WO2021078330A2

WO2021078330A2 - Sliding grate for a combustion furnace

Info

Publication number: WO2021078330A2
Application number: PCT/DE2020/100897
Authority: WO
Inventors: Andreas Mozuch
Original assignee: Steinmüller Babcock Environment Gmbh; Nippon Steel Engineering Co., Ltd.
Priority date: 2019-10-22
Filing date: 2020-10-16
Publication date: 2021-04-29
Also published as: DE102019128536B4; EP4048951A2; JP2021067453A; JP6986612B2; WO2021078330A3; DE102019128536A1

Abstract

The invention relates to a sliding grate (100) for a combustion furnace (101), comprising multiple grate bar rows (2a, 2b), each of which has a grate bar support (5a, 5b), multiple grate bars (3a, 3b) being connected to said grate bar support via first ends (4a, 4b) of the grate bars, wherein surfaces (7a, 7b) of the grate bars (3a, 3b) form a grate bar surface (8) for transporting a layer of fuel (1) along a flow direction (F), and the grate bars (3a, 3b) of adjacent grate bar rows (2a, 2b) lie one over the other in the manner of roof tiles such that the second end (6a, 6b) of each grate bar (3a, 3b) is supported on a surface (7a, 7b) of an adjacent grate bar (3a, 3b) in the flow direction (F). At least some of the grate bar rows (2a, 2b) are grate bar rows (2a) which are driven by a driving means (9), and a first drive movement (A1) can be introduced into the grate bars (3a) of the driven grate bar rows (2a) via the driving means (9) so that a relative movement is produced between the grate bars (3a) of the driven grate bar rows (2a) and the grate bars (3b) of the non-driven grate bar rows (2b). According to the invention, the surfaces (7a, 7b) of the grate bars (3a, 3b) of at least some grate bar rows (2a, 2b) have a nonplanar surface contour (13a, 13b) such that a second drive movement (A2) can be introduced into the grate bars (3a, 3b) that have second ends (6a, 6b) supported on the nonplanar surface contour (13a, 13b) as a result of the relative movement between the grate bars (3a, 3b) of driven and non-driven grate bar rows (2a, 2b).

Description

Sliding grate for an incinerator

The invention relates to a sliding grate for an incinerator, in particular a special waste incineration plant, according to the preamble of claim 1.

Such sliding grates are used, for example, in Müllverbrennungsanla conditions in which garbage is burned as fuel. Push grids are usually made up of individual rows of grate bars, which are arranged one behind the other in the direction of flow of the fuel and lie above one another like roof tiles. The grate bars of a row of grate bars are mounted on a grate bar support. At every second grate bar support drives attack that initiate a drive movement in the relevant driven rows of grate bars. As a result, the driven rows of grate bars are set in motion in relation to the non-driven, fixed rows of grate bars.

The movement of the driven rows of grate bars causes, on the one hand, a transport of the fuel applied to a sliding grate surface of the sliding grate through the furnace and, on the other hand, the stoking of the fuel layer. The sliding grate surface is formed by the surfaces of the individual grate bars. In known push grids, a circular segment-shaped first drive movement is initiated in the grate bar carrier by the drive via torsion shafts and torsion levers, so that a correspondingly based grate bar movement of the grate bars mounted on the driven grate bar carriers results, for example in US 6,332,410 B1. Alternatively, a straight first drive movement via linkage is also possible, resulting in a straight grate bar movement of the grate bars mounted on the driven grate bar supports.

DE 30 07 678 C2 also describes a sliding grate with a torsion shaft, the shaft bearings of which are adjustable in height so that the rows of grate bars can be driven again in a straight drive direction.

The disadvantage here is that the torsion shafts or rods together with the associated machine elements, e.g. bearings or guides, are inevitably located in the area of a wind below the incineration plant, where they are more susceptible to failure. If the intention is to implement more complex forms of movement of the rows of grate bars as well as the grate bars via the grate bar supports, the additional mechanical drive elements required for this in the downwind ensure an increased susceptibility to malfunctions, which makes the combustion process less reliable.

The object of the invention is therefore to provide a sliding grate with which even more complex forms of movement of the rows of grate bars can be represented with low susceptibility to failure and thus high reliability.

This object is achieved by a sliding grate according to claim 1. Preferred developments are given in the subclaims.

According to the invention, it is therefore provided that the surfaces of grate bars of at least some grate bar rows of the generic thrust grate for an incinerator, in particular a garbage incineration plant, have a non-planar surface contour, so that the grate with its second ends on the non- planar surface support contour, a second drive movement can be initiated by the relative movement between the grate bars of driven and non-driven grate bar rows.

Advantageously, a complex grate bar movement of the grate bars of the push grate can thereby be brought about, this complex grate bar movement being achieved by the surface shape of the grate bars which are already present. This means that no adjustments to the conventional propulsion equipment are necessary in the downwind, so that the susceptibility to malfunctions does not increase any further. The drive means conventionally ensure that at least some of the grate bar rows of the sliding grate, preferably every second grate bar row, are driven, whereby a first drive movement can be introduced into the grate bars via the drive means, so that a relative movement between the grate bars of the driven Rows of grate bars and the grate bars of non-driven, ie not driven by the drive means, grate bar rows results. This first drive movement, which is introduced into the grate bars via the first ends, is superimposed according to the invention on the second drive movement, which is introduced via the second ends.

It preferably follows that

- A first grate bar movement of the grate bars of the driven rows of grate bars is composed of the first drive movement induced via the first ends and the second drive movement induced via the second ends, and / or that

- A second grate bar movement of the grate bars of the non-driven rows of grate bars from the second drive movement induced via the second ends results.

Depending on which grate bars have the non-planar surface contour, complex movements can be made in the respective grate bar rows. Forms of supply are generated, by means of which the transport and / or the stirring of the fuel layer can be improved without increasing the susceptibility of the pusher grate to failure.

It is preferably also provided that the non-planar surface contours of the grate bars of the at least some grate bar rows have a curved profile running in the direction of flow. As a result, a second drive movement can advantageously be generated according to a predefinable curve profile when the second end of the respective grate bar slides along the curve profile due to the force of gravity due to the relative movement between the grate bars. Depending on the course of the curve profile, this causes a grate bar movement with a directional component in the direction of flow as well as perpendicular to the direction of flow, i.e. upwards, in order to enable the fuel layer to be transported and stoked according to a complex sequence of movements.

It is preferably also provided that the grate bars

- all rows of grate bars or

- only the driven rows of grate bars or

- only the non-driven rows of grate bars have a curved profile running in the direction of flow and the other grate bars are designed, for example, planar. This means that it is possible to flexibly determine which rows of grate bars should carry out a complex sequence of movements. Depending on the application, it can be provided, for example, that the second drive movement is only introduced into the non-driven rows of grate bars and the driven rows of grate bars are only actively driven by the drive means by the first drive movement. For this purpose, only the driven rows of grate bars need to be provided with a curve profile. It is preferably also provided that the curve profile has at least one curve area with a specific defined radius. Accordingly, the surface of the grate bar is curved with a certain radius, along which the respective second end of the grate bar supported thereon can slide continuously. In particular, in the case of several curve areas, it can be provided that adjacent curve areas have different radii. As a result, for example an up and down movement or, depending on the relative movement between the grate bars, a certain periodic movement of the sliding grate surface can be achieved.

For this purpose, it is preferably also provided that the at least one curve area is curved concavely or convexly with the respective radius and / or adjacent curve areas of a curve profile have different curvatures, for example alternating convex and concave curvatures. As a result, a correspondingly predetermined complex sequence of movements (up and down) can be generated in order to optimize the transport and the stoking.

It is preferably also provided that the grate bars - each grate bar row or

- only the driven rows of grate bars or

- only the non-driven grate bar rows are rotatably mounted on the respective grate bar supports. As a result, the complex sequence of movements can be achieved depending on the selected type of introduction of the two drive movements into the respective grate bars.

It is preferably also provided that the first drive movement runs in the shape of a segment of a circle or in a straight line. Accordingly, a drive means can be selected in the downwind, via which a first drive movement is applied to the first in a simple manner and without great susceptibility to malfunctions End of the grate bar can be transferred. For example, the drive means can have torsion levers attached to a torsion shaft that connect a linear actuator, for example a hydraulic cylinder, to the grate bar supports being driven to produce a circular segment-shaped first drive movement around a second axis of rotation defined by the torsion shaft when the linear actuator is actuated. Correspondingly, a straight-line movement can be transmitted from the linear actuator to the first end via a linkage, so that this is also moved in a straight line.

In this way, a complex form of movement of the grate bars or grate bars can advantageously be achieved with the drives of the state of the art which cause a straight or circular segment-shaped movement of the grate bar supports, in that the grate bars themselves - via the second drive movement - for influencing the straight-line or circular segment-shaped first drive movement to a more complex movement. The shape of the grate bars according to the invention does not cause any greater susceptibility to failure than in the prior art, so that no additional, potentially failure-prone drive mechanisms are required.

The invention is explained in more detail below with reference to figures. Show it:

1 shows a section of a sliding grate in a retracted drive position in a sectional view;

FIG. 2 shows the detail of the sliding grate in the retracted drive position according to FIG. 1 in a perspective view; 3 shows a detail of the sliding grate in an extended drive position in a sectional view;

4 shows a section of the sliding grate in the extended drive position according to FIG. 3 in a perspective view;

5a, 5b show exemplary curve profiles of a grate bar.

In Fig. 1 is a sectional view and in Fig. 2 in a perspective view of a thrust grate 100 for an incinerator 101, in particular a special waste incinerator, shown on which a fuel layer 1, for example from incinerated waste, applied during a combustion process is. The sliding grate 100 has a plurality of grate bar rows 2a, 2b arranged along a flow direction F, which are each formed from grate bars 3a, 3b lying next to one another in the transverse direction Q (perpendicular to the flow direction F).

The grate bars 3a, 3b of a grate bar row 2a, 2b are mounted on a grate bar carrier 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 carrier 5a, 5b . The grate bars 3a, 3b of the individual grate bar rows 2a, 2b still lie on top of each other like roof tiles, with a second end 6a, 6b of the respective grate bar 3a, 3b on a surface 7a, 7b of the adjacent grate bar 3a, 3b as seen in the direction of flow F due to gravity supports. The surfaces 7a, 7b of the individual grate bars 3a, 3b thus form a continuous sliding grate surface 8 on which the fuel layer 1 is transported, stoked and burned.

According to this embodiment, every second grate bar support 5 a (driven grate bar support) interacts with a drive means 9 which is arranged in a lower wind 200 of the incineration furnace 101. That one- intermediate grate bar supports 5b (non-driven grate bar supports) are not driven. About the drive means 9, a first Antriebbe movement A1 (see. Fig. 3 and Fig. 4) into the driven grate bar carrier 5a and thus also into the first end 4a of the grate bar 3a mounted thereon are introduced.

The first drive movement A1 can be in the form of a segment of a circle (dotted in FIGS. 3 and 4), the drive means 9 having at least two torsion levers 11a, 11b attached to a torsion shaft 10, which have a linear actuator 12, for example a hydraulic cylinder connect the driven grate bar supports 5a. Thus, by actuating the linear actuator 12, a circular segment-shaped first drive movement A1 about a second rotational axis D2 defined by the torsion shaft 10 can be brought about, whereby a circular segment-shaped movement of the driven grate bar supports 5a and the first end 4a of the grate bars 3a mounted thereon around the second Rotation axis D2 results.

In principle, however, drive means 9 are also possible, which cause a straight first drive movement A1 (dash-dotted lines in Fig. 3 and Fig. 4) and thus also a straight movement of the driven grate bar supports 5a and the first end 4a of the grate bars 3a mounted thereon.

The first drive movement A1 in the form of a segment of a circle or straight 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 transported along the flow direction F and can also be stoked at the same time. In order to optimize 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 Figs. 3 and 3). According to the embodiment shown, this second drive movement A2 can be introduced into the grate bars 3a, which are stored on the driven grate bar supports 5a, as well as into the grate bars 3b, which are supported on the non-driven grate bar supports 5b, as described below:

The surfaces 7a, 7b of the respective grate bars 3a, 3b have, in section, a non-straight surface contour 13a, 13b in the manner of a curve profile K. As a result, the second ends 6a, 6b of the respective grate bar 3a, 3b, which are supported thereon, are moved upwards or downwards depending on the position on the curve profile K, which results 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 curve profile K of the grate bar 3a, 3b adjacent in the flow direction F.

In summary, the result for the grate bars 3a, which are mounted on a driven grate bar carrier 5a, is a first Roststabbewe movement Ba, which is a combination of the first drive movement A1 and the second drive movement A2. For the grate bars 3b, which are mounted on a non-driven grate bar carrier 5b, there is a second grate rod movement Bb, which benefits only 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, this curve profile K itself not being fixed, since the surfaces 7a, 7b of the grate bars 3a, 3b are likewise due to the respective grate bar movement Ba, Bb move. The first and / or the second drive movement A complex grate bar movement Ba, Bb of the respective grate bars 3a, 3b is thus effected. The transport and digging process can thus be optimized by means of such a push grate 100

In Fig. 5a and Fig. 5b exemplary curve profiles K are shown, where there is a first curve area K1 with a first radius R1 towards the first end 4a, 4b of the respective grate bars 3a, 3b and one towards the second end 6a, 6b second curve area K2 with a second radius R2. 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 curve area K1 is concave and the second curve area K2 is convexly curved.

Per grate bar 3a, 3b, however, only one curve area K1 can be seen, which is convex or concave, or more than two curve areas K1, K2, K3, K4, ..., which have a different curvature and / or different Have radii R1, R2, R3, R4, ... in order to form, for example, an S-shape or a wave shape (see Fig. 5b).

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.

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 curve 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 that results from the curve profile K is only introduced into every second row of grate bars 2a, 2b. The support of the grate bars 3a, 3b on the respective grate bar supports 5a, 5b can accordingly only be done for every second row of grate bars 2a,

2b may be provided, in particular for the driven row of grate bars 2a. 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 further extensive drive means are to be positioned in the lower wind 200, so that the susceptibility to failure is not increased by this solution and the reliability is maintained.

List of the reference symbols used

1 fuel layer

2a driven row of grate bars

2b non-driven row of grate bars

3a Grate bar on the driven grate bar support 5a

3b grate bar on the non-driven grate bar support 5b

4a, 4b first end of the grate bar 3a, 3b

5a driven grate bar carrier

5b non-driven grate bar support

6a, 6b second end of the grate bar 3a, 3b 7a, 7b surface of the grate bar 3a, 3b 8 sliding grate surface

9 drive means

10 torsion shaft

11a, 11b torsion lever 12 linear actuator 13a surface contour of the grate bar 3a 13b surface contour of the grate bar 3b 100 push grate 101 incinerator 200 lower wind A1 first drive movement A2 second drive movement

Ba grate bar movement of the grate bars 3a

Bb grate bar movement of the grate bars 3b

D1 first axis of rotation D2 second axis of rotation

F direction of flow

K curve profile

K1, K2, K3, K4 ... first, second, third, fourth, ... curve area Q transverse direction R1, R2, R3, R4 ... first, second, third, fourth, ... radius

Claims

1. Push grate (100) for an incinerator (101), in particular a waste incineration plant, with several rows of grate bars (2a, 2b), each of which has a grate bar support (5a, 5b) with which several grate bars (3a, 3b) over their first ends (4a, 4b) are connected, the surfaces (7a, 7b) of the grate bars (3a, 3b) forming a push grate surface (8) for transporting a fuel layer (1) along a flow direction (F), the grate bars (3a , 3b) of adjacent rows of grate bars (2a, 2b) lie on top of each other like roof tiles so that a second end (6a, 6b) of the respective grate bar (3a, 3b) lies on a surface (7a, 7b) of a grate bar that is adjacent in the direction of flow (F) (3a, 3b), with at least some of the grate bar rows (2a, 2b) being driven grate bar rows (2a) via a drive means (9), with a first drive movement (A1) in the grate bars (3a) via the drive means (9) ) which can be initiated on driven rows of grate bars (2a), so there ss there is a relative movement between the grate bars (3a) of the driven grate bar rows (2a) and the grate bars (3b) of non-driven grate bar rows (2b), characterized in that the surfaces (7a, 7b) of the grate bars (3a, 3b) at least some rows of grate bars (2a, 2b) have a non-planar surface contour (13a, 13b), so that in the grate bars (3a, 3b), which are with the second ends (6a, 6b) on the non-planar Surface contour (13a, 13b) support, a second drive movement (A2) can be initiated by the relative movement between the grate bars (3a, 3b) of driven and non-driven rows of grate bars (2a, 2b).

2. push grate (100) according to claim 1, characterized in that - a first grate bar movement (Ba) of the grate bars (3a) of the driven nen rows of grate bars (2a) is composed of the first drive movement (A1) induced via the first ends (4a) and the second drive movement (A2) induced via the second ends (6a), and / or that

- A second grate bar movement (Bb) of the grate bars (3b) of the non-driven rows of grate bars (2b) results from the second drive movement (A2) induced via the second ends (6b).

3. Push grate (100) according to claim 1 or claim 2, characterized in that the non-planar surface contours (13a, 13b) of the

Grate bars (3a, 3b) of the at least some grate bar rows (2a, 2b) have a curved profile (K) running in the direction of flow (F).

4. push grate (100) according to claim 3, characterized in that the grate bars (3a, 3b)

- all rows of grate bars (2a, 2b) or

- only the driven rows of grate bars (2a) or

- only the non-driven rows of grate bars (2b) have a curve profile (K) running in the direction of flow (F).

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

6. Push grate (100) according to claim 5, characterized in that be adjacent curve areas (K1, K2, K3, K4) have different radii (R1, R2, R3, R4).

7. push grate (100) according to claim 5 or 6, characterized in that the at least one curve area (K1, K2, K3, K4) is concave or convex and / or adjacent curve areas (K1, K2, K3, K4) ei- nes curve profile (K) have different curvatures.

8. Push grate (100) according to one of the preceding claims, characterized in that every second row of grate bars (2a) is a row of grate bars (2a) driven by the drive means (9).

9. push grate (100) according to any one of the preceding claims, characterized in that the grate bars (3a, 3b)

- each row of grate bars (2a, 2b) or - only the driven rows of grate bars (2a) or

- only the non-driven rows of grate bars (2b) are rotatably mounted on the respective grate bar supports (5a, 5b).

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

11. Push grate (100) according to claim 10, characterized in that the drive means (9) on a torsion shaft (10) attached torsion levers (11 a, 11 b) have a linear actuator (12), for example one

Hydraulic cylinders, connect to the driven grate bar supports (5a) to bring about a first drive movement (A1) in the form of a circular segment around a second axis of rotation (D2) defined by the torsion shaft (10) when the linear actuator (12) is actuated.