Grate bar, grate, and combustion system

Description

[0001] The present invention relates to a grate bar, a grate and a combustion plant.

[0002] For the combustion of various fuels, such as household waste, industrial waste, wood waste, solid or porous fuels, as well as fuels with high and low ignition properties, conventional combustion plants with combustion chambers are used. In these plants, the fuel is applied, for example, to a mechanically operated grate and burned there. Combustion plants typically process materials with both high and low calorific values, which can lead to significant heat-related problems with the grate elements. In particular, the grate head area of ​​the grate elements can burn out or corrode due to excessive thermal stress.

[0003] To solve heat-related problems, grate bars are known to be cooled by means of cooling water. The cooling water is circulated through a single-strand cooling pipe coil cast into the grate bar. The cooling water enters the cooling pipe system and is redirected multiple times within the grate bar body via bends, turns, and / or curves before exiting. Several adjacent grate bars are connected to each other via connecting pipes. Thus, the cooling water dissipates the heat from the grate, thereby cooling it.

[0004] One disadvantage is that the overall long path, along with the bends, turns, and / or curves before the outlet, results in a significant pressure loss. This pressure loss is further amplified by connecting multiple grate bars side by side. Conversely, a high pressure must be generated to propel the cooling water through the very long cooling pipe coil at a sufficient flow velocity for cooling. This has the disadvantage, among others, that cooling water pumps must operate at high power to circulate the cooling water. Furthermore, cooling water pumps capable of delivering a correspondingly high output must be provided in the first place. These measures, currently necessary to ensure adequate cooling of the grate bars and the grate as a whole, are expensive, complex, and require frequent maintenance.Documents EP0757206 A2, EP0811803 A2, DE19613507 C1, JP2000146141 A and DE3902159 A1 disclose rust bars, with DE3902159 A1 disclosing the preamble of claim 1.

[0005] The object of the present invention is to provide a grate bar in which the problems known in the prior art are solved.

[0006] The problem is solved by the invention as defined in the attached set of claims.

[0007] Exemplary embodiments of the present invention are explained in more detail below with reference to the figures. The figures show: Fig. 1 a sectional view of a grate bar in top view in a first aspect of a first embodiment; Fig. 2A,B several sectional views of a grate bar in a second aspect of the first embodiment; Fig. 3A,B several sectional views of a grate bar in a third aspect of the first embodiment; Fig. 4 a sectional view of a grate bar in top view in a first aspect of a second embodiment, which is not part of the invention; Fig. 5A,B several sectional views of a grate bar in a second aspect of the second embodiment; Fig. 6 a sectional view of a transverse row of grate bars comprising several grate bars; and Fig. 7 exemplary cross-sections of cooling pipes.

[0008] Figur 1Figure 1 shows a sectional view of a grate bar 100 in a top view, in a first aspect according to a first embodiment. The grate bar 100 is a cast element with a grate cooling pipe system 102 cast into it and thus integrated within the grate bar 100 for conveying a cooling fluid, e.g., cooling water. The cooling water can thus be conveyed through the grate bar 100 by means of the grate cooling pipe system 102 to cool it and / or dissipate heat. The cooling water can be conveyed through several adjacent grate bars (not shown), these grate bars being connected to each other via corresponding connecting lines, as described below in connection with Fig. 6This is described in more detail below. The cooling water can then be fed into a heat exchanger (not shown) where it can be cooled before being returned to a specific grate in a closed circuit. Alternatively, and depending on the specific operation, the cooling water can also be heated.

[0009] The grate cooling pipe system 102 includes an inlet distributor 104 for the distributed supply of cooling water. The inlet distributor 104 can be connected at one point to an inlet line 106, through which the cooling water is directed into the grate bar 100. In the Figur 1In the illustrated embodiment, two cooling pipes 108', 108'' branch off from the inlet distributor 104 and extend parallel to each other towards the front section of the grate bar 100. These two cooling pipes 108', 108'' then connect to a deflection distributor 110, which extends substantially perpendicular to the cooling pipes 108', 108'' in the front section of the grate bar 100. The deflection distributor 110 can extend over the substantial width of the front section of the grate bar 100. Two further cooling pipes 112', 112'' extend from the deflection distributor 110, also running substantially parallel to each other, towards the rear section of the grate bar 100. These cooling pipes 112',112'' lead into an outlet collector 114. The outlet collector 114 is in turn connected to an outlet line 116, through which the cooling water flowing in parallel into the outlet collector 114 is discharged from the grate bar 100.The inlet distributor 104 and the outlet collector 114 are thus arranged together in the rear section of the grate bar 100. Furthermore, the inlet distributor 104 and outlet collector 114 can be arranged at the same height.

[0010] In the front area of ​​the grate bar 100, e.g. in the section of the support area, there is also another cooling pipe or

[0011] The support area cooling pipe 118 is arranged, which can also extend substantially across the width of the front area. This support area cooling pipe 118 is thus offset from a plane onto which the cooling pipes 108', 108'', 112', 112'' extend, more precisely, it is offset downwards. This support area cooling pipe 118 is connected to individual cooling pipes 108', 108'', 112', 112'' via corresponding connecting lines (described later) and is thus also supplied with cooling water.

[0012] For example, the cooling pipe 118 for the support area is connected to the outer cooling pipes 108' and 112'. This ensures that the support area, which is exposed to particularly high temperatures during operation, can continue to be reliably cooled.

[0013] In summary, the cooling water flows through the inlet line 106 into the inlet distributor 104 and then, in a direction indicated by arrows, flows parallel through the two cooling pipes 108', 108'' (i.e., divided into several parallel lines) to the front section of the grate bar 100 and into the diverting distributor 110 located there. The cooling water is diverted by the diverting distributor 110 in a direction indicated by arrows and then, also distributed in parallel, enters the two cooling pipes 112', 112''. In addition to the diverting distributor 110, a portion of the cooling water is also diverted via the support area cooling pipe 118, as also indicated by arrows. The cooling water then flows in the opposite direction parallel via the two cooling pipes 112',112'' (i.e. also divided into several parallel lines) to the rear area of ​​the grate bar 100 into the outlet collector 114 located here, as indicated by arrows.Starting from the outlet collector 114, the cooling water is discharged from the grate bar 100 via the outlet line 116, thereby dissipating heat.

[0014] Thus, the cooling water can be guided through the grate bar 100 via a parallel connection of the respective combination of cooling pipes, i.e., cooling pipes 108', 108'' (for the supply) and cooling pipes 112', 112'' (for the return). The total cross-sectional area of ​​the entire cooling water flow from the rear to the front of the grate bar 100 is composed of the individual cross-sectional areas of the cooling pipes 108', 108''. Furthermore, the total cross-sectional area of ​​the entire cooling water flow from the front to the rear of the grate bar 100 is composed of the individual cross-sectional areas of the cooling pipes 112', 112''. Compared to previously known solutions in which the cooling water is guided through the grate bar via a single-strand path, the solution according to the invention thus results in a significantly reduced pressure loss.Conversely, compared to the state of the art, only a reduced pumping capacity is required to transport the cooling water through the grate bar 100 between inlet line 106 and outlet line 116.

[0015] Figures 2A,B The figures show the grate bar 100 in a second aspect according to the first embodiment in several sectional views. Here, they show Figur 2A the rust rod 100 in a frontal sectional view, while Figur 2B Figure 1 shows the grate bar 100 in a side longitudinal section view. In this aspect, a total of six cooling pipes are arranged in the grate bar 100, namely cooling pipes 108', 108'', 108''' (supply) and cooling pipes 112', 112", 112‴ (return). The rear section of the grate bar 100 (i.e., in Figur 2BThe right end of the grate bar 100 is designed as a support area 120 with a cup-shaped socket. A correspondingly shaped pin 122 of a grate frame of a combustion plant (both not shown) engages in this socket. The front area of ​​the grate bar 100 includes a rounded nose section 128 between its surface or combustion surface 124 and the front edge 126 of the grate bar 100. The nose section 128 continues as a continuation of the combustion surface 124 above. The previously mentioned support area 130 is formed on the underside of the front area of ​​the grate bar 100. The grate bar 100 is bounded on its underside by side edges 132', 132'' extending in the edge region and in the longitudinal direction.

[0016] In this exemplary aspect according to the first embodiment, the inlet distributor 104 is supplied with cooling water via the inlet line 106. In this aspect, the inlet line 106 is routed in a section downstream of the spigot 122. As previously mentioned in connection with Figur 1 As described, the support area 130 is cooled by the support area cooling pipe 118 arranged therein. This support area cooling pipe 118 is connected to the cooling pipes, for example, via intermediate pipes. In the Figur 2B In the aspect shown, the support area cooling pipe 118 is connected to the cooling pipe 108' via an intermediate line 144'. For illustrative reasons, the connection between the support area cooling pipe 118 and another cooling pipe, e.g., cooling pipe 112', via a further intermediate line is not shown.

[0017] Figures 3A,B show the grate bar 100 according to the first embodiment in a third aspect. Compared to the one in Figures 2A,BIn the second aspect shown, the leading edge 126 continues downwards, so that its underside forms the support area 130 of the grate bar 100. In this aspect, the cooling pipes (for illustrative reasons, only cooling pipe 108' is visible) follow the curve from the section of the leading edge 126 to a section in the support area 130. The respective ends of the cooling pipes are connected to the deflector 110 in the manner described above. In this aspect, the leading edge 126 and / or the support area 130, which are exposed to particularly high heat input during operation, are reliably cooled by the cooling water flowing through the cooling pipes and simultaneously through the deflector 110.

[0018] Figure 4Figure 1 shows a grate bar 200 in a sectional view in top view in a first aspect according to a second embodiment, which is not part of the invention. A grate cooling pipe system 202 for dissipating heat by means of flowing cooling water is integrated into the grate bar 200. The grate cooling pipe system 202 includes an inlet distributor 204 for distributing the cooling water. The inlet distributor 204 is arranged in the region of the side wall of the grate bar 200 and runs substantially parallel to it. In this exemplary aspect, twelve cooling pipes 206<1 and 206<n< branch off from the inlet distributor 204.

[0019] Naturally, more or fewer cooling pipes can branch off from the inlet distributor 204. Furthermore, a leading-edge cooling pipe 210 with an enlarged cross-section is arranged at the distal end of the inlet distributor 204 in the front section of the grate bar 200. The leading edge of the grate bar 200 is cooled particularly reliably via this leading-edge cooling pipe 210.

[0020] The leading edge cooling pipe 210 and the individual cooling pipes 206 1< -206 n< each lead individually into an outlet manifold 214. Thus, the cooling water can be distributed via the inlet distributor 204 to the cooling pipes 206 1< -206 n< and the diverter distributor 210, as indicated by the arrows. The heated cooling water then flows to the outlet manifold 214, is collected there, and then flows from the outlet manifold 214 towards the rear of the grate bar 200, as indicated by the arrows. Finally, the heated cooling water is discharged from the grate bar 200. This discharge of the heated cooling water ensures reliable cooling of the grate bar 200.

[0021] Figures 5A,B The second aspect of the second embodiment is shown in several sectional views. In this aspect, too, the rear area of ​​the grate bar 200 is shown. Figur 5BThe right end of the grate bar 200 is designed as a support area 220 with a cup-shaped socket into which a correspondingly shaped pin 222 of the grate frame of a combustion plant can engage. The grate bar 200 is bounded on its underside by side edges 232', 232'' extending along the edge and longitudinally. A support area cooling pipe 234 is also arranged in the support area 230, which can extend substantially over the width of the front area 230. The support area 230 is cooled separately via this support area cooling pipe 234. The support area cooling pipe 234 is supplied with cooling water via the inlet distributor 204 through an intermediate line 236' shown in the figure. At the opposite end of the support area cooling pipe 234, the heated cooling water flows via a further intermediate line (not shown in the figure) into the outlet collector 214. In the Figur 5BIn the aspect shown, the inlet distributor 204 is supplied with cooling water via an inlet line 238. The heated cooling water is then discharged from the grate rod 200 via an outlet line (not shown).

[0022] Figure 6 shows sectional views of several adjacent grate bars 100'-100ʺʺ forming a transverse row 300 of a grate for an incineration plant. In the Figure 6 The example shown is the individual grate bars 100'-100ʺʺ according to the one in Figures 2A,B The second aspect of the first embodiment is configured as shown. Of course, the grate bars can also be configured according to other examples, aspects, or embodiments. An outer grate bar 100' from the transverse row 300 (in the Figure 6The grate bar 100', located at the far left, is supplied with cooling water via a supply line 302. The cooling water flows into an inlet distributor 104 of the grate bar 100', which is fluid-tight and connected to the supply line 302. From this inlet distributor 104, the cooling water flows in parallel via the three cooling pipes 108'-108‴ (into the plane of the figure) towards the front section of the grate bar 100'. The heated cooling water can then be discharged via a Figure 6 The cooling water is diverted via the deflection distributor (not shown) and distributed to the three cooling pipes 112'-112‴. The cooling water then flows, also distributed in parallel, through the three cooling pipes 112'-112‴ (out of the plane of the figure) back to the rear section of the grate bar 100' and empties into the outlet collector 114.

[0023] The outlet collector 114 is fluid-tightly connected at one end to a grate bar connecting pipe 304', which in turn is connected at its other end to the inlet distributor of the adjacent grate bar 100''. Thus, the cooling water flows through the first grate bar 100' in the manner described above and then reaches the next adjacent grate bar 100' via the grate bar connecting pipe 304', and so on. The respective grate bar connecting pipes 304'-304''' are U-shaped and run below the respective side edges 132', 132'' of the grate bars 100'-100''''. From the last grate bar 100'''' of the grate bar transverse row 300, the heated cooling water is discharged from the grate bar transverse row 300 via a discharge line 306 and can then be supplied, for example, to a heat exchanger not shown, in which the cooling water is cooled before it is supplied again to the grate bar 100' in a closed circuit.The grate bar connecting pipes 304'-304‴ can be welded to the respective outlet manifold and inlet distributor of the adjacent grate bars 100'-100ʺʺ. Alternatively, a flanged connection can be provided for the connection.

[0024] Figur 7The illustration shows different cross-sections of exemplary cooling pipes 108, 112, which can be used in the exemplary configurations described above. The cooling pipes 108, 112 can have a round, oval, or rectangular cross-section (with or without rounded corners). The cross-sectional areas can vary. When installed in a grate bar, the aspect ratio between the maximum width and maximum height of one or more of the cooling pipes 108, 112 can be less than 1. Under this assumption, the width of the cooling pipe 108, 112 is defined parallel to the surface of the grate bar, and the height of the cooling pipe 108, 112 is defined perpendicular to the width. In one example, the aspect ratio can be between 1 and 5. Alternatively or additionally, the inlet manifolds, outlet manifolds, and / or deflection manifolds described above and shown in the drawing can have a round, oval, or rectangular cross-section (not shown).

[0025] Due to the design described above, the cooling pipes, inlet distributors, outlet collectors, and / or deflection distributors occupy only a small height while maintaining a large cross-sectional area. Since the flow cross-section of the individual cooling pipes, inlet distributors, outlet collectors, and / or deflection distributors remains large, the overall height of the grate bar body can be reduced without compromising cooling capacity. This advantage allows for overall material savings (casting material) of the grate bar, thereby reducing both its cost and weight.

Claims

1. Grate bar (100; 200) for combustion plants, having a substantially closed top surface (124; 224) which faces towards the combustion side, having a rear supporting region (120; 220) which is configured to bear on a grate support and having a front nose region (128; 228) which extends between the top surface (124; 224) and a front edge (126; 226) and has a bearing region (130; 230) which is formed on the bottom side, and having a grate cooling-pipe system (102; 202) which is integrated in the grate bar (100; 200) and serves for conducting a cooling liquid, wherein the grate cooling-pipe system (102; 202) has an inlet distributor (104; 204) for feeding the cooling liquid, has supply cooling pipes (108'-108‴) connected thereto and extending parallel to one another and opening out into a diversion distributor (110) extending substantially perpendicularly to the supply cooling pipes (108'-108‴), and has trailing cooling pipes (112'-112"') branching off from the diversion distributor (110) and extending substantially parallel to one another and being situated in the rear region of the grate bar, and wherein the supply cooling pipes (108'-108‴) and the trailing cooling pipes (112'-112"') are connected in parallel, characterized in that a bearing-region cooling pipe (118; 234) is arranged in the bearing region (130; 230) so as to be offset in relation to a plane along which the supply and return cooling pipes (118'-118‴, 112'-112‴) extend, and in that the bearing-region cooling pipe (118; 234) is connected to individual cooling pipes via corresponding connecting lines.

2. Grate bar (100) according to Claim 1, in which a plurality of the cooling pipes (108'-108‴, 112'-112‴) are arranged substantially in a plane parallel to the top surface of the grate bar (100) and preferably parallel to one another, preferably parallel to the longitudinal extent of the grate bar (100).

3. Grate bar (100; 200) according to either of the preceding claims, in which the cooling pipes (108'-108‴, 112'-112‴; 2061-206n) are round, oval or polygonal in cross section.

4. Grate bar (100; 200) according to one of the preceding claims, further comprising at least one grate-bar connecting pipe (304'-304‴) which is configured for fluidic connection to at least one further, adjacent grate bar, preferably in such a way that the grate-bar connecting pipe (304'-304‴) is connectable in a fluid-tight manner to the inlet distributor and an outlet collector of respectively adjacent grate bars and is preferably of U-shaped form and at least sectionally extends below the side edge of the grate bar.

5. Grate comprising a plurality of transverse rows (300) of grate bars (100; 200) according to one of the preceding claims, wherein respectively adjacent grate bars are connected to one another in a fluid-tight manner via at least one grate-bar connecting pipe (304'-304‴).

6. Combustion plant comprising a grate according to Claim 5.

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