for exhaust gas to be extracted directly from the combustion chamber through the burner base element 10.

[0054] Above the transition body 22, the heat transfer body 21 connects to the recuperator 20, of which only a cylindrical outer wall is visible. Inside, the heat transfer body 21 has a complex geometric structure that is maximized in terms of the size of the heat exchange surfaces between the air and exhaust gas throughflow channels and can only be produced using an additive manufacturing process. Exhaust gas is first led from the combustion chamber at the exhaust gas intake openings 28 into the heat transfer body 21 and exits at the bottom of the transition body 22, from where it is then discharged through the exhaust gas guide-through opening 13.

[0055] Burner air is led through another gas guide-through opening in the burner base element 10 into another throughflow channel in the heat transfer body 21, where it is led in the opposite direction to the exhaust gas flow and heated by it. The burner air exits through an annular gap 25, where it acts as a jet pump, thereby promoting the intake of exhaust gas into the exhaust gas intake openings 28. Inside, the heat transfer body 21 in the embodiment shown has an inner tube 26 with an inner cavity 27.

[0056] FIG. 2 shows the burner base element 10 in perspective view with a view of the front side 10.1. At least one inner area has a flat surface, which serves as the support surface 10.3 for the additive manufacturing process. The contour of the support surface 10.3 may correspond to a center line 24 of the outer wall of the transition body 22 or be larger. The inner tube 26 of the recuperator 20 (cf. FIG. 1) connects to an inner line 23 on the burner base element 10.

[0057] The burner base element 10 has a special hole pattern in the example shown.

[0058] A first gas guide-through opening 13 formed by a through hole serves as the exhaust gas guide-through opening in the embodiment example shown. It is located outside the center line 24.

[0059] Another gas guide-through opening 14 is located between the inner line 23 and the center line 24 and serves as an air guide-through opening.

[0060] Further gas guide-through openings in the burner base element 10 form combustion gas ducts 11, 12. These are used to supply methane and hydrogen selectively or simultaneously into the combustion chamber. The combustion gas ducts 11, 12 begin in boreholes drilled into the side surfaces of the burner base element 10 and end within the inner line 23 at the front side 10.1.

[0061] Further through holes 15, 16 allow for ignition elements and / or sensors to pass through to the inner tube 26 of the heat transfer body 21 or can serve as a bypass line for fresh air to temporarily bypass the air passage through the heat transfer body 21.

[0062] Mounting holes 18 are located in corner areas outside of the center line 24. They are used to connect the recuperator burner base unit 100 with a furnace flange.

[0063] Further mounting holes 19 are located within the inner line 23. They are used to attach a burner insert element that carries at least one combustion gas line, at the mouth of which a burner nozzle is attached.

[0064] The inner line 23, which encloses the through holes 15, 16, 17, 18, is circular in the embodiment example shown. The center line 24 is circular arc-shaped only in sections 24.1 and only runs parallel to the inner line 23 in those sections 24.1, which are located near the outer mounting holes 18.

[0065] At the exhaust gas guide-through opening 13, the outer line 24 is concave in a section 24.2 and jumps inwards. It even connects selectively with the inner line 23. In a diametrically opposed section 24.3, the outer line runs around the gas guide-through opening 14 for the burner air, which is arranged on the inside between the inner line 23 and the center line 24. There, the distance between inner line 23 and center line 24 is increased to the diameter of the gas guide-through opening 14.

[0066] The contact of section 24.2 with the inner line 23 forms a two-part air duct 29. This is particularly visible in FIG. 3, where the recuperator 20 is shown in a cross-sectional representation at the transition to the burner base element 10.

[0067] The beak-shaped section 24.3 at the bottom left runs around the gas guide-through opening 14. From there, tangential sections 24.4 extend on both sides to the circular arc-shaped sections 24.1. Between the convex sections 24.1 is the concave section 24.2. Between the inner line 23 and the center line 24, the air duct 29 is formed. Due to the interruption in section 24.2, the latter is divided into two parts. A ring flow in the air guide-through opening 29 is thus not possible and turbulence in it is avoided. Rather, the division in two favors a vertical flow into the heat transfer body 21.

[0068] FIG. 4 shows a rear side 10.2 of the burner base element 10, wherein the inner and center lines 23, 24, which are actually located on the front side facing away in FIG. 4, are merely mirrored onto the rear side 10.2 for illustrative purposes.

[0069] In the following details, the hole pattern of the openings corresponds to the hole pattern on the front side (see FIG. 2): the gas guide-through opening 13 outside the center line 24; the gas guide-through opening 14 between inner line 23 and center line 24; holes 15, 16 as openings for the guide-through, e.g., of ignition elements and / or sensors; mounting holes 18 in corner areas outside the center line 24; and mounting holes 19 within the inner line 23.

[0070] The hole pattern differs only with regard to the combustion gas ducts 11, 12. At the rear side 10.2, the combustion gas ducts 11, 12 begin outside the center line 24 and end at the front side 10.1 inside the inner line 23 (see FIG. 2). The cross-connection is made by means of holes that are drilled in the side surfaces of the burner base element 10 and are sealed.

[0071] On a pitch circle, indicated by the semicolon line in FIG. 4, are the gas guide-through opening 13 and the gas guide-through opening 14. The center of this arrangement coincides with the center of the circular arc-shaped inner line 23.

[0072] FIG. 5 shows a recuperator burner 101, which is mounted on the recuperator burner base unit 100 described above.

[0073] The recuperator 20 is connected to a combustion chamber tube 40. At the transition between them, an eductor 42 is formed, which is mechanically connected to the recuperator 20 via connecting elements 44. In between, an annular gap opening 43 is formed, which is open to the outside, so that part of the exhaust gas can be drawn back into the combustion chamber tube 40 from the outside for post-combustion. The other part enters through the exhaust gas intake openings 28 into a throughflow channel in the heat transfer body 21 of the recuperator 20.

[0074] The recuperator burner base unit 100 is also connected to a furnace flange 50 in order to be able to attach the recuperator burner 101 to a furnace wall.

[0075] Connectors are inserted directly into the openings in the recuperator burner base unit 100 for: two combustion gas ports 32, e.g., to supply the burner with methane and / or hydrogen; a burner air port 33; an exhaust gas extraction port 34; an ignition electrode 36; and a guide-through tube 35 for a flame image monitoring sensor, which can also be used as a bypass line for burner air in order to lead fresh air directly to the burner nozzle during a warm-up phase and to temporarily bypass the post-combustion of exhaust gas.

[0076] FIG. 6 shows the recuperator burner 101 in perspective view of the back from diagonally behind. It can be seen that all connecting elements for the combustion gas connections 31, 32, the burner air port 33, the exhaust gas extraction port 34, the guide-through tube 35 and the ignition electrode 36 are screwed directly into the assigned holes of the burner base element 10. No other housing parts or other accessories are required.

[0077] FIG. 7 shows a section through the rear part of the recuperator burner 101 with the burner base 1 with the ports 31, 34, 35. The combustion gas ducts 11, 12 in the burner base element 10 are located in the cutting plane, as is a fastening screw 65, which is inserted into the middle of the mounting holes 19 visible in FIG. 4. A flange plate 63 of a burner insert 60 is held above it. Combustion gas lines 61, 62 are connected to the flange plate 63. A sealing plane is formed between the flange plate 63 and the area of the front side 10.1 of the burner base element 10, at which the combustion gas lines 61, 62 merge individually into the combustion gas ducts 11, 12. At the other end of the combustion gas lines 61, 62 there is a burner nozzle that can be positioned in an end section of the burner tube 40 (see FIG. 5). The burner insert 60 can be pushed as a whole into the burner tube 40 and the cavity 27 inside the recuperator until the flange plate 63 is in contact with the burner base element 10. This allows for the burner nozzle to be replaced quickly.

[0078] In order to simplify production and reduce its costs, it is advantageous to manufacture the recuperator in a single operation using additive manufacturing for several recuperator burner base units 100. For this purpose, the burner base elements 10 are placed in the production machine in a grid-shaped arrangement 2, which is schematically shown from above in FIG. 8. The external dimensions of the heat transfer bodies 21 of the recuperators 20 are chosen in such a way that they do not protrude laterally beyond the edges of the burner base elements 10 but rather maintain a small offset of at least 1 mm to the edges. As a result, adjacent heat transfer bodies 21 with a small gap between them can be produced in a single operation without the heat transfer bodies 21 fusing together and having to be separated afterwards.

[0079] In order to be able to manufacture even more recuperator burner base units on an existing support surface in the production machine, a polygonal burner base element 10′ can be provided as an alternative instead of the square contour of the burner base element described above. For example, if hexagonal burner base elements 10′ are provided, an even denser grid arrangement 2′ can be achieved, which is shown in FIG. 9. The offset of the middle row compared to the upper and lower rows makes it possible to make even better use of the available space in the production machine.

[0080] FIG. 10 shows a recuperator burner base unit 200 with a burner base element 210 and parts of a lower section of a recuperator 220. In FIG. 10, this is separated from the burner base element 210 for the purpose of better representation. In reality, the recuperator is printed by 3D printing on a flat area of the burner base element 210 and thus connected to it in a material-tight manner, or a one-piece element is formed that includes the burner base element 210 and the recuperator.

[0081] The recuperator 220 has a heat transfer body 221, which has an inner cavity 227, which is bounded by an inner tube 226. Outside of this, a transition body 222 is formed, through which the larger diameter of the heat transfer body 221 is reduced to a smaller diameter. An annular air duct 229 is formed between the inner tube 226 and the transition body 222, through which air from a gas guide-through opening 213 in the burner base element 210 enters the heat transfer body 221.

[0082] In the example shown, the burner base element 210 has an inner circular area which forms a support surface for the recuperator 220 at a front side 210.1 and which has a central opening 215 through which combustion gas lines, ignition elements and / or sensors can be routed to the inner tube 226 of the heat transfer body 221. Large, annular segment-shaped recesses form the gas guide-through opening 213 and a gas guide-through opening 214. On the outer perimeter, this area is surrounded by a furnace flange 250.

[0083] A gasket 240 is inserted at the back of the burner base element 210, which seals the gas guide-through openings 213, 214 with gasket sections 241, 242. In the case of the central opening 215, the corresponding section of the gasket 240 does not surround the entire opening cross-section but is divided into four holes that are assigned to the above-mentioned elements such as combustion gas lines, ignition elements and / or sensors.

[0084] To the rear, the recuperator burner base unit 200 is terminated via a flat gas connection flange 230. The latter has: two combustion gas ports on the outer perimeter, of which one combustion gas connection 231 is visible; a burner air port 233; an exhaust gas extraction port 234; and further recesses 235, 236 for an instrument tube and an ignition electrode.

[0085] FIG. 11 shows the burner base element 210 in perspective view with a view of the front side 210.1. At least one inner area, which is located within an outer furnace flange 250 with mounting holes 251, has a flat surface that serves as a support surface for the recuperator heat exchanger, which is produced by an additive manufacturing process. The contour of the support surface corresponds to a peripheral line 225, which represents the outer wall of a transition body on the recuperator. The inner tube of the recuperator connects to an inner line 223 on the burner base element 210. The combustion gas connections 231, 232 terminate in the center. In addition, the recesses 235, 236 are visible there.

[0086] Between the walls of the recuperator, which are built on lines 223, 224 and 225, an air duct 228 and an exhaust duct 229 are formed.

[0087] It can be seen in FIG. 11 that the annular segment-shaped, almost trapezoidal recesses in the burner base element 210, which form the gas guide-through openings 213, 214, merge into a round burner air port 233 and into a round exhaust gas extraction port 234 in the gas connection flange 230 attached at the rear. The annular segment-shaped recesses facilitate the transfer of gases from the gas guide-through opening 213 into the air duct 228 or from the exhaust duct 229 into the gas guide-through opening 214. The round holes in the gas connection flange 230 behind it make it easier to attach tube sockets and the like for connecting external lines.

[0088] FIG. 12 shows the front side 210.1 of the burner base element 210 again in a top view. It becomes clear that the air duct 228 is constricted where the gas guide-through opening 214 is located outside it. Conversely, the exhaust duct 229 is constricted at the gas guide-through opening 213. Since air and exhaust gas both flow into the recuperator from the drawing plane, a ring flow in the channels 228, 229 is not necessary, so that the constriction is not a hindrance. But even in the constricted areas, the air duct 228 and the exhaust duct 229 are not completely interrupted. On the one hand, this avoids dead zones that do not flow through in the air duct 228 and in the exhaust duct 229, and on the other hand, the walls that are built on the lines 223, 224225 can be formed with constant wall thicknesses, thus avoiding material accumulation and the resulting potential problems with 3D printing.

[0089] FIG. 13 shows another embodiment of a burner base element 310 for a recuperator burner base unit, in a perspective view from behind.

[0090] The burner base element 310 is extended forward, in the direction of a furnace chamber, via an extension ring 352, which is terminated by a furnace flange 350. The extension ring can be built up by 3D printing together with the recuperator on the burner base element 310. It is also technically possible to integrally form the furnace flange 350 at the same time, but for logistical reasons it is better to weld it on later, as the diameter and number and pitch of the screw connections depend individually on the design of the kiln chamber.

[0091] An air guide-through opening 313 and an exhaust gas intake opening 314 are provided directly in the burner base element 310 in the embodiment example shown. In the center of the burner base element 310 is a gas connection flange 330, which has lateral combustion gas connections 331 and further through openings 333, 334 for an ignition electrode and an inspection tube, among other things.

[0092] The exhaust gas intake opening 314 is located on the outside of the circumference. In order to be able to form them with a large cross-section, the burner base element 310 and the adjoining extension ring 351 are not completely circular in shape, but each have a convex area starting from the cylinder shell, which is arc-shaped in cross-section.

[0093] FIG. 14 is a plan view of a front side 310.1 of the burner base element 310 again in a top view. The front side forms the support surface for the production of the other components using 3D printing. The inner line 323 is used to manufacture an inner tube of a recuperator; a center line 324 is used to produce a transition body to which a heat transfer body is connected. On a peripheral line 325, the extension ring 352, which is visible in FIG. 13, is created during production.

[0094] An air duct 353 is formed between the inner line 323 and the center line 324, through which the combustion air suctioned in from the outside enters the recuperator, where it is preheated. Between the inner line 324 and the peripheral line 325, an exhaust duct 354 is formed, through which the exhaust gas sucked in from the combustion chamber via the recuperator is discharged.

[0095] The center line 324 is arranged eccentrically to the inner line 323. The peripheral line 325 is largely centered relative to the inner line 323, but it is not completely circular; rather, it is further widened by a convex bulge. This widens the exhaust duct 354 in the upper area in FIG. 14, so that a gas guide-through opening 314 with a large cross-section can be formed there.

[0096] The extension ring 352 is provided in order to be able to arrange the burner base element 310 with an offset in the longitudinal direction to the furnace flange.

[0097] FIG. 15 is a cross-sectional representation of the recuperator burner base unit 300 with the burner base element 310 and parts of a lower section of a recuperator 320 with a heat transfer body 321. The heat transfer body 321 transitions towards the burner base element 310 into a transition body 322, which is not rotationally symmetrical, and which extends partly radially outwards over the radius of an opening 355 in the furnace flange 350. Only in this way is the eccentric arrangement of the center line, visible in FIG. 14, on which the transition body 322 is built, possible.

[0098] It is also visible in FIG. 15 that the front side 310.1 of the burner base element 310, which serves as a support surface for additive manufacturing, and a rear side 310.2, which serves as a support surface on a bed of the printer, are plane-parallel. The gas connection flange 330 is sealed against the rear side 310.2.

[0099] The furnace flange 350 is welded to the extension ring 352, which is made in one piece with the burner base element 310.

[0100] The recuperator 320 does not connect directly to the front side 310.1 of the burner base element 310 with its inner tube 326, but a metal bellows element 329 is inserted in between in order to avoid different thermal expansions between the burner base element 310 and the inner tube 326 on the one hand and between the burner base element 310 and the transition body 322 on the other.

[0101] FIG. 16 is a cross-sectional representation in a cross-section plane rotated by 45° as compared to FIG. 15, so that the position of the combustion gas ducts in the gas connection flange 330 becomes clear. The combustion gas ducts lead from the interior 327 of the inner tube 326 of the recuperator 320 into the gas connection flange 330, are deflected laterally by 90° therein and open out at the combustion gas connections 331, 332 on the side edges.

[0102] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

1. A recuperator burner base unit comprising:a burner base having a burner air port for supplying burner air, an exhaust gas port for suctioning exhaust gas and a combustion gas port;a recuperator connected to the burner base; anda heat transfer body that has at least two separate throughflow channels provided for guiding counterflowing fluids and has an inner cavity for forming or guiding through at least one combustion gas line,wherein the burner base is designed as a flat burner base element,wherein the burner base element comprises at least one gas guide-through opening for connecting the burner air port to one of the throughflow channels in the recuperator and / or at least one gas guide-through opening for connecting to the exhaust gas port and / or at least one opening for connection to the combustion gas port,wherein at a front side of the burner base element intended for connection to the recuperator, at least one flat support surface is provided, andwherein the recuperator is integrally connected to at least one support surface of the burner base element.

2. The recuperator burner base according to claim 1, wherein a seating plane is formed at the rear side of the burner base element or wherein a seating plane if formable via at least one adapter element that is adapted to be attached to the rear side, and wherein at least one flat support surface parallel to the seating plane is provided for a front side intended for connection to the recuperator.

3. The recuperator burner base according to claim 1, wherein there is a material-tight connection between the support surface and an inner tube of the recuperator forming the inner cavity along a closed inner line within which at least one recess for guiding through or connecting at least one combustion gas line, wherein a material-tight connection is formed between the support surface and the recuperator along a closed center line on the burner base element, and wherein at least one gas guide-through opening is located between the inner line and the center line and at least one gas guide-through opening is located outside the center line.

4. The recuperator burner base according to claim 3, wherein the gas guide-through opening between the inner line and the center line serves as an air guide-through opening and is connected to the burner air port in a gas-conducting manner and wherein the gas guide-through opening outside the center line serves as an exhaust gas guide-through opening and is connected to the exhaust gas port in a gas-conducting manner.

5. The recuperator burner base according to claim 3, wherein the gas guide-through opening between the inner line and the center line serves as an exhaust gas guide-through opening and is connected to the exhaust gas port, and wherein the gas guide-through opening outside the centerline serves as an air guide-through opening and is connected to the burner air port.

6. The recuperator burner base according to claim 3, wherein the inner line is circular, wherein the distance between the inner line and the center line in at least one section is smaller than the diameter of the gas guide-through opening located between the inner and center lines, wherein the distance between the inner line and a section of the center line at the gas guide-through opening is at least equal to the diameter of the gas guide-through opening, and wherein the center line in the section is arc-shaped around an edge area of the gas guide-through opening and joins the arc-shaped section with further tangential sections.

7. The recuperator burner base according to claim 3, wherein the center line at the gas guide-through opening located outside it runs in an arc and parallel to the circumferential line of the latter in one section and is guided in the direction of the inner line.

8. The recuperator burner base according to claim 7, wherein the center line is led in one section at the gas guide-through opening to the inner line and is connected to it.

9. The recuperator burner base according to claim 3, wherein within the inner line, in addition to at least one opening for the connection with the combustion gas port, an opening is provided for a bypass line and / or for an ignition electrode and / or for a sensor element.

10. The recuperator burner base according to claim 3, wherein within the inner line an insert element is arranged which can be removed from the burner base element, in which at least the opening for the connection with the combustion gas port is arranged.

11. The recuperator burner base according to claim 3, wherein the heat transfer body of the recuperator is encased in a materially bonded outer jacket, and wherein a peripheral line is provided outside the center line, at which the outer jacket connects to the burner base element in a materially bonded manner.

12. The recuperator burner base according to claim 3, wherein the heat transfer body of the recuperator merges into a tapered transition body which terminates on the center line.

13. The recuperator burner base according to claim 3, wherein the combustion gas ports are formed in a separate combustion gas flange which is connected to the rear side of the burner base element.

14. A recuperator burner comprising:the recuperator burner base unit according to claim 1; anda combustion chamber tube connected to the recuperator in which at least one burner nozzle is positioned at which at least one combustion gas line connected to the combustion gas port is connected in a fluid-conducting manner.

15. The recuperator burner according to claim 14, wherein a burner insert is arranged in the inner cavity of the recuperator, which comprises at least the burner nozzle and the combustion gas line, wherein the combustion gas line terminates at a flange plate which is adapted to sealed to the front side of the burner base element.

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