EP3168534B1 - Grate bar, grate, and incinerator - Google Patents

Description

The present invention relates to a grate bar, a grate and an incinerator according to the independent claims.

For the combustion of different fuels, e.g. Household waste, industrial waste, wood waste, solid or porous fuels, as well as fuels with high and low ignition, come conventionally

Combustion systems with combustion chambers for use, in which the fuel is applied, for example, to a mechanically operated grate and burned on it. The grate may include one or more grate bars. Incineration plants generally process combustion products with high and low calorific value, so that large heat-related problems can occur with the grate bars used. In particular, in the grate head region of the grate bars can burn or corrode due to excessive thermal stress.

An object of the present invention is to provide a grate bar which has a long life. It is also an object to provide a grate for use in an incinerator and a combustion system with at least one such grate.

document US 4,460,333 discloses a grate bar according to the preamble of claim 1.

The object of the invention is achieved by means of a grate bar according to claim 1. Further embodiments are shown in the dependent claims.

Proposed is a grate bar having a substantially closed surface facing a combustion side, a grate bar support adapted to rest on a grate surface, a head portion and a plurality of air cooling fins projecting from the underside of the surface, the head portion comprising at least one flow channel, which is subdivided downstream into at least a first and second partial flow channel, wherein the first partial flow channel leads to at least one first outlet opening at the front side of the head part and the second partial flow channel leads to at least one second outlet opening spaced from the front side, which is open to the underside of the surface. Such a trained grate bar has a much longer life, since particularly heat-stressed portions of the grate bar faces a temperature-adapted cooling volume for dissipating the heat. In this case, in particular the head part of the grate bar, which is exposed to particularly high temperature influences and is therefore subject to high wear, reliably cooled. The first outlet opening can allow the airflow to escape to the front and / or to the side. The second outlet opening can allow the air flow to emerge upwards and / or to the side. Overall, an example triple cooling of the head part of the grate bar can be achieved. On the one hand, combustion air enters from below the grate bar in the flow direction, whereby a high heat dissipation is made possible by air circulation. For example, a substantial proportion of the air flowing directly from below the grate bar in the flow direction is ejected directly through the at least one second outlet opening in the surface upwards. On the other hand, advantageously, the head part of the grate bar in the area facing the combustion chamber side of the incinerator is cooled by circulating combustion air. Furthermore, the heat input of the grate bar during operation in the combustion system is removed by the plurality of cooling fins. The cooling fins extend from the bottom of the surface of the grate bar down. For example, six cooling fins running parallel to one another may be provided, wherein the two closing longitudinal edges of the grate bar may likewise be designed as cooling fins. The cooling fins are thus formed as cooling channels and provide sufficient cooling surface. As a result, a high heat dissipation is ensured, which is dissipated by the aforementioned circulating flow air to the outside. The number of cooling fins and / or their dimensions, for example their thickness, can be adaptable and can be matched to the respective combustion purpose.

Preferably, the first partial flow channel emerges forward relative to the longitudinal direction of the grate bar and / or extends forwardly from at least one of the sides of the grate bar. By e.g. Increased air is directed to the front side, the air supply to the front side and thus the fanning of the here burning material can be regulated. In order that the temperature at the front side does not become too high as a result of the fanning in, it is possible, for example. reduces air to the front and more air to be directed upwards.

Preferably, the second partial flow channel emerges upwards in relation to the longitudinal direction of the grate bar and / or upwards from at least one of the sides of the grate bar. In order for the temperature at the top to be removed from the surface of the grate bar by e.g. Fanning does not become too high, can e.g. decreases air upwards and more air is directed forward.

According to the invention, the flow channel is formed at least in sections between the inner surface of the end face of the head part and a portion of a flow air guide element arranged at a distance therefrom. Here, the flow-air guide element may also be formed as at least one cooling fin, which extends substantially perpendicular to the longitudinal extent of the grate bar. The end face and at least a portion of the flow air guide element may in this case run parallel to each other. Within the thus trained flow channel, the flow of air can flow freely and thereby advantageously dissipate heat to the outside.

According to the invention, the first outlet opening is formed by a gap between a section of the front side and a front edge section of the surface. This gap forms a portion of the first partial flow passage. In other words, a first portion of the divided flow air can escape through this gap. The first partial flow channel can be changed in its dimensions, so as to vary the air ejection or volume flow from the first outlet opening at the front end side. Advantageously, this proportion of the flow air cools the combustion chamber facing the front side of the grate bar by heat dissipation to the outside. In this case, the front edge section of the surface may overlap the upper end of the front side, so that the first portion of the flow air emerging from the first partial flow channel can be deflected by 180 °. This deflected portion of the flow air can then sweep downstream as large a surface area of the outer end face and thus dissipate heat. Of course, different deflection angles are adjustable, which differ from 180 °. Preferably, the front side and / or the surface is at least partially with a heat-resistant layer which comprises a plurality of ceramic sheets.

Preferably, the heat-resistant layer comprises a ceramic material. The refractory layer may alternatively or additionally comprise slag and / or non-combustible components. Here, the heat-resistant layer may be provided at least on the head part of the grate bar. For example, the heat-resistant layer can extend to the second outlet opening. Alternatively, the heat-resistant layer may extend across the second exit aperture to e.g. 50% to 70% of the length of the grate bar extend. Further alternatively, the heat-resistant layer may extend over the entire length of the grate bar. The heat-resistant layer comprises the plurality of ceramic sheets, which serve as a total heat shield and thus prevent excessive heating of the grate bar. Thus, the life of the grate bar can be extended.

Preferably, at least portions of the end face and / or the surface comprise a plurality of wedge-shaped depressions, within which the ceramic webs are registered at least in sections. The wedge-shaped depressions are formed such that they are tapered in the direction of the outside. By the term "wedge-shaped to the outside tapered recess" is meant that the cross-section of the recess decreases toward the outside. In other words, that is Edge length of the recess in the material of the grate bar greater than the edge length on the outside thereof. As a result of this embodiment, the material of the ceramic webs is reliably held in the depressions after curing. In the wells formed, other materials can alternatively be fixed, such as slag, non-combustible components or refractory concrete. The material of the grate bar and the material of the ceramic sheets usually have different thermal expansion coefficients. The design of the depressions in wedge-shaped form reliably prevents detachment of the ceramic sheets or the ceramic layer from the grate bar despite the entry of great heat and also different thermal expansion coefficients between the grate bar material and the ceramic sheet material. The ceramic material is thus reliable in the wells and thus provides a durable heat shield.

Preferably, the wedge-shaped depressions on the front side and / or on the surface in relation to the grate bar vertically and / or horizontally aligned. Thus, the ceramic sheets can run in a variant on the front side and / or on the surface in several parallel paths. In a preferred variant, however, the ceramic webs run on the front side and / or on the surface in vertical and horizontal paths. Here, the tracks preferably cross each other perpendicular. Due to the cross-shaped extent of Ceramic tracks are prevented from being levered out during operation. The cured ceramic sheets are in fact positively connected in all directions with the material of the grate bar and therefore can not be displaced by resting material, eg on the surface, or by adjacent material, for example on the front side. This reliably prevents portions of the ceramic layer or even the entire ceramic layer from detaching or detaching from the grate bar. Thus, the ceramic layer protects the grate bar overall reliable and durable against heat.

Preferably, the grate bar comprises at least one deflecting element, which is arranged at the first outlet opening, wherein at least one air guide surface of the deflecting element is aligned in such a way to deflect the exiting air flow directed at an angle to the front. In this case, the air flow can be deflected in such a way that the air flow impinges on the fuel at a predetermined distance from the end face of the head part, or impinges the burning fuel with air and thus ignites it. By appropriate selection of the angle thus the temperature can be adjusted on the front page. In addition, by redirecting the exiting air too much fluidization of material, e.g. Ashes, which lies in front of the front, are avoided.

Preferably, the deflection element comprises a arranged on the outside of the end face first Wedge portion and / or formed on the edge portion of the surface of the second wedge portion. In this case, air guide surfaces of the wedge sections facing each other and form an exit channel therebetween, which is aligned at an angle. Another advantage of the deflecting element is that it can generate air turbulence on the front side, which can bring about improved heat dissipation. Also, penetration of foreign matter such as fuel, ash, slag, etc., into the first discharge port can be prevented by the first and second wedge portions, whereby blockage of the first discharge port can be prevented.

Preferably, an end of the leading edge portion of the surface is spaced a predetermined distance from a support surface of the grate bar, the distance being at least 50%, preferably at least 70%, spaced from the overall height of the leading edge portion. In this way it can be ensured that the front outlet opening does not come into contact or is greatly reduced with externally applied materials, for example kiln, slag, ash, etc. Of course, the distance at which the front edge portion of the surface is spaced from a support surface of the grate bar, depending on the particular embodiment also assume other values, such as at least 80%, at least 90%, etc. Thus, is prevented in a simple and reliable manner that the front Outlet opening is clogged. Clogging of the front outlet opening has the undesired effect of interrupting the air circulation, which in turn has a negative effect on the cooling effect. Thus, the said embodiment allows a long-lasting and reliable cooling of the grate bar and an associated extended life of the grate bar.

Preferably, the second partial flow channel is at least partially formed between an underside of the surface and a spaced therefrom arranged portion of the flow air guide element. The second partial flow channel can be changed in its dimensions, so as to vary the air ejection or volume flow from the second outlet opening at the surface. Another section of the second partial flow channel is formed by the direct connection from below the grate bar via the cooling fins to the second outlet opening. The air ejection or volume flow respectively from the front first outlet opening and the upper second outlet opening of the surface are variable in relation to each other from 0 to 100%. For example, a volume flow of 30% from the first outlet opening and a volume flow of 70% from the second outlet opening of the surface can be set. All settings in the range of 0 to 100% are possible. This setting or variation can be achieved, for example, by appropriate dimensioning of the first and / or second Part flow channels can be realized. It should be noted that by reducing the first outlet opening, an increased volume flow is set via the direct path between the underside of the grate bar and the second outlet opening. Overall, this allows a cooling adapted to the respective application.

Preferably, the second partial flow channel is at least partially formed between the underside of the grate bar and at least one of the second outlet openings, which is introduced in the longitudinal side of the grate bar. By exiting the air from at least one opening on at least one of the longitudinal sides, in relation to the grate bar, the exit of air at the end face, i.e., at the end of the grate bar, can take place. forward, and / or on the surface, i. upwards, the grate bar adjusted or regulated.

Preferably, the flow-air guide element is formed integrally with the cooling fins and formed at least in sections as a wear element. As a result, during the progressive wear of the front head part, for example an operational material detachment on the particularly stressed end face of the grate bar (wear), the flow air guide element arranged behind the end face can simultaneously serve as a wear element. Thus, advantageously, a continued use of the grate bar can be realized. Overall, the life of the grate bar is extended. The cooling fins preferably extend in the longitudinal direction of the grate bar and protrude in relation to the longitudinal direction with a variable depth from the underside of the surface, wherein preferably the depth of the cooling fins is decreasing from the head part in the direction of the grate bar support in the longitudinal direction. For example, the cooling fins are more in the range of the claimed by particularly high temperatures headboard than in the area over the length of the grate bar opposite grate bar support. This transition can be linear or non-linear. In other words, the depth of the cooling fins over the length of the grate bar may be linear or non-linearly variable. Here, the variable in relation to the longitudinal direction of the grate bar depth of the cooling fins are related to the temperature profile of the grate bar during operation. Thus, the cooling fins are adapted to the temperature profile of the grate bar during operation, whereby on the one hand a further reliable heat dissipation is realized to extend the life and on the other hand material and weight and thus costs of the grate bar are saved altogether. It also costs in warehousing and transport are saved. The depth of the cooling fins can decrease from the head part in the direction of the grate bar support in the longitudinal direction. As a result, a greater heat dissipation can be realized in the region of the head part than in the region of the grate bar support opposite the length of the grate bar. This feature takes into account the fact that the front headboard is exposed to much higher temperatures and thus should be cooled more than the area of the grate bar support located at the opposite end of the grate bar. The spaces between each adjacent cooling fins are formed as cooling channels. As a result, the cooling surface is increased overall. Further, the heat radiated on the surface of the cooling fins can be easily dissipated by circulating air cooling within the cooling channels. The number and dimensions (eg depth) of the cooling channels can be adapted to different calorific values, fuels and grate systems. Furthermore, the cooling channels can be adjusted in size and number depending on the purpose of combustion. As a result, the efficiency of the grate bar can be increased, at the same time sufficient cooling and the resulting extended life. By reducing the temperature difference by means of the matched cooling fins, heat induced mechanical stresses in the grate bar are reduced. Thus, the risk of temperature fractures is significantly reduced.

Preferably, the at least one second exit opening is arranged at a maximum of 20% in relation to the total length of the surface away from the front edge. The distance between the second exit opening in relation to the total length of the surface from the leading edge may, of course, also have other values as long as the second exit opening is located at a position in the surface at which only fuel is run over during operation. This avoids that the second outlet opening of a grate bar is covered by one or more grate bars of a row of grate bars arranged above and in this way the air ejection from the second outlet opening is partially or completely blocked. The grate bar may comprise a material containing metal. The grate bar may be formed of a material of a metal alloy.

Preferably, the grate bar is designed as a Wenderoststab. Such reversible rods can, as soon as the end of the life of the first head part (advanced wear), which is exposed during operation particularly high temperature influences is reached, are turned, or turned 180 ° about the central axis perpendicular to the surface or pivoted. After turning then the former opposite headboard of the grate bar can be used again over a long period of operation. To realize the turning bar, two support surfaces or grate bar supports arranged symmetrically with respect to the center of the grate bar are formed on the underside of the grate bar. Thus, the life of the grate bar can be nearly doubled, thereby realizing high cost savings.

The above object is also achieved by a grate for use in an incinerator, wherein the grate comprises at least one grate bar according to one of claims 1 to 16. Such a rust for use in one Combustion plant offers a large combustion area. It can be arranged with their long sides parallel to each other aligned to a transverse row several grate bars.

Preferably, the grate comprises a plurality of successively arranged transverse rows of a plurality of grate bars. The transverse rows arranged one behind the other can be arranged overlapped at least in sections. At least one grate bar can overlap with its bearing surface the surface of a subsequent grate bar shingled. For example, a first transverse row of several grate bars is arranged to be movable and, following the first transverse row, an at least partially overlapped second transverse row of several grate bars is fixedly arranged. By this arrangement it is achieved that the combustion material can be continuously moved or advanced towards the combustion side.

The above object is also achieved by a combustion system comprising a grate according to claim 17 or 18. In such an incinerator maintenance intervals can be extended. Such an incineration plant therefore advantageously has to be shut down less frequently than in currently known incineration plants. Thus, the efficiency of the incinerator is improved.

Fig. 1:

eine Draufsicht auf eine Oberfläche eines Roststabes,

Fig. 2a:

eine Seitenschnittansicht entlang einer Linie E-E des in Fig. 1 gezeigten Roststabes in einer ersten Ausführungsform,

Fig. 2b:

eine Schnittansicht entlang einer Linie C-C des in Fig. 2a gezeigten Roststabes,

Fig. 3a:

eine schematische Seitenansicht des Roststabes in der ersten Ausführungsform,

Fig. 3b:

eine Ansicht auf ein hinteres Ende des Roststabes in der ersten Ausführungsform,

Fig. 3c:

eine Ansicht auf ein vorderes Ende des Roststabes in der ersten Ausführungsform,

Fig. 4:

eine Schnittansicht entlang einer Linie A-A des in Fig. 2a gezeigten Roststabes in einer Draufsicht,

Fig. 5a:

eine Seitenschnittansicht entlang einer Linie E-E des in Fig. 1 gezeigten Roststabes in einer zweiten Ausführungsform,

Fig. 5b:

eine Schnittansicht entlang einer Linie C-C des in Fig. 5a gezeigten Roststabes,

Fig. 6a:

eine schematische Seitenansicht des Roststabes in der zweiten Ausführungsform,

Fig. 6b:

eine Ansicht auf ein hinteres Ende des Roststabes in der zweiten Ausführungsform,

Fig. 6c:

eine Ansicht auf ein vorderes Ende des Roststabes in der zweiten Ausführungsform,

Fig. 7:

eine Seitenschnittansicht entlang einer Linie E-E des in Fig. 1 gezeigten Roststabes in einer weiteren Variante der zweiten Ausführungsform,

Fig. 8a:

einen Teilausschnitt des Kopfteils vom Roststab in einer ersten Variante einer dritten Ausführungsform,

Fig. 8b:

einen Teilausschnitt des Kopfteils vom Roststab in einer zweiten Variante der dritten Ausführungsform,

Fig. 8c:

eine Ansicht auf die Stirnseite des Kopfteils in der zweiten Variante der dritten Ausführungsform, und

Fig. 9:

eine schematische Seitenansicht von mehreren übereinander angeordneten Roststäben zur Ausbildung eines Rosts.

It is expressly understood that the above embodiments are arbitrarily combinable. Only those combinations of variants are excluded, which would lead to contradictions by the combination. In the following, the present invention will be explained with reference to embodiments shown in the drawings. Showing:

Fig. 1:

a top view of a surface of a grate bar,

Fig. 2a:

a side sectional view along a line EE of in Fig. 1 shown grate bar in a first embodiment,

Fig. 2b:

a sectional view taken along a line CC of the in Fig. 2a shown grate bar,

Fig. 3a:

a schematic side view of the grate bar in the first embodiment,

3b:

a view of a rear end of the grate bar in the first embodiment,

3c:

a view of a front end of the grate bar in the first embodiment,

4:

a sectional view taken along a line AA of in Fig. 2a shown grate bar in a plan view,

Fig. 5a:

a side sectional view along a line EE of in Fig. 1 shown grate bar in a second embodiment,

Fig. 5b:

a sectional view taken along a line CC of the in Fig. 5a shown grate bar,

6a:

a schematic side view of the grate bar in the second embodiment,

Fig. 6b:

a view of a rear end of the grate bar in the second embodiment,

Fig. 6c:

a view of a front end of the grate bar in the second embodiment,

Fig. 7:

a side sectional view along a line EE of in Fig. 1 shown grate bar in a further variant of the second embodiment,

8a:

a partial section of the head part of the grate bar in a first variant of a third embodiment,

8b:

a partial section of the head part of the grate bar in a second variant of the third embodiment,

8c:

a view of the front side of the head part in the second variant of the third embodiment, and

Fig. 9:

a schematic side view of several stacked grate bars to form a grate.

FIG. 1 shows a plan view of a grate bar 10th FIG. 2a shows a side sectional view of the in FIG. 1 shown grate bar 10 along a line EE in a first embodiment. The grate bar 10 comprises a arranged at its front end head portion 12. Further, the grate bar 10 comprises a arranged at the opposite end of the grate bar 10 grate bar support 14 for resting on a Rostbelagswelle 16 for supporting the grate bar 10. The grate bar 10 is from above by a planar surface 18 completed. The top of the surface 18 is the Furnace combustion chamber (not shown) exposed while the underside of the surface is, for example, by an airflow unit, not shown, with an upward flow of air flow.

The head part 12 comprises an end face 20, the outside of which is exposed to the combustion chamber of the incinerator. The upper end of the end face 20 is surmounted by a front edge portion 22 of the surface 18, wherein the front edge portion 22 at least partially follows the contour of the upper end of the end face 20. The end face 20 and the front edge portion 22 of the surface 18 are spaced from each other by a predetermined gap. The front edge portion 22 of the surface 18 is bent around the upper end of the end face 20 substantially oriented at 90 ° downwards.

The downwardly directed distal end of the front edge portion 22 overlaps only with the upper end of the end face 20. This provides the distance between the downwardly bent distal end of the surface 18 and the underside of the end face 20, which hereinafter also referred to as support surface 23 In other words, the distance between the distal end of the leading edge portion 22 of the surface 18 and the support surface 23 in relation to the total height of the grate bar 10 is a predominant proportion As a result, the gap between the end face 22 and the surface 18 as far as possible from the support surface 23 and the underside of the grate bar 10 spaced, which can be avoided that foreign substances enter the gap and can clog it.

The grate bar 10 further includes a flow air guide element 24 which is disposed within the grate bar 10 and is integrally formed therewith. The flow air guide element 24 comprises a vertical section 24a, which is aligned substantially parallel to the front side 20, and a horizontal section 24b, which is aligned substantially parallel to the surface 18. All sections 24a, 24b of the flow-air guide element 24 are in this case both the end face 20 and the underside of the surface 18 spaced.

The longitudinal sides of the grate bar 10 are delimited by side surfaces 26 to the outside. The inner region of the grate bar 10, that is to say the underside thereof streamed by the air flow, is equipped with a multiplicity of cooling ribs 28 which project from the underside of the surface 18, as best illustrated in FIG FIGS. 2b . 3b and 3c to recognize. The cooling fins 28 are used for air cooling and extend parallel to each other in the longitudinal direction, as best with reference to FIGS. 1 and 4 to recognize. The cooling fins 28 also extend parallel to the side surfaces 26 and together form one increased surface area, thus offering a significantly increased heat radiation surface. For example, four cooling fins 28 (exclusively the two side surfaces 26) may be provided. Of course, the number of cooling fins 28 may vary depending on the application. The cooling fins 28 are preferably formed integrally with the entire grate bar 10.

As previously mentioned, the grate bar 10 is flown from below with an air flow. A portion of this air flow flows within cooling channels, which are each formed between the cooling fins 28 as well as between the side surfaces 26 and a respectively spaced apart therefrom cooling fin 28. Thus, the heat radiated from the cooling fins 28 as well as the side surfaces 26 can be easily dissipated by means of the air flow through the cooling channels, whereby the total temperature of the grate bar 10 can be reduced during operation.

In operation, the head portion 12 is exposed to a particularly high temperature in relation to other portions of the grate bar 10. It has therefore been shown in practice that in particular the head part 12 of the grate bar 10 may be exposed to a relatively rapid heat-related wear, this wear can lead to failure of the entire grate bar 10. In order to discharge this very high heat input in the region of the head part 12 in a particularly reliable manner, the cooling ribs 28 protrude in the region of the Head portion 12 maximum from the bottom of the surface 18 before. With increasing distance from the head part 12 in the direction of the opposite grate bar support 14, the cooling fins 28 protrude progressively reduced from the underside of the surface 18. The decreasing from the head portion 12 to the grate bar support 14 depth of the cooling fins 28 is based on the FIGS. 2a and 3a particularly clearly visible. In other words, the cooling fins 28 have a dimension or depth adapted to the temperature profile. Advantageously, heat induced mechanical stresses in the grate bar 10 can be reduced by reducing temperature differences across the grate bar 10 by means of the matched cooling fins 28. Thus, the risk is substantially reduced that the grate bar 10 is destroyed by temperature breakage.

Another portion of the flowed air stream flows along a flow channel 30, which is formed between the end face 20 and a vertical portion 24 a of the flow air-guiding element 24. In this case, the air flowing inside the flow channel 30 carries off the heat radiated from the end face 20. In the upper region of the flow channel 30, the flow channel 30 merges into a first partial flow channel 32. The first partial flow channel 32 leads to an outlet opening 36 (gap) between the upper end of the front side 20 and the downwardly bent front edge portion 22 of the surface 18th

A second partial flow channel 34 leads to at least one introduced in the surface 18 second outlet opening 38. It should be noted that a high proportion of the total volume flow supplied via the second partial flow channel 34, ie the direct path from below the grate bar on the cooling fins 28, at the second outlet opening 38 can be ejected. The second outlet opening 38 is preferably formed as an outlet slot. A proportion of the air flow flowing via the second partial flow channel 34 can be conducted via a channel between the horizontal section 24b and the underside of the surface 18 in the direction of the first outlet opening 36 and ejected there. The first and second partial flow channel 32, 34 and the flow direction of the volume flows are in the FIG. 3a indicated schematically by arrows. In the embodiment shown in the figures, two second outlet openings 38 are designed as slots. Although not shown, second exit openings may be provided laterally which laterally vent at least a portion of the airflow, spaced from the end face. Of course, the number of second outlet openings 38 may vary. The second outlet openings 38 are arranged in areas of the surface 18 between the cooling fins 28. The second outlet openings 38 can be introduced into the surface 18 in each case in an area to the right and to the left of a respective cooling rib 28 and / or side surface 26. The portions of the air flow or of the volume flow respectively flowing in the first and second partial flow channels 32, 34 are thus expelled to the outside through the front first outlet opening 36 and the upper second outlet opening 38, thereby dissipating heat to the outside. The expelled by the first outlet opening 36 portion of the air flow is ejected in the first embodiment, due to the deflection of substantially 180 ° down. The expelled portion of the air flow can flow over significant portions of the outer surface of the end face 20 and thus dissipate the heat radiated therefrom. Although not shown, a plurality of first outlet openings can be provided, through which a portion of the air flow in the region of the head part 12 can be ejected laterally.

The first and second partial flow channel 32,34 are at least partially variable to variable flow rates or variable air outlet adjustable. Thus, the volume flows of each of the air ejection from the first outlet opening 36 on the end face 20 and the air ejection from the second outlet opening 38 on the surface 18 are advantageously variable. Of course, in addition or alternatively, the respective volume flows of the air ejection from the first outlet opening 36 and / or the air outlet from the second outlet opening 38, in each case from at least one of the sides of the grate bar 10, be variable. The The setting can be 0 to 100% in relation to the total volume flow supplied. It can be provided, for example, that 30% of the total volume flow is expelled through the front outlet opening 36, while 70% thereof is ejected through the upper second outlet opening 38. By the variably adjustable volume flows in the region of the head part 12 of the grate bar 10, an application-specific efficient cooling thereof can be set.

The volume flow of the portion flowing through the second outlet opening 38 can be achieved, for example, by adjusting or adapting the second outlet opening 38 itself. For this purpose, for example, the extent or the dimension of the second outlet opening 38 can be changed. In one example, the length of the slot of the second exit port 38 may be changed (shortened or extended). Alternatively or additionally, the width can be changed. Although in FIG. 2b two outlet openings 38 are indicated in a region of the surface 18 between the second and third and the third and fourth cooling rib 28, the outlet openings 38 may alternatively or additionally be arranged in a region of the surface 18 between the further cooling fins 28 and outside the side surfaces 26 , If the front first outlet opening 36, for example, by changing the variably adjustable exiting air volumes, is greatly narrowed or completely blocked, the portion of the air flow flowing through the flow channel 30 is wholly or partly passed through the channel between the horizontal portion 24 b and the underside of the surface 18 in the direction of the second outlet opening 38.

Another advantage of the variably adjustable air volumes exiting is that this also the respectively expelled air pressure can be regulated. For example, when burning biomass and wood chips, it is desired that the air emanates under the grate with a relatively low air pressure. The reduction of the air pressure at this point can be achieved, for example, by increasing the second outlet openings 38. Thus, overall, the dust turbulence within the combustion chamber is reduced by the incinerator. By ejecting the air from at least one of the sides of the grate bar 10, the dust re-agitation can be further reduced in an application-specific manner.

In order to continue to ensure a reliable air ejection from the second outlet opening 38, this second outlet opening 38 is positioned such that it is run over only by fuel. In other words, the outlet opening (s) 38 is or are arranged such that they are not covered by sections of a grate bar 10 arranged above it (eg the support surface of an upper grate bar) and thus blocked. The dimension of the second outlet opening 38 can also advantageously be chosen such that no or only reduced foreign material from above, such as ash and light metals, can pass through the second outlet openings 38 and thus fall through the grate bar 10. Overall, a drop of foreign material can be prevented by a particularly narrow design of the outlet openings 38. Due to the adaptability of the outlet openings 38, a high air resistance of the rust coating can be achieved, which is particularly advantageous for the combustion of waste. A levering of the grate bar 10 can be prevented by the grate bar support 14 is adapted to the Rostbelagswelle 16 the shape of this wave.

FIG. 5a shows a grate bar 10 of a second embodiment in a side sectional view taken along a line EE of FIG FIG. 1 shown grate bar 10, and FIG. 5b shows a sectional view taken along a line CC of FIG FIG. 5a shown grate bar 10. FIG. 6a shows a schematic side view of the grate bar 10 in the second embodiment, and FIGS. 6b, c each show a view of a rear or a front end of the grate bar 10 in the second embodiment. In different embodiments of the grate bar 10, the same components are also given the same reference numerals throughout the description.

The grate bar 10 in the second embodiment comprises a deflecting element 39, which is arranged at the first outlet opening 36, wherein at least one air guide surface of the deflecting element 39 is oriented such that the outgoing air flow is deflected at an angle facing the front. Thus, a targeted air deflection is possible. In this case, the air flow can be deflected such that the air impinges on a predetermined distance to the end face 20 of the head part 12 on the upstream fuel and the burning fuel is supplied with air and thus, for example. fanning. By appropriate selection of the angle thus the temperature at the end face 20 can be reduced. In addition, by redirecting the exiting air too much fluidization of the upstream material, e.g. Ash, to be avoided.

The deflecting element 39 comprises a first wedge section 39a arranged on the outer side of the end face 20 and / or a second wedge section 39b formed on the edge section by the surface 18. In this case, air guide surfaces of the wedge sections 39a, 39b face each other and form therebetween an outlet channel, which is aligned at an angle to the front. Another advantage of the deflecting element 39 is that air turbulences can advantageously be produced on the end face 20, which can bring about improved heat dissipation. Further, these air turbulences may have beneficial effects of fuel combustion. Further advantageously, by the first and second wedge portion 39a, 39b penetration of eg fuel, ash and slag in the first outlet opening 36 can be prevented. Thus, a blocking of the first outlet opening 36 is advantageously prevented.

FIG. 7 shows a side sectional view along a line EE of in FIG. 1 shown grate bar 10 in a third embodiment. In the illustrated embodiment of the grate bar 10, a further flow air guide element 24 'is provided, which is arranged in the direction of the interior of the grate bar 10 behind an upstream flow air guide element 24. In the case of wear of the upstream flow air guide element 24 ", this further serves Flow air guide element 24 'then as Verschleissobjekt. Thus, continued operation of the grate bar 10 is ensured even after wear of the upstream flow air guide 24 ", thereby extending the overall life of the grate bar 10, thereby delaying intervals for exchanging the grate bar 10. Overall, high cost savings can thus be realized.

FIG. 8a shows a partial section of the head part 12 of the grate bar 10 in a first variant of a third embodiment, and FIG. 8b shows a partial section of the head part 12 of the grate bar 10 in a second variant of the third embodiment. In the third embodiment of the grate bar 10 is equal to the second embodiment, the downstream flow air guide element 24 ', which is arranged behind the upstream flow air guide element 24 ", so as to serve in the event of wear of the upstream flow air guide element 24" as a further Verschleissobjekt.

In the third embodiment, in addition, the end face 20 and a portion of the surface 18 in the region of the head part 12 are covered with a heat-resistant layer, which is also referred to below as a ceramic layer. The ceramic layer comprises a plurality of refractory sheets 40, which may comprise ceramic. The heat-resistant webs 40 are also referred to below as ceramic webs 40. Overall, the ceramic layer protects the grate bar 10 reliably against heat.

For this purpose, the end face 20 and the portion of the surface 18 in the region of the head part 12 are provided with wedge-shaped recesses 42, within which the ceramic sheets 40 are registered. At the end face 20, the wedge-shaped recesses 42 are shown in the transverse direction to the grate bar 10 and horizontally aligned (see FIGS. 8a, b ). On the surface 18, the wedge-shaped recesses 42 are also shown aligned transversely to the grate bar 10 (see FIG. 8b ). Thus, the ceramic sheets 40 are aligned parallel to each other tracks.

As in FIG. 8c shown, in a preferred variant, the ceramic sheets on the end face 20 and on the surface or at the front edge portion 22 can extend in horizontal and vertical paths. For this purpose, the recesses 42 are entered perpendicular to each other in the material of the grate bar. Once the ceramic material is recessed into the recesses 42 and cured, the ceramic sheets extend perpendicular to each other (not shown). Due to the cross-shaped extent of the ceramic sheets whose Aushebung from the recesses 42 is reliably prevented. In other words, the cured ceramic sheets are positively connected in all directions with the material of the grate bar. Thus, it is avoided that the ceramic sheets are displaced by resting on the surface of the material and applied to the end face 20 material. In addition, a detachment of the ceramic sheets is also prevented on the heavily stressed front edge portion 22. Overall, it is reliably prevented by the cross-shaped arrangement or formation of the ceramic sheets that detach portions of the ceramic layer or even the entire ceramic layer detaches from the grate bar. Thus, the ceramic layer protects reliable overall and durable the grate bar against strong heat.

Another advantage of in FIG. 8c shown crosswise arrangement of the ceramic sheets 40 is that they thus provide an enlarged area. In other words, As a result, a smaller area of the material of the grate bar 10 is exposed to the intense heat.

For better illustration, in FIGS. 8a, b In the region of the front side 20 or additionally in the region of the surface portion of the head part 12, the depressions 42 are shown with recessed ceramic sheets 40. The ceramic sheets 40 may alternatively or in addition to the ceramic also include slag, non-combustible components or refractory concrete. As in FIG. 8b shown, the ceramic sheets 40 may be provided at least in the region of the head portion 12 of the grate bar 10 on the surface 18 and in this case extend only to the second outlet opening 38. Although not shown, the ceramic sheets 40 may extend across the second exit opening 38 along, for example, 50% to 70% of the length of the grate bar 10. Also, the ceramic sheets 40 may extend over the entire length of the grate bar 10. The ceramic layer with the respective ceramic tracks 40 serves as a heat shield and protects the grate bar 10 against excessive heating.

As previously mentioned, the ceramic sheets 40 are inserted within the wedge-shaped recesses 42. In this case, the top of the respective ceramic tracks 40 with the upper edge of the recesses 42, ie the not removed portions of the grate bar, close substantially flush. The wedge-shaped recesses 42 are formed so that they are in the direction of the outside rejuvenate. In other words, the cross-section of the depressions 42 decreases towards the outside, or the edge length of the respective depressions 42 in the material of the grate bar 10 is greater than the edge length on the outside thereof. Thus, after curing, the ceramic layer 40 is reliably held within the recesses 42. In the recesses 42, other materials can alternatively be fixed, such as slag, non-combustible components or refractory concrete.

The coefficient of thermal expansion of the grate bar 10 is higher than that of the ceramic sheets 40. In order nevertheless to prevent detachment of the ceramic sheets 40 from the grate bar 10 while the grate bar 10 is exposed to high temperatures, the recesses 42 are wedge-shaped such that the recesses 42 in the direction taper to the outside, or the cross-section of the recesses 42 decreases towards the outside. Thus, the ceramic sheets 40 remain reliably connected to the grate bar 10, even if its material expands by heat stronger than the ceramic sheets 40 itself. An additional stop is through the in FIG. 8c shown cross-like arrangement of ceramic tracks 40 given to each other. The ceramic sheets 40 are thus positively connected in all directions with the material of the grate bar 10. The ceramic sheets 40 thus remain reliably within the recesses 42 and therefore form a durable and reliable heat shield.

As in FIG. 9 shown, a plurality of grate bars 10 are arranged in several rows one above the other stepwise and thus form an inclined plane over which the kiln (not shown) runs, or thus serve to transport the kiln via a thus formed overall grate 44. Here, overlap cross rows each several grate bars 10 partially over each other. The individual transverse rows may be displaceable relative to one another, in order thus to enable a transport of the fuel by a mutual displacement of the overlapping grate bars 10. In one example, a fixed, that is not movable, transverse row of grate bars 10 may be interposed between two movable transverse rows of grate bars 10.

Claims (19)

1. A grate bar (10) comprising a substantially closed surface (18) facing a combustion side, a grate bar support (14) adapted to rest on a grate decking shaft (16), a head portion (12), and a plurality of cooling fins (28) for air cooling, which project from the bottom of the surface (18), wherein the head portion (12) comprises at least one flow channel (30) which is subdivided downstream into at least a first and second partial flow channel (32, 34), wherein the first partial flow channel (32) leads towards at least one first outlet opening (36) at the end face (20) of the head portion (12) and the second partial flow channel (34) leads towards at least one second outlet opening (38), which is spaced apart from the end face (20), which is opened towards the bottom of the surface (18), wherein the flow channel (30) is formed at least partially between the inner surface of the end face (20) of the head portion (12) and a portion (24a) of a flow air-guiding element (24), which is arranged spaced apart therefrom, characterized in that the first outlet opening (36) is formed through a gap between a portion of the end face (20) and a leading edge portion (22) of the surface (18).
2. The grate bar (10) according to claim 1, wherein the first partial flow channel (32), in relation to the longitudinal direction of the grate bar (10), emerges forwardly and/or forwardly from at least one of the sides of the grate bar (10).
3. The grate bar (10) according to claim 1 or 2, wherein the second partial flow channel (34), in relation to the longitudinal direction of the grate bar (10), emerges upwardly and/or upwardly from at least one of the sides of the grate bar (10).
4. The grate bar (10) according to one of the preceding claims, wherein the end face (20) and/or the surface (18) is at least partially covered with a heat-resistant layer, which comprises a plurality of ceramic sheets (40).
5. The grate bar (10) according to claim 4, wherein the heat-resistant layer comprises a ceramic material.
6. The grate bar (10) according to claim 4 or 5, wherein at least portions of the end face (20) and/or the surface (18) comprise a plurality of wedge-shaped depressions (42), within which the ceramic sheets (40) are at least partially inserted.
7. The grate bar (10) according to claim 6, wherein the wedge-shaped depressions (42) at the end face (20) and/or at the surface (18) are aligned vertically and/or horizontally in relation to the grate bar (10).
8. The grate bar (10) according to one of the preceding claims, further comprising at least one deflecting element (39) which is arranged at the first outlet opening (36), wherein at least one air guiding surface of the deflecting element (39) is aligned such to angular redirect the exiting air flow to the front.
9. The grate bar (10) according to claim 8, wherein the deflecting element (39) includes a first wedge section (39a) arranged at the outside of the end face (20) and/or a second wedge section (39b) formed at the edge section (22) of the surface (18).
10. The grate bar (10) according to one of claims 1 to 9, wherein an end of the leading edge portion (22) of the surface (18) is spaced apart from a support surface (23) of the grate bar (10) by a predetermined distance, wherein the distance being spaced apart from the overall height of the leading edge portion by at least 50%, preferably at least 70%.
11. The grate bar (10) according to one of the preceding claims, wherein the second partial flow channel (34) is formed at least partially between a bottom of the surface (18) and a portion (24b) of the flow air-guiding element (24), which is arranged spaced apart therefrom.
12. The grate bar (10) according to one of the preceding claims, wherein the second partial flow channel (34) is formed at least partially between the bottom of the grate bar (10) and at least one of the second outlet openings (38), which is formed into the longitudinal side of the grate bar (10).
13. The grate bar (10) according to one of the preceding claims, wherein the flow air-guiding element (24) is formed integrally with the cooling ribs (28) and is formed at least partially as a wear element.
14. The grate bar (10) according to one of the preceding claims, wherein the cooling fins (28) extend in the longitudinal direction of the grate bar (10) and, in relation to the longitudinal direction, project with variable depth from the bottom of the surface (18), wherein preferably the depth of the cooling fins (28) from the head portion (12) in the direction to the grate bar support (14) is decreasing in the longitudinal direction.
15. The grate bar (10) according to one of the preceding claims, wherein the at least one second outlet opening (38), in relation to the total length of the surface, is arranged at most 20% apart from the leading edge.
16. The grate bar (10) according to one of the preceding claims, designed as a turnaround bar.
17. A grate (44) for use in an incinerator, comprising at least one grate bar (10) according to one of claims 1 to 16.
18. The grate (44) according to claim 17, comprising a plurality of successively arranged transverse rows, each comprising a plurality of grate bars (10).
19. An incinerator comprising a grate (44) according to claim 17 or 18.

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