DE102023103912A1 - Method of making a coated tube and web component for use in an incinerator - Google Patents

Abstract

The invention relates to a method for producing a tube-web component (1, 1*, 1a) for use in an incineration plant, comprising at least the following steps: providing or producing at least one tube (2'), preferably a plurality of tubes ( 2'), and at least one web (3', 3*), preferably a plurality of webs (3', 3*), with preferably at least the web (3*), optionally at least a part of the webs (3 *), consists essentially of a metallic protective material (4), preferably nickel; Coating the tube (2') and optionally the web or at least part of the webs (3`) by means of at least one galvanically applied metallic protective material (4); Welding the coated pipe (2) and the coated web (3) and/or the web (3*) consisting essentially of protective material (4), preferably nickel, to form a pipe-web component (1, 1*), leaving a continuous outer protective material surface (O) on the tube-web component (1, 1*, 1a). A corresponding tube-fin component (1, 1*), in particular a tube-fin-tube wall (1, 1*) and a superheater (1a), is also described.

Description

The invention relates to a method for producing a tube and web component with a protective material surface for use in an incinerator.

Tube-web components are used in many places in incinerators, ie components which consist of at least one tube and at least one web welded thereto, preferably running in the longitudinal direction of the tube. A typical example of this are so-called tube-web-tube walls. A "tube-web-tube-wall" is understood to be a wall made of parallel (metal) hollow tubes or tubes, with a metal web (also referred to as a so-called "fin" or "membrane") between each two adjacent tubes. is welded in so that the wall is smoke gas-tight. Such tube web tube walls are z. B. cooling water flows inside for energy conversion and come, for example, in steam generators for (waste, hazardous waste or biomass) incineration plants or (industrial) power plants for the combustion or disposal of solid, liquid and / or gaseous, possibly polluted fuels in combustion chambers of their Incinerators are used to limit the combustion chamber and as walls for the flue gas flues. Due to the extreme conditions prevailing there (sometimes over 1000-1200° C) and the requirements of 24/7 continuous operation of the systems, they must be protected against corrosion as sustainably and long-term as possible in order to have a long service life as long as possible to form a tight wall. The smoother and more even the surface, the fewer particles stick to the pipe-web-pipe wall and the fewer weak points or points of attack for corrosion.

In practice, methods for coating such. B. nickel plating of such tube-web-tube walls is known. Conventionally, tube-web-tube-walls are welded together in ever larger sections and then covered with a thin metal coating as an anti-corrosion layer, e.g. B. nickel coated. As is generally known, this entails many problems for which there have previously only been very complex, conditionally satisfactory solutions. Typically, problems can arise when e.g. B. no sufficiently uniform layer thickness distribution of the coating was achieved. Non-uniform layer thicknesses ensure non-uniform thermal conductivities, which can have a negative effect on heat transfer efficiency. In addition, non-uniform layer thicknesses can also influence subsequent deformability of the tube-web-tube wall. In fact, a deflection of tube web tube walls, z. B. for the integration or inclusion of a maintenance door or for the integration of a burner in a wall surface of a combustion chamber, etc., associated with considerable effort.

It is the object of the present invention to specify a simpler, alternative method for producing coated tube-fin components and tube-fin components produced in a simpler manner in this way, in particular tube-fin-tube walls or superheaters with fins.

This object is achieved by a manufacturing method according to patent claim 1 and a tubular web component according to patent claim 8 .

• Zunächst wird in einem ersten Schritt zumindest ein separates, längliches Rund-Rohr bzw. Rohr sowie zumindest ein dazu separater Steg bereitgestellt oder hergestellt.

The method for producing a tube-web component mentioned at the outset comprises at least the following steps:

• In a first step, at least one separate, elongate round tube or pipe and at least one web separate therefrom are provided or manufactured.

These are usually (and preferably) straight, elongate tubes. Webs are flat, strip-shaped wide flat steel sections or cuts. If the webs are used to connect two components, ie z. B. connect two pipes, straight, web-like, they are here called connecting webs. Bars, especially connecting bars, are sometimes also referred to as "fins" by experts in this field because of their original method of manufacture.

A plurality of tubes and preferably a plurality of webs can preferably be provided or produced in a first step. For example, a tube and two webs can be provided or manufactured.

Tubes and webs can particularly preferably be used here, which, for example, each comprise metals and/or an alloy, particularly preferably steel.

In a second step, at least the tube, or at least a part of the tubes in the case of several tubes, and at least the web-or, in the case of at least two tubes, the webs z. B. as connecting webs - in a still separate state by means of at least one applied metallic protective material layer, d. H. a layer of protective material. This can e.g. B. parallel in time or completely independently of each other.

Preferably, the protective material can be nickel. However, the protective material layer is not limited to a single protective material. Rather, it could also include several components that together form a protective material such. B. alloys of nickel, chromium, molybdenum and / or cobalt.

Especially in the case of a tube-web-tube wall, all tubes and connecting webs or half-webs used for the tube-web-tube wall (half-webs serve as the lateral termination of a tube-web-tube wall in order to To connect web tube wall) in the still separate state with a protective material layer, particularly preferably nickel layer provided.

In fact, however, this is only relevant for the further process to the extent that the tubes and connecting webs or half webs used have a protective material surface. Therefore, at least one web or, in the case of several webs, a part of the webs can optionally also consist essentially of protective material, preferably nickel. Essentially made of protective material means that the relevant part of the webs consists of at least 95%, preferably at least 98%, particularly preferably at least 99%, very particularly preferably essentially 100% of protective material, in particular nickel.

In the case of such webs which are already essentially made of protective material, in particular nickel, a protective material coating is of course obsolete since their surface already consists of the protective material anyway. The possibility of protective material solid material, such. B. use of solid nickel material, especially for the webs, since they are not designed as a pressure part.

According to the invention, at least the coated pipe and the coated web and/or a web consisting essentially of protective material are converted into a pipe-web component while leaving a continuous, i. H. welded to the finished tube-web component with a consistently intact outer protective material surface. Continuously or consistently intact means that the tube-web component is surrounded along its surface or superficially by a continuous protective material layer, which has as few interruptions as possible.

Accordingly, a tube-web component according to the invention comprises at least one tube which is welded to at least one web.

The tube and optionally the web or at least a part of the webs (if there are several webs) are coated with at least one protective material, preferably nickel, which is applied galvanically. Optionally, the web can also essentially consist directly of nickel, so that it does not require a protective material coating.

According to the invention, the coated tube and the coated web and/or the web consisting essentially of nickel are formed into a tube-web component while leaving at least one continuous outer protective material surface on the tube-web component, and preferably also a continuous protective material surface between the Web and the tube, welded.

With the manufacturing method according to the invention, the complex process of nickel-plating a sometimes very complex, manufactured welded tube-web component made of at least one tube and one web, in particular a tube-web-tube wall (as explained in more detail below) can be made of several welded pipes and webs, with all the problems mentioned at the beginning, such as e.g. B. an uneven layer thickness, hardness, thermal conductivity, etc. due to narrow internal angles and a complex geometric contour, largely eliminated or avoided. Next is achieved with the method according to the invention that a rework that is usually necessary on a pipe-web component, e.g. B. at the edges etc. can be almost eliminated after coating. The method is thus simpler than the currently known methods, since z. B. when coating the individual tubes and webs, can be used without masks or covers, since the contours of the individual components to be coated are comparatively easy and unproblematic to coat due to their uniform geometry. The production method according to the invention can therefore increase a process speed and ultimately reduce costs. Despite the slight additional need for protective material, such. B. nickel, when coating the individual tubes and bars (since the layer between the tubes and bars must also be applied and the bars are usually nickel-plated on both sides because of the higher efficiency), the overall material expenditure can even be lower, since the layers are more uniform and therefore no unnecessarily thick layers are needed to compensate for irregularities, and the overall reject rate can also be reduced.

The construction according to the invention also means that logistical effort can be reduced, since the tube-web component, in particular the tube-web-tube wall, can be manufactured on an industrial scale with the aid of a membrane wall welding machine without length limitations imposed by the bath.

Further, particularly advantageous refinements and developments of the invention result from the dependent claims and the following description, whereby the independent claims of one claim category can also be developed analogously to the dependent claims and exemplary embodiments of another claim category and in particular also individual features of different exemplary embodiments or variants can be combined to form new exemplary embodiments or variants.

Various components or variants can be used as tube-web components.

According to a preferred variant, the tube-web component can comprise a tube-web-tube wall that has already been mentioned several times.

For this purpose, preferably at least two tubes with at least one web as a connecting web between them and particularly preferably two lateral half webs can be welded to form a finished tube-web-tube wall. i.e. it is usually attached to the two outer tubes of the tube-web-tube-wall in each case as a conclusion - and for simple welding, e.g. B. on site in an incinerator, namely, for example, with another such pipe-web-pipe-wall - welded a half web, d. H. in fact, the tube-bar-tube-wall ends with a bar at each of the lateral edges. To build a tube-web-tube wall, any number of tubes and webs can be welded together, depending on how wide the wall should ultimately be. For better handling, walls with a width of six to eight tubes and webs in between and two webs at the end are relatively common. That is why there are already production systems that weld six to eight tubes (and the webs) together in parallel to form such tube-web-tube walls.

In particular, for example, the coated pipes and coated webs can be used as connecting webs and/or the webs consisting essentially of protective material as connecting webs between them to form a pipe-web-pipe wall, leaving a continuous, i.e. H. be welded to the finished pipe-web-pipe-wall with a consistently intact outer protective material surface.

There are various options for the process of coating, preferably nickel-plating, of the method for producing a coated tube-fin component, in particular coated tube-fin-tube walls.

Among other things, as a protection against corrosion, the tubes and webs are protected by means of at least one galvanically applied layer of protective material, such as e.g. B. a nickel layer of pure nickel, especially pure nickel with 99.99% nickel content, coated or nickel-plated. For example, a few millimeters of nickel can be deposited on the tubes and webs. For a particularly safe anti-corrosion layer, the protective material layer z. B. include 3 mm to save material even possibly only 2 mm.

In order to save even more protective material, the protective material layer can preferably be at most 1.3 mm, particularly preferably at most 1.1 mm.

Alternatively or additionally, the protective material layer can preferably have at least 0.5 mm, particularly preferably at least 0.9 mm.

i.e. a protective material layer between 0.9 mm and 1.1 mm is very particularly preferred.

Due to the procedure according to the invention of coating the tubes and webs before they are welded together, the manufacturing method according to the invention advantageously does not require such a large galvanic bath, if the tubes and webs are galvanically nickel-plated, as is the case, for. B. for galvanic nickel plating of a 6 × 2 m large, ready-welded fin wall or tube-web-tube-wall made of one piece.

There are also other preferred options for the welding process.

In principle, it is possible to weld the tubes and webs conventionally, for example by means of metal active gas welding (MAG welding) or tungsten inert gas welding (TIG welding) or English. "Tungsten inert gas welding" (TIG) to weld together under protective gas. Alternatively, it is z. B. also possible, the tubes and webs conventionally by means of submerged arc welding (submerged arc welding) or engl. Submerged Arc Welding (SAW) under a layer of coarse-grained mineral welding powder.

When using such welding methods, which work with a relatively high heat input and thus generate stresses in the anti-corrosion layer or protective material layer, it can then be advantageous to restore the corrosion resistance of the welded components as completely as possible after welding make the components, e.g. B. by means of a nail strip, in order to release the stresses generated by the heat input and to subsequently strengthen the surface (in the area of the weld seams and in an area surrounding the weld seams).

However, the welding of the tubes and webs can preferably be carried out by means of a laser hybrid method. In laser hybrid welding, a laser beam first heats the surface of the component and creates a deep, narrow penetration. The arc then forms a wide weld pool for excellent gap bridging ability. At the same time, if necessary, a large penetration depth can be generated, as will be explained later using an exemplary embodiment. Compared to conventional welding processes, laser hybrid welding uses less energy. As a result, the tube-web component, in particular the tube-web-tube wall, is exposed to less stress or stress, which means that a risk of corrosion of the welded components can be reduced in use, since the protective material layer protecting against corrosion is more likely to remains completely intact during welding.

Preferably, the welding can be done in such a way that only within a z. B. the uppermost, preferably the applied, protective material layer is welded and thus everywhere on the tube-web component, in particular the tube-web-tube wall, a continuous protective material surface remains. By this is meant that the uncoated metal underneath is never exposed to the surface.

For example, if one has a coated tube and a coated web, a tube-web-tube wall can remain with a continuous protective material layer all over the surface of the tube-web-tube wall. This means that the uncoated metal is also not exposed to the surface at the points where it would be or will be covered again later after the end of the welding process with a further pipe or connecting piece welded thereto. This means that a layer of protective material also remains between the pipes and connections at the welding point.

Preferably, a penetration with a depth of preferably less than 2 mm, particularly preferably less than 1.5 mm, further preferably less than 1 mm, can be produced during the welding. In this case, the penetration into the applied protective material layer can extend less deeply than a layer thickness of the applied protective material layer.

Particularly preferably, the burn-in can extend at most up to approximately two-thirds, more preferably even at most only up to half into the protective material layer applied. This ensures that the protective material layer applied is not damaged as far as possible, i. H. a continuous protective material layer or protective material surface remains on the tube-web component.

As already mentioned above, at least one of the webs consisting essentially of protective material, preferably nickel, can be provided or produced from preferably at least 95%, particularly preferably at least 98%, more preferably at least 99% and very particularly preferably essentially 100% of protective material .

The tube-web component can preferably comprise a multi-part tube-web-tube wall in which (a plurality of or) several tubes and webs as connecting webs between the tubes and optionally two lateral or external half-webs as a termination of the two outermost ones or end-side pipes (which, at least at this point in time, are not connected to any further connecting webs for further pipes, since the pipe-web-pipe-wall is assembled or manufactured in the relevant, practical size so that it can still be logistically justified in road traffic Effort can be delivered to the place of use) are welded to form a finished tube-web-tube-wall. This means that a web is welded between two tubes.

Preferably, the tubes and optionally at least a part, preferably all, of the connecting webs are coated by means of at least one protective material, preferably nickel, applied by electroplating. Optionally, however, as mentioned, part of the connecting webs can also essentially consist directly of nickel, so that this part, as already mentioned above, does not require a protective material coating.

There are preferred dimensions for the multi-part tube-web-tube-wall.

The pipes (calculated without the applied protective material) can preferably have a thickness or wall thickness of at least 3 mm. The tubes can particularly preferably have a thickness of at least 3.25 mm.

Alternatively or additionally, the tubes can preferably have a thickness of at most 6.3 mm, particularly preferably at most 4 mm.

There are various options for selecting a suitable material for the tubes and webs. In principle, the webs could essentially be made of steel, i. H. the main mass fraction is iron with a carbon content of less than or equal to 2%.

Preferably, however, at least one of the webs can be made of at least 95% protective material, such as. B. Reinstnickel or nickel exist. Particularly preferably, at least one of the webs can be at least 98%, more preferably at least 99%. Very particularly preferably, at least one of the webs can be completely, d. H. essentially 100% protective material. In particular, all webs can consist of a corresponding proportion of protective material.

Before a specific embodiment is described below, it should be mentioned at this point that the preferred embodiments and preferred embodiments of the method according to the invention described above with reference to this preferred embodiment of a tube-web-tube wall do not apply to such a tube-web-tube Wall are limited, but - if this is not explicitly mentioned otherwise - can also be transferred to a tube-web component in the same or slightly adapted form.

According to a further preferred variant, the tube-web component can include a superheater with fins. The superheater can particularly preferably be a so-called bulkhead superheater, as is the case, for example, in a flue gas space, ie z. B. a boiler train, a boiler system (with natural circulation boiler or forced circulation boiler) is used. Depending on the design of the boiler system, the superheater can usually be arranged horizontally in a vertical water-tube boiler and vertically in a horizontal water-tube boiler, also known as a "tailend" boiler. Horizontal or vertical means that the predominant part or section of the tubes runs or is arranged horizontally or vertically in the flue gas space, in particular a part or section of the tubes in the relevant boiler pass where the heat transfer takes place. An exemplary embodiment of a "horizontally" arranged superheater will be described later using a drawing.

In order to produce such a superheater, it is particularly preferable for a plurality of webs to be welded as fins to at least one tube of the superheater. By welding the fins, for example in the form of sheet metal, to one or more tubes or tube sections of the superheater, a geometry or a cross section of the relevant tube or tubes is modified, which changes the flow or flow properties of the tube or of the pipes changed. As a result, when the superheater is used as intended, in which flue gas flows around the superheater, buildup and contamination on the tube or multiple tubes can be reduced, which in turn increases the efficiency of the superheater.

In the case of a superheater, there can preferably be a tube in the form of a tube arrangement with 180° deflections that lie in one plane of extent. A pipe arrangement with 180° deflections is understood to mean an arrangement of a pipe system (i.e. one or possibly also several pipes) in which the pipe or pipes are repeatedly deflected by 180° in the opposite direction after a pipe section that runs in one direction . In this case, the tube or tubes are connected by the 180° deflections to form a continuous tube (i.e. in a “row”). This pipe arrangement enables, for example, hot water and/or steam to be passed through a flue gas space of a boiler system multiple times in the same pipe, in which the steam is continuously superheated by repeatedly passing through the flue gas space. Alternatively, a passage in several parallel tubes is also conceivable. The extension plane is essentially a two-dimensional plane, i. H. a plane in which one spatial direction is significantly less pronounced in relation to the other two orthogonal spatial directions, resulting in a "flat" plane. The tube arrangement consequently extends in two orthogonal spatial directions (in length and width) over a relatively large area and in a third spatial direction (in depth) perpendicular or normal to the other two spatial directions only over the thickness or diameter of the tube.

Particularly preferably, the tube arrangement can have pairs of opposite, partially straight tube sections in the extension plane, at the respective end of which the tube is bent from a straight or rectilinear tube section in the form of a 180° deflection to the next straight tube section. In other words, it is a meandering tube arrangement with short 180 ° deflections and relatively long, straight tube sections in between, ie the tube arrangement consists mainly of straight, parallel tube sections that have relatively short 180° turns, such as B. 180 ° elbows are connected.

As already mentioned, a pipe arrangement with several parallel pipes can also be used as an alternative to a pipe with a pipe arrangement with 180° deflections.

One half of the fins can be welded to one of the straight pipe sections parallel to the extension plane, preferably next to one another, particularly preferably leaving a minimum distance between the fins. i.e. the fins are arranged with their flat side parallel to the plane of extension and point in the direction of the next, adjacent straight tube section.

The other half of the fins are correspondingly welded oppositely to the next (said adjacent) pipe section so that they are preferably aligned with the aforementioned fins. In other words, the fins can be welded to the front and rear tube crests at the level of the latter in such a way that, viewed in cross section, they are aligned (see the description of an embodiment example below).

This ensures that one fin of a straight tube section always points to a fin of another, opposite straight tube section and the fins together form a fin surface that is closed at least in sections, if necessary as far as possible, so that opposite tube sections are not connected or at least partially connected.

The fact that the fins together preferably form two almost closed fin surfaces running parallel to one another and to the extension plane between two straight pipe sections, namely one the pipe arrangement in depth at a front (windward) pipe apex forward and one the pipe arrangement in depth at one The rear (leeward) tube crest is limited to the rear by a fin surface that is almost closed by the tube sections and the fin surfaces, in which the adhesion or accumulation of dirt and bridging due to soot deposits in the form of so-called "cornices" on the tube sections can be reduced.

As an alternative to the above-described symmetrical attachment (the front, windward fin surface compared to the rear, leeward fin surface) of opposite fins to adjacent tube sections, the fins can also be welded to the tube sections asymmetrically, i. This means that the fins are welded to the individual pipe sections in a different number and arrangement. For example, the fins on one or more pipe sections can only be on the windward side (i.e. on the side of the pipes facing the smoke gas flow), on the leeward side (i.e. on the opposite side of the pipes facing away from the smoke gas flow), below, above or diagonally , i.e. H. with a pipe section z. B. only on the leeward side and the next, neighboring pipe section only on the windward side, welded. In any case, the surface area for heat transfer is increased by the surface of the additionally welded fins. Depending on the constellation or arrangement of the fins on the pipe sections, the flue gas flow and thus also the deposit of slag or ash particles on the pipes can be changed.

In general, the formation of Karman vortices (which in turn can be responsible for dirt adhesion or ripple formation) on the superheater is prevented by the changed geometry or by the cross-section of the pipe arrangement of the superheater. In total, the efficiency of the superheater can be increased by 20% compared to a conventional superheater without such fins or intermediate fins.

• 1 ein grob schematisches Ablaufdiagramm eines Ausführungsbeispiels eines erfindungsgemäßen Verfahrens zur Herstellung einer beschichteten, hier vernickelten, Rohr-Steg-Rohr-Wand,
• 2 eine vereinfachte Schnittdarstellung eines Querschnitts der einzelnen, unterschiedlichen Komponenten eines Ausführungsbeispiels der erfindungsgemäßen Rohr-Steg-Rohr-Wand, im bereits vernickelten Zustand,
• 3 eine schematische Schnittdarstellung eines Querschnitts der einzelnen Komponenten eines Ausführungsbeispiels der erfindungsgemäßen Rohr-Steg-Rohr-Wand beim Zusammenschweißen,
• 4 eine vereinfachte Schnittdarstellung eines Querschnitts durch ein Ausführungsbeispiel der erfindungsgemäßen Rohr-Steg-Rohr-Wand im fertiggestellten Zustand,
• 5 eine vereinfachte Schnittdarstellung eines Querschnitts analog zu 4 durch ein weiteres Ausführungsbeispiel der erfindungsgemäßen Rohr-Steg-Rohr-Wand im fertiggestellten Zustand,
• 6 eine perspektivische Ansicht einer ersten Variante eines weiteren Ausführungsbeispiels eines Rohr-Steg-Bauteils in Form eines Überhitzers, bei dem zwischen einem Teil der geraden Rohrabschnitte dieselben verbindende Flossen angeschweißt sind,
• 7 eine vergrößerte, perspektivische Ansicht einer zweiten Variante des Ausführungsbeispiels aus 6, diesmal mit Flossen, die aus mehreren einzelnen, voneinander beabstandeten Flossenteilen bestehen,
• 8 einen leicht perspektivisch dargestellten Querschnitt entlang der Schnittlinie aus 7 durch einen Ausschnitt eines weiteren Überhitzers, an dem sich über einen Testzeitraum Ablagerungen bzw. Verschmutzungen auf einer Flossenaußenseite der Flossen abgelagert haben.

The invention is explained in more detail below with reference to the attached figures using exemplary embodiments. The same components are provided with identical reference numbers in the various figures. The figures are generally not to scale. Show it:

• 1 a roughly schematic flowchart of an embodiment of a method according to the invention for the production of a coated, here nickel-plated, tube-web-tube wall,
• 2 a simplified sectional view of a cross section of the individual, different components of an embodiment of the tube-web-tube-wall according to the invention, in the already nickel-plated state,
• 3 a schematic sectional view of a cross section of the individual components of an exemplary embodiment of the pipe-web-pipe-wall according to the invention during welding together,
• 4 a simplified sectional view of a cross section through an embodiment of the pipe-web-pipe-wall according to the invention in the finished state,
• 5 a simplified sectional view of a cross section analogous to 4 by a further exemplary embodiment of the pipe-web-pipe-wall according to the invention in the finished state,
• 6 a perspective view of a first variant of a further exemplary embodiment of a tube-web component in the form of a superheater, in which fins connecting the same are welded between part of the straight tube sections,
• 7 an enlarged, perspective view of a second variant of the embodiment 6 , this time with fins consisting of several individual fin parts spaced apart from each other,
• 8th a slightly perspective cross-section along the cutting line 7 through a section of a further superheater, on which deposits or dirt have accumulated on the outside of the fins over a test period.

1 shows a sequence of the production method according to the invention. As shown therein roughly schematically in blocks, in a first step I, I' of the method according to the invention for producing a coated, here nickel-plated tube-fin-tube wall 1, 1*, tubes 2' in a step I and connecting fins 3' in a z. B. temporally parallel or completely independent step I ', provided or produced. Typically, such a tube-web-tube wall 1, 1* comprises six to eight tubes 2', corresponding to five to seven connecting webs 3' and usually two half-webs as the external end, which are then each connected to another half-web of a further tube-web Pipe-wall in the connected or welded state, e.g. B. form a whole connecting web, so that the weld seam of two tube-web-tube-walls is as preferred centrally between the respective outer tubes.

Said components are in a second step II, II 'z. B. nickel-plated again in parallel or completely independently, ie coated with a continuous nickel layer 4 or nickel coating 4 . The finished nickel-plated condition of such a nickel-plated (or nickel-coated) tube 2 and a nickel-plated connecting bridge 3 is in 2 shown.

The illustrated section of a tube-web-tube-wall 1 according to the invention shows here an example of two nickel-plated tubes 2 or hollow tubes with a connecting web 3 in between and the two cut-off ends of two further connecting webs or possibly half-webs.

The nickel-plated tubes 2 and connecting bars 3 are here in 2 shown roughly schematically in cross section (the cross section runs, as in all other figures, perpendicular to the longitudinal direction of the nickel-plated tubes 2 and connecting webs 3). The nickel-plated tubes 2 shown are hollow tubes which are hollow on the inside and have an average thickness 2d or wall thickness 2d of approximately 3.5 mm. On the surface they have a nickel coating 4, which is about 1 mm thick here.

The nickel-plated connecting web 3 is a strip-shaped wide flat steel section which is also coated with such a nickel layer 4 or nickel coating 4 . This is also about 1 mm thick.

Alternatively, however, a pure nickel web 3* could also be used as the connecting web 3*, which no longer requires any further coating, which means that the second method step can also be omitted, at least for a nickel web 3* or a connecting web 3* consisting essentially of nickel.

In a third step III, the tubes 2 and connecting webs 3 are finally welded or welded together to form a tube-web-tube wall 1.1*-if necessary using connecting webs 3* consisting essentially of nickel. The process of welding together is roughly shown in Fig 3 shown. A particularly preferred laser hybrid method for welding the coated tubes 2 and connecting webs 3 is used here.

At this point it should be pointed out once again that here in 4 only two coated tubes 2 and one such coated connecting web 3 are shown in full, since this is an exemplary section of a tube-web-tube-wall 1.

5 shows accordingly only an exemplary section of a tube-web-tube-wall 1* with a nickel web 3* instead of a nickel-plated connecting web 3.

In laser hybrid welding, a laser beam first heats a surface or weld point 5, 5' of the pipes 2 and connecting webs 3, at which the two components held flush in position on one another are to be welded or connected to one another (see 3 ).

As shown by the top weld 5 in 4 shown as an example for illustration, in a first variant in the third step III, the laser beam generates a deep, but very narrow one Penetration 5 with a depth 6, which extends through the entire web thickness 3d of the connecting web 3 in the area of the nickel coating 4. The arc that is generated during this welding process forms a wide molten pool 7 (see dashed area) with a width 8, which excellently bridges the "gap" between tube 2 and connecting web 3 and seamlessly connects the components to one another. The width 8 is nevertheless chosen to be thin enough so that the molten bath 7 is in any case limited only to the nickel layers 4 on the respective tube 2 and the connecting web 3 . The molten pool 7 is also somewhat wider on the entry side of the weld point 5 and becomes somewhat narrower again toward the end. As mentioned, however, it extends through the entire web thickness 3d, with which the tubes 2 and connecting webs 3 can be continuously welded very quickly and easily with little energy input and thus significantly less stress or material stress. As mentioned, the welding takes place only inside, ie in the previously applied nickel layer 4, as in FIG 4 can be seen, so that the workpiece 1 has a continuous outer nickel surface O.

Based on the bottom weld 5' in 4 shows the preferred variant of the third step III for welding the tubes 2 and connecting webs 3, in which a "half" penetration 5' is generated from two sides of the connecting web 3 with an arc, so that a molten pool 7′ extending approximately up to half or an even smaller part of the web thickness 3d of the connecting web 3 (see dashed areas). For this, the in 3 Schematically shown welding device for introducing the two welding points 5' once (as in 3 shown) from the top into the interface between connecting web 3 and tube 2 and then a second time from the bottom (in 3 not shown) in turn in the same interface for the introduction of the second weld 5 '.

Here, too, the welding takes place within or in the nickel layer 4, although a depth 6' of the molten bath 7' is significantly shallower and a width 8' is significantly wider. The molten baths 7' are introduced in such a way that, as a rule, the entire web thickness 3d in the region of the weld point 5' is melted and the semi-finished metal products 2, 3 are thus welded again over the entire contact length.

When welding, preferably by means of a laser hybrid process, a tube-web-tube-wall 1* with a connecting web 1* or nickel web 1* consisting essentially of nickel, the above variants of the third step III are equally applicable, whereby here however, advantageously, it is not necessary to ensure that the penetration 5, 5' and the molten pool 7, 7` on the web side are limited to the "nickel coating" (which is actually not present), since the entire connecting web 3* consists essentially of nickel and so that this danger is practically avoided.

Based on 6 until 8th is now a section of another embodiment of a tube-web component, namely a superheater 1a with a tube arrangement 2 in the form of a tube 2, which in a plane of extension E in several straight, parallel paths or tube sections 2g with 180° deflections or -pipe bends between the individual straight pipe sections 2g meandering.

In a first variant of this embodiment according to 6 webs 3 are welded on as fins 3 or intermediate fins, for example, between a part of these parallel, straight tube sections 2g. The fins 3 are respectively welded to the straight tube portions 2g of the continuous tube 2 so as to be connected to the front (in 6 facing the viewer) and rear (in 6 facing away) tube crests form a front fin surface and a rear fin surface in alignment with the tube crests of the straight tube sections 2g. In alignment here means that neither the tube apex protrudes relative to the fins 3 nor vice versa, but both are welded flush to one another and thus form a largely “straight” surface. In this variant, the fins 3 are elongated, one-piece webs 3 which extend continuously over the entire length of the straight pipe sections 2g from one pipe section 2g to the adjacent pipe section 2g. In the variant shown, for example, two adjacent tube sections 2g are always connected in pairs via a total of two fins 3 between them, with a gap being left between the individual pairs here, purely by way of example, in which no fins 3 are welded between them. However, fins can also be arranged between all tube sections 2g, so that z. B. the entire superheater 1a is covered with fins between all pipe sections.

In a second, enlarged variant of this embodiment according to 7 Instead of two elongate continuous fins 3 (along the entire length) between two such straight pipe sections 2g, a plurality of spaced apart, non-contiguous, fin parts or smaller fins 3 tile-like welded in the same orientation to adjacent pipe sections 2g. The individual smaller fins 3 together form a slightly permeable fin surface that is continuous except for slits between the individual fins 3, i.e. not entirely closed, and shields an interior space between the straight tube sections 2g in a “lattice-like” manner. In this variant, the fins 3 are welded, for example, to the tube sections 2g both at the top and at the bottom.

In the case of the variants described above, too, the components can particularly preferably be welded by means of a laser-hybrid method.

With the help of such fins 3 - as described in the two variants above - dirt deposits D, such as soot or the like in a tube gap of the tube sections 2g between the front and rear fin surfaces can be reduced as far as possible, as in 8th based on a cross-section along the section line AA 7 is shown. In 8th the results of a test arrangement are indicated as an example, which show that here (in particular in relation to the left here, flow-facing windward side of the superheater 1a) z. B. deposit no deposits on the pipe sections 2g in the shielded by the fins 3 pipe space between the pipe sections 2g. A consistently effective heat transfer takes place there. Furthermore, due to the additional fins 3, the cross-sectional shape of the pipe sections 2g reduces the formation of Karman vortices, as a result of which less pollution in the form of so-called bulges is deposited or accumulates on the pipe sections themselves. In total, the efficiency of superheaters can be increased by around 20% because, among other things, the surface area for absorbing the heat is increased by the additional fins.

Finally, it is pointed out once again that the tube-web-tube walls described above are merely exemplary embodiments of a possible tube-web component, which can be designed or modified in a wide variety of ways for different applications by a person skilled in the art without departing from the scope of the invention. For example, the tubes and connecting webs shown in the respective exemplary embodiments, in particular their number and shape, are only to be understood as examples, i. H. they could e.g. B. also shorter, smaller or larger in relation to each other, in larger numbers or differently shaped. In particular, the superheaters can also be suitably designed and oriented depending on the needs in the current boiler. As an alternative or in addition to this, the connecting webs can, for example, be made entirely of pure nickel or, if another protective material is used, also be made of this protective material and no longer require a coating. Alternatively, other tube-web components with tubes and webs, such. B. doors etc. are coated and welded with the method according to the invention. Furthermore, the use of the indefinite article "a" or "an" does not rule out the possibility that the characteristics in question can also be present more than once.

Reference List

1, 1*

tube web tube wall

1a

Superheater / bulkhead superheater

2

nickel-plated tube

2'

Pipe

2d

Thickness / wall thickness of a tube

2g

pipe sections, straight

3

nickel-plated connecting bridge / nickel bridge

3'

connecting bar

3*

Connecting bar, mainly made of nickel

3d

Thickness / web thickness of a connecting web

4

Protective material (layer) / nickel coating / nickel layer

5, 5'

Penetration / weld

6, 6'

depth of penetration

7, 7`

melt pool

8, 8'

Width of the weld pool

D

deposits

E

extension plane

O

Protective material surface / nickel surface

I, I', II, II', III

process steps

Claims (15)

Method for producing a tube-web component (1, 1*, 1a) for use in an incinerator, comprising at least the following steps: - Providing or producing at least one tube (2'), preferably a plurality of tubes (2'), and at least one web (3', 3*), preferably a plurality of webs (3', 3*), with preferably at least the web (3*), optionally at least part of the webs (3* in the case of several webs), essentially consists of a metallic protective material (4), preferably nickel, - Coating of the tube (2') and optionally the web or at least part of the webs (3') by means of at least one galvanically applied metallic protective material (4), - Welding the coated pipe (2) and the coated web (3) and/or the web (3*) consisting essentially of protective material (4), preferably nickel, to form a pipe-web component (1, 1*) , leaving a continuous outer protective material surface (O) on the tube-web component (1, 1*, 1a). procedure after claim 1 , wherein the tube-web component (1, 1*) comprises a tube-web-tube wall (1, 1*). procedure after claim 1 or 2 , wherein in each case at least two tubes (2) with at least one web (3, 3*) as a connecting web (3, 3*) in between and preferably two lateral half webs, forming a tube-web-tube wall (1, 1 *) are welded. Method according to one of the preceding claims, in which the tube-fin component (1, 1*, 1a) comprises a superheater (1a), preferably a bulkhead superheater (1a), a plurality of fins ( 3, 3*) is welded as fins (3, 3*) to at least one tube (2) of the superheater (1a). procedure after claim 4 , wherein the tube (2) is in the form of a tube arrangement with 180° deflections, which lie in a plane of extent (E), preferably with one another, in the plane of extent (E) in pairs opposite, partially straight tube sections (2g), wherein preferably one half of the fins (3, 3*) is welded next to one another, leaving a minimum distance from one another, to one of the straight tube sections (2g) parallel to the plane of extension (E), and the other half of the fins (3, 3*) are correspondingly opposite the next pipe section (2g) is welded on. Method according to one of the preceding claims, wherein the welding is carried out by means of a laser hybrid method. Method according to one of the preceding claims, in which the welding takes place in such a way that welding takes place only within a metallic protective material layer (4), preferably a nickel layer (4). Method according to one of the preceding claims, wherein when a coated pipe (2) and a coated web (3) are welded, a continuous metallic protective material layer (4) remains between the coated pipe (2) and the coated web (3). Method according to one of the preceding claims, wherein a penetration (5) with a depth (6), preferably less than 2 mm, particularly preferably less than 1.5 mm, more preferably less than 1 mm, is produced during the welding, the penetration (5) is less deep than a layer thickness of the protective material layer (4) applied, preferably extending at most up to approximately two thirds, particularly preferably at most approximately half into the applied protective material layer (4). Method according to one of the preceding claims, wherein at least one of the webs (3*), consisting essentially of protective material (4), preferably nickel, accounts for at least 95%, preferably at least 98%, particularly preferably at least 99%, very particularly preferably essentially 100 % consisting of the protective material (4). Tube-web component (1, 1*, 1a), preferably for use in an incineration plant, comprising at least one tube (2'), preferably a plurality of tubes (2'), which is connected to at least one web (3', 3rd *), preferably welded to a plurality of webs (3', 3*), preferably at least the web (3*), optionally with several webs (3', 3*) at least a part of the webs (3*) consists essentially of a metallic protective material (4), wherein the tube (2') and optionally the web (3') or at least part of the webs (3') are coated by means of at least one protective material (4) applied electrolytically, and wherein the coated tube (2) and the coated Web (3) and/or the web (3*) consisting essentially of protective material (4), preferably nickel, to a tube-web component (1, 1*), leaving a continuous outer protective material surface (O) on the tube - Web component (1, 1*, 1a) are welded. Pipe-web component according to claim 11 , wherein the tube (2) or the tubes (2) have at least a thickness (2d) of 3 mm, preferably at least 3.25 mm and/or at most a thickness (2d) of 6.3 mm, preferably at most 4 mm . Pipe-web component according to claim 11 or 12 , wherein at least the web (3*), preferably at least one of the webs (3*), consists of at least 95%, preferably at least 98%, particularly preferably at least 99%, very particularly preferably substantially 100% of protective material (4), preferably nickel. Tube-web component according to any of the preceding Claims 11 until 13 , wherein the tube-web component (1, 1*) comprises a tube-web-tube wall (1, 1*), in which several tubes (2) and webs (3) form a tube-web-tube Wall (1, 1 *) are welded. Tube-web component according to any of the preceding Claims 11 until 14 , wherein the tube-fin component (1, 1*, 1a) comprises a tube-fin-tube wall (1, 1*) and/or a superheater (1a), wherein the superheater (1a) has fins (3, 3*) as webs (3, 3*).

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