Sliding grate for an incinerator

Description

[0001] The invention relates to a moving grate for an incinerator, in particular a waste incineration plant, according to the preamble of claim 1.

[0002] Such moving grates are used, for example, in waste incineration plants where waste is burned as fuel. Moving grates usually consist of individual rows of grate bars arranged one behind the other in the direction of fuel flow, stacked on top of each other like roof tiles. The grate bars of a row of grate bars are mounted on a grate bar support. Drives engage every other grate bar support, initiating a drive movement in the corresponding driven grate bar rows. This sets the driven grate bar rows in motion relative to the non-driven, stationary grate bar rows.

[0003] The movement of the driven grate bar rows transports the fuel applied to a moving grate surface through the furnace and stokes the fuel layer. The moving grate surface is formed by the surfaces of the individual grate bars. In known moving grates, a circular segment-shaped first drive movement is introduced into the grate bar supports by the drive via torsion shafts and torsion levers, resulting in a corresponding grate bar movement of the grate bars mounted on the driven grate bar supports, as described, for example, in US 6,332,410 B1. Alternatively, a linear first drive movement via linkages is also possible, resulting in a linear grate bar movement of the grate bars mounted on the driven grate bar supports.

[0004] DE 30 07 678 C2 also describes a moving grate with a torsion shaft, the shaft bearings of which are height-adjustable so that the drive of the grate bar rows can again be carried out in a straight-line drive direction.

[0005] The disadvantage here is that the torsion shafts or rods, along with associated mechanical components such as bearings or guides, are inevitably located in the downdraft area of ​​the combustion plant, where they are more susceptible to failure. Therefore, if more complex motion patterns of the grate bar rows and the grate bars via the grate bar supports are intended, the additional mechanical drive elements required in the downdraft increase the susceptibility to failure, making the combustion process less reliable.

[0006] Further sliding grates with grate bars having a non-planar surface contour are disclosed in DE 20 20 17 00 6 429 U1, JP H04 320713 A and DD 11 482 B2.

[0007] The object of the invention is therefore to provide a moving grate with which even more complex movement patterns of the grate bar rows can be realized with low susceptibility to failure and thus high reliability.

[0008] This object is achieved by a sliding grate according to claim 1. Preferred developments are specified in the subclaims.

[0009] According to the invention, it is therefore provided that the surfaces of grate bars of at least some grate bar rows of the generic pusher grate for an incinerator, in particular a waste incineration plant, have a non-planar surface contour, so that a second drive movement can be introduced into the grate bars, which are supported with their second ends on the non-planar surface contour, by the relative movement between the grate bars of driven and non-driven grate bar rows.

[0010] This advantageously makes it possible to bring about a complex grate bar movement of the grate bars of the moving grate, whereby this complex grate bar movement is achieved by the surface shape of the grate bars that are already present. This means that no adjustments to the conventional drive means in the downdraft are necessary, so that the susceptibility to faults is not increased further. The drive means conventionally ensure that at least some of the grate bar rows of the moving grate, preferably every second grate bar row, are driven, whereby for this purpose a first drive movement can be introduced into the grate bars via the drive means, so that a relative movement results between the grate bars of the driven grate bar rows and the grate bars of non-driven grate bar rows, i.e. those not driven by the drive means.According to the invention, the second drive movement, which is introduced via the second ends, is superimposed on this first drive movement, which is introduced into the grate bars via the first ends.

[0011] It follows preferably that a first grate bar movement of the grate bars of the driven grate bar rows is composed of the first drive movement induced via the first ends and the second drive movement induced via the second ends. Furthermore, according to the invention, a second grate bar movement of the grate bars of the non-driven grate bar rows results from the second drive movement induced via the second ends.

[0012] Depending on which grate bars have the non-planar surface contour, complex movement patterns can be generated in the respective grate bar rows, which can improve the transport and / or stoking of the fuel layer without increasing the susceptibility of the moving grate to failure.

[0013] Preferably, it is further provided that the non-planar surface contours of the grate bars of at least some grate bar rows have a curved profile running in the direction of flow. This advantageously allows a second drive movement to be generated according to a predeterminable curved profile when the second end of the respective grate bar slides along the curved profile due to gravity as a result of the relative movement between the grate bars. Depending on the course of the curved profile, this brings about a grate bar movement with a directional component in the direction of flow and perpendicular to the direction of flow, i.e. upwards, in order to enable transport and stoking of the fuel layer according to a complex movement sequence.

[0014] Preferably, it is further provided that the grate bars all grate bar rows or only the driven grate bar rows or only the non-driven grate bar rows have a curved profile running in the direction of flow and the other grate bars are, for example, planar. This allows for flexible determination of which grate bar rows are to perform a complex movement sequence. Depending on the application, it can be provided, for example, that the second drive movement is only introduced into the non-driven grate bar rows and the driven grate bar rows only are actively driven by the drive mechanism during the first drive movement. For this purpose, the driven grate bar rows simply need to be provided with a curved profile.

[0015] Preferably, the curved profile further comprises at least one curved section with a specific, defined radius. Accordingly, the surface of the grate bar is curved with a specific radius, along which the respective second end of the grate bar supported thereon can slide continuously. In particular, if there are multiple curved sections, adjacent curved sections can have different radii. This can, for example, achieve an up-and-down movement or, depending on the relative movement between the grate bars, a specific periodic movement of the sliding grate surface.

[0016] Preferably, it is further provided that the at least one curved section is concave or convex with the respective radius and / or adjacent curved sections of a curved profile have different curvatures, for example, alternating convex and concave curvatures. This allows a correspondingly predefined complex movement sequence (up and down) to be generated in order to optimize transport and stoking.

[0017] Preferably, it is further provided that the grate bars each grate bar row or only the driven grate bar rows or only the non-driven grate bar rows are rotatably mounted on the respective grate bar supports. This allows the complex movement sequence to be achieved depending on the selected method of initiating the two drive movements in the respective grate bars.

[0018] Preferably, the first drive movement is circular or linear. Accordingly, a drive means can be selected in the downwind direction, via which a first drive movement can be transmitted to the first end of the grate bar in a simple manner and without significant susceptibility to failure. For example, the drive means can comprise torsion levers attached to a torsion shaft, which connect a linear actuator, for example a hydraulic cylinder, to the driven grate bar supports to effect a circular first drive movement about a second axis of rotation defined by the torsion shaft upon actuation of the linear actuator. In Correspondingly, a linear movement can be transmitted from the linear actuator via linkages to the first end, so that this is also moved in a straight line.

[0019] Thus, with the prior art drives that effect a linear or circular segment-shaped movement of the grate bar supports, a complex movement pattern of the grate bar rows or grate bars can also be advantageously achieved, in that the grate bars themselves—via the second drive movement—influence the linear or circular segment-shaped first drive movement toward a more complex movement. The inventive shape of the grate bars does not cause any greater susceptibility to failure than in the prior art, thus eliminating the need for additional, potentially failure-prone drive mechanisms.

[0020] The invention is explained in more detail below with reference to the figures. They show: Fig. 1 shows a section of a sliding grate in a retracted drive position in a sectional view; Fig. 2 shows the section of the sliding grate in the retracted drive position according to Fig. 1in a perspective view; Fig. 3 a section of the sliding grate in an extended drive position in a sectional view; Fig. 4 a section of the sliding grate in the extended drive position according to Fig. 3 in a perspective view; Fig. 5a, 5b exemplary curved profiles of a grate bar.

[0021] In Fig. 1 is in a sectional view and in Fig. 2 A perspective view of a moving grate 100 for an incinerator 101, in particular a waste incineration plant, is shown, onto which a fuel layer 1, for example, consisting of incinerated waste, is applied during a combustion process. The moving grate 100 has a plurality of grate bar rows 2a, 2b arranged along a flow direction F, each of which is formed from grate bars 3a, 3b arranged next to one another in the transverse direction Q (perpendicular to the flow direction F).

[0022] The grate bars 3a, 3b of a grate bar row 2a, 2b are mounted on a grate bar support 5a, 5b via a first end 4a, 4b, so that each grate bar 3a, 3b can rotate about a first axis of rotation D1 defined by the respective grate bar support 5a, 5b. The grate bars 3a, 3b of the individual grate bar rows 2a, 2b continue to lie one above the other like roof tiles, with a second end 6a, 6b of the respective grate bar 3a, 3b being supported by gravity on a surface 7a, 7b of the adjacent grate bar 3a, 3b, viewed in the flow direction F. The surfaces 7a, 7b of the individual grate bars 3a, 3b thus form a continuous moving grate surface 8, on which the fuel layer 1 is transported, stoked, and burned.

[0023] According to this embodiment, every second grate bar support 5a (driven grate bar support) cooperates with a drive means 9 arranged in a downdraft 200 of the combustion furnace 101. The intermediate grate bar supports 5b (non-driven grate bar supports) are not driven. A first drive movement A1 (see Fig. 3 and Fig. 4 ) into the driven grate bar supports 5a and thus also into the first end 4a of the grate bar 3a mounted thereon.

[0024] The first drive movement A1 can be circular segment-shaped (dotted in Fig. 3 and Fig. 4), wherein the drive means 9 for this purpose have at least two torsion levers 11a, 11b fastened to a torsion shaft 10, which connect a linear actuator 12, for example a hydraulic cylinder, to the driven grate bar supports 5a. Thus, by actuating the linear actuator 12, a circular segment-shaped first drive movement A1 about a second axis of rotation D2 defined by the torsion shaft 10 can be effected, resulting in a circular segment-shaped movement of the driven grate bar supports 5a and of the first end 4a of the grate bars 3a mounted thereon about the second axis of rotation D2.

[0025] In principle, however, drive means 9 are also possible which provide a rectilinear first drive movement A1 (dotted line in Fig. 3 and Fig. 4 ) and thus also cause a rectilinear movement of the driven grate bar supports 5a and the first end 4a of the grate bars 3a mounted thereon.

[0026] The circular segment-shaped or rectilinear first drive movement A1 already results in a first grate bar movement Ba of the grate bars 3a mounted on the driven grate bar supports 5a, which has a directional component both in the flow direction F and vertically upwards (to the flow direction F and to the transverse direction Q), whereby the fuel layer 1 can be transported along the flow direction F and simultaneously also stoked.

[0027] In order to optimise this, the surfaces 7a, 7b of the individual grate bars 3a, 3b are designed in such a way that a second drive movement A2 can be introduced into the respective grate bar 3a, 3b via the second end 6a, 6b of the respective grate bar 3a, 3b (see Fig. 3 and Fig. 3). According to the illustrated embodiment, this second drive movement A2 can be introduced both into the grate bars 3a, which are mounted on the driven grate bar supports 5a, and into the grate bars 3b, which are mounted on the non-driven grate bar supports 5b, as described below:

[0028] The surfaces 7a, 7b of the respective grate bars 3a, 3b have, in section, a non-rectilinear surface contour 13a, 13b in the manner of a curved profile K. As a result, the second ends 6a, 6b of the respective adjacent grate bar 3a, 3b opposite to the flow direction F, which are supported thereon, are moved upwards or downwards depending on their position on the curved profile K, resulting in the second drive movement A2. The second drive movement A2 introduced into the second end 6a, 6b of the respective grate bar 3a, 3b is therefore particularly dependent on the position of the second end 6a, 6b on the curved profile K of the adjacent grate bar 3a, 3b in the flow direction F.

[0029] In summary, for the grate bars 3a mounted on a driven grate bar support 5a, a first grate bar movement Ba results, which is a combination of the first drive movement A1 and the second drive movement A2. For the grate bars 3b mounted on a non-driven grate bar support 5b, a second grate bar movement Bb results, which results solely from the second drive movement A2. The second drive movement A2 is determined by the curve profile K of the respective surface contours 13a, 13b, whereby this curve profile K itself is not fixed, since the surfaces 7a, 7b of the grate bars 3a, 3b also move due to the respective grate bar movement Ba, Bb. The first and / or second drive movement A1, A2 thus causes a complex grate bar movement Ba, Bb of the respective grate bars 3a, 3b. The transport and stoking process can therefore be optimized using such a moving grate 100.

[0030] In Fig. 5a and Fig. 5b Exemplary curved profiles K are shown, wherein a first curved region K1 with a first radius R1 results towards the first end 4a, 4b of the respective grate bars 3a, 3b and a second curved region K2 with a second radius R2 results towards the second end 6a, 6b. On the one hand, according to this embodiment, the first radius R1 is smaller than the second radius R2 and, on the other hand, the first curved region K1 is concave and the second curved region K2 is convex.

[0031] However, for each grate bar 3a, 3b, only one curved area K1 can be provided, which is convex or concave, or more than two curved areas K1, K2, K3, K4, ..., which have a different curvature and / or different radii R1, R2, R3, R4, ..., for example to form an S-shape or a wave shape (see Fig. 5b ) to form.

[0032] It is also possible that the grate bars 3a, which are mounted on driven grate bar supports 5a, have a different curve profile K than grate bars 3b, which are mounted on non-driven grate bar supports 5b.

[0033] In principle, it can also be provided that only the grate bars 3a, 3b of every second grate bar row 2a, 2b (driven or non-driven) have a curved profile K, and the other grate bars 3a, 3b have a planar surface 7a, 7b. As a result, the portion of the second drive movement A2 resulting from the curved profile K is only introduced into every second grate bar row 2a, 2b. The mounting of the grate bars 3a, 3b on the respective grate bar support 5a, 5b can also be provided accordingly only for every second grate bar row 2a, 2b, in particular for the driven grate bar row 2a.

[0034] Overall, a complex grate bar movement Ba, Bb can therefore be achieved from a combination of the two drive movements A1, A2 via the first end 4a, 4b and the second end 6a, 6b of a grate bar 3a, 3b, without having to change the drive means 9 or position further extensive drive means in the underwind 200, so that the susceptibility to failure is not increased by this solution and reliability is maintained.

[0035] List of reference symbols used 1 Fuel layer 2a Driven grate bar row 2b Non-driven grate bar row 3a Grate bar on driven grate bar support 5a 3b Grate bar on non-driven grate bar support 5b 4a, 4 First end of grate bar 3a, 3b 5a Driven grate bar support 5b Non-driven grate bar support 6a, 6b Second end of grate bar 3a, 3b 7a, 7b Surface of grate bar 3a, 3b 8 Pushing grate surface 9 Drive means 10 Torsion shaft 11a, 11b Torsion lever 12 Linear actuator 13a Surface contour of grate bar 3a 13b Surface contour of grate bar 3b 100 Pushing grate 101 Incinerator 200 Underdraft A1 First drive movement A2 Second drive movement BaGrate bar movement of the grate bars 3a BbGrate bar movement of the grate bars 3b D1First axis of rotation D2Second axis of rotation FFlow direction KKurve profile K1, K2, K3, K4First, second, third, fourth, ... Curve area QTransverse direction R1, R2, R3, R4First, second, third, fourth, ... Radius

Claims

1. Sliding grate (100) for a combustion furnace (101), in particular, a waste incineration plant, including multiple rows of grate bars (2a, 2b), each comprising a grate bar support (5a, 5b), connected to which are multiple grate bars (3a, 3b) via their first ends (4a, 4b), where surfaces (7a, 7b) of the grate bars (3a, 3b) form a sliding grate area (8) for transporting a layer of combustible material (1) along a direction of flow (F), the grate bars (3a, 3b) of adjacent rows of grate bars (2a, 2b) lie imbricated on top of one another in such a way that a second end (6a, 6b) of the respective grate bar (3a, 3b) rests on a surface (7a, 7b) of a grate bar (3a, 3b) adjacent in the direction of flow (F), where some of the rows of grate bars (2a, 2b) are rows of grate bars (2a) driven via a driving means (9), the driving means (9) being capable of inducing a first drive movement (A1) in the grate bars (3a) of the driven rows of grate bars (2a) so as to result in a relative movement between the grate bars (3a) of the driven rows of grate bars (2a) and the grate bars (3b) of non-driven rows of grate bars (2b), the surfaces (7a, 7b) of the grate bars (3a, 3b) of at least a few rows of grate bars (2a, 2b) having a non-planar surface contour (13a, 13b) so that a second drive movement (A2) can be induced in the grate bars (3a, 3b) the second ends (6a, 6b) of which rest on the non-planar surface contour (13a, 13b) by virtue of the relative movement between the grate bars (3a, 3b) of driven and non-driven rows of grate bars (2a, 2b), and where a second grate bar movement (Bb) of the grate bars (3b) of the non-driven rows of grate bars (2b) results purely from the second drive movement (A2) induced via the second ends (6b).

2. Sliding grate (100) according to claim 1, where - a first grate bar movement (Ba) of the grate bars (3a) of the driven rows of grate bars (2a) is composed from the first drive motion (A1) induced via the first ends (4a) and the second drive motion (A2) induced via the second ends (6a).

3. Sliding grate (100) according to claim 1 or claim 2, where the non-planar surface contours (13a, 13b) of the grate bars (3a, 3b) of said at least a few rows of grate bars (2a, 2b) have a curve profile (K) running in the direction of flow (F).

4. Sliding grate (100) according to claim 3, the grate bars (3a, 3b) - of all rows of grate bars (2a, 2b) or - merely of the driven rows of grate bars (2a) or - merely of the non-driven rows of grate bars (2b) comprising a curve profile (K) running in the direction of flow (F).

5. Sliding grate (100) according to claim 3 or 4, where the curve profile (K) has at least one curve area (K1, K2, K3, K4) with a radius (R1, R2, R3, R4).

6. Sliding grate (100) according to claim 5, where adjacent curve areas (K1, K2, K3, K4) have different radii (R1, R2, R3, R4).

7. Sliding grate (100) according to claim 5 or 6, where the at least one curve area (K1, K2, K3, K4) is curved concavely or convexly und / or adjacent curve areas (K1, K2, K3, K4) of a curve profile (K) have different curving.

8. Sliding grate (100) according to one of the above claims, where every second row of grate bars (2a) is a row of grate bars (2a) driven via the drive means (9).

9. Sliding grate (100) according to one of the above claims, where the grate bars (3a, 3b) - of each row of grate bars (2a, 2b) or - merely of the driven rows of grate bars (2a) or - merely of the non-driven rows of grate bars (2b) are pivot-mounted on the respective grate bar supports (5a, 5b).

10. Sliding grate (100) according to one of the above claims, where the first drive movement (A1) runs in a circle segment or in a straight line.

11. Sliding grate (100) according to claim 10, the drive means (9) comprising torsion levers (11a, 11b), mounted on a torsion shaft (10), connecting a linear actuator (12), for example, a hydraulic cylinder, to the driven grate bar supports (5a) so as to effect a circle segment-like first drive movement (A1) about an axis of rotation (D2) defined by the torsion shaft (10) upon activation of the linear actuator (12).