Grate block with rising nose

Abstract

A grate block including a block body formed as a cast part with a rear end and a front end that lies opposite the rear end in the conveying direction. The block body includes an upper wall which forms an outer rear bearing surface, running at least in part parallel to a longitudinal axis of the block body, for the waste that is to be treated, wherein the bearing surface defines a substantially horizontal plane. The block body further includes a raised nose arranged in the region of front end, which nose has an outer front bearing surface with a middle part that rises in the manner of a ramp in the conveying direction. The raised nose includes, following the outer front bearing surface, an apex and, after the apex in the conveying direction, a declining end portion with a discharge surface that drops away in a substantially arcuate manner.

Claims

1. A grate block, as part of an incineration grate for thermal treatment of waste, in which the grate blocks are arranged one above the other in a staircase-like manner and are designed in such a manner that, by means of advancing movements executed relative to one another, during incineration the incineration material is rearranged and conveyed in a direction of conveyance F, wherein the grate block comprises a block body, realized as a casting, having the following components: a rear end and a front end that is opposite to the rear end in the direction of conveyance F, an upper wall, which is substantially parallel to a longitudinal axis L of the block body and forms a rear bearing surface for the waste to be treated, wherein the rear bearing surface defines a substantially horizontal plane, and a nose, which is arranged in the region of the front end and is raised with respect to the horizontal plane, wherein the raised nose comprises a front bearing surface rising in the direction of conveyance F up to a culmination point, as well as a downwardly sloping end portion that adjoins the front bearing surface after the culmination point, wherein the downwardly sloping end portion comprises a discharge surface that slopes downward substantially in an arcuate manner in the direction of conveyance F, and wherein the front bearing surface is S-shaped as viewed in longitudinal section along the direction of conveyance F.

2. The grate block as claimed in claim 1, wherein the culmination point is spaced in the vertical direction at a distance of 10-35 mm from the horizontal plane.

3. The grate block as claimed in claim 1, wherein the rising front bearing surface is realized in the form of a ramp, and in a middle portion has an average gradient of 10-35%.

4. The grate block as claimed in claim 1, wherein the discharge surface that slopes downward in an arcuate manner comprises a rounded discharge edge at a point that is foremost in the direction of conveyance F.

5. The grate block as claimed in claim 1, wherein the downwardly sloping end portion comprises a first arcuate segment in the region between the culmination point and a point that is foremost in the direction of conveyance F.

6. The grate block as claimed in claim 5, wherein the first arcuate segment has a first radius of curvature R1 of a length of 60-120 mm.

7. The grate block as claimed in claim 5, wherein the first arcuate segment spans in longitudinal section a sector surface that has a center angle a of between 60° and 72°.

8. The grate block as claimed in claim 5, wherein the downwardly sloping end portion comprises a second arcuate segment that adjoins the first arcuate segment in the direction of conveyance F.

9. The grate block as claimed in claim 8, wherein the second arcuate segment has a second radius of curvature R2.

10. The grate block as claimed in claim 9, wherein the second arcuate segment, as viewed in longitudinal section, defines a sector surface having a center angle β of between 70° and 120°.

11. The grate block as claimed in claim 4, wherein the block body has a front wall that is set back from the foremost point of the downwardly sloping end portion in the direction opposite to the direction of conveyance F, such that an undercut is formed.

12. The grate block as claimed in claim 11, wherein there are ventilation openings in the region of the front wall of the undercut.

13. The grate block as claimed in claim 1, wherein there is a depression realized in the rear bearing surface.

14. A grate comprising a plurality of grate blocks according to claim 1.

Description

(1) The grate block 1 depicted in FIGS. 1 and 2 comprises a block body 3, realized as a casting, having an upper wall 4 that extends in the direction of conveyance F from a rear end 5 to a front end 7. In the region of the rear end 7, the block body comprises a fastening device 9, by means or which the block body 3 is coupled to a drive system (not represented) in the grate and which initiates its movements in or counter to the direction of conveyance F. Further, in the region of the rear end 5, the block body 3 comprises an outer, rear bearing surface 11 for thermal treatment of the waste to be incinerated. In the region of the front end 7, the block body 3 comprises a raised nose 13. The latter, as viewed in the direction of conveyance F, comprises an outer front bearing surface 15 that rises to a culmination point 17, and a downwardly sloping end portion 19 adjoining the culmination point 17 and having discharge surface 21 that slopes downward substantially in an arcuate manner. The rear bearing surface 11 defines a substantially horizontal plane 23 that has a depression 25. Adjoining the horizontal plane 23 in the direction of conveyance F is the outer, front bearing surface 15. The rising, outer front bearing surface 15 is in the form of a ramp and substantially S-shaped as viewed in longitudinal section. In the embodiment shown, the gradient of the front bearing surface 15 increases steadily from the horizontal plane 23 until it remains constant in a middle portion 27, and then decreases toward the culmination point such that the gradient approaches zero in the direction of the culmination point 17. The culmination point 17 is realized here as a singular point between the front bearing surface 15 and the downwardly sloping end portion 19, but could alternatively also be realized as a “culmination plane”. The downwardly sloping end portion 19 of the raised nose 13 comprises a rounded discharge edge 31 at a point 29 that is foremost as viewed in the direction of conveyance F.

(2) The block body 3 further comprises a front wall 33, set back from the foremost point 29 of the downwardly sloping end portion 19 in the direction opposite to the direction of conveyance F, that forms an undercut 35 with the downwardly sloping end portion 19. Adjoining the front wall 33 of the block body 33 at the bottom is a sliding surface 37, by means of which the block body 3 slides on the outer rear be surface 11 of a second grate block located underneath (not represented). The front wall 33 comprises ventilation openings 39, which are protected from falling waste by their position in the region of the undercut 35, such that clogging of the ventilation openings 39 can be counteracted. The upper wall 4 also comprises, in the region of the horizontal plane 23, a further ventilation opening 41, which constitutes the outlet of an air channel through a pyramid-shaped or volcano-shaped elevation. The diameter of the air channel widens concentrically from the ventilation opening 41 toward the interior of the block body, so that waste entering the air channel through the ventilation opening 41 falls through downwardly due to the widening diameter, without clogging the ventilation opening 41. The ventilation openings 39 and 41 serve to deliver primary or secondary air in order to enable efficient incineration.

(3) FIG. 3 shows an enlarged view of the raised nose 13 and of the front region 7 of the grate block from FIG. 1. A vertical axis V, represented by dashed lines, runs through the culmination point 17. Starting from the culmination point 17, the outer contour of the downwardly sloping end portion 19 slopes downward in the direction of conveyance F, forming a first arcuate segment 43. The first arcuate segment 43 has an average radius of curvature R1, and spans an angle ∝ between the vertical axis V and a first segment axis A1. Adjoining the first arcuate segment 43 is a second arcuate segment 45. The second arcuate segment 45 has an average radius of curvature R2, and spans an angle β between the first segment axis A1 and a second segment axis A2. The first and the second arcuate segment 43, 45 may be connected to each other directly or via a middle piece (not represented). The middle piece in this case may be realized as a straight surface or also as an arcuate segment. Depending on the magnitude of the angles ∝ and β, the foremost point 29 with the rounded discharge edge 31 may be positioned in the first or second arcuate segment 43, 45.