EP2771615B1 - Incineration grate consisting of grate bars and method for fitting grate bars in and removing same from an incineration grate - Google Patents

Description

The invention relates to combustion grate consisting of grate bars according to claim 1 and a method for assembly and disassembly of grate bars in and out of a combustion grate according to claim 9.

In the course of the production of chip, plastic or insulating panels and / or mats are usually offered in large-scale systems thermal energy systems that burn on the one hand rejects from production and / or contaminated exhaust air from the production process to gain the necessary thermal energy that require individual process steps during the production of the above products. Usually this is heated thermal oil or steam generated. In particular, in the production of particle board or in the debarking of logs in the course of MDF production produces a large amount of materials or waste that are not directly usable, which are usually supplied for thermal utilization. These are, for example, bark, start-up materials, faulty fillings, scrap material, inferior fuels, waste wood, grinding dust or the like.

For this purpose, the energy generation systems usually provide an air-cooled combustion grate (advancing grate) in a combustion chamber, which generally conveys the material to be burned via a staircase-shaped combustion surface. The combustion surface consists in this case of side by side in width and longitudinally staggered grate bars in length. The fuel is given up on a staircase forming combustion grate and carried down the combustion surface through periodically moving staircase steps. The combustion surface is supplied from below with primary air for cooling the grate bars and for supplying the combustion chamber with oxygen. The primary air enters between the grate bars through into the combustion chamber. At the end of the staircase-shaped combustion surface, the burned-out fuel is thrown off as ash and discharged via a wet ash pan. During the combustion of the fuel, high temperatures are generated, preferably up to almost 1,000 ° C., so that heat-resistant stainless steel casting is used for the grate bars. Nevertheless, these grate bars are subject to tribological wear due to thermal and mechanical stress and must occasionally be replaced. Examples in the prior art would be: DE 36 10 819 A1 . US 4 103 627 A or US 4 676 176 A ,

The necessary for the formation of a combustion grate grate bars generally have geometric features that are subject to a function-related, but also production-related needs.

In order to make consistent statements in the following statements, the following assumptions regarding the geometry and arrangement of the grate bar within a combustion chamber to form a combustion surface are recorded on a combustion grate:

A grate bar essentially has an upper side oriented toward the combustion chamber, a lower side aligned with at least one (possibly movable) support. In their width, a plurality of juxtaposed grate bars form a step, wherein the longitudinal extent of the grate bars in the conveying direction of the fuel and the possibly. Movable support is arranged. The surface of a grate bar, which essentially connects the upwardly directed burn surfaces of two grate bars, is defined here as a push or joint surface, since usually every second step of the combustion grate is designed to be movable and thus causes a promotion and mixing of the fuel during combustion.

Thus, the grate bars in their width and their length form the combustion surface and in their height the steps of a combustion grate or the distance between the combustion surfaces of two steps. To summarize the geometry of a grate bar, the upper side of the grate bar is the bearing surface for the fuel, the rear side the side with a support for a stationary or movable grate bar, the front side of the usually slightly rounded connecting surface from the upper support surface to the lower side of the grate bar, wherein the lower side of the grate bar is illuminated with the cooling primary air. The front side, or the connecting surface, can be configured in many geometries. The necessary overlap between the grate bars is to prevent falling through of too much ash and fuel between the grate bars and is usually realized by a web on a grate bar and an overlying part of the support surface of an adjacent grate bar. Within the overlap, respectively, the groove formed by the overlap spacing surfaces are arranged, which provide the necessary distance vertically as well as horizontally for the ventilation of the fuel with primary air. The longitudinal center plane is arranged from top to bottom and in the longitudinal direction from front to back.

From known embodiments of such combustion grates, it is known to overlap the combustion-side surfaces of the grate bars to the adjacent grate bar in order to obtain a positive connection. However, this also has the disadvantage that when replacing a grate bar in a row (step) almost all grate bars must be removed until the damaged grate bar is reached to replace it. Due to the asymmetrical design and force in the grate bar this is exposed in the proposed embodiment but also increased wear. Is due to an asymmetric design of the grate bar In the longitudinal direction (along the steps), the grate bars do not lift up in front of one another in the course of the pushing work and fuel material gets between the grate bars or even into the area of the primary air supply. Here, too, it comes to increased wear, local overheating problems in the combustion grate and other difficulties that could even trigger an emergency shutdown of the combustion chamber. This circumstance is usually remedied by the fact that several grate bars are combined by means of threaded rods to form a package. Due to the high weight of several grate bars lifting is indeed avoided, but the precautionary labor and manufacturing effort in terms of the introduction of suitable holes (undercuts) in the mold and the mounting of the threaded rods is significant. Also, several connected grate bars are very difficult to handle and load fitters beyond all measure. To make matters worse, that when replacing a grate bar, the entire grate bar battery removed, dismantled and fitted with the new replacement parts must be reinstalled. In general, the further addition of manpower or mechanical aids (lifting equipment, cranes) is indispensable. Again, it is possible that for the replacement of a single grate bar a complete row of grate bars must be removed in order to replace a defective grate bar.

The object of the invention is now to provide a combustion grate consisting of a variety of grate bars, which allows easy replacement of individual grate bars and at the same time ensures the highest level of operational safety. Next, a possible geometrically simple system of easily demountable grate bars without undercuts should be ensured to optimize the cost of the grate bars and thus the combustion grate. Finally, a method for assembling and disassembling individual grate bars in a combustion grate with the grate bars according to the invention is to be created.

The solution to the problem of creating a combustion grate consists of the features of independent claim 1.

• Verfahren zur Montage- und Demontage von Roststäben in und aus einem Verbrennungsrost mit einer Vielzahl an Roststäben, die in Reihen nebeneinander und in Reihen untereinander angeordnet sind und mit ihren oberen Auflageflächen stufenförmige Brennflächen ausbilden,
• wobei eine stufenförmige Brennfläche über die Breite des Verbrennungsrostes aus mehreren ersten und zweiten Roststäben A, B gebildet wird, die auf einer Seite mit einem Auflager auf einer Roststange gelagert sind,
• wobei die ersten Roststäbe A über ihre Breite b zumindest einmalig im Bereich der Auflagefläche mittels einer Abstufung nach innen in Richtung der Längsmittenebene eine kleinere Auflagefläche für das Brennmaterial ausbilden als die zweiten Roststäbe B und wobei die zweiten Roststäbe B im Bereich der Auflagefläche zur Ausbildung einer Überlappung mit den ersten Roststäben A mittels einer Abstufung über ihre Breite b nach außen eine Auflagefläche größerer Breite b' aufweisen, wobei angrenzend und/oder benachbart zu den Verbindungsflächen die zweiten Roststäbe B zumindest einen die Breite b' zusätzlich auf eine Breite b" vergrößernden Stift aufweisen, der in eine korrespondierende Tasche der ersten Roststäbe A einführbar ist, wobei zur Demontage ein zweiter Roststab B auf der Seite des Auflagers von der Roststange soweit abgehoben wird, dass dieser entlang der Längsmittenebene verschoben werden kann, um den Stift aus der Tasche der benachbarten Roststäbe A zu entfernen, wobei zur Montage des zweiten Roststabes B die umgekehrte Reihenfolge angewendet wird.

The solution for a method for assembly and disassembly consists of the features of claim 9:

• Method for assembling and disassembling grate bars into and out of a grate with a plurality of grate bars arranged in rows next to one another and in rows below one another and with their upper support surfaces forming stepwise firing surfaces,
• wherein a step-shaped focal surface is formed across the width of the combustion grate of a plurality of first and second grate bars A, B, which are mounted on a side with a support on a grate bar,
• wherein the first grate bars A over their width b at least once in the area the bearing surface by means of a gradation inwardly in the direction of the longitudinal center plane form a smaller bearing surface for the fuel than the second grate bars B and wherein the second grate bars B in the region of the support surface to form an overlap with the first grate bars A by means of a gradation over its width b to outside a support surface of greater width b ', wherein adjacent and / or adjacent to the connecting surfaces, the second grate bars B have at least one width b' in addition to a width b "magnifying pin which is insertable into a corresponding pocket of the first grate bars A, wherein for disassembly, a second grate bar B on the side of the support of the grate bar is lifted so far that it can be moved along the longitudinal center plane to remove the pin from the pocket of the adjacent grate bars A, wherein for mounting the second grate bar B, the reverse Order ang is used.

Advantageously, now the grate bars, which preferably and consist essentially of at least two different geometries, form-fitting manner in such a way nested that they do not tend in normal operation to stand out from the underlying level of grate bars. In particular, this should not happen in overrun when each or every xth row of grate bars is displaced during the combustion process to optimize combustion of the fuel.

It should be possible to dispense with additional components such as screws, nuts, bolts, threaded rods or the like, on the one hand to save material and assembly costs, on the other hand to significantly accelerate the assembly and disassembly of the grate bars and simplify. Since the grate bars are usually made of expensive stainless steel casting, the grate bars should have no undercuts and be demoulded in two directions. As a result, the casting tool is also greatly simplified and the production costs of the grate bars lowered.

The grate bars are constructed such that when installed a first grate bar A is held by two (left and right) adjacently arranged grate bars B of a second and the first grate bar A diverging geometry. This is made possible by the fact that preferably both variants of the grate bars have substantially the same width b, but the first grate bar A by a gradation of the bearing surface for the fuel inside it the second grate bar B of substantially equal width b with a correspondingly opposite gradation ( and a concomitant broadening of the bearing surface for the fuel) makes it possible to limit the first grate bar in its freedom of movement upwards in the direction of the combustion chamber by the overlap that has arisen. In their longitudinal extension, all grate bars are essentially fixed by a grate bar and a suitable support to the grate bars.

Thus, the first grate bar A is positively held in this system of two grate bars and can not move during operation.
The second grate bars B would be able to move away from their position upwards relatively easily during operation, if they would not additionally have an engaging in the adjacent first grate bars A pin or a nose. Preferably, this pin is arranged opposite to the support for the grate bar, in particular preferably in the region of the connecting surface of two bearing surfaces of different grate planes respectively different grate bars. The arrangement of the pin and preferably corresponding pockets in the adjacent grate bars to prevent the second grate bars B can stand out with the wide bearing surfaces for the fuel upwards. They would also have to lift off the adjacent and positively connected grate bars via the pins. The opposite sides of the grate bars, which have the support and are positively connected to the grate bar, are held by the weight of the overlying grate bars the next higher level / level.

It will be appreciated that the pocket or pin may have other possible geometries, but must be arranged so that the grate bar can not be displaced upwardly with the pin projecting outwardly (substantially parallel to the width of the combustion grate).

For this purpose, the bag or the engagement of the pin on the adjacent grate bar should have no direct opening upwards in the direction of the fuel.

However, in order to assemble or disassemble the various grate bars, it is necessary that the pocket, respectively the possibility of engagement of the pin of the grate bar B in the grate bar A, form or make possible an opening or freedom of movement towards the front.
This is due to the fact that for disassembly of the grate bars any second grate bar B can be lifted unilaterally at its support (rear) of the grate bar or the thrust bearing, while the other side (front) remains with the pin in engagement with the corresponding pocket , The pin thus essentially assumes the function of a rotary joint. If the rear part of the grate bar (the support) is no longer in engagement with the grate bar, the grate bar can be moved forward. In this case, the pin slides out of the pocket and the grate bar can be removed. Finally, the adjacent grate bars only have to be moved across the width in order to push them out of the area of the overlap (bar / support surface) and these can then also be removed. Thus, it is possible in a simple manner to remove any grate bar from the combustion grate, without cumbersome to lift several connected grate bars or dismantle a whole series grate bars. It is understandable that the top row Grate bars, which rest with their front ends (connecting surfaces) on the grate bars, must be lifted before removing a grate bar. This can easily be done with wedges or other lifting equipment.

In summary, it should be noted that the grate bars A and B should be made substantially symmetrical. In this case, the grate bar A in the front lower area (right and left) on a recess (pocket). In return, the grate bar B has a pin (nose) in the lower front area (right and left). Due to the fact that the grate bars have gradations in the upper area, the grate bar A inwards and grate bar B outwards, when the grate bars are put together to form a row of grate bars, a positive connection is created without additional components. This ensures that a single grate bar can never lift off during operation. The fact that the pocket or the nose is located directly in the vicinity of the parting plane of the casting, there is thus no undercut. The demolding of the mold can be done in two directions and the tool costs remain low. Extrusive slides can be dispensed with in such an embodiment. When disassembling a single grate bar (during maintenance or spare parts work), simply raise the grate bar B in the rear area (about 7 °). Subsequently, the grate bar unhindered forward, in the direction of the connection surface, are pushed out.

Further advantageous measures and embodiments of the subject matter of the invention will become apparent from the dependent claims and the following description of a preferred embodiment with the drawing.

Figur 1

in zwei schematischen Seitenansichten jeweils einen Teilausschnitt eines treppenförmigen Verbrennungsrostes mit stufenförmig angeordneten Roststäben, wobei die alternierenden Reihen der Roststäbe mit einem Festlager und einem beweglichem Schublager verbunden sind,

Figur 2

in einer dreidimensionalen Ansicht einen ersten Roststab A mit einer gegenüber seiner normalen Breite b kleineren Breite seiner Auflagefläche für das Brennmaterial und der Ausbildung eines Steges und zweier Taschen,

Figur 3

in einer dreidimensionalen Gegenüberstellung einen zweiten Roststab B mit einer gegenüber seiner normalen Breite b größeren Breite seiner Auflagefläche für das Brennmaterial zur Überlappung mit einem ersten Roststab A,

Figur 4

in mehreren Schnittansichten den Roststab A nach Figur 2

Figur 5

in mehreren Schnittansichten den Roststab B nach Figur 3,

Figur 6

das Verfahren zur Demontage eines zweiten Roststabes B aus einer vollständig montierten Reihe an Roststäben und

Figur 7

eine 3D-Ansicht der zumindest vier notwendigen Roststäbe A, B, A' und B' zur Herstellung eines vollständigen Verbrennungsrostes.

Show it:

FIG. 1

in two schematic side views in each case a partial section of a staircase-shaped combustion grate with stepwise arranged grate bars, wherein the alternating rows of grate bars are connected to a fixed bearing and a movable thrust bearing,

FIG. 2

in a three-dimensional view a first grate bar A with respect to its normal width b smaller width of its bearing surface for the fuel and the formation of a web and two pockets,

FIG. 3

in a three-dimensional juxtaposition a second grate bar B with a width of its bearing surface, which is larger than its normal width b, for the fuel material for overlapping with a first grate bar A,

FIG. 4

in several sectional views the grate bar A after FIG. 2

FIG. 5

in several sectional views the grate bar B after FIG. 3 .

FIG. 6

the method for disassembling a second grate bar B from a fully assembled row of grate bars and

FIG. 7

a 3D view of the at least four necessary grate bars A, B, A 'and B' for producing a complete combustion grate.

To FIG. 1 a combustion grate 11 consists of several stages of a plurality of grate bars 1, which are arranged in rows next to each other and in rows with each other and form with their upper bearing surfaces 2 fuel surfaces 17 for the fuel 14. A grate bar 1 has a rear end with a support 15 for positive connection with a grate bar 16 and a front end with a connecting surface 3 between the upper support surface 2 and the lower contact surface of the grate bar 1 with the grate bar 1 of the next lower level. These step-shaped combustion surfaces 17 are formed over the width of the combustion grate 11 from first and second grate bars A, B, preferably in alternating sequence, wherein at the respective end of the focal surface 17 special grate bars A '/ B' ( FIG. 7 ) can be arranged. The connecting surface 3 can be embodied in a multiplicity of geometries, but should essentially positively connect the support surface 2 of a grate bar A, B with the support surface 2 of a further grate bar A, B such that the fuel 14 continues to move to the one step during the displacement arranged below grate bars 1 can fall. In higher-quality combustion grates 11 every second stage is usually by means of a Fixed bearing 12 and each staggered second stage designed to move a step of the combustion grate by means of a thrust bearing 13. FIG. 2 now shows a first grate bar A with a smaller contact surface for the fuel 14 than the grate bar B after FIG. 3 , In the rear area, both grate bars A, B have a support 15 for positive connection with the grate bar 16 and in the front region of the support surface 2 passes into a connecting surface 3, on the lower side of the grate bar A, B substantially in contact with the Support surface 2 of the next grate bar A or B ends. The transition between the support surface 2 and the connection surface 3 is usually fluent and dependent on the fuel to be burned 14. If the two grate bars A, B are now arranged side by side on a grate bar 16, it follows that an overlap 9 through the below the support surface 2 of the second grate bar B arranged web 4 of the first grate bar A is formed. Thus, with a simultaneous form-fitting position of the supports 15 on a grate bar 16, it is no longer possible for a grate bar A lying between two grate bars B to form an overlap 9, to be lifted upwards. The spacers 19 of the two grate bars A and B but provide in vertical and horizontal alignment to the necessary spacing of the grate bars A, B in order to be able to supply sufficient primary air for cooling the grate bars and the firing of the fuel.

After the FIG. 4 and 5 the first grate bars A on their width b at least once in the area of the support surface 2 a gradation 7 inwardly to form a smaller support surface 2 for the fuel 14 than the second grate bars B, wherein the second grate bars B in the region of the support surface 2 for training an overlap 9 with the first grate bars A by means of a step 8 to the outside a support surface 2 of greater width b 'have. To further obtain a positive connection for fixing the grate bars B in the installed state, the grate bars B adjacent and / or adjacent to the connecting surfaces 3 at least one width b 'in addition to a width b "magnifying pin 5, preferably on both sides, the in a corresponding pocket 6 of the adjacent first grate bars A. Accordingly, the second grate bar B can no longer be positively lifted by the pins 5 fixed in the pockets 6 without also lifting the adjacent grate bars A. It is preferably provided that the cross section Preferably, the grate bars A, B should have substantially the same width b, so that substantially equal dimensions result in the configuration of the steps in that each bearing surface 2, the Abstufun gen 7, 8, the overlaps 9 of the grate bars A, B, the webs 4, the pockets 6 and / or the pins 5 symmetrical to the top to bottom and in the longitudinal direction of the grate bars A, B extending longitudinal center plane 10th are formed. Preferably, the pocket 6 should be arranged at a distance from the support surface 2.

In particular, it is advantageous if the pockets 6 and / or the pins 5 are arranged adjacent to the demoulding plane 18 or are cut by it. The demolding 18 is shown by dashed lines and indicates the level from which the grate bar 1 can be demoulded from two sides after pouring. This is particularly advantageous to avoid unnecessary undercuts, as previously customary in the prior art. It is understandable that the pockets 6 and / or the pins 5 can not be arranged arbitrarily far above in the direction of the support surface 2, otherwise no positive connection can be realized, which can prevent the unintentional lifting of the grate bars 1 from the underlying grate bars ,

Preferably, the first grate bars A in the region of the support surface 2 for overlapping 9 with the second grate bars B should have a web 4, which is arranged below the gradation 8.

In FIG. 6 Now the sequence of a method for disassembling a grate bar B from a positive connection between two grate bars A is shown. In this case, the grate bar B is raised at its rear support upwards and rotates about the auxiliary bearing consisting of the pins 5 of the grate bar B and the associated pockets 6 of the adjacent grate bars A. After sufficiently raising the rear side of the grate bar B, the support 15 of the grate bar B is no longer engaged with the grate bar 16, so that the grate bar B can be moved forward and the pins 5 of the grate bar B leave the pockets 6 of the adjacent grate bars A. Now the grate bar B can be removed without problems. In order now to remove the adjacent grate bar A, this only has to be pushed slightly in the direction of the now vacant gap of the already removed grate bar in order to dissolve the positive overlap 9 with the further grate bar B. The insertion and mounting of the grate bars A, B takes place essentially analogously and in the reverse order.

In FIG. 7 is now still the sake of completeness, a whole set of necessary grate bars for optimal production of a combustion grate shown. Depending on the requirements, it may be sufficient to arrange all grate bars in the same alignment. However, it may also be desirable to arrange them staggered in relation to each other. In this context, it may therefore be useful to produce grate bars A ', B' for the edge area. Alternatively, the outer walls and the burning surfaces 17 could be designed to simulate geometric edges and / or surfaces in order to achieve positive locking of the grate bars A, B with the walls.

List of Reference Numerals: P1427

1.

grate bar

Second

support surfaces

Third

interface

4th

web

5th

pen

6th

bag

7th

Gradation inside

8th.

Gradation outside

9th

overlap

10th

Longitudinal plane

11th

combustion grate

12th

fixed bearing

13th

thrust bearing

14th

fuel

15th

In stock

16th

stainless rod

17th

burning surface

18th

Entformungsebene

19th

spacer

20th

primary air

FROM

first and second grate bar

b

normal width without gradations

b '

Gradation outwards

b "

Width of nose / pin 5

Claims (9)

1. An incineration grate consisting of several steps, comprising a plurality of grate bars (1), which are arranged in rows alongside one another and in rows one above another, and form step-like combustion surfaces (17) with their upper supporting surfaces (2), wherein a step-like combustion surface (17) is formed over the width of the incineration grate (11) from several first and second grate bars (A, B), wherein connecting surfaces (3) are arranged on the grate bars (1) for compensating the difference in height between two adjacent combustion surfaces (17) of the grate bars (1), wherein at least once in an area of the supporting surface (2) the first grate bars (A) form a smaller supporting surface (2) over their width (b) for the fuel (14) than that of the second grate bars (B) via a shoulder (7) disposed inwards in the direction of a longitudinal centre plane (10), wherein in the region of the supporting surface (2) the second grate bars (B) have a supporting surface (2) of greater width (b') in order to form an overlap (9) with the first grate bars (A) by means of a shoulder (8) disposed outwards over their width (b), characterized in that adjacent to and/or bordering the connecting surfaces (3) the second grate bars (B) comprise at least one pin (5) which additionally enlarges the width (b') to a width (b") and which can be inserted into a corresponding pocket (6) of the first grate bars (A).
2. An incineration grate according to claim 1, characterized in that the cross-section of the grate bars (A, B) outside of the regions of the shoulders is substantially equal and preferably consists of T-shaped profile.
3. An incineration grate according to claim 1 or 2, characterized in that the grate bars (A, B) substantially have the same width (b).
4. An incineration grate according to one or several of the preceding claims, characterized in that the supporting surfaces (2), the shoulders (7, 8), the overlaps (9) of the grate bars (A, B), the webs (4), the pockets (6) and/or the pins (5) are formed symmetrically relative to the longitudinal centre plane (10) extending from top to bottom and in the longitudinal direction of the grate bars (A, B).
5. An incineration grate according to one or several of the preceding claims, characterized in that the pocket (6) is arranged at a distance from the supporting surface (2).
6. An incineration grate according to one or several of the preceding claims, characterized in that the pocket (6) and/or the pin (5) are arranged adjacent to or adjoining the demoulding plane (18) or the connecting surface (3), or are intersected by the same.
7. An incineration grate according to one or several of the preceding claims, characterized in that the first grate bars (A) comprise a web (4) in the region of the supporting surface (2) to the overlap (9) with the second grate bars (B), which web is arranged beneath the shoulder (8).
8. An incineration grate according to one or several of the preceding claims, characterized in that spacers (19) are arranged on the adjacent contact surfaces between the grate bars (A, B).
9. A method for mounting and dismounting grate bars in and from an incineration grate with a plurality of grate bars (1) which are arranged in rows alongside one another and in rows one above another and form step-like combustion surfaces (17) with their upper supporting surfaces (2), wherein a step-like combustion surface (17) is formed over the width of the incineration grate (11) from several first and second grate bars (A, B), which are mounted on one side on a support (15) on a grate bar (16), wherein at least once in an area of the supporting surface (2) the first grate bars (A) form a smaller supporting surface (2) over their width (b) for the fuel (14) than that of the second grate bars (B) via a shoulder (7) disposed inwards in the direction of a longitudinal centre plane (10), and wherein in the region of the supporting surface (2) the second grate bars (B) have a supporting surface (2) of greater width (b') in order to form an overlap (9) with the first grate bars (A) by means of a shoulder (8) disposed outwards over their width (b), wherein adjacent to and/or bordering the connecting surfaces (3) the second grate bars (B) comprise at least one pin (5) which additionally enlarges the width (b') to a width (b"), and which can be inserted into a corresponding pocket (6) of the first grate bars (A), wherein for dismounting a second grate bar (B) is lifted on the side of the support (15) from the grate bar (16) to such an extent that it can be displaced along the longitudinal centre plane (10) in order to remove the pin (5) from the pocket (6) of the adjacent grate bars (A), wherein the reverse sequence is applied for mounting the second grate bar (B).

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