EP2381174B1 - Coating element for constituent device parts of incinerators - Google Patents

Description

The invention relates to a cladding element for device parts of incinerators according to claim 1.

The invention relates in particular to a cladding element for device parts of incinerators which consists of a lower plate made of steel and a top plate made of steel, which are superimposed and which are tightly interconnected at least in edge regions and wherein between the lower plate and the top plate a meandering channel for guiding a cooling medium the cladding element is formed.

Apparatus parts of incinerators, especially incinerators for refuse, are usually exposed to very high loads. These are thermal, chemical and mechanical loads, often of course also combinations thereof. Since waste incinerators usually also push grates are used on which the combustion material is mechanically conveyed into the combustion chamber, here are particularly strong abrasive loads too expect, which are further enhanced by the softening of the metal parts due to the high temperatures. For this reason, in such pushrods the most vulnerable moving parts, namely the grate plates of the individual grate stages, usually designed as medium-cooled hollow body. As a coolant, water is usually used. Cooling achieves a reduction in mechanical wear as a result of abrasion and ultimately, of course, reduced maintenance, since the metal parts exposed to wear have to be replaced less often.

The EP-0 621 449 shows a method for burning garbage on a combustion grate and a usable combustion grate. The individual grate plates of the combustion grate have the external shape of a board, which is made of sheet metal and forms a hollow body with a top and a bottom. This hollow body is made of either two half-shells or a hollow profile. On the one side of the bottom there is a connecting piece and on the other side of the bottom it has a discharge pipe for the supply and removal of a cooling medium, which flows through the hollow body. The grate plate also extends in its longitudinal direction over the entire width of the combustion grate. Inside the grate plate baffles may be welded in a way that a labyrinthine meandering channel for the cooling medium results.

To the heat resistance of the grate plates of the combustion grate according to the EP-0 621 449 To ensure this, for example, made of a manganese-alloyed sheet of such a thickness that it is just still be folded, that is, of a thickness of the order of about 10 mm. In addition, it is also stated that the sheet should have a sufficiently good thermal conductivity, so that no large temperature differences can occur within the grate and so stresses in the material can be avoided.

It has been found that today's water cooled grate plates according to the EP-0 621 449 have a number of disadvantages. Initially, these are heavy and complex components, the manufacture, installation and replacement of which are associated with great expense. Alone the high weight of individual grate plates requires elaborate preparations for the repair work.

Furthermore, it is known that manganese sheets and manganese steels, because of their high manganese content, achieve exceptionally high degrees of hardness and thus also very high wear resistance, but that these materials also have a high susceptibility to change in the Have material properties (embrittlement) during reheating. Reheating beyond certain limits will occur in the case of welding (ie, for example, in the manufacture or repair of such objects) or, in the case of use in incinerators, overheating during operation. Since in the case of occurring leaks due to excessive wear often instead of the costly replacement of entire components initially only the broken section cut out of the sheet and a new section is welded, just by this welding process again the danger that the original wear resistance is no longer achieved and the repair site subsequently causes subsequent and further repairs.

Of course, as these inherent disadvantages have been recognized, solutions have been sought to facilitate replacement of wear parts. An example of an alternative solution is in the WO / 2007/107024 shown. This document discloses a liquid-cooled grate with wear plates. The grate consists of a liquid-cooled grate plate and a wear plate which can be placed thereon. Between the grate plate and the wear plate is advantageously a layer of a heat-conducting material in the form of a highly heat-conductive soft silicone film clamped. The silicone film serves to ensure good heat transfer between the wear plates and to create the flow-through grate plates. This is to ensure that during operation, the wear plates always remain in a non-critical temperature range by being cooled by the underlying cooled, about 50 ° C hot grate plates. For the wear plate it is stated that any material is suitable which is sufficiently hard and mechanically resistant and which can be kept cool by means of the underlying plate at a temperature which does not endanger its hardness. For example, a Hardox steel is given as suitable. Hardox wear plates are steel alloys that also contain manganese and in which the strength properties of the delivery state after heating above a certain temperature limit, for example about 250 ° C, are not accessible again. The intended thickness of such wear plates is about 5 to 10 mm.

Thus, the solution according to the WO / 2007/107024 still similar disadvantages as that of the EP-0 621 449 on. Although the replacement of wear plates is facilitated because no very large and heavy parts must be removed and installed more, but the dependence on compliance with certain temperature limits remains, because only so the original wear resistance is maintained. Another disadvantage is that in the case of leaks occurring nevertheless not only the wear plates but also the underlying highly heat-conducting films must be replaced because they have no comparable wear resistance.

Another solution is from the EP-1 321 711 known. It shows an air-cooled grate bar for a grate firing. Although it is also a two-plate construction with a top plate and a bottom plate, but between these two plates there is not a meandering channel, but only a cooling gap. In addition, the grate bar is designed as a casting. It is therefore also a conventional solution with the disadvantages of a high weight and an undifferentiated cooling air distribution, because the cooling air namely flows through the cooling gap only in the longitudinal direction of the grate bar.

Finally is from the DE-38 20 448 a cooled wall element for metallurgical furnaces known. The disclosed wall element may consist, for example, of a metal plate and metal tube half-shells welded thereto, with a copper layer of high thermal conductivity being applied to the inside of the metal on the metal plate. This copper layer can be applied by means of welding plating. However, the basic element structure does not include two continuously superimposed metal plates, but instead of the one plate a plurality of individual metal tube half-shells. It is therefore about a very expensive to produce component, which is also due to the completely different application in metallurgical furnaces also not provided with a particularly wear-resistant, but only a good thermal conductivity inner coating.

From the EP-1 355 112 is known a grate bar having a lower plate and a top plate made of high-alloy cast material and a lying between the lower and the upper plate milled and meandering channel. In this meandering channel cooling tubes are inserted. The two plates are connected by screw connections, which are not arranged in edge areas.

It is therefore an object of the invention to provide an improved solution. In particular, a simple, lightweight, efficient and well-cooled design method is to be provided, which can also be brought into a desired final shape even later.

This object is solved by the features of patent claim 1.

Welding cladding per se have already been proposed in the field of rust floors of incinerators, such as in the JP-7004634 , However, these are castings, in particular castings with a high chromium content, which are also not provided with specific features for the targeted distribution of cooling air or cooling medium flows. In other known medium-cooled gratings for incinerators (for example " The combustion grate technology of SFA Handels GmbH for biomass, refuse derived fuel and waste "PDF document from May 2010 ) are also used cast grate plates with a high chromium content. Traditionally, it seems to be assumed that castings should preferably be used on highly stressed grate plates. Surprisingly, it has now been shown that in many cases, good results can be achieved with ordinary steel plates, but which are provided with a high-quality and wear-resistant welding plating.

One of the main advantages of such a construction method is that in contrast to the conventional solutions no longer difficult, complex and complex compilations requiring components must be made, but that only individual sheets (bottom and top plate) must be edited, their joining finally special can be simple and efficient. The required sheet metal processing methods include only standard methods such as cutting, drilling and milling in particular, ie there are all the procedures that are suitable for the largely automatic production on editing tables and thus allow efficient and cost-effective production. In addition, the base material for both the lower plate as well as for the top plate in principle be a common steel, which of course also has a cost effect.

Because the channel is designed to guide a cooling medium either in the top plate or the bottom plate as a meandering milling, the course and cross section of the site and the conditions of use can be designed to be flexible, which is greatly facilitated with the numerically controlled machining methods commonly used today. Thus one achieves also an additional flexibility in the production.

The main advantage, however, results from the introduction of a weld cladding on the 'wear side' of the top plate. The wear side is, as already mentioned, especially in refuse incinerators exposed to very large abrasive, thermal and chemical loads. Weld-plating is a process known per se, which is also called 'cladding' or build-up welding. Here, a high-alloy steel is applied as a surface protection on highly loaded, but usually lower alloyed metallic base materials. Such an order can be done for example by means of a welding robot. Here, the base material, which is sweat-plated, receives a usually several mm thick application layer. Of course, the high-alloyed steel used for this coating layer is selected according to the stress requirements (hardness, chemical resistance, etc.). Examples For such coating or protective layers are, inter alia, Inconel od. A-major 600. Such welding plating have the advantage that they with appropriate selection and especially if additional cooling is present, which ensures that the softening of the material due to the influence of temperature as small as possible is held, have much better abrasion resistance as the previously used Hardox sheets. In particular, the emergency running properties are greatly improved. Short-term exceedances of temperature limits to be observed so far no longer necessarily cause a permanent and irreversible weakening of the abrasion resistance of the affected material parts. It is even possible that in less critical areas, cooling no longer needs to be sustained or even eliminated altogether.

Advantageously, several layers are applied successively in the welding plating. The reason for this is that parts of the base material mix with the coating material due to the high welding temperatures, which of course changes the properties of the coating material. By serial application of several layers, this effect can be reduced.

Since cladding elements with the described structure can be produced efficiently and in series, it is much easier and easier to design as easy to handle spare parts. Thus, it is possible to provide the inventive cladding elements with connecting means with which they can be easily and quickly attached to a support provided for the substructure or other parts of a waste incineration and attachable again. These connecting means may be, for example, screw, plug or suspension means. Assuming that manual handling of spare parts is only possible without excessive effort, if the individual cladding elements weigh at most about 40 - 50kg, so is also readily apparent that this requirement in the intended scope most likely with a for the rational Mass production can meet suitable object, because the parts are then usually required in larger quantities. Of course, this also implies, of course, that the cooling medium connections also meet the condition of easy attachment and removability. However, this can usually be done well, for example with screw-threaded sockets for the cooling line connections.

Overall, the solution according to the invention offers the advantage that the proposed design can be extended to a large number of possible embodiments. For example, an occupancy schedule for an incinerator may cover a whole range of differently shaped Provide cladding elements, the individual embodiments are of course adapted to the naturally occurring environmental conditions of course. It is thus easy to see that, for example, conditions prevail in a feed chute with different conditions than in the actual combustion zone. Nevertheless, inventive cladding elements can also be used here.

The cladding elements can also be built or built into existing components.

Also with regard to manufacturability, there are various possibilities. Thus, on the one hand, it may be provided that a cladding element according to the invention is first produced as a flat article and only then brought into the desired final shape by bending. Of course, this is only possible if the cladding element is not too thick, because otherwise the machining forces or the processing machines required for this purpose become much too large. It is believed that this is well possible for plate thicknesses of up to about 20 mm.

On the other hand, of course, it can also be provided that the lower plate and the upper plate are manufactured separately as sub-objects which are bent in mutually matching form and are subsequently connected to one another. In this way can be made paneling elements with greater wall thickness. In addition, it can be provided that in the plate with the milled recess (bottom or top plate), the milled first runs exactly at those points where then the subsequent turn occurs (because the turn at the thinner, milled places is of course relieved). In such cases, of course, for the purpose of producing the integrity of the meandering channel at the 'additional' milled places before assembly of the lower plate with the top plate again corresponding channel wall parts must be welded. However, with such manufacturing methods, cladding elements according to the invention can easily be produced with overall wall thicknesses of up to about 50 mm.

Overall, the proposed solution that allows today's designs of water-cooled elements can be produced more cost-effective and above all service-friendly. Thus, leaks that arise are no longer required to be repaired and it is no longer necessary, for example, to replace entire feed shafts with great effort. With the proposed sweat-plated, medium-cooled cladding elements this costly repairs can be prevented. For the inclusion of the cladding elements you only need a suitable substructure, ie, in the case of shaft walls, for example, a rib frame on which the Cladding elements are screwed sealing. Should the hard facing cladding of a cladding element be damaged in the continuous sliding movement of the garbage, individual damaged cladding elements can be easily replaced. The substructure, ie the ribbed frame, is used again and again for receiving the cladding elements. The whole construction as well as the accruing service work become thereby much more cost-effective.

• Fig. 1 ein erfindungsgemässes flaches Verkleidungselement in einer Ansicht von unten, einem Querschnitt und einer Ansicht von oben,
• Fig. 2 eine Oberplatte für ein Verkleidungselement nach Fig. 1 in einer Ansicht von unten,
• Fig. 3 eine Unterplatte für ein Verkleidungselement nach Fig. 1 in einer Ansicht von unten,
• Fig. 4 einen Belegungsplan für erfindungsgemässe Verkleidungselemente in Ausführungen A-L in einem Verbrennungsofen,
• Fig. 5 ein weiteres erfindungsgemässes Verkleidungselement in einer Ausführung F,
• Fig. 6 ein weiteres erfindungsgemässes Verkleidungselement in einer Ausführung D,
• Fig. 7 ein weiteres erfindungsgemässes Verkleidungselement in einer Ausführung K und G,
• Fig. 8 ein erfindungsgemässes Verkleidungselement in einer Ausführung K für einen Schubrost auf einer Unterkonstruktion,
• Fig. 9 eine Oberplatte im Querschnitt die als separater Teilgegenstand herstellbar ist, und
• Fig. 10 eine Unterplatte im Querschnitt die als separater Teilgegenstand herstellbar ist und die mit der Oberplatte nach Fig. 9 zu einem Verkleidungselement in einer Ausführung K zusammenfügbar ist.

In the following the invention will be explained in more detail with reference to embodiments. It shows

• Fig. 1 a flat cladding element according to the invention in a view from below, a cross section and a view from above,
• Fig. 2 a top plate for a cladding element according to Fig. 1 in a view from below,
• Fig. 3 a sub-panel for a cladding element according to Fig. 1 in a view from below,
• Fig. 4 a layout for inventive cladding elements in versions AL in a combustion furnace,
• Fig. 5 another inventive cladding element in an embodiment F,
• Fig. 6 another inventive cladding element in an embodiment D,
• Fig. 7 another panel element according to the invention in an embodiment K and G,
• Fig. 8 an inventive cladding element in a version K for a sliding grate on a substructure,
• Fig. 9 a top plate in cross-section which can be produced as a separate part of the subject, and
• Fig. 10 a lower plate in cross-section which can be produced as a separate part of the subject and with the top plate after Fig. 9 to a cladding element in a design K is joined together.

The FIG. 1 shows a flat cladding element according to the invention for device parts of incinerators in a view from below, a cross section and a view from above. The cladding element has a lower plate 1 made of steel and a top plate 2 made of steel, which are superimposed and between where a channel 3 is designed to guide a cooling medium through the cladding element. In the illustrated embodiment, the channel 3 is incorporated as a meandering milled 4 in the top plate 2. The top plate 2 has on the side facing away from the bottom plate 1 on a welding cladding 5. The welding cladding 5 is, as mentioned above, a hard application layer of particularly high abrasion resistance, for example, by means of robot welding. Other properties, such as high temperature resistance, high corrosion resistance, etc. are of course also sought. This application layer usually has a total layer thickness of several mm. In addition, a multi-layered structure of the application layer is often desirable and advantageous, because it enables physical properties of the hard application material to be realized more reliably. The weld clad 5 is in the top view (see lower part of the FIG. 1 ) is displayed as a scale-like pattern in the absence of any other suitable representation. The lower plate 1 and the upper plate 2 are at least in the edge regions sealed together (not shown). This achieves the required tightness for the meandering channel 3 by flowing cooling medium. Of course, the lower plate 1 may be connected at other locations, for example by means of welding connection with the top plate 2. This is in the FIG. 1 shown with additional welds 6, in the present embodiment Of course, can only be done in places where the lower plate 1 and upper plate 2 touch, so here in the range of webs between individual channel sections.

Furthermore, the shows FIG. 1 two welded in the lower plate 1 threaded sleeves 7, via which an inlet and outlet of the cooling medium can take place. These threaded sleeves allow pipelines, for example for cooling water, to be quickly and easily connected.

The simple embodiment according to the FIG. 1 also shows that the meandering channel 3 between inlet and outlet has a non-narrowing cross-section. The meandering channel 3 also has a number of approximately over the entire length and a number of approximately over the entire width of the cladding element extending channel sections. With these measures, the best possible heat distribution within the cladding element should be achieved.

The FIG. 2 shows the top plate 2 for a cladding element FIG. 1 still in a view from below.

The FIG. 3 shows the bottom plate 1 for a cladding element FIG. 1 still in a view from below.

For fastening the cladding element to a dedicated substructure or other device parts of the incinerator, the cladding element has connecting means with which it can be easily and quickly attached to a holder provided for this purpose. These connecting means may be formed in a manner known to those skilled, for example, as a screw, plug or suspension means. Since these are known design aids, they are not shown here.

Furthermore, the cladding element can also have through holes, passage slots or ducts for the passage of combustion air (see Fig. 8 ). At certain points, for example at the grate plates in the grate level region of a combustion furnace, it is usually necessary to supply combustion air from below to promote good combustion. In the present embodiment according to the Figures 1-3 However, no such bushings are provided.

1. A ist ein flaches Verkleidungselement für die Belegung des Müllschachtes,
2. B ist ein flaches oder abgewinkeltes Verkleidungselement für die Belegung in einem Übergangsteil,
3. C ist ein abgewinkeltes Verkleidungselement für die Belegung der Kolbenführung,
4. D ist ein flaches Verkleidungselement für die Belegung des Beschickungstisches und der Kolben,
5. F ist ein gerundetes Verkleidungselement für die Belegung des Sammlerschutzes,
6. G ist ein abgewinkeltes Verkleidungselement für die Belegung der Rostseitenführung,
7. H ist ein doppelt abgewinkeltes Verkleidungselement für die Belegung des Mitteltunnels im Rostbereich,
8. K ist ein abgewinkeltes Verkleidungselement für die Belegung der Roststufen (ähnlich wie Fig. 1).
9. L ist ein flaches Verkleidungselement für die Belegung des Schlackeschachtes.

The FIG. 4 purely by way of example shows an allocation plan for cladding elements according to the invention in embodiments AL in a combustion furnace. It has already been mentioned that cladding elements in the proposed construction basically at different locations within a Incinerator can be used. They usually differ only in size, shape, quality of the Schweißplattierung, type of cooling equipment, as well as more secondary features such as method of attachment and integration of combustion air supply. Thus, for example, it is possible that at relatively 'cool' locations, such as the feed chute, no medium cooling must be done, or that another quality of the weld plating can be selected. The FIG. 4 serves to illustrate in various embodiments AL:

1. A is a flat cladding element for the occupation of the garbage chute,
2. B is a flat or angled cladding element for occupancy in a transitional part,
3. C is an angled covering element for occupying the piston guide,
4. D is a flat covering element for the occupancy of the loading table and the piston,
5. F is a rounded covering element for the occupancy of the collector protection,
6. G is an angled covering element for the occupancy of the grate side guide,
7. H is a double-angled cladding element for the allocation of the central tunnel in the grate area,
8. K is an angled covering element for the occupation of the rust steps (similar to Fig. 1 ).
9. L is a flat cladding element for the assignment of the slag shaft.

The FIGS. 5, 6 and 7 show for further clarification cladding elements of embodiments F, D and K. Clearly visible is the same basic structure with a lower plate 1 and a top plate 2 in all embodiments.

The FIG. 8 shows a trim element according to the invention in a version K for a rust level of a sliding grate on a substructure. This embodiment is merely illustrative of how the trim elements may be attached. Waste incinerators have, as in the FIG. 4 schematically shown, usually stair-like feed grids on which the kiln is transported into the combustion area and ash and slag from the combustion area in a slag shaft. Such a feed grate consists of juxtaposed grate steps. Usually, it is also the case that at least a number of the grate stages can perform lifting movements in the transport direction. The rust levels are heavily loaded, especially in the combustion area, which is why the easy substitution is of great importance here.

The substructure for a rust stage is a push frame 10. On this push frame 10 is an angled Cladding element for the occupation of the grate level by means of screws 11 screwed. The cooling medium connection 12 is screwed onto the threaded sleeve 7. In the area of the leading edge, a sealing strip 14 is attached. In the rear region of the push frame, ie in the area in which overlap the individual grate levels, there is a känelartige molding 15. The känelartige shaping 15 serves to support and positioning of the grate level on a round rod (not shown) of the sliding grate construction. In the end face area, there are also through holes 16 for the supply of combustion air in this embodiment.

From the FIG. 8 It can be seen that the replacement of a defective cladding element for the occupation of the grate steps can be done easily and on site. For this purpose, only the fastening screws 11, the sealing strip 14 and the cooling medium connections 12 must be solved, after which the cladding element is pulled out to the front.

As mentioned above, there are basically two options for the production of the cladding element according to the invention. Thus, it can be provided that a cladding element according to the invention is first produced as a flat object and only then brought into the desired final shape by bending. This method is, as already stated, because of applied bending forces applicable only for relatively thin trim elements.

For thicker cladding elements it can be provided that the lower plate 1 and the upper plate 2 can be manufactured separately as sub-objects which are bent in mutually matching form and only subsequently can be connected to one another. In this way, lining elements can be produced with greater wall thicknesses.

In addition, it can be provided with separate production of lower and upper plate, that in the plate with the milled recess (which may be the lower or the upper plate), the milled first runs exactly at that point, where then the turn. This production variant is exemplary in the FIGS. 9 and 10 shown.

It shows the Fig. 9 a top plate 2 in cross-section with Teileinfräsungen 20. This top plate 2 is a separate part of the article can be produced. The entirety of the Teileinfräsungen 20 forms the channel 3. The Teileinfräsung 20a, which is also part of the channel 3, runs continuously from edge to edge and is located at the point where the turn (indicated by dashed lines). Thus, the top plate 2 can be bent at a position where the turn is due to the smaller plate thickness is relieved. Prior to assembly with the lower plate of course, in order to produce the integrity of the meandering channel at the 'intentionally' milled places again corresponding channel wall parts must be welded in such cases. These additions are needed at least in the edge regions of the cladding element, but of course it depends on the intended course of the channel 3.

The FIG. 10 shows a corresponding lower plate 1 in cross section. This sub-plate 1 can be produced as a separate sub-item. This sub-plate 1 fits to the top plate according to Fig. 9 and it is also bent at the corresponding point (indicated by dashed lines). After bending, the top plate can Fig. 9 and the lower plate after Fig. 10 be joined together to form a cladding element, or, for example, connected to each other by means of welding.

LIST OF REFERENCE NUMBERS

1

lower plate

2

top plate

3

channel

4

milled

5

Weld

6

Welding seam

7

threaded nut

8-9

not used

10

thrust frame

11

fixing screw

12

Cooling medium connection

13

front

14

Schleissleiste

15

känelartige shaping

16

Through hole for combustion air

17-19

not used

20

Teileinfräsungen

A-L

Embodiments of the cladding element

Claims (8)

1. Cladding element for constituent device parts of incinerators, wherein the cladding element consists of a lower plate (1) made of steel and an upper plate (2) made of steel, which are positioned one on top of the other and are connected in sealing manner at least in edge areas thereof, and wherein a serpentine channel (3) is formed between the lower plate (1) and the upper plate (2) for guiding a cooling medium through the cladding element, and wherein
   each of the upper plate (2) or the lower plate (1) is designed as a single sheet in which a serpentine recess (4) has been creating by milling to form the channel (3), characterized in that
   the side of the upper plate (2) facing away from the lower plate (1) comprises an abrasion-resistant weld plating (5), and the cladding element in its entirety can be manufactured as a flat object and subsequently bent into a shape.
2. Cladding element according to claim 1, characterized in that the weld plating (5) has increased resistance capability with respect to thermal and/or chemical and/or abrasive loads.
3. Cladding element according to either of claims 1 or 2, characterized in that the weld plating (5) is made up of multiple layers.
4. Cladding element according to any one of claims 1 to 3, characterized in that the cladding element comprises connecting elements with which it can be easily and quickly attached to a substructure provided for supporting the cladding element or to other constituent device parts of the incinerator.
5. Cladding element according to claim 4, characterized in that the connecting elements are threaded, plugged or suspension means.
6. Cladding element according to any one of claims 1 to 5, characterized in that the cladding element comprises through holes (17), slits or feedthroughs to allow the passage of combustion air or for the attachment of fastening means.
7. Cladding element according to any one of claims 1 to 6, characterized in that the serpentine channel (3) has a non-tapering cross section.
8. Cladding element according to any one of claims 1 to 7, characterized in that the serpentine channel (3) comprises a number of channel sections that extend essentially over the entire length of the cladding element and a number of channel sections that extend essentially over the entire width of the cladding element.

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