GRATE BLOCK FOR A COMBUSTION GRATE

Abstract

A grate block for a combustion grate, wherein consecutive grate blocks are arranged in a staircase and are designed to rearrange and convey the combustible material during combustion through pushing motions. The grate block includes a block body, an upper wall forming a supporting surface, and an extension parallel to a longitudinal axis L of the body. The supporting surface drops into a pushing surface formed by a front wall, which has at least one air supply opening for supplying air to the combustion grate, which extends at a right angle or slant to the pushing surface. In the lowest region of the front wall, formed as a foot, which lays on the supporting surface of a grate block, is adjacent in the pushing direction. The front resting edge of the pushing surface is arranged in a plane E extending at a right angle to the longitudinal axis L.

Claims

1. A grate block for a combustion grate in which sequential grate blocks are arranged one above the other in a step-like manner and are configured so as to rearrange and convey the combustion material during combustion by means of pushing movements which are carried out relative to each other, wherein the grate block comprises a block member which is constructed as a cast component and which comprises an upper wall which forms a support face which extends at least partially parallel with a longitudinal axis L of the block member and along which the combustion material is intended to be conveyed and whose foremost end when viewed in the pushing direction S forms an edge via which the support face descends into a pushing face which is formed by a front wall, the front wall has at least one air supply opening which when viewed as a longitudinal section extends perpendicularly or obliquely with respect to the pushing face in order to supply air to the combustion grate and is constructed in the lowest region thereof in the form of a base which is intended to be positioned on the support face of a grate block which is adjacent in the pushing direction S, wherein at least the front support edge of the pushing face is arranged in a plane E which extends substantially perpendicularly to the longitudinal axis L, wherein the edge is offset forward with respect to the plane E when viewed along the longitudinal axis L and in the pushing direction S.

2. The grate block as claimed in claim 1, wherein the at least one air supply opening is arranged below the edge and is offset backward with respect to the edge when viewed along the longitudinal axis L and in the pushing direction S.

3. The grate block as claimed in claim 1, wherein the upper wall and the front wall are constructed in a thickened manner in the region in which they meet each other and the wall thickening is constructed in a curved manner when viewed as a longitudinal section.

4. The grate block as claimed in claim 1, wherein the edge when viewed along the longitudinal axis L and in the pushing direction S is offset forward with respect to the plane E by at least 3 mm.

5. The grate block as claimed in claim 1, wherein the edge when viewed along the longitudinal axis L and in the pushing direction S is offset forward with respect to the plane E by maximum of 100 mm.

6. The grate block as claimed in claim 1, wherein the at least one air supply opening when viewed as a longitudinal section extends at an angle ? with respect to the region of the pushing face directly adjacent to the respective air supply opening, wherein ? is from 90? to 135?.

7. The grate block as claimed in claim 1, wherein the grate block is closed at least at one side by a side wall which extends in the longitudinal direction and at least one side wall has a wear marking which describes a contour which is spaced apart from the plane of the support face and/or from the plane of the pushing face.

8. The grate block as claimed in claim 7, wherein the contour of the wear marking is spaced apart from the plane of the support face and/or from the plane of the pushing face by from 15 mm to 30 mm.

9. The grate block as claimed in claim 7, wherein the contour of the wear marking extends at least partially parallel with the plane of the support face and/or the plane of the pushing face.

10. The grate block as claimed in claim 9, wherein the contour of the wear marking extends parallel at least with the region of the support face and the pushing face where they meet each other.

11. The grate block as claimed in claim 7, wherein the wear marking is constructed in the form of a continuous or interrupted notch or a recess.

12. A grate block for a combustion grate in which sequential grate blocks are arranged in a step-like manner one above the other and are configured so as to rearrange and convey the combustion material during the combustion operation by means of pushing movements which are carried out relative to each other, wherein the grate block comprises a block member which is constructed as a cast component and which comprises an upper wall which forms a support face which extends at least partially parallel with a longitudinal axis L of the block member and along which the combustion material is intended to be conveyed and whose foremost end when viewed in the pushing direction S forms an edge via which the support face descends into a pushing face formed by a front wall, and the grate block is closed laterally by a side wall which extends in the longitudinal direction, wherein at least one side wall has a wear marking which describes a contour which is spaced apart from the plane of the support face and/or from the plane of the pushing face.

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

14. A method comprising burning waste of a combustion grate as claimed in claim 13.

15. A waste combustion installation comprising a combustion grate as claimed in claim 13.

Description

[0041] The invention is illustrated with reference to the appended Figures, in which:

[0042] FIG. 1 is a side view of a grate block according to the prior art;

[0043] FIG. 2 is a plan view from above of the grate block of the prior art as shown in FIG. 1;

[0044] FIG. 3 is a longitudinal section through the plane of section A-A of the grate block of the prior art as shown in FIGS. 1 and 2,

[0045] FIG. 4 is a side view of a grate block according to the first aspect of the present invention;

[0046] FIG. 5 is a plan view from above of the grate block according to FIG. 4;

[0047] FIG. 6 is a longitudinal section through the plane of section A-A of the grate block according to FIGS. 4 and 5;

[0048] FIG. 7 is a side view of a grate block according to the second aspect of the present invention; and

[0049] FIG. 8 is a plan view from above of the grate block according to FIG. 7.

[0050] As can be seen in FIGS. 4 to 6 in comparison with FIGS. 1 to 3, the grate block 10 according to the invention has in common with previously known grate blocks the fact that it comprises a block member 12 which is constructed as a cast component and which is constructed substantially in the form of an elongate parallelepiped 121 with a longitudinal axis L.

[0051] The block member 12 comprises an upper wall 14, which forms a support face 16 which extends parallel with the longitudinal axis L and along which the combustion material is intended to be conveyed and whose foremost end when viewed in the pushing direction S forms an edge 19 via which the support face 16 descends into a pushing face 22 formed by a front wall 20. In the embodiments shown, the support face has a first support face region 16a and a second support face region 16b which both extend parallel with the longitudinal axis L, but wherein the first support face region 16a is arranged so as to be offset in an upward direction with respect to the second support face region 16b and is connected thereto by means of a chamfered transition 17.

[0052] Furthermore, in the embodiment of the prior art as shown in FIGS. 1 to 3, the region of the support face located directly in front of the edge is constructed in the form of a chamfer 21.

[0053] At the side opposite the front wall 20, the block member 12 has a rear wall 24 which is provided with at least one hook 26 by means of which the grate block 10 can be suspended in a block retention pipe. At the lower side of the grate block 10 facing away from the support face, a central web 29 is additionally arranged.

[0054] Laterally, the grate block 10 is closed in each case by means of a side wall 28a, 28b which extends in the longitudinal direction.

[0055] Within the combustion grate, the grate block 10 is positioned on a grate block which follows in the pushing direction S. To this end, the lowest region 32 of the front wall 20 is constructed in the form of a base 34 which is intended to be positioned on the support face of a grate block which is adjacent in the pushing direction S. The lowest region including the front support edge of the pushing face formed thereby is arranged in a plane E which extends substantially at right-angles with respect to the longitudinal axis L.

[0056] As shown in FIGS. 3 and 6, in the previously known grate block and in the specifically illustrated grate block according to the invention, in an upper region 36 of the front wall 20, that is to say, in a region facing the edge 19, two air supply openings 38 which extend through the wall for supplying air are formed on the combustion grate, wherein only one of these air supply openings is shown in the Figure.

[0057] In contrast to the grate block of the prior art, in the grate block 10 according to the invention in the region in which the upper edge 14 and the front wall 20 meet each other they are constructed in a thickened manner. Specifically, the wall thickening 40 is constructed in a curved manner when viewed as a longitudinal section.

[0058] The edge 19 formed by the wall thickening 40 is consequently when viewed along the longitudinal axis L and in the pushing direction S offset forward with respect to the plane E, wherein in the embodiment shown the spacing D between the edge 19 and the plane E is approximately 25 mm.

[0059] Furthermore, the air supply openings when viewed along the longitudinal axis L and in the pushing direction S are offset backward with respect to the edge, in the specifically shown embodiment by a spacing d of approximately 8 mm.

[0060] In the grate block according to the invention illustrated in FIG. 6, the air supply openings 38 extend when viewed as a longitudinal section at an angle ? of approximately 90? with respect to the pushing face 22 in the region thereof directly adjacent to the respective air supply opening.

[0061] According to the grate block of the second aspect of the present invention as shown in FIGS. 7 and 8, the side wall 28a has a wear marking 42 in the form of a recess 421 which describes a contour 44 which is spaced apart from the plane of the support face 16, in particular of the second support face region 16b and the chamfer 21, and from the plane of the pushing face 22. In this instance, the wear marking 42 or the contour 44 extends substantially parallel with the second support face region 16b and the chamfer 21 of the support face 16 and the pushing face 22. Consequently, the contour 44 extends in a first region 44a parallel with the plane of the second support face region 16b, in a second region 44b parallel with the chamfer 21 and in a third region 44c parallel with the pushing face 22.

[0062] In specific terms, the wear marking is in the embodiment shown spaced apart from the plane E of the pushing face 22 by a distance ? of approximately 20 mm.

[0063] During operation, the grate blocks 10 are moved relative to each other by means of the block retention pipes. Depending on whether the block retention pipes are associated with a stationary or a movable grate block, the block retention pipes are either secured to fixed consoles or to consoles which are arranged in a movable grate carriage. The driving is carried out by means of hydraulic cylinders which move the grate carriage back and forth via rollers on corresponding running surfaces.

[0064] As a result of the relative movement which is obtained thereby, the base 34 of a first grate block 10 is pushed forward and backward over the support face 16 of the subsequent grate block 10 in each case, wherein the combustion material is conveyed over the support face 16 before it is discharged over the edge 19 onto the support face 16 of the subsequent grate block 10.

[0065] As a result of the fact that the edge 19 is offset forward with respect to the plane E as described, it may be possible for at least a portion of the pushing face 22 to be subjected to reduced erosion by the combustion material and in particular for the air to be able to be discharged more readily through the air supply openings 38. Furthermore, as a result of the wall thickening 40 in the region of the grate block 10 which is subjected to particularly significant wear, a significantly greater abrasion can be tolerated, whereby an increased service-life of the grate block is ultimately achieved.

[0066] The degree of abrasion can be very easily determined by sight by means of the wear marking of the embodiment shown in FIGS. 7 and 8: if the abrasion has reached such an extent that the outer contour of the grate block 10 at least partially coincides with the contour of the wear marking 42 in the side view or the contour 44 of the wear marking 42 is no longer visible at all, the grate block 10 is worn and must be replaced.

[0067] As a result of the fact that the original spacing between the contour 44 of the wear marking 42 and the outer contour of the grate block 10 is known, it can additionally be predicted in a relatively reliable manner when the grate block will be worn with operation remaining consistent.

LIST OF REFERENCE NUMERALS

[0068] 10 Grate block [0069] 12; 121 Block member; parallelepiped [0070] 14 Upper wall [0071] 16 Support face [0072] 16a,b Regions of the support face extending parallel with the longitudinal axis [0073] 17 Chamfered transition [0074] 19 Edge [0075] 20 Front wall [0076] 21 Chamfer [0077] 22 Pushing face [0078] 23 Front support edge [0079] 24 Rear wall of the block member [0080] 26 Hook [0081] 28a, b Side walls [0082] 29 Central web [0083] 30 Block member inner space [0084] 32 Lowest region of the front wall [0085] 34 Base [0086] 36 Upper region of the front wall [0087] 38 Air supply opening [0088] 40 Wall thickening [0089] 42; 421 Wear marking; recess [0090] 44; 44a-c Contour, different regions of the contour [0091] L Longitudinal axis [0092] S Pushing direction [0093] d Spacing by which the air supply openings are offset backward with respect to the edge when viewed along the longitudinal axis L and in the pushing direction S [0094] E Plane in which the front support edge is arranged [0095] D Spacing by which the edge is offset forward with respect to the plane E along the longitudinal axis L and when viewed in the pushing direction S [0096] ? Angle at which the air supply opening extends with respect to the pushing face when viewed as a longitudinal section [0097] ? Distance by which the wear marking is spaced from the plane of the pushing face