EP3926237B1 - Grate bar, grate bar assembly and method for operating a grate bar assembly - Google Patents

Description

The invention relates to a grate bar with a grate bar head, two side walls, a running surface behind the grate bar head between the side walls and an underside lying between the side walls under the running surface, with a recess in a side wall between the running surface and the underside forming at least one air slot.

The invention also relates to a grate bar arrangement with a plurality of grate bars, each with a running surface and a grate bar head, in which an upper grate bar with its grate bar head is arranged to be movable relative to a lower grate bar in such a way that the grate bar head slides over a front and a rear region of the running surface of the grate bar can.

Furthermore, the invention also relates to a method for operating a grate bar arrangement with a plurality of grate bars, each with a running surface and a grate bar head, in which an upper grate bar with its grate bar head is moved relative to a lower grate bar in such a way that the grate bar head moves over a front and a rear area of the grate bar The running surface of the grate bar slides.

The grate combustion is a solid fuel combustion in which the fuel lies on a grate and burns. The grate is a surface with openings. The openings in the grate are used to supply the air necessary for combustion ("underdraft") and the ash is removed via a purifier. In larger grate furnaces, the movements necessary to stir up the fire occur automatically by moving the grate.

A stair grating / bulk grating looks similar to a flat staircase with a gradient of usually between 0 and 30, such as 24 or 26 degrees. The fuel is moved across the grate by the steps moving and thus transport the fuel. Depending on the direction of the grate bar movement, the step grate is also called a moving grate or a reversing grate (in both cases, however, there is a forward movement for the fuel).

Stair gratings are used for coarse and ash-rich fuels that require improved stoking, e.g. E.g. household and commercial waste, biomass, processed waste or, more rarely today, lignite.

Stair gratings have a large number of grate bars that can be firmly connected to one another or can be movable relative to one another in order to move the material to be fired on the grate.

Grate bars usually have air slots in front of the running surface in a grate bar head. For this purpose, recesses are provided on the side wall of the grate bar or in the form of round openings in the surface, which make it possible to convey air to the underside of the grate bar, which can then escape between the grate bars through the air slot to the combustion bed. However, round openings can also be provided in the surface of the grate bar, for example.

Particularly when treating waste with a high metal content, metal parts can get caught in the air slots in the area of the grate bar head and become stuck.

To avoid this, the EP 2 614 304 A1 Air slots that are arranged in the side walls of the grate bar in the area of the grate bar head and the running surface. Since these air slots are arranged on both sides of the grate bar, when the grate bar is installed there are recesses opposite each other, which together form an air slot. When grate bars lying next to one another move relative to each other, particles that have penetrated into the air slots are cut up and thereby comminuted in such a way that they are conveyed back into the combustion bed by the air flow in the air slots.

However, this arrangement has the disadvantage that the forces acting on metal particles in the air slots also cause counterforces that act on the individual grate bars and can result in uncontrolled movements of the grate bars and also destruction in the area of the air slots.

The US 9,038,550 B2 suggests arranging a recess on one side of a grate bar, which, when several such grate bars are placed side by side, forms an air slot that is partially run over by a grate bar lying above it. This causes the volume flow that flows through the air slot to constantly change. There is no opening in the grate head.

The KR10-2013-0053519A describes a grate bar with the features of the preamble of the first claim. The grate bar has three recesses arranged one behind the other, which form air slots. It is not clear from the publication how many of the recesses are in the area of the tread.

The invention is therefore based on the object of further developing such known grate bars in order to protect the grate bars in practical operation and to achieve defined ventilation of the combustion bed.

This task is achieved with a grate bar with the features of patent claim 1.

The fact that air slots are only arranged on one side wall prevents particles from penetrating into the area of opposite air slots and being exposed to shear stress that acts on at least one grate bar. The arrangement of the air slots in the area of the running surface and not in the area of the grate bar head ensures that a grate bar above it, which slides on the running surface, exerts a force on metal particles that get caught in an air slot.

The shearing effect therefore essentially does not act between two grate bars lying next to one another, but between a grate bar lying below, in which particles can possibly penetrate into the air slot, and a grate bar above, which slides on the running surface and thus also pushes out particles that have penetrated into an air slot .

The passage of the grate bar head of the grate bar arranged above over the air slots arranged in the running surface ensures that the air slot is temporarily in the combustion bed and is temporarily covered by the grate bar above it. This reduces thermal wear on the louver. In addition, the passage over the air slot by the grate bar head of the grate bar sliding over it causes the running surface to be cleaned or at least pushed free. The top of the air vent is also cleaned. In the area of the air vents, the fire is fueled by the air supplied. This can result in so-called forge fires, which lead to thermal wear, particularly in the area of the air slots. A particular advantage is that these forge fires are extinguished by the upper grate head moving over them. The air slots are even temporarily covered by the grate rod head that moves over them, so that they can cool down a little. But even after this, the air slots that have been passed over can continue to cool down because the burning material above them has been pushed away.

Since, according to the invention, the grate bar above frees the air slots from particles caught in them in the area of the running surface of the grate bar underneath, it is further proposed that the side wall only has at least one air slot in the area of the running surface. Thus, the grate bar no longer has any air slots in the area of the grate bar head and in the area of the running surface either one air slot is provided or there are several air slots one behind the other, with two air slots preferably being arranged one behind the other in the area of the running surface.

If there are no air slots in the area of the grate bar head, no air slots will be pushed into the combustion bed with the grate bar head. This prevents material, such as metal particles, from being pressed into air slots in the grate head when the grate head is moved into the combustion bed.

In order to further reduce the risk of metal parts getting caught in the air slots of the grate bar, it is proposed that the air slot has a cross-sectional area which widens from the tread to the underside. The air slot thus widens from the upper running surface to the underside underneath and this means that particles that get into the air slot from the combustion bed and thus from the running surface can fall down through the air slot if they pass through one above the The upper grate bar guided by the tread can be pressed or cut into the air slot.

For this purpose, there can also be a cutting edge between the running surface and the area underneath that has an enlarged cross-sectional area, which makes it easier to shred a particle that gets into the air slot.

An air slot is usually designed with a front side directed transversely to the extent of the grate bar and opposite a rear side and a side wall lying in between. In this case, it is advantageous if the front, rear and/or side walls are arranged at an acute angle to the tread, so that on the one hand the cross-sectional area expands directly under the tread and on the other hand an edge is created on the tread that allows the cutting of particles favored.

In practice, the lower end of the grate bar head lies on the running surface of a grate bar underneath and the sliding surface of the upper grate bar head touches the running surface of the grate bar underneath. This sliding surface can have a clearing bar that is shaped in such a way that it acts with a defined force on particles that lie on the running surface or that have possibly penetrated into the air slots.

Accordingly, the clearing bar can have, as a cutting edge, a contact surface that extends at an acute angle or an arc with a radius of less than 200 mm and in particular around a circular sector of less than 80 ° to the sliding surface. This cutting edge can be arranged in the longitudinal direction of the grate bar at the front end of the sliding surface in order to move over when the grate bar is pushed forward to cut, scrape or advance a tread of an underlying grate bar material from the surface of the underlying grate bar.

However, the cutting edge can also be arranged at the rear end of the sliding surface in order to use the cutting edge to clean the surface of the underlying running surface over which the sliding surface of the grate bar above is pulled when the upper grate bar is pulled back relative to the running surface of a grate bar located underneath. The grate bar head therefore preferably has two cutting edges, each of which cleans the running surface of a grate bar underneath when the grate bar is advanced and retracted.

However, the sliding surface of the grate bar can also have a clearing bar which, as a pushing edge, has a contact surface which extends at an obtuse angle or an arc with a radius of more than 200 mm and in particular around a circular sector of more than 100 ° to the sliding surface. This pushing edge can also be formed on the front area of the sliding surface and/or on the rear area of the sliding surface in order to allow the sliding surface of the grate bar head to slide securely over such deposits even if the running surface underneath the grate bar head is dirty.

A particularly preferred embodiment has a cutting edge in the front area of the sliding surface and a pushing edge in the rear area of the sliding surface. Depending on the design of the grate and depending on the material to be burned, the grate bar can have a cutting edge or a pushing edge at different points and different grate bars can also be combined in order to use the optimal grate bar in different combustion areas, the push bar tailored to the area. and has cut edges. This allows grate bars to be individually adapted to the combustion process, which leads to optimal combustion.

The grate bar according to the invention can also have a bar that is in one or two parts, regardless of the aforementioned features. Under a one-piece A bar is a bar that is not cast or welded on, but rather is a removable part. This bar can be arranged in a positive or non-positive manner on a side wall of the grate bar. For example, it can have a head that is inserted into an elongated hole and secured by twisting.

The latch is preferably in two parts and in particular designed as a combination of screw and nut. It is therefore suggested that the latch of the grate bar has a screw. This enables easy dismantling of grate bars, especially in the edge area of the fuel bed. The screw-on nut can be under the tread or outside next to the tread. The screw head is preferably on the outside and the nut is protected under the tread.

A special embodiment variant provides that the bolt of the bolt has a head that has an internal polygon. The screw can then be, for example, a so-called Allen screw, a hexagon socket or a square socket. The head of the screw is preferably located on a side wall in such a way that it projects outwards over the side wall and takes on the function of the latch, while a nut is arranged below the running surface and only serves to hold the screw and, if necessary, replace the screw.

In the case of a removable bolt, the head of the bolt performs the function of the known bolt, since this head can engage in a bolt window of an adjacent grate bar. It is advantageous if this head has a round cross section, as no disruptive material can then collect on the bolt. The round surface of the bar no longer forms a plane on which disruptive material agglomerates.

A grate bar can also have several bars at different points on the grate bar. However, it is advantageous if the grate bar only has one bar, since the problems arising with the bar are then reduced to one problem area.

While in the prior art, internals such as cooling fins are usually arranged on the underside of the grate bar, it is proposed that the underside between the side surfaces in the area of the bar is essentially flat. This means that a counterpart of the bolt, such as a nut, can be arranged in an easily accessible manner and the entire grate bar requires less material and ultimately has less weight.

Another advantageous feature of the grate bar is that it has a locking window into which a bar of an adjacent grate bar can engage and which has an opening on the side opposite the running surface. This embodiment is intended for the edge bars, as there it is not necessary to hold the grate bar down, i.e. to secure it against lifting off.

The transom window therefore has an opening at the bottom through which material that gets into the transom window can fall out of the transom window again.

Even independently of the aforementioned features, the feature that is essential to the invention is that the grate bar has a core bar that is cast into the grate bar. There are known grate bars made of different materials. These grate bars have a special material on the running surface, while the rest of the grate bar is made of a different material. This enables particularly stable running surfaces.

However, a core bar cast into the grate bar has a different function. It can be particularly ductile so that it does not break if the rod breaks or at least holds the fragments of the rod together so that the rod cannot fall down. This means that the grate can continue to operate until the next controlled standstill even if the grate bar is broken, without a broken bar missing from the grate that has fallen into the funnel below.

A grate bar is not used in the operation of a combustion system as a single grate bar, but rather as a grate bar arrangement with several grate bars. There is an upper one Grate bar with its grate bar head arranged movably relative to a lower grate bar in such a way that the grate bar head can slide over a front and a rear area of the running surface of the grate bar. With such a grate bar arrangement, it is advantageous if the running surface has air slots in the front and rear areas and the grate bar head can be moved relative to these air slots in such a way that the opening cross section of all ventilation slots remains constant.

This means that by moving the grate bars relative to one another, all the air slots on the grate bar below are temporarily covered by the grate bar above, while at times only the front air slots and sometimes no air slots at all are covered by the grate bar above. As a result, more or less air initially flows through the grate bar below. However, since more or fewer air slots are also covered on the grate bar above it during the movement of the grate bar by the grate bar arranged above it, the opening cross section of all ventilation slots is constant in the arrangement according to the invention.

In the case of a grate with several rows of grate bars lying one above the other, many areas are created in which there is a grate bar arrangement with several grate bars, which are arranged and movable in such a way that the opening cross section of all ventilation slots in this grate bar arrangement remains constant. The arrangement of the air slots is such that the same free area is always available for air to pass through, results in alternating air distribution and leads to stable combustion. The relative stroke of the grate bars lying one on top of the other leads to air slots that can be driven over and to the cutting out of interfering particles that can collect in the area of the air slots.

Grate bars arranged one above the other are movable relative to one another and grate bars arranged next to one another can either be movable relative to one another or can also be firmly screwed together.

In terms of method, the object on which the invention is based is achieved with a method for operating a grate bar arrangement with several grate bars, each with a running surface and a grate bar head, in which an upper grate bar with its grate bar head is moved relative to a lower grate bar in such a way that the grate bar head is moved over one front and a rear area of the running surface of the grate bar slides. The running surface has air slots in the front and rear areas and the grate bar head is moved relative to these air slots in such a way that the opening cross section of all ventilation slots remains constant. This grate bar arrangement does not have to contain all the grate bars of the combustion system. It is sufficient if these grate bars are arranged in an area of several grate bars arranged one above the other and are provided with air slots in such a way that the opening cross section of all ventilation slots remains essentially constant even during operation.

Figur 1

einen Roststab mit einem vorderen und einem hinteren Riegel,

Figur 2

eine vergrößerte Darstellung des in Figur 1 gezeigten vorderen Riegels,

Figur 3

einen Schnitt durch zwei Roststäbe im Bereich des in Figur 2 gezeigten Riegels,

Figur 4

eine vergrößerte Darstellung einer alternativen Ausführungsform zum in Figur 2 gezeigten Riegel,

Figur5

einen Schnitt durch zwei Roststäbe im Bereich des in Figur 4 gezeigten Riegels,

Figur 6

eine Ansicht einer Roststabanordnung mit drei nebeneinander liegenden Roststäben,

Figur 7

eine Ansicht einer Roststabanordnung mit jeweils zwei nebeneinander und zwei übereinander angeordneten Roststäben,

Figur 8

einen Schnitt durch einen Roststabkopf mit vorne einer Schnittkante und hinten einer Schubkante,

Figur 9

einen Schnitt durch einen Roststabkopf mit vorne einer Schnittkante und hinten einer erhöhten Schnittkante,

Figur 10

einen Schnitt durch einen Roststabkopf mit vorne einer Schnittkante und hinten einer nach unten weisenden Schnittkante,

Figur 11

schematisch einen Ausschnitt aus Figur 1 mit dem vorderen Luftschlitz,

Figur 12

schematisch einen Längsschnitt durch den in Figur 11 gezeigten Bereich des Roststabes,

Figur 13

schematisch einen Querschnitt durch den in Figur 11 gezeigten Bereich des Roststabes,

Figur 14

schematisch ein vergrößertes Detail aus Figur 13,

Figur 15

eine Roststabanordnung mit einem beweglichen Roststab in der untersten Position,

Figur 16

die in Figur 15 gezeigte Roststabanordnung mit dem beweglichen Roststab in einer mittleren Position,

Figur 17

die in Figur 15 gezeigte Roststabanordnung mit dem beweglichen Roststab in der obersten Position,

Figur 18

die Unterseite eines Roststabes,

Figur 19

einen Längsschnitt durch den in Figur 18 gezeigten Roststab,

Figur 20

schematisch einen in einen Roststab eingegossenen Kernstab und

Figur 21

den in Figur 20 gezeigten Roststab in gebrochenem Zustand.

Exemplary embodiments of grate bars and grate bar arrangements are shown in the drawing and are described in more detail below. It shows

Figure 1

a grate bar with a front and a rear bar,

Figure 2

an enlarged view of the in Figure 1 front latch shown,

Figure 3

a cut through two grate bars in the area of the in Figure 2 bar shown,

Figure 4

an enlarged view of an alternative embodiment to the one in Figure 2 bar shown,

Figure5

a cut through two grate bars in the area of the in Figure 4 bar shown,

Figure 6

a view of a grate bar arrangement with three grate bars lying next to each other,

Figure 7

a view of a grate bar arrangement with two grate bars arranged side by side and two one above the other,

Figure 8

a section through a grate bar head with a cutting edge at the front and a pushing edge at the back,

Figure 9

a cut through a grate bar head with a cut edge at the front and a raised cut edge at the back,

Figure 10

a cut through a grate bar head with a cut edge at the front and a cut edge pointing downwards at the back,

Figure 11

schematically cut out a section Figure 1 with the front air vent,

Figure 12

schematically a longitudinal section through the in Figure 11 shown area of the grate bar,

Figure 13

schematically a cross section through the in Figure 11 shown area of the grate bar,

Figure 14

schematically an enlarged detail Figure 13 ,

Figure 15

a grate bar arrangement with a movable grate bar in the lowest position,

Figure 16

in the Figure 15 grate bar arrangement shown with the movable grate bar in a middle position,

Figure 17

in the Figure 15 Grate bar arrangement shown with the movable grate bar in the top position,

Figure 18

the underside of a grate bar,

Figure 19

a longitudinal section through the in Figure 18 shown grate bar,

Figure 20

schematically a core bar cast into a grate bar and

Figure 21

the in Figure 20 Rust bar shown in broken condition.

The in Figure 1 The grate bar 1 shown has a grate bar head 2, two side walls 3 and 4 and a running surface 5. The grate bar head 2 lies in a front area of the grate bar 1 and behind it lies the running surface 5 in a rear area of the grate bar 1. Below the running surface 5 lies between the Side walls 3 and 4 the underside 6 of the grate bar 1.

In the area of the tread 5 there are recesses 7 and 8 in the side wall 4 on one side of the grate bar 1. These laterally arranged recesses 7 and 8 form air slots 9, 10 running transversely from the underside 6 to the tread 5.

The air slots 9 and 10 are only arranged in the area of the running surface 5 and not in the area of the grate bar head 2. As a result, the air slots 9, 10 are completely run over by a grate bar head of another grate bar pushed onto the running surface 5.

The front flank 11 and the rear flank 12 of the air slot 9 are each arranged at an acute angle to the running surface 5, so that the cross-sectional area 13 (cf. Figure 6 ) extended from the running surface 5 to the underside 6 of the grate bar 1.

The flanks 15, 16 of the air slot 10 are also corresponding - as in Figure 12 shown - arranged at an acute angle 17, 18 to the running surface 5, so that the cross-sectional area 14 of the air slot 10 also expands there from the running surface 5 to the underside 6.

The expansion of the cross sections 13 and 14 from the running surface 5 to the underside 6 of the grate bar 1 is also increased by the fact that the recesses 7 and 8 between the flanks 11 and 12 or 15 and 16 are at an acute angle to the running surface 5 are arranged such that the cross-sectional area 13, 14 of the air slots 9, 10 widens from the tread 5 to the underside 6.

The Figure 6 shows how several grate bars 1, 21, 22 are arranged next to one another in order to provide running surfaces 5, 23, 24 with air slots 25 to 28 in between, essentially in one plane.

The Figure 7 shows how the grate bar heads 29 and 30 of further grate bars 31 and 32 slide along on the running surfaces 5 and 23 of the grate bars 1 and 21. The grate bar heads 29 and 30 move over the air slots 9, 10 and 27 and 28 of the grate bars 1 and 21 in order to push material from the fuel bed lying on the running surfaces 5 and 23 away from the air slots 9, 10 and 27 and 28.

For this purpose, the front end of the grate bar head 2, 29, 30 has a special shape, which depends on the purpose and area of use - as in the Figures 8, 9 and 10 shown in cross section - can be formed.

The in Figure 8 The grate bar head 33 shown has a lower end 34 with a sliding surface 35 which has a cutting edge 37 at the front end of the grate bar head 33. This cutting edge 37 has an acute angle 38 between the sliding surface 35 and a thrust surface 36.

When the grate bar head is pulled back, the inside 40 serves as a clearing bar, which is in the in Figure 8 shown embodiment in the transition to the sliding surface 35 is designed as a pushing edge 41. This thrust edge 41 has an obtuse angle 42 between the sliding surface 35 and a thrust surface 40. While the Figure 8 as a thrust edge 41 has an arc with a radius of approximately 6 mm and a circular sector of approximately 105 °, shows Figure 9 on the grate bar head 45 a cut edge 46 - as in Figure 8 - And as a pushing edge 41 in cross section, it is designed as a corner with an obtuse angle.

The Figure 10 shows a grate bar head 50 with a cutting edge 51 with an acute angle 52 in the front area of the sliding surface 53 and a further cutting edge 54 with an acute angle 55 in the rear area of the sliding surface 53 of the grate bar head 50.

The Figures 2 to 5 show two-part bars 60, 61, each consisting of a screw 62, 63 and a nut 64, 65. The screw 62 has a screw head 66 with an internal polygon 67 and the screw 63 has a mushroom-shaped design as a screw head 68. In both cases, the bolt 60, 61 has a bolt head with a round cross section, which is either arranged in the wall of the adjacent grate bar ( Figure 3 ) or is arranged under the underside 69 of the adjacent grate bar ( Figure 5 ). The undersides 6 and 69 of adjacent grate bars 1 and 23 are essentially flat between the side walls 3 and 4 in the area of the bars 60 and 61, so that the screws 62 and 63 and the nuts 64 and 65 are easily accessible.

Each grate bar 1, 23 has a locking window 70, 71 on one side wall 3 and a locking bar 60, 61 on the opposite side wall 4, so that when the grate bars 1, 23 are next to each other, a locking bar 60, 61 is inserted into the locking window 70, 71 of the neighboring one Riegel can intervene. The latch window 70, 71 can accommodate the latch 60, 61 of the adjacent grate bar in the upper area and have an opening (not shown) on its side opposite the running surface 5.

The one in the Figures 18 to 21 The grate bar shown has only a single bar 66 and a core bar 80 is cast into the grate bar 1. This cast core rod 80 lies under the tread in such a way that it does not touch the tread. Cast in means that the core bar is preferably completely surrounded by the remaining material of the grate bar and is therefore completely surrounded by other material.

The Figure 21 shows how the core bar 80 bends when the grate bar 1 breaks and how it bridges this gap 81 when a gap 81 arises during the break and holds the fragments 82, 83 of the grate bar 1 together.

The Figures 15 to 17 show a grate bar arrangement 90 with two fixed grate bars 91 and 92 and a movable grate bar 93 arranged between them Figures 15 to 17 can be seen how the movable grate bar 93 between the fixed grate bars 91 and 92 from the in Figure 15 shown lower position above the in Figure 16 middle position shown in Figure 17 can be pushed to the upper position shown.

The arrangement and design of the grate bars are designed such that regardless of the position of the movable grate bar 93, the opening cross section of all air slots 94 to 97 remains constant. For this purpose, the grate bars 91 and 93 have a running surface 98, 99 and each have a grate bar head 100, 101 and the grate bar 93 is arranged to be movable as an upper grate bar with its grate bar head 101 relative to the grate bar 91, which serves as a lower grate bar. When the upper grate bar 93 is pushed over the lower grate bar 91, the grate bar head 101 slides over a front area 102 and a rear area 103 of the running surface 98 of the grate bar 91. The air slot 95 in the rear area 103 is first passed over by the grate bar head 101 of the grate bar 93, so that the air slot 95 then - as in Figure 16 shown - is covered by the grate bar head 101 of the grate bar 93. However, the air slot 96 in the grate bar 93, which was previously covered by the grate bar 92, is exposed. Thus, in the in Figure 15 In the grate bar position shown, the air slots 94 and 95 are open, while in the in Figure 16 position shown the air slots 94 and 96 are open.

The Figure 17 shows the grate bar 93 pushed completely upwards, which now covers both the air slot 95 and the air slot 94 of the grate bar 91. Here, the air slots 96 and 97 of the movable grate bar 93 are exposed, so that two air slots are exposed again in this position of the movable grate bar 93.

This example of a grate bar arrangement shows how the arrangement of the air slots 94, 95, 96, 97 in the area of the running surfaces 98, 99 makes it possible to always ensure that the opening cross section of all air slots remains constant during the movement of the grate bars.

Claims (15)

1. Grate bar (1) having a grate bar head (2), two side walls (3, 4), a running surface (5) behind the grate bar head (2) and between the side walls (3, 4), and an underside (6) located between the side walls (3, 4) and under the running surface (5), wherein, in the case of a side-by-side arrangement of multiple grate bars of this type, a recess (7, 8) in a side wall (4) between the running surface (5) and underside (6) forms at least one air slot (9, 10), wherein the recess (7, 8) is arranged only on one side wall (4) and not in the opposite side wall (3), characterized in that no openings are provided in the grate bar head and multiple recesses (7, 8), which form multiple air slots, are provided one behind the other only in the area of the running surface (5).
2. Grate bar according to claim 1, characterized in that two recesses (7, 8), which form two air slots, are provided one behind the other in the area of the running surface.
3. Grate bar according to one of the preceding claims, characterized in that the air slot (9, 10) has a cross-sectional area (13) which expands from the running surface (5) toward the underside (6).
4. Grate bar according to one of the preceding claims, characterized in that the grate bar head (2, 33) has, as a lower end (34), a sliding surface (35) with a cutting edge (37) which has an acute angle (38) or a curve with a radius of less than 200 mm and in particular a circular sector of less than 80° between the sliding surface (35) and pushing surface (36).
5. Grate bar according to one of the preceding claims, characterized in that the grate bar head (2) has, as a lower end, a sliding surface (35) with a pushing edge (41) which has an obtuse angle (42) or a curve with a radius of more than 200 mm and in particular a circular sector of more than 100° between the sliding surface (35) and pushing surface (40).
6. Grate bar according to one of the preceding claims, characterized in that it has a latch (60, 61) which is one-part or two-part.
7. Grate bar according to claim 6, characterized in that the latch (60, 61) has a screw (62, 63).
8. Grate bar according to claim 7, characterized in that the screw (62, 63) has a screw head (66) which has a polygonal socket (67).
9. Grate bar according to one of the preceding claims, characterized in that it has a latch (60, 61), which has a bolt head with a round cross section.
10. Grate bar according to one of the preceding claims, characterized in that it has only one latch (60, 61).
11. Grate bar according to one of claims 6-10, characterized in that the underside (6) is substantially flat between the side walls (3, 4) in the area of the latch (60, 61).
12. Grate bar according to one of the preceding claims, characterized in that it has a latch window (70, 71), in which a latch (60, 61) of an adjacent grate bar (1) can engage, and which has an opening on the side opposite the running surface.
13. Grate bar according to one of the preceding claims, characterized in that it has a core bar (80) which is embedded into the grate bar (1).
14. Grate bar assembly (90) comprising multiple grate bars (91, 92, 93) according to one of the preceding claims, each comprising a running surface (98, 99) and a grate bar head (100, 101), in which assembly an upper grate bar (93) with its grate bar head (101) is arranged to be movable relative to a lower grate bar (91) in such a way that the grate bar head (101) can slide over a front area (102), and a rear area (103) of the running surface (98, 99) of the grate bar (91), wherein the running surface (98, 99) has air slots (94, 95, 96, 97) in the front and rear areas (102, 103) and the grate bar head (100, 101) is displaceable relative to these air slots (94, 95, 96, 97) in such a way that the opening cross section of all air slots (94, 95, 96, 97) remains constant.
15. Method for operating a great bar assembly comprising multiple grate bars (91, 92, 93) according to one of preceding claims 1-13, each comprising a running surface (98, 99) and a grate bar head (100, 101), in which assembly an upper grate bar (93) with its grate bar head (101) is moved relative to a lower grate bar (91) in such a way that the grate bar head (101) slides over a front area (102) and a rear area (103) of the running surface (98, 99) of the grate bar (91), wherein the running surface (98, 99) has air slots (94, 95, 96, 97) in the front and rear areas (102, 103) and the grate bar head (100, 101) is displaced relative to these air slots (94, 95, 96, 97) in such a way that the opening cross section of all air slots (94, 95, 96, 97) remains constant.

Images