Grate bar for step grate

Description

Technical area

[0001] The invention relates to a grate bar front section and a grate bar with the grate bar front section. State of the art

[0002] Waste incineration is a collective term for waste disposal processes in which accumulating waste materials are burned. Waste incineration reduces the original volume of the waste. One waste incineration process is grate combustion. This can include stepped grates and / or moving grates. The grate consists of several rows of grate bars, usually braced laterally. The different rows of the grate overlap one another, with the front section of each grate bar overlapping the rear section of the grate bars upstream in the conveying direction. This creates a flat staircase along which the waste to be incinerated is pushed forward by an oscillating movement. Depending on their position in the moving grate, the grate sections can be air-cooled and / or water-cooled. A lateral division into two or more grate tracks is also possible.

[0003] EP 0 170 803 A1 discloses a multi-part grate bar and various designs for connecting the parts.

[0004] US 2006 / 0011114 A1 discloses a one-piece grate plate with a top side, a bottom side, two long sides and two wide sides for a combustion grate, a combustion grate made of grate plates and a waste incineration plant with such a combustion grate.

[0005] EP 3 048 369 B1 discloses a grate bar for a moving grate for waste incineration. The grate bar is made in one piece from a ceramic composite material. For this purpose, a ceramic matrix is ​​cast into a shell with a base and side walls made of sheet metal and a perforated support structure. The grate bar has a front section for receiving fuel and a rear section designed for attachment to a cross member.

[0006] From utility model DE 75 21 218, a grate plate with a base plate is known, onto the rear end of which a wear bar 5 is pushed. With its front end, the wear bar engages in a gap extending in the longitudinal direction of the base plate and, with its rear end, encompasses the rear end of the base plate.

[0007] German Patent Application DE 2930406 A proposes a stepped grate for a clinker cooler, in which one-piece grate plates are mounted in rows next to each other on crossbeams. To secure the grate plates, they are clamped to the crossbeam from below using a tension bolt. For this purpose, the tension bolts each have an angled, free leg at their upper end that engages a complementary hook-like recess on the underside of the respective grate plate. Description of the invention

[0008] The invention is based on the object of developing a lightweight, inexpensive grate bar that promotes the processes on the grate and can withstand high thermal and mechanical loads, such as those that occur in waste incineration reactors and cement clinker coolers.

[0009] This object is achieved by a grate bar front section according to claim 1. The grate bar front section can be connected to a preferably complementary grate bar rear section to form a grate bar according to claim 2.

[0010] For example, the grate bar can be designed for a waste incineration grate or a clinker cooler grate and used as part of such a grate. Further advantageous embodiments of the invention are specified in the subclaims.

[0011] The grate bar front section, hereinafter referred to as the "front section," can be mounted to a grate bar rear section, hereinafter referred to as the "rear section," for example, as described in detail below. The front section can be attached to a supporting structure, e.g., a cross member, via the rear section in the conventional manner. Alternatively or optionally, the front section can be attached to existing rear sections or directly to at least one supporting structure, e.g., a cross member, of a grate.

[0012] The front section comprises a refractory mineral material. For example, the front section can be made of or comprised of refractory or highly refractory concrete, preferably ceramic. These materials make the front section resistant to thermal, mechanical, and chemical influences, such as heat, abrasion, or corrosion.

[0013] For example, the front section can consist at least substantially (i.e., more than 30%, better still, more than 50%, preferably more than 75%, more than 85%, or more than 90%) of the refractory mineral material. The term "ceramic" is used below as a general term for a refractory mineral material. The ceramic can be reinforced, for example, with steel fibers or other fibers, and otherwise the front section is preferably monolithic. Alternatively, only the top few centimeters of the front section's upper surface can be made of ceramic.

[0014] The front section has a top side, a bottom side, a front side, two narrow sides, a back side, and a grate bar longitudinal axis extending parallel to the top side through the front side and the back side. The designations of the sides refer to the conveying direction of the grate, i.e. to the installation position of the grate bar in the finished grate. When the grate bar is installed, the grate bar longitudinal axis preferably extends at least approximately parallel to the conveying direction (i.e. it forms an angle of ±20°, preferably ±10°, particularly preferably ±2.5° with the conveying direction or is parallel to the conveying direction). The top side can accommodate the material to be processed, be it material to be burned (such as garbage or wood chips) or cement clinker to be cooled (clinker for short). For the sake of simplicity, the space above the surface is therefore called the reactor, even though chemical processes do not necessarily take place there.For example, the material to be processed can be transported on the top side towards the front side by an oscillating movement of the grate bars. The top side can be in direct contact with the material to be processed and can be exposed to extreme thermal and chemical stress. The underside is the side of the front section facing away from the top side. The top side and the underside are connected by the front side, the back side and the two narrow sides. As usual, the front side points in the conveying direction and is opposite the back side. The two narrow sides each connect the front side to the back side. When assembled, the narrow sides of adjacent front sections typically lie against one another. The front sections of a grate row are referred to as adjacent here, with the grate rows extending orthogonal to the conveying direction.An (imaginary) longitudinal grate bar axis of the front section runs through the front and rear. An (imaginary) vertical grate bar axis runs orthogonal to the longitudinal grate bar axis and orthogonal to the at least approximately flat upper side. An (imaginary) transverse grate bar axis then extends, as usual, orthogonal to the other two axes through the narrow sides and, when assembled, corresponds to the longitudinal direction of a grate bar row and the transverse direction of the grate.

[0015] In summary, the front side defines the front section in the conveying direction, shares an edge with the top and bottom sides, and is preferably flat, for example, although it can also have other geometries. The rear side is located on the side of the front section facing away from the front side and, like the front side, therefore shares an edge with the top and bottom sides. The rear side can serve as a contact surface for the rear section and / or a supporting structure for the grate.

[0016] The narrow sides each have a common edge with the front and rear sides, as well as the top and bottom sides. The narrow sides preferably extend at least approximately parallel (i.e., ±20°, preferably ±10°, particularly preferably ±2.5° or parallel) to the grate bar's longitudinal axis.

[0017] Starting from the underside of the front section, at least one recess extends from an opening in the underside towards the top side. The recess does not necessarily end in an opening in the top side, but preferably below the top side. In this sense, the recess can preferably be a blind hole. The recess preferably has at least one contact surface on the edge of the recess facing the rear side or the front side. The contact surface can then introduce a force acting in the direction of the rear side or front side, for example in a form-fitting and / or force-fitting manner, into the front section. The contact surface is preferably convex or flat. Compressive forces can then be introduced into the ceramic of the front section via the form-fitting or force-fitting connection in a way that is gentle on the material. This increases the service life.

[0018] Starting from the rear side and / or the front side, at least one channel connects the rear side and / or the front side and optionally at least one side surface to the recess. The channel has a longitudinal channel axis. The channel can, for example, have a cylindrical, in particular circular-cylindrical, contour, i.e., be delimited by a corresponding lateral surface. The channel can preferably taper from the rear side and / or the front side toward the recess, for example, taper continuously. The channel can also be at least partially open to the underside.

[0019] The channel is configured, for example as explained in more detail below, to accommodate a bolt or other connecting element for fastening, namely for bracing, the front section to a rear section. The recess, with the at least one contact surface, offers an abutment for bracing the connecting element and also access to the connecting element or to the channel. The channel, together with the recess, therefore enables the front section to be connected, preferably detachably, to a rear section and / or a front plate. The rear section, which is subject to only minimal wear, can therefore be reused, e.g. if the corresponding front section is worn or otherwise damaged and is replaced.In addition, the front section, the optional rear section, and / or the optional front panel can be manufactured from different materials, allowing the front section and the optional rear section to be cost-effectively adapted to their respective tasks. The same applies to an optional front panel.

[0020] Herein, the term bolt is used as a pars pro toto for a fastener. The term bolt could therefore simply violate the term connecting element be replaced, whereby this particularly includes the typical connecting bolt, e.g. a threaded bolt.

[0021] The ceramic makes the front section corrosion- and wear-resistant. Ceramic also has a high permissible operating temperature. The ceramic makes the front section dimensionally stable even under high temperature loads and also exhibits a low specific gravity. The disadvantages of the ceramic material are its rather low tensile strength and brittle behavior. Therefore, the tensile stress exerted on the grate bar must be minimized. In contrast to their low tensile strength, ceramic and the other preferred refractory materials exhibit high compressive strength at high temperatures. Due to the bolt fastening described, the ceramic of the front section is at least essentially only subjected to compressive stress.

[0022] The preferred tapering of the channel facilitates demolding of the front section from a casting mold, as the front section can be easily released from the mold by pivoting and / or rotating movements and frictional forces are minimized.

[0023] Another advantage of the optional tapered channel is that it facilitates subsequent assembly and disassembly from a complementary rear section or front panel. This allows, for example, a bolt to be inserted more easily into the channel during assembly. Furthermore, a stuck bolt can be quickly and easily released during disassembly with a pivoting motion. The risk of the bolt sticking to the edge of the channel is greatly reduced, if not eliminated.

[0024] Starting from the rear and / or bottom side, at least one gas line can preferably extend toward the top and / or front side and open into the top and / or front side. The number of gas lines can vary as required (i.e., preferably at least one gas line, particularly preferably two, three, or more gas lines). In other words, the at least one gas line connects at least one inlet in the rear and / or front side with at least one outlet in the top and / or front side. The gas line can be used to cool the front section, and a process gas (shortly "gas") that heats up as it flows through the gas line can also be conveyed to the top of the front section. The gas can, for example, be air or another gas or gas mixture that promotes combustion, e.g., possibly preheated primary air for waste incineration or other applications.When used in a cement clinker cooler, the gas can be a cooling gas for cement clinker.

[0025] Preferably, at least a section of the at least one gas line is located above a plane parallel to the longitudinal axis of the grate bar and the transverse axis of the grate bar, and also above the channel. In the assembled state, the gas line is then arranged above the bolt for securing the rear section. A gas flowing through the gas line therefore cools the area of ​​the front section located above the bolt (or more generally, the connecting element), reducing the thermal load on the bolt. Accordingly, the service life of the bolt is increased, and it can also be dimensioned with smaller safety margins.

[0026] The gas line thus enables the transport of gas located below the front section to the top of the front section. For example, in a waste incineration plant, primary air can flow from the underside of the grate to the top via the gas line. This primary air heats up, i.e., it absorbs heat from the front section. As a result, the gas reaches the top of the front section at a higher temperature, and less energy is required to heat the primary and / or secondary air.

[0027] The gas line can have a circular cross-section, but the cross-section can also be oval, e.g. elliptical, or polygonal.

[0028] At least a section of at least one insulating body can preferably be arranged between the channel and the upper side and / or preferably between the recess and the upper side. The number of insulating bodies can vary (ie preferably one insulating body, particularly preferably two, three or more insulating bodies). The insulating body is made of a material with lower thermal conductivity than the surrounding ceramic and can, for example, be a rod-shaped body. Such a body can be easily inserted into a casting mold and thus easily introduced into the front section. Mineral wool and / or air, for example, can be selected as the insulating medium.

[0029] The insulation body reduces heat transfer to the underlying section and thus acts as a thermal barrier. This can reduce the thermal load exerted on a bolt located in the channel.

[0030] If at least one gas line as described above is provided, at least one insulating body can preferably be arranged between the gas line and the channel and / or the recess. This does not reduce the heating of gas flowing through the gas line and further reduces the heat input into the region of the channel.

[0031] In particular, if the insulation body is rod-shaped, its rod longitudinal axis can extend at least approximately (preferably ±10°, particularly preferably ±2.5° or exactly) in the direction of the grate bar longitudinal axis and / or the channel longitudinal axis. In this case, the insulation body can be arranged above the channel, for example, and thus protect the channel and the optional bolt particularly efficiently from the heat on the upper side. Alternatively or additionally, the or another insulation body is aligned at least approximately orthogonally (i.e. ±20°, preferably ±10°, particularly preferably ±2.5° or orthogonally) with respect to the grate bar longitudinal axis. This variant is particularly easy to manufacture, and good thermal protection of the channel and the bolt can be achieved by a plurality of insulation bodies arranged next to one another.

[0032] The insulating body may have a circular cross-section, but the cross-section may also be oval, e.g., elliptical, or polygonal. The insulating bodies may be arranged tangent, overlapping, or preferably adjacent to one another, e.g., spaced apart from one another and / or at least approximately parallel to one another (within ± 10°, preferably ± 5°, particularly preferably ± 2.5° or less).

[0033] Preferably, at least one gas passage extends from an inlet in the underside towards the top side and ends in an outlet in the top side. The number of gas passages can vary as required (i.e. preferably one gas passage, particularly preferably two, three or more gas passages). At least one gas passage enables gas located below the front section to be transported to the top side of the front section. The gas can, for example, be a process gas for processes taking place on top side of the grate, for example air or another gas or gas mixture that promotes combustion. For example, in a waste incineration plant, primary or secondary air can flow from the underside of the grate to the top side by means of the gas passage.The gas passage allows for a uniform introduction of process gas into the reactor or cooling chamber located above the front section, so that the processes in the reactor run more evenly and it is operated more economically.

[0034] The gas passage can be tilted toward the front with respect to the inlet. For example, the gas passage can have a longitudinal axis tilted in the conveying direction, i.e., toward the front, forming an acute angle with the top surface. This promotes uniform combustion on the grate surface. More generally, the process gas is supplied particularly evenly to the processes in the reactor (combustion, cooling, etc.).

[0035] Preferably, the gas passage is curved towards the front side at least in a region adjacent to the top side. If a tangent is applied to the lower side of the gas passage in the region adjacent to the top side at a contact point, this tangent forms an acute angle with the top side. As the distance of the contact point of the tangent from the outlet decreases, the value of the angle formed by the tangent and the top side preferably decreases, particularly preferably continuously. In particular, the underside of the gas passage at the outlet can merge continuously into the top side. By tilting and / or curving the gas passage, the gas can flow out in the direction of conveyance and adheres to the surface in the direction of conveyance. All of these measures therefore further increase the homogenization of the processes in the reactor.

[0036] At least one optional gas channel can extend from an inlet in the recess toward the top and / or front side and ends, for example, in at least one outlet in the top and / or front side. At least a portion of the inlet of this gas channel can be arranged in the region of the channel's longitudinal axis. This gas channel can accommodate a cooling fluid (e.g., a process gas) that flows over a surface of a bolt (or other connecting element) that, after assembly, sits with a rear portion in the channel, thereby cooling it. For example, the bolt can be a hollow bolt with the cooling fluid flowing through its axial recess. Additionally or alternatively, at least a portion of a lateral surface of a connecting element can be overflowed by the cooling fluid. The cooling fluid, e.g.,A cooling gas then flows from the underside of the grate bar through and / or over the bolt (as a pars pro toto for a connecting element) and optionally via the gas channel, e.g. to the top of the front section, whereby the bolt can be cooled particularly effectively. In order to achieve a continuous gas flow through a hollow bolt, the opening of the recess on the underside can be at least partially closed after assembly. A reduction in the diameter of the opening can be achieved, for example, by a plug with a passage of smaller diameter than the opening of the recess. If the passage in the plug is omitted, the opening is completely closed.

[0037] The gas passages can, for example, have ribs that support the stability of the front section but do not, or only minimally, impair the gas flow. The ribs can, for example, extend from the bottom to the top.

[0038] The top side of the front section can have a greater longitudinal extension than the bottom side. Due to the difference in length, the back side has an overhang. The back side can, for example, form an at least approximately right angle with the bottom side (within +25°, preferably ±10°, particularly preferably ±2.5° or better). Alternatively or additionally, the back side can connect tangentially to the top side. The back side can connect the top side to the bottom side in a stepped or curved manner. The back side is preferably continuously curved. The curvature can therefore vary.

[0039] When installed, the overhang can serve as a thermal and / or chemical shield for the rear section. The rear section can therefore be made of easily processable, less temperature-resistant materials such as sheet steel. At least one section of the overhang can be located above the rear section, thus protecting the rear section from the thermal and chemical stress emanating from the top.

[0040] The grate bar rear section, or simply the "rear section," can be mounted to a front section, for example, as described in detail below. The rear section can be made of metal. The rear section has a central part, which is preferably arranged between a first side element and a second side element. However, it can also be constructed from more or fewer individual components. The central part is an angle profile with a first leg and a second leg. Preferably, the first leg and the second leg are aligned at least approximately orthogonally (i.e., 90°±20°, preferably 90°±10°, particularly preferably 90°±2.5° or orthogonally (90°)) to each other. The common edges of the two legs preferably run parallel to the grate bar transverse axis (when installed as intended). The common edges of the two legs each end on either side in one of the two long sides of the legs.One leg has at least one through-hole and / or preferably at least one through-opening (i.e., one through-opening, preferably two, three, or more through-openings). One of the two side elements is attached to each of the two long sides of the central part. The narrow sides correspond to the long sides of the legs.

[0041] The side elements can be easily cut or punched from sheet steel, for example, and, like the center section, are very inexpensive to manufacture. Reinforcements can be added by bending. The expensive steel casting technique otherwise required for grate bars can be dispensed with. Alternatively, the rear section can also be made as a cast part.

[0042] The contours of the side elements are preferably adapted to the cross braces of a grate substructure, so that the grate bars can be easily hooked into the cross braces with their rear sections. For this purpose, the side elements can preferably each have at least one cutout into which a cross member engages from below when assembled.

[0043] The side elements can be attached to the middle part by gluing, clamping, screwing or, preferably, by welding.

[0044] The middle part of the grate bar rear section can have a third leg. The third leg can, for example, share a common edge with the second leg. For the sake of simplicity, it is assumed below that the first leg is located between the second and third legs, i.e., the first leg is the middle leg, which preferably has the above-mentioned through hole.

[0045] The third leg is preferably aligned at least approximately parallel (ie ±20°, preferably ±10°, particularly preferably ±2.5° or parallel) to the second leg, both of which, together with the first, form at least approximately a Z-profile in this sense, ie their free ends point away from each other.

[0046] According to the invention, the front section is designed to be connected to the rear section to thereby form a grate bar. According to the invention, the connection is detachable, as the less stressed rear section can then be reused particularly easily. As already described at the beginning, the rear section is optional; the front section can also be attached directly to a supporting structure. For this purpose, the connecting element described above can be used, for example.

[0047] The middle part of the rear section can rest against the rear side of the front section, preferably in a flat manner, at least in sections. At least the first leg (i.e., the first, second, and third legs, preferably the first leg, particularly preferably the first and / or third leg) can rest against the rear side. For example, the middle part can rest against the rear side at at least three different points (preferably flatly). The contact surfaces of the legs can form an abutment. The underside of the front section can rest on the third leg.

[0048] One leg can be fastened, preferably clamped, to the rear with a bolt passing through the through hole and the channel. This joins the front section to the rear section to form a grate bar. The bolt can be a threaded bolt with either a threaded pin (partially threaded bolt) or a full thread. In this sense, the bolt can also be a screw. The bolt can be inserted into the through hole of the middle section adjacent to the rear. The bolt can be received by the channel and end in the recess. Again, the term "bolt" stands for a connecting element as a pars pro toto.

[0049] In the recess, the bolt can be connected, for example, clamped, to a pressure plate resting against the contact surface. The bolt and the pressure plate can be irremovably connected, for example, by a material bond or compression (as an example of a frictional connection). Preferably, the bolt and the pressure plate are positively and removably connected. The pressure plate can, for example, be a nut with or without a washer or a plate with a connecting part intended for connection. The fastening can be achieved, for example, by a bayonet lock, a connecting element with barbs, or a thread.

[0050] The bolt can, for example, be solid or designed as a hollow bolt. The bolt can have a through-channel extending along the bolt axis with a proximal inlet and a distal outlet. The distal outlet can end in the mouth region of a gas channel that communicates between the recess and the upper side. The terms proximal and distal refer to the position of the bolt in relation to the through-hole of the first leg or the rear side of the front section, respectively. The proximal end is therefore located at the through-hole of the first leg or at the rear side of the front section. The distal end here refers to the end remote from it, in other words, the part of the bolt that ends in the recess.

[0051] The hollow bolt has the advantage that a gas flowing through it can cool the bolt. This further reduces the thermal stress on the bolt and increases its service life.

[0052] The hollow bolt and its distal outlet in the area of ​​the gas duct inlet enable, as already described with reference to the gas line and the gas passage, the transport of gas located below the front section to the top of the front section. For example, in a waste incineration plant, primary or secondary air can flow from the underside of the grate to the top via the gas duct. This primary or secondary air is heated in the process, meaning it absorbs heat from the front section.

[0053] The tangents mentioned are, of course, imaginary tangents that extend orthogonally to the grate bar transverse axis or parallel to the grate bar transverse axis. Description of the drawings

[0054] The invention is described below without limiting the general inventive concept by means of exemplary embodiments with reference to the drawings. Figure 1 shows an embodiment of a grate bar in the assembled state. Figure 2 shows a longitudinal section of the grate bar after Figure 1 . Figure 3 shows the top view of another grate bar. Figure 4 shows the underside of the grate bar Figure 3 . Figure 5 shows a longitudinal section of a detail of the grate bar according to the Figures 3 and 4 . Figure 6 shows a simplified schematic of the rear end of another variant of a grate bar. Figure 7 shows a view of a rear section of yet another grate bar front section. Figure 8 shows a perspective partial section of the grate bar front section according to Figure 7 with a grate bar back section. Figure 9shows a simplified schematic of the rear end of another grate bar. Figure 10 shows an exploded view of the grate bar after Fig. 9 . Figure 11 shows a simplified schematic of the rear end of another grate bar. Figure 12 shows an exploded view of the grate bar after Fig. 11 .

[0055] Figure 1 shows an embodiment of a grate bar 1 with a front section 10 and a rear section 20. The front section 10 and the rear section 20 are detachably connected with a connecting element 30, which is shown here as a bolt 30 by way of example.

[0056] The front section 10 has a front side 16, a rear side 18, a top side 14 and a bottom side 12. The bottom side 12 has an optional shoulder 13. The top side 14 of the front section 10 has, for example, an optional slot-shaped outlet 69 and three optional circular outlets 64, 65, which can be Fig.2will be explained in more detail. The number of outlets 64, 65, 69 is merely exemplary, ie, it should be understood as preferably at least one outlet. The outlets may also be omitted.

[0057] As shown, the upper side 14 preferably has a greater longitudinal extent along the grate bar longitudinal axis 2 than the underside 12, whereby the rear side 18 has an overhang which covers part of the upper side of the rear section 20.

[0058] The rear section 20 comprises a central part 22, a first side element 24, and a second side element 26, which can be manufactured cost-effectively from sheet steel, for example. Alternatively, the rear section 20 can also be constructed as a single piece or consist of a different number of individual components.

[0059] In Figure 2 is a longitudinal section of the Figure 1The grate bar 1 has a front section 10 and a rear section 20. The front section 10 has a top side 14, a bottom side 12, a front side 16, and a rear side 18. The front section 10 extends along a grate bar longitudinal axis 2.

[0060] The underside 12 can have a shoulder 13 in a section adjacent to the front side 16. In the area of ​​the front side 16, a clamping device 50 can fully or partially penetrate the front section 10 in the transverse direction. Accordingly, the front section 10 preferably has at least one transverse hole in its front third for receiving at least one clamping device 50. The transverse hole can be designed as a through hole or as a blind hole. The optional clamping device 50 can clamp the grate bar 1 to other, adjacent grate bars, thus forming a grate row.

[0061] The upper side 14 can have a greater longitudinal extent along the grate bar longitudinal axis 2 than the underside 12. Due to the optional difference in the longitudinal extent of the upper side 14 and the underside 12, the rear side 18 can limit an optional downward overhang. Preferably, the rear side 18 can have a flat partial surface that shares an edge with the upper side 14. Adjacent to the flat partial surface is a preferably curved second partial surface of the rear side 18, which connects the first partial surface to the underside 12.

[0062] The underside 12 may have an opening. A recess 70 extends from the opening toward the top side 14. The recess 70 is illustrated here as a blind hole and preferably has a support surface 71 that delimits the recess toward the rear side.

[0063] Starting from an opening in the rear side 18, an optional channel 32 extends into the recess 70 along a channel longitudinal axis 33. The channel 32 can preferably taper starting from the rear side 18 in the direction of the recess 70.

[0064] The front section 10 can have at least one optional gas line 60, at least one optional gas channel 61 and / or at least one optional gas passage 68. Both the gas line 60 and the gas channel 61 and the gas passage 68 each enable transport of gas (or another fluid) located below the front section 10 to the upper side 14 of the front section 10. Due to the gas line 60, gas channel 61 and gas passage 68 being inclined towards the front side 16, the fluid flows out at an angle to the surface 14 (assuming a corresponding pressure gradient), whereby the flow in the direction of the front side 16 adheres to the upper side 14.

[0065] The optional at least one gas passage 68 extends from an inlet 67 in the bottom side 12 to an outlet 69 in the top side 14, wherein the inlet 67 may have a larger diameter than the gas passage 68, whereby the flow velocity in the gas passage 68 increases towards its outlet, which prevents the fall-through of material located on the top side 14 and at least prevents clogging of the gas passage 68 by material penetrating from above.

[0066] The gas passage 68 is preferably curved, as shown, toward the front side 16, at least in a region adjacent to the top side 14. In an alternative variant, the gas passage can also be uncurved. A tangent 80 can be applied to the lower side of the gas passage 68. This tangent 80 forms an acute angle 82 with the top side 14. As the distance between the point of contact of the tangent 80 and the outlet 69 decreases, the value of the acute angle 82 formed by the tangent 80 and the top side 14 continuously decreases, and the gas passage 68 merges continuously into the top side 14 at the outlet 69, whereby the flow adheres particularly effectively to the top side 14. The outlet 69 is shown here as being slit-shaped by way of example, wherein the longitudinal direction of the slit preferably runs at least approximately parallel (within ±10°, preferably ±5°, 2.5° or better) to the transverse axis 4 of the grate bar.

[0067] The at least one optional gas channel 61 extends from an inlet 63 in the recess 70 to an outlet 65 in the upper side 14, wherein the inlet 63 can preferably have a larger diameter than the gas channel 61. The outlet 65 has, for example, a circular cross-section here.

[0068] A gas line 60 extends from an inlet 62 in the rear side 18 to an outlet 64 in the top side 14. Concealed by the front section 10 is a second optional gas line, whose outlet 64 also opens into the top side 14. The gas lines 60 are located above a plane that is parallel to the grate bar longitudinal axis 2 and the grate bar transverse axis 4 and also above the channel 32. The outlets 64 have, for example, a circular cross-section (other cross-sections are also possible, in particular oval or polygonal cross-sections).

[0069] Eight optional insulating bodies 66 are aligned parallel to one another, preferably at least approximately orthogonal to the grate bar longitudinal axis 2 (within ± 10°, preferably ± 5°, 2.5° or better). In the example shown, the insulating bodies 66 are arranged above the channel 32 and the recess 70 and thus protect the bolt 30 and the pressure plate 40 in the channel 32 or the recess 70. The number of insulating bodies 66 is also to be understood as an example, ie they can be omitted, but preferably at least one insulating body 66 is realized, which is preferably arranged above the channel 32, ie the at least one insulating body is preferably arranged as a heat shield above the channel 32.

[0070] The longitudinal section of the rear section 20 shows the central part 22 and a first side element 24. The central part 22 has, for example, a first leg 220, a second leg 221, and a third leg 222. The legs 220, 221, and 222 of the rear section 20 form, for example, an angle with a Z-profile. However, the rear section can also be designed with more or fewer individual components.

[0071] The first side element 24 of a rear section, for example a three-part one, is attached to the central part 22. This can preferably be done by a material connection, for example by gluing or preferably welding. The side elements each form a receptacle for a cross member of a grating substructure, on which the rear sections 20 with their side elements 24, 26 (see Fig. 1 ) rest on.

[0072] The central part 22 can rest against the rear side 18 in the region of the transition from the first leg 220 to the second leg 221 and in the region of the transition from the first leg 220 to the third leg 222. The central part 22 can, for example, also rest flatly against the rear side 18 or not at all.

[0073] The first leg 220 can have at least one through-opening 62' (two through-openings 62' are shown as an example) and at least one through-hole 21. After the assembly described above, the through-channels 62' are arranged in the region of the inlet 62 and an inlet 62 concealed by the central part 22. In this way, a gas can flow through the gas line 60 despite the mounted rear section 20. The through-hole 21 is arranged in the region of the opening of the channel 32 on the rear side 18.

[0074] The bolt 30 is received by the through-hole 21 and the channel 32. The bolt 30 can have a through-channel 34 along the channel's longitudinal axis 33, a proximal inlet 31, and a distal outlet 35. A pressure plate 40 is located in the recess 70, with the pressure plate 40 abutting the contact surface 71. The bolt 30 is releasably connected to the pressure plate 40, thereby releasably connecting the front section 10 and the rear section 20. The distal outlet of the bolt can be located in the mouth area of ​​the inlet 63 and the proximal inlet is located on the middle part 22. The proximal inlet 31, the through-channel 34 and the distal outlet 35 enable transport of a gas from below the grate bar 1 through the bolt 30 into the gas passage 61 up to the top side 14 of the front section 10. The flow through the through-channel 34 can be improved if the opening of the recess 70 is closed with a plug.

[0075] The Figures 3 and 4 show views of one of the Figures 1 and 2 shown similar embodiment of a grate bar. The description of the Figures 1 and 2 can therefore also be applied to the Figures 3 and 4 read (and vice versa). The top view of grate bar 1 ( Fig. 3) shows the top side 14 of the front section 10 and a top view of the rear section 20. The top side 14 can, for example, have two slot-shaped outlets 69 and, for example, two circular outlets 64, 65. The slot-shaped outlets 69 extend, for example, transversely across the top side 14, where "transverse" means that the slots run at least approximately parallel to the grate bar transverse axis 4 or at a small angle thereto. The circular outlets 64, 65 can be arranged centrally. At least one outlet could also exit at the front side. The rear section 20 is located on the rear side 18 of the front section 10. The top view of the rear section 20 shows the upper side of the second leg 221, as well as the upper sides of a first side element 24 and a second side element 26. The side elements 24, 26 are attached to the second leg 221.

[0076] The bottom 12 (see Fig. 4) of the front section 10 has a common edge with the front side 16 and the rear side 18. In the area of ​​the front side 16, the front section 10 has a shoulder 13 (which can also be omitted). The underside 12 comprises two inlets 67 as an example for at least one inlet 67 and a recess 70 extends from an opening in the underside 12. The recess 70 can take on the function of a further gas inlet. The recess 70 comprises a contact surface 71 against which a pressure plate 40 is placed. A connecting element 30, here for example a bolt 30, fastens, for example clamped, the rear section 20 to the front section 10 in that the bolt 30 is positively connected to the pressure plate 40.

[0077] The view of the underside of the rear section 20 shows a second leg 221, a third leg 222, a first side element 24, and a second side element 26. The underside 12 of the front section 10 rests on the third leg 222. The first side element 24 and the second side element 26 are attached to at least the second leg 221 (ie, to the first, second, and third legs 220, 221, 222, preferably to the second leg 221, more preferably to the first and second legs 220, 221).

[0078] In Figure 5 is a longitudinal section of a schematic partial view of another embodiment of a front section 10 of a grate bar 1. Again, the description of the Figures 1 to 4 except for the following special features also applies to the design according to Fig. 5 read (and vice versa).

[0079] The partial view of the front section 10 in Fig. 5shows front side 16, top side 14, bottom side 12, and recess 70. Bottom side 12 has a shoulder 13. The longitudinal section reveals a gas channel 61 curved toward front side 16 and two similarly curved gas passages 68. The two gas passages 68 each extend from an inlet 67 in bottom side 12 to an outlet 69 in top side 14.

[0080] The optional gas channel 61 extends from an inlet 63 in the recess 70 to an outlet 65 in the top side 14.

[0081] Both the gas channel 61 and the gas passages 68 are each curved in the direction of the front side 16 in an area adjacent to the upper side 14. A tangent 80 can be applied to the lower side of the gas channel 61 or the gas passages 68, respectively. These tangents 80 each form an acute angle 82 with the upper side 14 (cf. Fig. 2). With decreasing distance of the contact point of the tangent 80 from the outlet 69, the value of the acute angle 82 formed by the tangent 80 and the upper side 14 continuously decreases and the gas channel 61 and the gas passages 68 continuously merge into the upper side 14 at the respective outlet 65, 69.

[0082] Figure 6shows a simplified schematic of the rear end of a grate bar 1 with a rear section 20 which has been fastened to the rear side 18 of a front section 10 via connecting means 30, 40. For this purpose, the front section 10 has a recess 70 in its underside 16 which extends towards the top side 14. A channel 32 with a longitudinal channel axis 33 opens into the rear boundary of the recess 70. The connecting means 30, which is shown here as a bolt by way of example, extends through the channel 32. The rear end 308 of the connecting means 30 passes through an opening 295 in the rear section 10 and bears against it in a form-fitting manner with a radial projection (with the interposition of an optional spring ring, a washer, etc.). The front end of the connecting means 30 is connected here, for example, via a thread to a pressure plate 40 which is supported on the rear boundary of the recess 70, ie on a contact surface 71.As an alternative to screwing, other connection techniques (pressing, wedging, material bonding, etc.) are of course also possible.

[0083] The back 18 of the front section 10 in Figure 6 has a concave segment 181 that is curved with a first radius. A leg of the rear section 20 rests against this first segment 181 with a convexly curved surface 226. The convexly curved surface 226 has a smaller radius of curvature than the concave segment 181. Accordingly, in the event of a sudden load on the grate bar, the connection can yield elastically, with the connecting element 30 serving as an elastic restoring element. Overloading of the ceramic front section 10, which would otherwise lead to its fracture, can thus be prevented.

[0084] The return section 20 in Fig. 6 is different than in the Figures 1 to 4 made in one piece. The Fig. 6The rear section 20 shown can also be connected to the front sections 10 according to the Figures 1 to 4 and also allows the grate bar 1 to be suspended in a cross member of a substructure. Accordingly, the rear section 10 can be Fig. 6 against a return section to one of the Figures 1 to 4 be replaced.

[0085] The return section 20 in Fig. 6has a downwardly open profile 29, i.e. it has a downwardly open opening 28. The grate bar 1 can be suspended from the opening 28, for example, in a cross member, although other fastening options are also possible (e.g. screwing, welding, etc.). Accordingly, the rear section 20 can form and / or have at least approximately a downwardly open U-profile 29. The free end of the rear first leg 291 of the profile preferably points at least approximately downwards in this case. A middle leg 292 adjoins the first leg 291 at the front and then merges into a front (third) leg 293. The front side of the front leg forms the convex surface 226 already described. At the lower end of the front leg 293, a projection 296 preferably adjoins the front and can serve as a support for the underside 16 of the front section 10.

[0086] The free end of the rear free leg of the rear section 20 preferably has a mounting recess 294 in the extension of the channel axis 33. The optional mounting recess 294 is preferably located in the extension of the opening 295 in the opposite leg 293, ie in the assembled state the mounting recess 294 is preferably located at least approximately in the extension of the channel longitudinal axis 33. This makes the rear end of the connecting element 30 easily accessible for an assembly tool.

[0087] Figures 7 and 8 show an alternative front section of a grate bar front section 10 which is otherwise as in the Figures 1 to 5 can be trained. The description of the Figures 1 to 4 and 8 to 9 reads accordingly also on the Figures 7 and 8 . Therefore, only differences are discussed below: The front section 10 can, as in the Figures 6 and 7shown, have in its front section in the underside 12 a recess 70 which extends in the direction of the upper side 14. Starting from the recess 70, a channel 32 can extend along a channel longitudinal axis 33. The optional channel 32 connects the recess 70 in this example with the front side 16 and is shown here as an example as a channel 32 open downwards, i.e. towards the underside 12. Such a downwardly open channel 30 is particularly easy to manufacture and improves the cooling of the connecting means 30. Alternatively, the channel 32 can also be as in the Figures 1 to 6 Likewise, the channels 32 can be designed according to the Figures 1 to 6 be designed as downwardly open channels 32.

[0088] As in the Figure 8As shown, a front panel 160 can be attached to the front side 16 by means of the connecting element 30. A front section 306 of the connecting element 30 passes through a recess in the front panel 160 and rests against the front side of the front panel 160 with a radial projection (here with the interposition of an optional spring ring, a washer, or the like). The rear end 308 of the connecting element can be supported on the wall of the recess 70 via a pressure plate 40. In Figure 7 The pressure plate 40 is integrated into an optional skid 90.

[0089] As in the Figures 7 and 8As can be clearly seen, the front side 16 of the front section 10 can have at least two segments 161, 162. In this example, the front plate 160 lies at least approximately flush against at least one of the two segments 161, 162. The surface normal of this first segment 161 is preferably at least approximately parallel to the longitudinal channel axis 33. Accordingly, when the front plate 160 is clamped against the front side 16, at least essentially compressive forces are introduced into the front section 10. As shown, this first segment 161 can be followed by a second segment 162 that is angled relative to the first. The angling can optionally form an overhang.

[0090] The optional skid 90 (see Fig. 8) can, for example, have a bracket with, for example, three legs 91, 92, 93. One leg engages with a section that also at least partially forms the pressure plate 40, in the recess 70 in the front plate. An angled second leg 92 can be connected to this first leg 91. The second leg 92 can have an underside 922, which can then form the underside of the runner 90. With the underside 12 or with a section of the underside 12, the runner 90 can then rest on a support, for example in a displaceable manner. The upper side 14 of a front section arranged upstream in the conveying direction can serve as the support, for example. The second leg 91 preferably merges into a third leg 93 via a further angle. For example, with an end face of the third leg 93, the runner 90 can support the front section 10 on its underside 12.In the example shown, the front section 10 therefore rests on an upwardly pointing end of the third leg 93.

[0091] Figures 9 and 10 show a simplified schematic of another variant of a grate bar in the assembled state ( Fig. 9 ) or as an exploded view ( Fig. 10 ). Like all other variants described herein, the grate bar 1 has a grate bar front section 10 and a grate bar rear section 20. Optional gas channels 61 as well as optional gas passages 68, as in the Figures 1 to 8 , are not shown in this variant for the sake of simplicity, but can also be provided. The same applies to the optional clamping device 50 and at least one optional transverse hole in the front third of the front section 10 for receiving at least one clamping device 50 as well as for the attachment of an optional bracket 90 and / or a front plate 160 according to the Figures 7 and 8 .

[0092] The front section 10 has in its rear third a recess 70 which is open to the rear and downwards (cf. Fig. 10 ). The recess 70 is delimited upwards and laterally by preferably ceramic material of the front section 10. This means that the front section has at least one web 19 which delimits the recess in the lateral direction. The webs 19 can, for example, each be delimited inwards by opposing inner surfaces 191 and outwards by the side surfaces 15 of the front section 10. The two webs 19 are each penetrated by a transverse channel 32. The two transverse channels have a common longitudinal axis 192. In this example, the recess 70 has the function of the channel 32 in the Figures 2 , 6 and 7 and could also be described as such. The transverse channel 32 has the function of the recess 70 in the Figures 2 , 6 and 7 and could therefore also be described as such.

[0093] A preferably metallic hook 20 can be inserted into the recess 70, preferably at least approximately flush (cf. Fig. 9 and Fig. 10 ). The hook 20 here forms the rear section 20. The rear section 20 has a downwardly open opening 28, for example, in the form of a claw, with which the grate bar can be hooked into a cross member. The rear section 20 also has a through hole 21, which is designed here as a transverse hole (cf. Fig. 10 ). In the assembled state (see Fig. 9 ) a transverse bolt 30 sits in the through hole 21 and the two transverse channels 32. The pivot angle of the rear section 20 about the transverse axis 192 is limited by contact surfaces 71. The contact surfaces 71 limit the recess 70 upwards and downwards.

[0094] The Figures 11 and 12 show a simplified schematic of another variant of a grate bar in the assembled state ( Fig. 11 ) or as an exploded view ( Fig. 12). This variant is very similar to the one in the Figures 9 and 10 shown variant. The description of the Figures 9 and 10 is therefore also on the Figures 11 and 12 The main difference between the two variants is that the variant according to the Figures 11 and 12 has two hooks 20, which together form the rear section 20. These two hooks 20 are each located in a recess 70, which, unlike in the Figures 9 and 10 is also open on one side, ie between the two recesses, the front section 10 forms at least one web 19 with at least one through hole 32. The two hooks 20 are fastened in a respective recess 70 by means of a bolt 30. The embodiments according to the Figures 9 and 11can also be combined, ie for example three (or more) hooks 20 can be provided, each of which is seated in a recess 70, between which preferably at least one optional web 19 extends. The two lateral recesses 70 in the Figures 11 and 12 can be closed laterally, e.g. by a further web 19 (cf. Figs. 9 and 10 ). The bolt 30 has been described here as one-piece, ie one bolt fixes the hook(s) 20. Alternatively, two or more bolts 30 can be provided, which are inserted into the Figures 9 to 12 like pins, serve to absorb forces acting in the radial direction. For example, at least one bolt 30 can be provided for each hook 20. The term "bolt 30" should therefore be understood as "at least one bolt 30." List of reference symbols

[0095] 1 Grate bar 2 Grate bar longitudinal axis 3 Grate bar vertical axis 4 Grate bar transverse axis 10 Grate bar front section, short: Front section 12 Bottom 13 Heel 14 Top 15 Side surface 16 Front 160 Front plate 161 First segment of the front 16 162 Second segment of the front 16 18 Rear 19 Web 191 Inner surface 192 Axis 181 Concave surface segment 20 Grate bar rear section,short: rear section 21 through-hole 22 middle section 226 convex surface segment 24 first side element 26 second side element 28 opening 29 profile 291 first profile leg 292 middle leg of the profile 293 second profile leg 294 mounting recess 295 opening for connecting means 296 projection 30 bolt / connecting element 306 front section / front end of the connecting element 308 rear section / rear end of the connecting element 31 proximal inlet 32 ​​channel 33 channel longitudinal axis 34 through-channel 35 distal outlet 40 pressure plate 50 clamping means 60 gas line 61 gas channel 62 inlet 62 through-opening 63 inlet 64 outlet 65 outlet 66 insulation body 67 inlet 68 gas passage 69Outlet 70Recess 71Contact surface 80Tangent 82Acute angle 90Skid 91First leg 92Second leg 922Underside of the skid e.g. underside of the second leg 92 93Third leg 220First leg 221Second leg 222Third leg,

Claims

1. A grate bar front section (10) to be mounted to a grate bar rear section (20), to thereby form a grate bar (1) for example for a waste incineration plant, wherein the grate bar front section (10) has an upper surface (14), a lower surface (12), a front surface (16), two narrow side surfaces, a rear surface (18), and a grate bar longitudinal axis (2) extending parallel to the upper surface (14) through the front surface (16) and the rear surface (18), wherein a recess (70) extends from the lower surface (12) towards the upper surface (14), wherein - the grate bar front section (10) has a refractory mineral material, - the recess (70) has at least one contact surface (71) to transmit a force acting in the direction of the rear surface (18) and / or the front surface (16) into the grate bar front section (10), and - at least one channel (32) with a channel longitudinal axis (33) connects the rear surface (18) and / or the front surface (16) with the recess (70), wherein the channel (32) is configured to receive a bolt (30) or another connecting element (30) to brace the grate bar front section (10) with a rear section or a front plate (160), wherein the contact surface (71) is configured to be an abutment for tensioning the connecting element (30).

2. A grate bar (1), with a grate bar front section (10) according to claim 1 and a grate bar rear section (20), wherein the grate bar rear section (20) is releasably connected with the grate bar front section (10), wherein - the grate bar rear section (20) has a middle part (22), a first side element (24), and a second side element (26), - the middle part (22) has at least one first leg (220) and a second leg (221), wherein the first leg (220) and second leg (221) form an angle profile, - the first leg (220) has at least one through hole (21), and - the middle part has two longitudinal sides, and one of the two side elements (24, 26) is connected to one side of the two longitudinal sides of the middle part (22) respectively.

3. A grate bar front section (10) according to claim 1 or a grate bar (1) according to claim 2, characterized in that, the channel (32) is at least partly open to the lower surface (12).

4. A grate bar front section (10) according to claim 1 or 3 or a grate bar (1) according to claim 2 or 3, characterized in that, at least one gas duct (60) extends from the rear surface (18) in the direction of the upper surface (14) and / or the front surface (16), wherein the gas duct (60) has an inlet (62) on the rear surface (18) and an outlet (64) on the upper surface (14) and / or the front surface (16).

5. A grate bar front section (10) or a grate bar (1) according to claim 4, characterized in that, at least one section of the gas duct (60) is located above a plane, wherein the plane is located parallel to the grate bar longitudinal axis (2) of the grate bar front section (10) and above the channel (32).

6. A grate bar front section (10) or a grate bar (1) according to one of the previous claims, characterized in that, at least a section of an insulation body (66) extends between the channel (32) and the upper surface (14) and / or between the recess (70) and the upper surface (14).

7. A grate bar front section (10) or a grate bar (1) according to one of the previous claims, characterized in that, at least one gas passage (68) extends in the direction of the upper surface (14) and / or front surface (16) starting from the lower surface (12), wherein the gas passage (68) has an inlet (67) in the lower surface (12) and an outlet (69) in the upper surface (14) and / or front surface (16).

8. A grate bar front section (10) or a grate bar (1) according to claim 7, characterized in that, the gas passage (68) has a longitudinal axis, which forms an acute angle with the upper or the front side (14).

9. A grate bar front section (10) or a grate bar (1) according to claim 7, characterized in that, - the gas passage (68) is curved in the direction of the front surface (16) at least in a area adjacent to the upper surface (14), - an acute angle (82) is formed by the upper side and a tangent (80), - the tangent is positioned to a contact point at the lower side of the gas passage in the area adjacent to the upper surface (14), and - the value of the acute angle decreases with decreasing distance of the alignment point of the tangent to the outlet.

10. A grate bar front section (10) or a grate bar (1) according to claim 9, characterized in that, the value of the acute angle (82) decreases continuously with decreasing distance of the contact point from the outlet and / or the gas passage (68) merges continuously into the upper surface (14) at the outlet (69).

11. A grate bar front section (10) or a grate bar (1) according to one of the previous claims, characterized in that, the upper surface (14) has a larger length than the lower surface (12), resulting in an overhang of the rear surface (18) and / or front surface (16).

12. Grate bar (1) according to one of claims 2 to 11, characterized in that, the first leg (220) has at least one passage (62').

13. Grate bar (1) according to one of claims 2 to 12, characterized in that, the middle part (22) has a third leg (222).

14. Grate bar (1) according to claim 13, characterized in that, the second leg (221) and the third leg (222) point in opposite directions at least in a range of ± 30°, wherein the first leg (220) is the middle leg.

15. A grate bar (1) according to one of claims 2 to 14, characterized in that, at least a section of the grate bar rear section (20) abuts the rear surface (18) of the grate bar front section (10) and is fastened to the rear surface (18) with a connecting element (30) traversing the through hole (21) and the channel (32).

16. A grate bar (1) according to claim 15, characterized in that, the connecting element (30) is fixed via a pressure plate (40) abutting the contact surface (71).

17. A grate bar (1) according to claim 15 and claim 16, characterized in that, the connecting element (30) has a through channel (34) extending along its axis and having a distal outlet (35), which ends in the inlet area of an inlet (63).

18. Cement clinker cooler with a cooling grate or incineration plant with a firing grate, characterized in that, the respective grate has at least one grate bar front section (10) according to one of claims 1, 3 to 11 and / or at least one grate bar (1) according to one of claims 2 to 17.