DE102004056619A1 - Method for producing a heat exchange partition between a heating space and a heat exchange medium useful for refuse incineration heating chambers - Google Patents

Abstract

Method for producing a heat exchange partition (1) between a heating space and a heat exchange medium, especially for installation in refuse incineration heating chambers. The partition consists of a base steel supporting element (2), with a special corrosion resistant steel armor plating on its surface facing the heating space. The armor plating is in strip form, and is applied continuously to element (2) with welding during application to it via its contact surface (4). An independent claim is included for a heat exchanger separation wall, constructed with the aid of laser welding.

Description

The The invention relates to a method for producing a heat exchanger partition wall between a boiler room and a heat exchanger medium, in particular for the Installation in the heating chambers of waste incineration plants, consisting of a carrier element from mass steel, which at its the boiler room facing surface with an armor made of corrosion-resistant stainless steel is provided. The invention further relates to a manufactured by this method Heat-exchanger partition wall.

such Armouring is carried out for example in particularly stressed areas of waste containers the heat exchanger partitions before through the burning of garbage To protect emerging, aggressive hot gases and thus the service life to increase the heat exchanger partitions. The Armor is usually as hardfacing carried out, where the build-up welding by superficial Melting of the support element metallurgically connects with this and thus for a correspondingly good heat conduction between armor and carrier element provides. For this example, a heat exchanger tube with a schraubenlinig applied weld whose turns overlap, one as possible complete To obtain a layer of armor. The procedure is already only because of the relatively expensive welding wire quite expensive. Furthermore, the support member is due to the necessary high heat input by the build-up welding thermally heavily loaded. It has also been shown that the overlapping areas can form a weak point in corrosion protection. In addition, the surface of the Application layer relatively uneven and can therefore be damaged more easily erosive or abrasive and corrosive.

task The invention is therefore a more cost effective method of manufacture a heat exchanger dividing wall to provide with an armor. Furthermore, should by the inventive method the carrier element Less thermally loaded and improved the layer properties of the armor become.

According to the invention Task solved by that as an armor a band-shaped Material is used that the strip material continuously stripes on the carrier element is applied and that the strip material during the application process with its contact surface on the carrier element welded becomes.

The contact surface Here is one of the broader side surfaces of the strip material. For this can be commercial Band material can be used as a prefabricated semi-finished product same material quality is much cheaper than a corresponding welding wire. Furthermore, as a result, the necessary heat input is considerably reduced since only the three following areas, namely the contact surface, the to be coated surface the carrier element locally and possibly a welding filler, be melted and not, as in surfacing, the Armor in its entire layer thickness and the to be coated surface the carrier element must be melted. As a result, compared to the build-up welding, the necessary heat input per armor surface is significantly reduced, the bands with correspondingly increased Feed rate can be applied to the Trägerele element can, for a comparable heat input to reach per unit of time. Furthermore, the band material used as semi-finished a smooth surface have, since only its contact surface when applied to the support element is melted, as received to the firebox facing protective layer surface remains so that the smooth surface as an armor surface substantially is preserved, the opposite a rougher layer by build-up welding less prone to corrosive and abrasive or erosive wear and thus have longer life can. Since the heating chamber facing side of the strip material unmelted stays, keeps the band material in this side area its previously set advantageous material properties, such as uniform distribution of corrosion-inhibiting alloying elements, substantially at. There by the welding process in usually a deterioration of the corrosion behavior of the materials can occur cost-effectively a little less high quality Material as a strip material than in the manufacture of an armor by Cladding used to provide the same corrosion protection receive.

The strip material can for example be applied to a tubular, rotating about its longitudinal axis support member and connected by, for example, via a deflection and / or pressure roller schraubenlinig and tangent to the tube and radially pressed against the tube, while leading, that is before Impact of the contact surface of the strip material, a bead is applied to the surface of the carrier element, which runs exactly in the connection region of the belt with the carrier element surface. The following contact surface is then pressed into the still liquid weld bead. Because of a bes Due to their ability to guide the strip material, the strip material is preferably guided under longitudinal tensile stress against the tube. Instead of a welding bead and two preferably laterally interconnecting weld beads can be applied in advance on the support member, one of which is preferably applied leading to the other and then overlapping. In the still liquid weld beads then a correspondingly broader strip material can be pressed for welding to the carrier element, whereby the process can be carried out correspondingly faster and a more closed armor can be achieved as a protective layer.

In a method modified for this purpose, the required heat for weld together the contact surface with the surface the carrier element be introduced directly into the gusset, extending through the contact surface of the tangentially guided against the pipe Strip material and the tube surface results. For this purpose, a filler metal can be used or a direct welding of carrier element with strip material without welding consumable material respectively. To the required heat preferably targeted to bring in the gusset, especially when welding without welding filler a welding process with a finely focusable energy beam, e.g. Laser or Electron beam, preferred.

to Cost reduction can be the armoring of the heat exchanger partition in one Another variant of the method only at the points of the heat exchanger partition take place, which flows directly from the hot gases and thus most heavily loaded become. For this purpose, for example, a pipe at the heating gas flow facing outside with parallel to the tube longitudinal axis extending strip of the strip material are provided.

In a development of the method, the strip material such on the carrier element is applied that between the individual strips of the strip material a free space remains, and that the clearance is made with a weld corrosion Stainless steel is bridged. Thus, a complete welding of the strip material to the support material without interruptions, and it is a continuous pan of the carrier material by applying the strip material by means of the welding sources ensured. As a result, a complete, uniform corrosion protection is achieved. Furthermore, this is a complete, lateral or a parallel to the surface Successful heat conduction between adjacent strip sections, allowing local heat concentrations on the surface the armor by, for example, an inhomogeneous heating gas flow easier are degradable.

In In another variant of the method, the seam bridging the free space can be so is introduced deeply that it penetrates into the surface of the support element. hereby a firm connection between the weld and the carrier element is achieved. Furthermore, the heat conduction through the metallurgical connection of weld and carrier element optimized.

The Weld can be built so high in a process variant on its outside be that flush with the surface completes the applied tape material. Thus, a flat surface is achieved the a relatively even heat absorption per unit area the armor possible power. Furthermore, this is the wear protection against a erosive and / or abrasive removal by the hot gases and in it possibly existing aerosols improved.

Prefers can the weld be built in two or more stages. Through this successive Construction becomes smaller compared to a single-stage construction heat input achieved per level. This is especially for larger layer thicknesses of the armor advantageous.

The Strips of the strip material can flush be applied side by side on the support surface. Here you can the flush adjacent band edges by laser welding with or without filler metal welded become. By laser welding is due to the focusable laser beam LESS energy per weld seam to the Melting the band edges needed. The same applies to a usable here electron beam welding.

It can other welding methods be used, which focuses the necessary heat accordingly fine can contribute. Thus, the necessary heat is introduced for lateral welding the strip material further reduced. Furthermore, the proportion of prefabricated strip material per unit area of the produced armor economical elevated. Will when applying the strip material with its contact surface the carrier element as well as during welding the flush to each other bordering band edges no filler metal used, the armor consists entirely of inexpensive Strip material.

In a further development of the method for producing a tubular partition, which is provided with an armoring around its entire circumference, the band material can be wound helically onto the support tube and welded onto the support element during the winding process. For this purpose, the support tube can be rotated about its longitudinal axis, while the Band material tangential to the pipe for welding can be performed. In this case, the strip material can be kept under longitudinal tensile stress in order to achieve a secure guidance and a pressing of the strip material on the surface of the support tube.

In another variant of the method may be parallel to each other Strip on the support tube or to others to protect Elements of the heat exchanger be applied. To the heat input at a location of the heat exchanger partition expand laterally and thus heat peaks to avoid adjacent stripes in a mutually time-staggered course with the surface welded become.

The parallel to each other stripes can, for example, in a flat Element of the heat exchanger parallel to each other in a suitable direction, such as a longitudinal direction a heat exchanger element or in a tubular Heat exchanger element helically over the Tube surface same a double-course or multiple threads guided become. As a result, the carrier element be provided with an armor faster.

The The object of the invention is further achieved in that a heat exchanger partition, in particular for the Installation in heating chambers of waste incineration plants, consisting of a carrier element from mass steel, which at its the boiler room facing surface with an armor made of corrosion-resistant stainless steel, is provided, which is characterized in that the Armoring from a band-shaped Material is that the band-shaped Material is continuously applied in strips on the support element and that the bearing surface the strip material on the carrier element welded is.

By the welding becomes an optimal heat transfer from the strip material to the carrier element achieved. Furthermore, the adhesion is due to the metallurgical bond the strip material with the carrier element usually so big that the strip material only under destruction of the surface of the support element from the carrier element be solved can.

The Strip material may preferably have a width of about 10 mm. This will be a common Width of a strip material specified as a low-cost semi-finished product. Of course other dimensions are possible provided that the strips easily with the support heat-conducting connect.

The Thickness of the strip material may preferably be about 2 mm. Herewith a thickness is specified with which one is usually sufficient Thickness of the armor can be achieved. Of course, there are others here as well Dimensions possible, provided a smaller or larger thickness the armor desired is.

The Heat exchanger partition can between the strips of the welded on the support member strip material have a continuous clearance. Here is the free space through a weld with a rustproof Stainless steel can be bridged as welding filler material. Conveniently, consists of the filler metal from a slightly higher quality, that means higher alloyed Material than that of the strip material to a possible reduction in quality through the welding process to catch and thereby uniform corrosion properties to achieve the armor. But the filler metal can also be the same material as the band material. Latter, Cost-reducing material choice is possible in particular if the amount of welding consumable per unit length the weld relatively low is, that is, if the space to be bridged relatively narrow is.

The the free space bridging weld can preferably be designed as a V-seam whose lower tip is into the material of the carrier element extends. As a result, weld and carrier element connect metallurgical with each other, so that at the given material pairing of filler metal and / or Aufpanzerungswerkstoff optimal adhesion and heat conduction can be achieved. As is also provided, the contact surface of the Strip with the carrier element too weld, the armor forms a closed surface layer by melting the surface the carrier element Metallurgical and thus optimally adhesive and heat-conducting with the support element connected is.

It can be provided that the strips of the strip material flush with each other abut and by laser welding with or without filler material connected to each other. As a result, no welding filler material or only a small amount of welding filler material needed and thus also the necessary heat input further minimized. Instead of a laser welding is also an electron beam welding or another welding process conceivable that the necessary heat can be bundled over Introduce energy beams or the like.

In a heat exchanger partition wall in the form of a heat exchanger tube may be provided be that the strip material is wound helically on the support tube and that the facing edges of the strip material are connected to each other via a weld.

Further It is conceivable that in order to achieve a particularly thick armor, For example, a correspondingly thick strip material with a multi-stage Structure of the weld to fill up the open spaces between the strips is used. Or it can make multiple layers welded together Band material are constructed, with the directions of the strips unchanged from layer to layer can stay. It can but also change the directions of the stripes from layer to layer, being at a planar support element should preferably be perpendicular to each other.

to appraisal the possible Cost reduction through the use of the method according to the invention the following invoice can be carried out: For one waste boiler For example, today about 20,000 m of pipe are manufactured. It will in the prior art armor approx. a lot of 50,000 kg welding wire processed. At a price of z.Z. about 60.00 EUR / kg results alone for the material of the armor is worth 3,000,000 EUR. thanks to the inventive method is for the same use consumes only about 10,000 kg of welding wire. The cost of the Total material usage will then decrease from 3,000,000 EUR to 1.200.000 EUR.

The according to the invention for producing a heat exchanger partition wall with an armor as well as a manufactured by the process Heat exchanger partition be due to two embodiments with an associated drawing explained in more detail. In show the drawing:

1 a schematic sectional view of a process structure for armoring a heat exchanger partition wall with a band-shaped material,

2 in a schematic longitudinal sectional view of a process structure for armoring a heat exchanger tube with two-layer welds,

3 a schematic section through a heat exchanger partition wall with armor according to the section III 2 and

4 a plan view of a heat exchanger partition wall of a flat plate with parallel strips of the band-shaped material

In 1 is a schematic representation of the process structure for armoring a heat exchanger partition 1 between a heating chamber and a heat exchanger medium, in particular for installation in the heating chambers of waste incineration plants, as shown in a sectional view, wherein the heat exchanger partition 1 from a carrier element 2 from mass steel and a band-shaped material 3 consists. This is the strip material 3 continuous stripwise or helical or helical on the support element 2 applied and during the application process with its contact surface 4 on the carrier element 3 welded. This is the strip material 3 via a deflection or pressure roller 5 approximately tangential to the coating surface of the carrier element 2 brought, wherein the strip material 3 is acted upon by a longitudinal tensile force K, to better lead it. The band material 3 becomes in the feed direction a to the support element 2 guided, with the pulley 5 rotated accordingly in the direction of rotation b. For welding the strip material 3 with the carrier element 2 is a source of sweat 6 provided that the strip material 3 with respect to the coating surface of the carrier element 2 leading, that is before application of the contact surface 4 of the band material 3 on the carrier element 2 a welding bead 7 on the surface of the carrier element 2 which applies exactly in the connection area of the strip material 3 with the surface of the carrier element to be coated 2 runs and the surface of the support element 2 locally melted. Through the deflection or pressure roller 5 then becomes the strip material 3 with its contact surface 4 into the still liquid welding bead 7 pressed, causing the contact surface 4 is melted and with the liquid weld bead 7 and the fused surface of the support element 2 a welding layer 8th forms the band material 3 with the carrier element 2 combines. As a result, a metallurgical connection between the carrier element 2 and the band material 3 achieved, which is characterized by high adhesion and thermal conductivity.

Like here in 1 not shown, it is also possible that the welding source melts without additional welding material, the contact surface of the strip material and the surface to be coated of the support member prior to pressing the strip material on the support member, so with the pressing of the strip material on the support member both to form a bonding layer Weld parts of the strip material and the carrier together.

Based on 2 a further method step is explained, which follows the above-mentioned method step. In 2 is a section of a heat exchanger tube 9 in longitudinal section shown, the heat exchanger tube 9 according to the method step already described already with the strip material 3 which are helically or helically guided around the shell of the heat exchanger tube that between the strips 10 of the band material 3 a corresponding schraubenlinig trained space 11 remains. (Here is the free space 11 the easier readability of the drawing half in relation to the strip 10 shown as optimal in terms of the method.) The free space 11 is in the process variant shown here in two stages by two other welding sources 6 filled with filler metal, with the side surfaces of the strips 10 as well as the reason of the free space 11 melted and by the resulting double-layered weld 12 be connected to each other.

As in the right section of the heat exchanger tube 9 in 2 is located at the bottom of the open space 11 after application of the strip material 3 according to the basis of 1 described process step remains of the weld bead 7 which, however, may turn out to be different in their scope and distribution. The remainders of the welding bead can therefore come from that the welding bead 7 wider than the width of the strip material 3 is designed and / or that parts of the weld bead 7 with the pushing in of the band material 3 into the weld bead 7 side of the strip material 3 be squeezed out and thus in the open space 11 reach. The covering of the open space reason 11 with parts of the welding bead 7 gives advantageous that the surface of the support element 2 , which, as described above, consists of a less noble, non-corrosion-resistant material is already protected after the first step against the ambient air and thus a cleaner filling of the spaces 11 allowed. However, it is possible in another variant of the method that the material of the weld bead when pressing the strip material for welding the strip material to the support element only slightly, the free space base is only partially covered or not pushed into the space. Additionally is in 2 the feed direction c of the heat exchanger tube 9 drawn, indicating that the successive replenishment of the free space 11 to a weld 12 here from right to left.

In 3 is in a greatly simplified form a section III of the heat exchanger partition 1 of the heat exchanger tube 9 in 2 shown, wherein the cut portions of the weld 12 and the welding layer 8th marked with dots. Here is the free space 11 already completely with the double-layered weld 12 filled. It becomes clear that the free space 11 bridging weld 12 with its temporally first and thus locally lower layer is inserted so deeply that it enters the surface of the support element 2 penetrates. As a result, the through the band material 3 and the weld 12 resulting armor 13 the carrier element 2 even stronger with the carrier element 2 anchored and thus has a further increased thermal conductivity. The weld 12 is built on its outside so high that it is flush with the surface of the applied strip material 3 concludes. This results in a flat overall surface of the armor 13 achieved, whereby a corrosive and erosive abrasive attack is made difficult by the hot gases and the like.

To illustrate further possible arrangements of the strip material 3 is in 4 a view of one as a plate 14 formed heat exchanger partition 1 shown, with the stripes 10 of the band material 3 are guided parallel to a side edge of the plate. The Stripes 10 are here according to the invention by the lateral welds 12 with each other as well as through the bottom-side welding layer not visible here 8th with the here also hidden support element 2 connected. Of course, other geometrical arrangements of strips fall within the scope of the invention, the possible special geometries of the support element invoice gene, provided that these arrangements can be achieved by the method described here for armoring a heat exchanger partition wall.

1

Heat exchanger partition

2

support element

3

band material

4

contact surface

5

Deflection and pressure roller

6

welding source

7

bead

8th

welding layer

9

Heat exchanger tube

10

strip

11

free space

12

Weld

13

armouring

14

plate

a

feed direction

b

direction of rotation

c

feed direction

K

traction

Claims (15)

Method for producing a heat exchanger partition wall ( 1 ) between a heating chamber and a heat exchanger medium, in particular for installation in the heating chambers of waste incineration plants, consisting of a carrier element ( 2 ) of mass steel, which at its the heating space-facing surface with an armor ( 13 ) made of corrosion-resistant stainless steel, characterized in that as an armor ( 13 ) a strip-shaped material is used, that the strip material ( 3 ) continuously stripwise on the support element ( 2 ) is applied and that the strip material ( 3 ) during the application process with its contact surface ( 4 ) on the carrier element ( 2 ) is welded. Method according to claim 1, characterized in that the strip material ( 3 ) in such a way on the carrier element ( 2 ) is applied, that between the individual strips ( 10 ) of the strip material ( 3 ) a free space ( 11 ) and that the free space ( 11 ) with a weld ( 12 ) is bridged from corrosion-resistant stainless steel. A method according to claim 2, characterized in that the free space ( 11 ) bridging weld ( 12 ) is inserted so deeply that it penetrates into the surface of the carrier element ( 2 ) penetrates. A method according to claim 2 or 3, characterized in that the weld ( 12 ) is constructed so high on its outside that it is flush with the surface of the applied strip material ( 3 ) completes. A method according to claim 4, characterized in that the weld ( 12 ) is built up in two or more stages. Method according to claim 2, characterized in that the strips ( 10 ) of the strip material ( 3 ) flush with each other on the support element ( 2 ) are applied and that the flush adjoining strip edges are welded by laser welding without or with welding filler material. Method according to one of claims 1 to 6 for the production of a tubular partition wall which is provided with an armor around its entire circumference ( 13 ), characterized in that the strip material ( 3 ) is wound on the carrier tube in a screw-thread manner and that the strip material ( 3 ) is welded onto the support tube during the winding process. Heat exchanger partition wall, in particular for installation in heating chambers of waste incineration plants, consisting of a carrier element ( 2 ) of mass steel, which at its the boiler room facing surface with an armor ( 13 ) made of corrosion-resistant stainless steel, characterized in that the armor ( 13 ) of a band-shaped material ( 3 ) that the band-shaped material ( 3 ) continuously stripwise on the support element ( 2 ) is applied and that the contact surface ( 4 ) of the strip material ( 3 ) on the carrier element ( 2 ) is welded. Heat exchanger partition according to claim 8, characterized in that the strip material ( 3 ) has a width of about 10 mm. Heat exchanger partition according to claim 8 or 9, characterized in that the thickness of the strip material ( 3 ) is about 2 mm. Heat exchanger partition according to one of claims 8 to 10, characterized in that between the strips ( 10 ) of the on the support element ( 2 ) welded strip material ( 3 ) a continuous clearance ( 11 ) and that the free space ( 11 ) by a weld ( 12 ) is bridged with a stainless steel as welding filler material. Heat exchanger partition wall according to claim 11, characterized in that the welding filler material of the same material as that of the strip material ( 3 ). Heat exchanger partition according to claim 11 or 12, characterized in that the free space ( 11 ) bridging weld ( 12 ) is formed as a V-seam whose lower tip extends into the material of the carrier element ( 2 ). Heat exchanger partition according to one of claims 8 to 13, characterized in that the strips ( 10 ) of the strip material ( 3 ) lie flush against each other and are connected to each other by laser welding with or without filler material. Heat exchanger partition according to one of claims 8 to 14 in the form of a heat exchanger tube 9 , characterized in that the strip material ( 3 ) is wound helically on the support tube and that the mutually facing edges of the strip material ( 3 ) via a weld ( 12 ) are interconnected.