GRATE BLOCK FOR A COMBUSTION GRATE

Abstract

A grate block for a combustion grate, wherein consecutive grate blocks are arranged one over the other in a staircase manner and rearrange to convey the combustible material during combustion by means of pushing motions performed in relation to each other. The grate block includes a block body including an upper wall forming a bearing surface, along which wall the combustible material is conveyed, and a front wall forming a push surface, which has first air supply openings formed by a first air supply channel for feeding air to the combustion grate, and a lower bearing edge intended to come into contact with the bearing surface of a grate block located adjacent in the pushing direction S. Further air supply channels, which traverse and are directed obliquely with respect to the direction of the first air supply channels, are arranged in the upper and front walls for cooling the walls.

Claims

1. A grate block for a combustion grate, in which successive grate blocks are disposed one on top of one another in the manner of steps and are designed in such a manner that the incinerator charge is shifted and conveyed during the combustion by means of thrust movements performed relative to one another, wherein the grate block has a block body which has an upper wall and defines a longitudinal axis L, wherein the upper wall forms a bearing face along which the incinerator charge is to be conveyed and the foremost end thereof, when viewed in a thrust direction S aligned substantially parallel to the longitudinal axis L forms an edge by way of which the bearing face descends into a thrust face formed by a front wall, the front wall has first air supply openings which are in each case formed by a first air supply duct for supplying air onto the combustion grate that, when viewed in the longitudinal section, runs orthogonally or obliquely to the thrust face, and has a lower bearing edge which is disposed in a plane E running substantially orthogonally to the longitudinal axis L and is specified for coming into contact with the bearing face of a grate block adjacent in the thrust direction S, characterized by further air supply ducts for cooling the upper wall and the front wall that extend through into the upper wall and into the front wall and are aligned obliquely to the direction of the first air supply ducts.

2. The grate block as claimed in claim 1, wherein the upper wall and the front wall, in that region where the upper wall and the front wall meet, when viewed in the longitudinal section, are configured in thickened form as a wall thickening, and in that the edge, when viewed in the thrust direction S, is set forward in relation to the plane E.

3. The grate block as claimed in claim 2, wherein the further air supply are disposed in the wall thickening.

4. The grate block as claimed in claim 1, wherein the further air supply ducts, when viewed in the longitudinal section, run at an angle β to the longitudinal axis L of the block body, where β is from 10° to 60°.

5. The grate block as claimed in claim 1, wherein a first group of the further air supply ducts are configured in a first plane that runs at a first angle β1 to the bearing face of the block body, and a second group of the further air supply ducts are configured in a second plane that runs at a second angle β2 to the bearing face of the block body, where β1 is from 10° to 35°, and β2 is from 35° to 60°.

6. The grate block as claimed in claim 5, wherein the further air supply ducts of the first group are configured so as to be parallel to one another and the further air supply ducts of the second group are configured so as to be parallel to one another.

7. The grate block as claimed in claim 5, wherein the further air supply ducts in the first plane and/or in the second plane are distributed so as to be at least approximately uniformly spaced apart from one another across the width of the grate block.

8. The grate block as claimed in claim 1, wherein the further air supply ducts are distributed symmetrically to a longitudinal plane of symmetry of the grate block that runs orthogonally to the bearing face.

9. The grate block as claimed in claim 1, wherein the further air supply ducts, substantially across the length thereof, have a consistent cross-sectional area which is 40 mm.sup.2 to 100 mm.sup.2.

10. The grate block as claimed in claim 1, wherein the further air supply ducts across the length thereof are configured so as to widen continuously from the incinerator charge side to the cooling air side, wherein the cross-sectional area of the further air supply ducts on the incinerator charge side and the cross-sectional area of the further air supply ducts on the cooling air side are at a ratio of 1:1.2 to 1:2.5.

11. A combustion grate comprising at least one grate block as claimed in claim 1.

12. A method comprising applying a combustion grate as claimed in claim 11 for the incineration of waste.

13. A waste incineration plant comprising a combustion grate as claimed in claim 11.

Description

[0044] Furthermore, the present invention relates to the use of a combustion grate described above for the incineration of waste and to a waste incineration plant comprising such a combustion grate. The invention is illustrated by means of the appended figures, in which:

[0045] FIG. 1 shows a grate block according to the invention in a perspective view; and

[0046] FIG. 2 shows a fragment of the grate block according to FIG. 1 in the longitudinal section through the section plane II-II shown in FIG. 1; and

[0047] FIG. 3 shows a fragment of the grate block according to FIG. 1 in cross section through the section plane III-III shown in FIG. 2.

[0048] As can be seen from FIG. 1, the grate block 10 comprises a block body 12 which is configured as a casting and configured substantially in the form of an elongate cuboid with a longitudinal axis L.

[0049] The block body 12 comprises an upper wall 14 which forms a bearing face 16 which runs parallel to the longitudinal axis L and along which the incinerator charge is to be conveyed and which defines an incinerator charge side of the upper wall 14. The foremost end of the bearing face 16, when viewed in the thrust direction S, forms an edge 19 by way of which the bearing face 16 descends into a thrust face 22 formed by a front wall 20. The side of the upper wall 14 that faces away from the bearing face and the side of the front wall 20 that faces away from the thrust face 22 define a cooling air side of the block body 12.

[0050] In the embodiment shown, the bearing face has a first bearing face region 16a and a second bearing face region 16b, wherein the first bearing face region 16a is however disposed offset upward in relation to the second bearing face region 16b and connected by way of a beveled transition 17 to the latter.

[0051] On the side opposite the front wall 20, the block body 12 has a rear wall 24 which is equipped with at least one hook 26 with which the grate block 10 can be hooked into a block mounting tube. A central web 29 is also disposed on the lower side of the grate block 10 that faces away from the bearing face 16.

[0052] The grate block 10 is laterally delimited in each case by a lateral wall 28a, 28b that extends in the longitudinal direction L.

[0053] Within the combustion grate, the grate block 10 bears on a grate block that follows in the thrust direction S. To this end, the lowermost region of the front wall 20 is configured in the form of a block 34 which is specified to bear on the bearing face of a grate block adjacent in the thrust direction S. The lowermost region, including a lower bearing edge 23 of the thrust face configured by said lowermost region, is disposed in a plane E which runs substantially orthogonally to the longitudinal axis L.

[0054] Furthermore, the grate block 10, in that region in which the upper wall 14 and the front wall 20 meet, is configured so as to be thickened. Specifically, the wall thickening 40, when viewed in the longitudinal section, is configured so as to be curved on the incinerator charge side of the upper wall 14.

[0055] The edge 19 formed by the wall thickening 40 in the embodiment shown is set forward along the longitudinal axis L and, when viewed in the thrust direction S, in relation to the plane E, wherein the distance D between the edge 19 and the plane E is approx. 25 mm.

[0056] Thus, in the embodiment shown, the second bearing face region 16b runs first substantially in one plane and subsequently in a descending manner in a curved region which, when viewed in the thrust direction S, extends up to the foremost end of the bearing face 16.

[0057] The edge 19 formed by the foremost end of the bearing face 16 in the present case is situated below the plane of the second bearing face region 16b. The thrust face 22 begins over the edge 19 and first runs in set back form in relation to the edge 19 and subsequently extends into the plane E.

[0058] As can be seen from FIGS. 2 and 3, the front wall 20 has two first air supply openings 25 which are in each case formed by a first air supply duct 27 that extends through the front wall 20. In the present case, the first air supply ducts 27 open into an undercut of the front wall 20 that is formed by the wall thickening 40 and the plane E. The first air supply openings 25 in FIG. 1 are situated below the wall thickening 40 and are not visible. Primary air is supplied to the combustion grate, or the combustion bed on the combustion grate, through the first air supply ducts 27.

[0059] Moreover, the first air supply openings 25 along the longitudinal axis L and when viewed in the thrust direction S are set back in relation to the edge 19, in the specifically shown embodiment by a distance d of approximately 12 mm.

[0060] In the grate block illustrated in FIG. 2, the first air supply ducts 27, when viewed in the longitudinal section, in the region thereof that is directly adjacent to the respective air supply opening, run at an angle α of approximately 110° to the thrust face 22.

[0061] Furthermore, the grate block 12 comprises further air supply ducts 38 for cooling the upper wall 14, which run through into the upper wall 14, are disposed in the wall thickening 40 and aligned obliquely to the direction of the first air supply ducts 27, wherein the further air supply ducts 38 form further air supply openings 35 in the wall thickening 40.

[0062] In the embodiment shown, a first group of two further air supply ducts 38 is configured in a first plane G1 that runs at a first angle β1 to the bearing face 16. Furthermore, a second group of two further air supply ducts 38 is configured in a second plane G2 running at a second angle β2 to the bearing face 16. The first angle β1 here is 15°, and the second angle β2 is 45°. For the sake of clarity, the angles β1 and β2 in FIG. 2 are illustrated in relation to the longitudinal axis L which runs parallel to the bearing face 16.

[0063] As is illustrated in FIG. 3, the two first air supply ducts 27 and the two groups of two further air supply ducts 38 are each distributed in pairs so as to be symmetrical to a longitudinal plane of symmetry P of the grate block 12 that runs orthogonally to the bearing face.

[0064] Furthermore, the two first air supply ducts 27 and the two groups of two further air supply ducts 38, when viewed in the direction toward the interior of the grate block 12, are configured so as to widen continuously so that combustion residues that have entered the first or the further air supply ducts 27 or 38 can be discharged more easily and a blockage of the air supply can thus be avoided. The diameter of the first and the further air supply ducts 27 and 38, at the end thereof that faces the interior of the grate block 10 here is 15 mm and at the other end thereof is 10 mm.

[0065] In operation, the grate blocks 10 are moved relative to one another by means of the block mounting tubes. Depending on whether the block mounting tubes are assigned to a stationary or a movable grate block, the block mounting tubes are either attached to stationary consoles or to consoles which are disposed in a movable grate carriage. The driving takes place by hydraulic cylinders, which move the grate carriages back and forth over rollers on corresponding running surfaces.

[0066] As a result of the relative movement obtained in this way, the foot 34 of a first grate block 10 is pushed back and forth over the bearing face 16 of the respectively subsequent grate block 10, wherein the incinerator charge is conveyed across the bearing face 16 before being dropped over the edge 19 onto the bearing face 16 of the following grate block 10.

LIST OF REFERENCE SIGNS

[0067] Grate block 10 [0068] Block body 12 [0069] Upper wall 14 [0070] Bearing face 16 [0071] Bearing face region 16a, 16b [0072] Transition 17 [0073] Edge 19 [0074] Front wall 20 [0075] Thrust face 22 [0076] Lower bearing edge 23 [0077] Rear wall 24 [0078] First air supply opening 25 [0079] Hook 26 [0080] First air supply duct 27 [0081] Lateral wall 28a, 28b [0082] Central web 29 [0083] Block 34 [0084] Further air supply opening 35 [0085] Further air supply duct 38 [0086] Wall thickening 40 [0087] Longitudinal axis L [0088] Thrust direction S [0089] Plane E [0090] Longitudinal section plane P [0091] Distance d by which the air supply openings are set back in relation to the edge along the longitudinal axis L and when viewed in the thrust direction S [0092] Distance D by which the edge along the longitudinal axis L and when viewed in the thrust direction S is set forward in relation to the plane E [0093] Angle α [0094] Angle β1, β2