Grate barrier element for a combustion grate

Description

[0001] The present invention relates to a grate track limiting element for a combustion grate for the combustion of waste and to a combustion grate comprising at least one such grate track limiting element.

[0002] Combustion grates for the large-scale incineration of waste have long been known to those skilled in the art. Such grates can be in the form of pusher grates, which include moving parts to perform stoking strokes. The material to be combusted is conveyed in the direction of travel from an inlet end of the grate to an outlet end and is incinerated during this process. To supply the grate with the oxygen required for combustion, appropriate air inlets are provided through the grate, through which the air – also called primary air – is introduced.

[0003] A commonly used type of combustion grate is the so-called stepped grate. This consists of grate blocks arranged side by side, each forming a row of grate blocks. The rows of grate blocks are arranged one above the other in a step-like fashion, whereby in so-called feed grates, the front end of a grate block (viewed in the direction of feed) rests on a support surface of the adjacent (underlying) grate block (viewed in the direction of transport) and is moved along this support surface during the corresponding feed motion.

[0004] Due to the high temperatures during combustion and in the firebox, the grate blocks are subjected to very high thermal stress. This thermal stress promotes erosion through abrasion and chemical reactions occurring on the contact surface, which further damage it. Ultimately, all of this leads to a reduction in the service life of the grate block.

[0005] To reduce thermal stress, the grate bars are normally cooled from below, i.e., on the side of the combustion grate opposite the combustion process, using a coolant or cooling fluid. Water or air is typically used as the coolant, which is why they are often referred to as air-cooled or water-cooled grate blocks.

[0006] Since the grate sections expand due to the heat generated during combustion and contract again when the moving grate of the sliding grate furnace stops, the individual grate sections are arranged so that they can expand at least on one longitudinal side. This expansion can lead to problems if it deforms parts and / or creates gaps through which primary air enters the combustion chamber uncontrollably. This primary air promotes uncontrolled combustion, which further increases the thermal stress.

[0007] In the case of two-lane sliding grates or those which have multiple two-lane grates arranged side by side, a grate separation is formed in the middle between the two grates, consisting of individual stationary grate separation elements, which is also referred to as a center beam.

[0008] DE 69105120 T2 discloses a connecting beam designed to guarantee thermal expansion compensation and tightness of a space between two laterally attached grate panels.

[0009] WO 2018 / 149516 A1 discloses a grate separation element which is designed as a single-piece casting. Due to its one-piece design, the grate separation element can only partially accommodate the lateral expansion of the grate, which can lead to the aforementioned gaps and, consequently, to the unintended entry of primary air into the combustion chamber.

[0010] It is therefore the object of the present invention to eliminate the disadvantages of the prior art and to provide a grate track limiting element which compensates for the thermal expansion of the grate tracks and thus prevents the uncontrolled escape of primary air into the combustion chamber.

[0011] This problem is solved according to the invention with a grate track limiting element according to claim 1 and a combustion grate comprising the grate track limiting element according to claims 12 and 13, as well as a combustion system according to claim 14. Preferred embodiments of the invention are described in further dependent claims.

[0012] The invention relates to a grate track limiting element for a combustion grate for waste incineration. The grate track limiting element comprises a channel element and a channel cover for covering the channel element. The channel cover comprises at least one cover element and an end element with a locking device. The end element comprises a bearing surface facing away from the channel element and a first engagement element oriented towards the cover element. The cover element comprises a bearing surface facing away from the channel element, a retaining element oriented towards the channel element, a second engagement element oriented towards the end element and designed to receive the first engagement element, and a recess oriented towards the end element for receiving the locking device of the end element. The locking device is designed such that it releasably locks the end element in the channel element.

[0013] In the context of the invention, the term "engaging element" is understood to mean an element that engages with another element or is engaged by another element. Accordingly, both a nose and a recess for such a nose are referred to as engagement elements.

[0014] The grate track limiting element according to the invention has the advantage over prior art solutions that the expansion of the grate tracks is compensated for by compressing the channel element. This leads to improved sealing of the entire construction and, consequently, to less uncontrolled flow of primary air into the combustion chamber. A design according to WO 2018 / 149516 A1 with a fixed cover does not lead to the same improved sealing. Tightness,because the expansion of the grate tracks can be compensated less effectively due to the lower elasticity of the "one-piece" channel element.

[0015] In a preferred embodiment of the grate track limiting element, the channel cover comprises a second cover element, which is preferably designed identically to the first cover element.

[0016] When attaching the duct cover, a compromise is preferably chosen between the number of individual parts to be installed and their weight. In an embodiment with an even distribution of cover element to end element, either the cover elements become relatively heavy or the effort required to fix the end elements is considerable. With the heavier cover elements, which thus cover a larger area of ​​the duct element, two installers are required to jointly position the cover element on the duct element. Furthermore, the effort required to fix the end elements should not be underestimated. Therefore, a sequence of two preferably identical cover elements with an end element is preferably used. This makes the individual parts lighter and thus easier to install, and reduces the number of end elements, thereby decreasing the effort required to fix them.

[0017] Preferably, the first engagement element is configured as a projection and the second engagement element as a recess. Accordingly, the engagement elements can be configured either as a projection or as a recess for receiving the projection. In the preferred embodiment, the cover element comprises an engagement element configured as a recess, and the cover element comprises an engagement element configured as a projection (also known as a nose), which is designed to fit the recess of the cover element. In a further preferred embodiment, the end element comprises two opposing engagement elements configured as projections, each of which engages in the recesses of the cover elements.

[0018] This design achieves improved fixation of the channel cover in the channel element, which increases the tightness of the grate barrier element.

[0019] In a preferred embodiment of the grate barrier element, the channel element comprises an opening oriented towards the channel cover for receiving the retaining element of the cover element. The opening is designed as a groove with incisions and is narrower than the width of the retaining element. The incisions are wider than the width of the retaining element of the cover element.

[0020] In the context of the invention, a groove with incisions is understood to be an elongated opening parallel to the longitudinal axis of the channel element, which has local widenings (incisions) that are wider than the groove.

[0021] This preferred design allows the cover elements and end caps to be inserted at the point of the cuts in the duct element and then slid to their final installation location. This design thus enables simplified installation and removal of the cover elements and end caps without compromising their sealing capacity.

[0022] Preferably, the channel element comprises a cooling fluid channel with a cooling fluid inlet and a cooling fluid outlet. By incorporating a fluid channel or using the channel element as a fluid channel, it can be cooled, which reduces the wear of the grate track limiting element and thus increases its service life.

[0023] In a preferred embodiment of the grate track limiting element, the opening of the channel element oriented towards the channel cover extends into the fluid channel. This preferred design allows for simplified production of the individual elements, which reduces their price and thus the price of the entire system.

[0024] Preferably, the grate track limiting element includes a sealing element attached laterally to the wall of the channel element. This sealing element further increases the grate's tightness and reduces the uncontrolled flow of primary air into the combustion chamber.

[0025] The feed grates typically comprise movable and fixed grate blocks arranged in rows. While the fixed grate block rows compress the grate track limiting element due to thermal expansion, this is not the case to the same extent for the movable grate block rows, as these must remain movable. It is therefore preferred that a sealing element be attached to the grate track limiting element above the contact point of the grate blocks, and particularly preferably that this sealing element is attached only above the movable grate blocks.

[0026] In a preferred embodiment of the grate barrier element, the bearing surface of the cover element pointing away from the channel element and the bearing surface of the end element pointing away from the channel element are designed in a gable roof or mansard roof shape, preferably with rounded edges.

[0027] In the context of the invention, the term "gable-shaped" refers to a form resembling a gable roof. That is, a form in which a roof surface slopes down on both sides of a longitudinally oriented gable. In the context of the invention, "mansard-shaped" refers to a specific form of gable roof in which the lateral roof surface sloping down from the gable does not extend as a flat plane, but is divided into several planes with different slopes.

[0028] Other preferred embodiments of the bearing surface of the cover element and the end element pointing away from the channel element are a semicircular shape, an elliptical shape or a flat plane.

[0029] The aforementioned preferred embodiments of the support surface proved to be particularly efficient in the transport and distribution of fuel on the combustion grate, so that no fuel remains on the grate track limiting element.

[0030] Preferably, the locking device is designed as a clamp, wherein the clamp is particularly preferably arranged between the bearing surface of the end element and the channel element.

[0031] This preferred embodiment of the locking device allows for easy installation and removal, while maintaining high stability of the fixation, so that the end element can be stably fixed, but is also easy to assemble and disassemble.

[0032] The arrangement of the clamp below the support surface protects the clamp from direct contact with the material being burned, thus preventing it from being blocked or stuck by the material and making it easy to assemble and disassemble.

[0033] In another preferred embodiment, the locking device is designed as a bolt with a locking pin, as a screw with or without a nut, or as an expanding element. All embodiments allow the locking device to be released with minimal effort in order to remove the end element. Even in embodiments where the locking device is designed as a bolt with a locking pin, as a screw with or without a nut, or as an expanding element, it is preferred that the locking device be arranged below the support surface to protect it from direct contact with the material being burned.

[0034] In a preferred embodiment of the grate barrier element, the bearing surface of the cover element pointing away from the channel element and the bearing surface of the end element pointing away from the channel element are designed in a sloping roof shape.

[0035] In the context of the invention, the term "shed roof-shaped" refers to a form resembling a shed roof. In a shed roof, one side slopes downwards from the gable at an angle of 10-80°, while the opposite side slopes vertically or nearly vertically. This embodiment is preferred when the grate edge element extends along the wall of the combustion chamber.

[0036] A sloping roof-shaped support surface has the advantage that fuel does not remain on the sides, preferably not on the side walls of the combustion chamber, which can lead to uncontrolled combustion.

[0037] Preferably, the locking device comprises a plate and a bolt that secures the plate in the end element. This allows for easy installation and removal of a grate barrier element that is only accessible from one side, for example, a grate barrier element that extends along the wall of the combustion chamber.

[0038] The invention further relates to a combustion grate comprising at least two grate tracks and a grate track limiting element arranged between the grate tracks as described above.

[0039] The combustion grate according to the invention has, as described above, the advantage that the flow of controlled combustion air into the combustion chamber is prevented.

[0040] The invention further relates to a combustion grate comprising at least one grate track and a grate track limiting element arranged between the grate track and a side wall of a combustion chamber of a combustion plant as described above.

[0041] The combustion grate according to the invention has the advantage, as described above, that the flow of controlled combustion air into the combustion chamber is prevented and no burning material remains along the side walls.

[0042] The invention further relates to an incineration plant for the thermal treatment of waste comprising one or more combustion grate(s) as described above.

[0043] The incineration plant according to the invention has the advantage, as described above, that the flow of controlled combustion air into the combustion chamber is prevented, which allows the combustion of waste to proceed more efficiently and reduces the maintenance required for the plant.

[0044] The invention will now be explained in more detail with reference to some exemplary embodiments illustrated in the figures. Where alternative embodiments differ only in individual features, the same reference numerals have been used for the features that remain the same. The figures are shown purely schematically: Fig. 1 a perspective view of a combustion chamber of a combustion plant; Fig. 2 a perspective view of a combustion grate with a grate track limiting element; Fig. 3 a perspective view of the grate track limiting element of Figure 2 Fig. 4 shows an exploded view of the grate track limiting element of Figure 3Fig. 5 a perspective view of an embodiment of a duct cover; Fig. 6 a bottom view of an embodiment of a cover element; Fig. 7 a bottom view of an embodiment of a finishing element; Fig. 8. A perspective view of a combustion grate with a grate track limiting element; Fig. 9. A longitudinal section through the combustion grate of Figure 8 ; Fig. 10 a perspective view of the grate track boundary element of Figure 8 ; Fig. 11 an exploded view of the grate track limiting element of Figure 10 ; Fig. 12 a detail view of a sealing element attached laterally to the wall of the channel element;

[0045] The in Figure 1 The combustion chamber 1 of a combustion plant shown in the illustration comprises a side wall 3, a combustion grate 5 comprising an air-cooled grate track 7 and a water-cooled grate track. 9. Furthermore, the combustion grate 5 comprises two grate track limiting elements 11, 13.

[0046] The Figure 2 The combustion grate 5 includes the air-cooled grate track 7, the water-cooled grate track 9 and the grate track limiting element 11 arranged between the two grate tracks.

[0047] The Figure 3 The grate barrier element 11 shows comprising a channel element 15, a channel cover 17 and a sealing element 19.

[0048] The Figure 4 Figure 1 shows the grate barrier element 11 with the channel cover 17 raised. The channel cover 17 consists of two cover elements 21, 23 and an end element 25. The channel element 15 includes a groove 27 extending longitudinally along the channel element 15, which has incisions 29.

[0049] The Figure 5Figure 1 shows a detailed view of the channel cover 17, comprising the cover elements 21, 23 and the end element 25. The cover elements 21, 23 include retaining elements 31, 32, which are located on the side of the cover elements 21, 23 facing the channel element 15. On the side facing away from the channel element 15, the cover elements 21, 23 have support surfaces 33, 35 on which the fuel rests. In this embodiment, the support surfaces 33, 35 are shaped like a mansard roof with rounded edges. Furthermore, the cover elements 21, 23 have engagement elements 37, 39, which are designed here as recesses. The engagement elements 37, 39 are oriented towards the end element 25. Below the engagement elements 37, 39, the cover elements 21, 23 each have a recess 41, 43 (whereby the recess 43 is not visible in this figure for the cover element 23).The recess 41 serves to accommodate a locking device (as described later). The . Figure 5 Figure 25 further shows a termination element 25 with a bearing surface 45 and two engagement elements 47, 49, which are designed as projections. The termination element 25 also includes a locking device 51, which is designed as a clamp.

[0050] The Figure 6 shows a bottom view of the cover elements 21, 23 including the retaining elements 31, 32, the recesses 41, 43 and the engagement element 39 (the engagement element 37 is not visible).

[0051] The Figure 7 shows a bottom view of the end element 25 with the engagement element 47 and the locking device 51.

[0052] The Figure 8Figure 1 shows a detailed view of the combustion plant including the side wall 3, the combustion grate 5 with the air-cooled grate track 7 and the grate track limiting element 13 arranged between the side wall 3 and the grate track 7.

[0053] The Figure 9 shows a longitudinal section through the combustion plant of the Figure 8 with the side wall 3, the combustion grate 5, the air-cooled grate track 7 and the grate track limiting element arranged between the side wall 3 and the grate track 7 13.

[0054] The Figure 10 shows a detailed view of the grate barrier element 13 comprising the channel element 15 with the sealing element 19 attached to the side and the channel cover 17 comprising the cover elements 21, 23 and the end element 25.

[0055] The Figure 11Figure 1 shows a detailed view of the channel cover 17 with the cover elements 21, 23 and the end element 25. The bearing surfaces 33, 35 of the cover elements 21, 23 are designed here as a sloping roof with rounded edges. The cover elements 21, 23 have the retaining elements 31, 32 on the side facing the channel element 15. Furthermore, the cover elements 21, 23 include the engagement elements 37, 39 on the side facing the end element 25, which are designed here as recesses. In addition, the cover elements 21, 23 also include the recesses 41, 43 (recess 41 is not visible) for receiving the locking device 51. Figure 11 further shows the end element 25 with the locking device 51, which here is designed as a plate with bolts.

[0056] The Figure 12Figure 1 shows a detailed view of the transition from the grate track limiting element 13 to the combustion grate 5. The channel element 15 includes sealing elements 19 attached to its sides. The sealing elements 19 are located above a series of movable grate blocks 57, which move back and forth on sliding surfaces 53 of stationary grate blocks 55. The sealing element 19 closes a gap (not shown) that forms when the combustion grate 5 contracts, through which primary air could enter the combustion chamber uncontrollably.

Claims

1. A grate line bordering element (11, 13) for a combustion grate (5) for incinerating waste comprising: a channel element (15) and a channel covering (17) for covering the channel element (15) comprising at least one covering element (21, 23) and one termination element (25) with a locking apparatus (51); wherein the termination element (25) has a supporting surface (45), pointing away from the channel element (15), and a first engagement element (47, 49), oriented toward the covering element (21, 23); wherein the covering element (21, 23) has a supporting surface (33, 35), pointing away from the channel element (15), a retaining element (31, 32), oriented toward the channel element (15), a second engagement element (37, 39), oriented toward the termination element (25) and configured to receive the first engagement element (47, 49), and a cutout (41, 43), oriented toward the termination element (25), for receiving the locking apparatus (51) of the termination element (25); wherein the locking apparatus (51) is configured in such a way that it locks the termination element (25) releasably in the channel element (15).

2. The grate line bordering element as claimed in claim 1, characterized in that the channel covering (17) comprises a second covering element (21, 23) which is preferably of identical configuration to the first covering element (21, 23).

3. The grate line bordering element as claimed in claim 1, characterized in that the first engagement element (47, 49) is configured as a projection and the second engagement element (37, 39) is configured as a cutout.

4. The grate line bordering element as claimed in one of claims 1 to 3, characterized in that the channel element (15) comprises an opening (27), oriented toward the channel covering (17), for receiving the retaining element (31, 32) of the covering element (21, 23), wherein the opening (27) is configured as a groove (28) with notches (29), and wherein the groove (28) is of narrower configuration than the width of the retaining element (31, 32), and the notches (29) are of wider configuration than the width of the retaining element (31, 32) of the covering element (21, 23).

5. The grate line bordering element as claimed in one of claims 1 to 4, characterized in that the channel element (15) comprises a cooling fluid channel with a cooling fluid inlet opening and a cooling fluid outlet opening.

6. The grate line bordering element as claimed in claim 5, characterized in that the opening (27), oriented toward the channel covering (17), of the channel element (15) extends into the fluid channel.

7. The grate line bordering element as claimed in one of claims 1 to 6, characterized in that the grate line bordering element (11, 13) comprises a seal element (19) which is attached laterally to the wall of the channel element (15).

8. The grate line bordering element as claimed in one of claims 1 to 7, characterized in that the supporting surface (33, 35, 45), pointing away from the channel element (15), of the covering element (21, 23) and of the termination element (25) is of gabled roof-like or mansard gabled roof-like configuration with preferably rounded edges.

9. The grate line bordering element as claimed in one of claims 1 to 8, characterized in that the locking apparatus (51) is configured as a clamp, wherein the clamp is preferably arranged between the supporting surface (45) of the termination element (25) and the channel element (15).

10. The grate line bordering element as claimed in one of claims 1 to 7, characterized in that the supporting surface (33, 35, 45), pointing away from the channel element (15), of the covering element (21, 23) and of the termination element (25) is of pent roof-like configuration.

11. The grate line bordering element as claimed in one of claims 1 to 7 and 10, characterized in that the locking apparatus (51) comprises a plate and a bolt which fixes the plate in the termination element (25).

12. A combustion grate (5) comprising at least two grate lines (7, 9) and a grate line bordering element (11) as claimed in one of claims 1 to 9 which is arranged between the grate lines (7, 9).

13. A combustion grate (5) comprising at least one grate line (7) and a grate line bordering element (13) as claimed in one of claims 1 to 7, 10 and 11 which is arranged between the grate line (7) and a side wall (3) of an incineration chamber of an incineration system.

14. An incineration system for the thermal treatment of waste comprising one or more combustion grates (5) as claimed in one of claims 12 and / or 13.