GRATE BAR, GRATE BAR ARRANGEMENT, AND METHOD FOR OPERATING A GRATE BAR ARRANGEMENT

Abstract

A grate bar has a grate bar head, two side walls, a running surface behind the head and between the side walls and an underside disposed below the surface and between the side walls. A recess in one side wall forms an air slot between the surface and underside and is arranged only on one side wall, not in its opposite side wall. In a grate bar arrangement including multiple grate bars, each including a running surface and a grate bar head, in which an upper grate bar with grate bar head is moveably arranged relative to a lower grate bar so that the head may slide over front and rear grate bar running surface areas, the running surface has air slots in the front and rear areas and the head is displaceable relative to these slots so that the opening cross section of all slots remains constant.

Claims

1. A grate bar arrangement (90) comprising at least three grate bars (91, 92, 93) each comprising a running surface (98, 99) and a grate bar head (100, 101), in which arrangement 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) may 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.

2. The grate bar arrangement according to claim 1, wherein adjacently arranged grate bars (1, 21, 22) are movable relative to one another.

3. The grate bar arrangement according to claim 1, wherein adjacently arranged grate bars (1, 23) are fixedly screwed to one another.

4. The grate bar arrangement according to claim 1, wherein each grate bar (1) is designed with 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) disposed below the running surface (5) and between the side walls (3, 4), wherein precisely two recesses (7, 8) in one side wall (4) between the running surface (5) and underside (6) form the air slots (9, 10) due to an interaction of two structurally identical grate bars, wherein the air slots (9, 10) are arranged only on one side wall (4) and not in its opposite side wall (3).

5. The grate bar arrangement according to claim 4, wherein the side wall (4) of each grate bar (91, 92, 93) has air slots (9, 10) only in the area of the running surface (5).

6. The grate bar arrangement according to claim 4, wherein each air slot (9, 10) has a cross-sectional area (13) which expands from the running surface (5) to the underside (6).

7. The grate bar arrangement according to claim 4, wherein each 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).

8. The grate bar arrangement according to claim 4, wherein each 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).

9. The grate bar arrangement according to claim 4, wherein each grate bar (91, 92, 93) has a core bar (80), which is embedded into the grate bar (1).

10. A method for operating a grate bar arrangement comprising at least three grate bars (91, 92, 93) each comprising a running surface (98, 99) and a grate bar head (100, 101), in which arrangement 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) 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 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.

11. The method according to claim 10, wherein, due to the displacement of the grate bars (91, 92, 93) relative to one another, all air slots (94, 95, 96, 97) of a lower-lying grate bar (91) are temporarily covered by the grate bar (93) lying thereabove, only the air slots (94, 96) in the front area (102) are temporarily covered by the grate bar (93) lying thereabove, and absolutely no air slots (94, 95, 96, 97) are temporarily covered by the grate bar (93) lying thereabove, such that initially more or less air flows through the lower-lying grate par (91), while more or fewer air slots (94, 95, 96, 97) are also covered at the grate bar (93) lying thereabove by the grate bar (92) arranged in turn over the same during the movement of the grate bar (93).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0046] In the drawings,

[0047] FIG. 1 shows a grate bar with a front and a rear latch;

[0048] FIG. 2 shows an enlarged depiction of the front latch shown in FIG. 1;

[0049] FIG. 3 shows a sectional view through two grate bars in the area of the latch shown in FIG. 2;

[0050] FIG. 4 shows an enlarged depiction of an alternative embodiment of the latch shown in FIG. 2;

[0051] FIG. 5 shows a sectional view through two grate bars in the area of the latch shown in FIG. 4;

[0052] FIG. 6 shows a view of a grate bar arrangement with three adjacent grate bars;

[0053] FIG. 7 shows a view of a grate bar arrangement with two grate bars arranged adjacently and two grate bars arranged above one another in each case;

[0054] FIG. 8 shows a sectional view through a grate bar head with a cutting edge in front and a pushing edge in back;

[0055] FIG. 9 shows a sectional view through a grate bar head with a cutting edge in front and an elevated cutting edge in back;

[0056] FIG. 10 shows a sectional view through a grate bar head with a cutting edge in front and a downward-facing cutting edge in back;

[0057] FIG. 11 shows a schematic section from FIG. 1 with the front air slot;

[0058] FIG. 12 shows a schematic longitudinal section through the area of the grate bar shown in FIG. 11;

[0059] FIG. 13 shows a schematic cross section through the area of the grate bar shown in FIG. 11;

[0060] FIG. 14 shows an enlarged, schematic detail from FIG. 13;

[0061] FIG. 15 shows a grate bar arrangement with a movable grate bar in the lowest position;

[0062] FIG. 16 shows the grate bar arrangement shown in FIG. 15 with the movable grate bar in a center position;

[0063] FIG. 17 shows the grate bar arrangement shown in FIG. 15 with the movable grate bar in the highest position;

[0064] FIG. 18 shows the underside of a grate bar;

[0065] FIG. 19 shows a longitudinal section through the grate bar shown in FIG. 18;

[0066] FIG. 20 shows a core rod schematically embedded into a grate bar; and

[0067] FIG. 21 shows the grate bar shown in FIG. 20 in a broken state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0068] Grate bar 1, shown in FIG. 1, has a grate bar head 2, two side walls 3 and 4, and a running surface 5. Grate bar head 2 lies in a front area of grate bar 1 and running surface 5 lies therebehind in a rear area of grate bar 1. Underside 6 of grate bar 1 lies under running surface 5 and between side walls 3 and 4.

[0069] Recesses 7 and 8 in side wall 4 are on one side of grate bar 1 in the area of running surface 5. These laterally arranged recesses 7 and 8 form air slots 9, 10 extending from underside 6 to running surface 5 in a view transverse to this.

[0070] Air slots 9 and 10 are only arranged in the area of running surface 5 and not in the area of grate bar head 2. By this means, air slots 9, 10 are completely overrun by a grate bar head of another grate bar pushed on running surface 5.

[0071] Front flank 11 and rear flank 12 of air slot 9 are each arranged at an acute angle to running surface 5 so that cross-sectional area 13 (see FIG. 6) expands from running surface 5 to underside 6 of grate bar 1.

[0072] Correspondingly, flanks 15, 16 of air slot 10 are arranged at an acute angle 17, 18 to running surface 5—as shown in FIG. 12—so that cross sectional surface 14 of air slot 10 also expands from running surface 5 to underside 6.

[0073] The expansion of cross sections 13 and 14 from running surface 5 to underside 6 of grate bar 1 is also increased in that recesses 7 and 8 between flanks 11 and 12 or 15 and 16 are arranged at an acute angle to running surface 5 in such a way that cross-sectional areas 13, 14 of air slots 9, 10 expand from running surface 5 to underside 6.

[0074] FIG. 6 shows how multiple grate bars 1, 21, 22 are arranged adjacently in order to provide running surfaces 5, 23, 24 substantially in one plane with air slots 25 to 28 lying therebetween.

[0075] FIG. 7 shows how grate bar heads 29 and 30 of other grate bars 31 and 32 slide along running surfaces 5 and 23 of grate bars 1 and 21. Grate bar heads 29 and 30 thereby move across air slots 9, 10, and 27 and 28 of grate bars 1 and 21 in order to push material of the firebed disposed on running surfaces 5 and 23 away from air slots 9, 10, and 27 and 28.

[0076] For this purpose, the front end of grate bar head 2, 29, 30 has a specialized shape, which may be designed according to the intended use and area of application, as is shown in cross section in FIGS. 8, 9, and 10.

[0077] Grate bar head 33 shown in FIG. 8 has a lower end 34 comprising a sliding surface 35 which has a cutting edge 37 on the front end of grate bar head 33. This cutting edge 37 has an acute angle 38 between sliding surface 35 and pushing surface 36.

[0078] When pulling the grate bar head back, inner side 40 functions as a spacer, which is designed in the exemplary embodiment shown in FIG. 8 as a pushing edge 41 transitioning into sliding surface 35. This pushing edge 41 has an obtuse angle 42 between sliding surface 35 and pushing surface 40. While FIG. 8 has a curve with a radius of approximately 6 mm and a circular sector of approximately 105° as pushing edge 41, FIG. 9 shows a cutting edge 46 on grate bar head 45—like in FIG. 8—and a pushing edge 41 shaped in cross section as a corner with an obtuse angle.

[0079] FIG. 10 shows a grate bar head 50 comprising a cutting edge 51 with an acute angle 52 in the front area of sliding surface 53 and another cutting edge 54 with an acute angle 55 in the rear area of sliding surface 53 of grate bar head 50.

[0080] FIGS. 2 to 5 show two-part latches 60, 61, which each comprise a screw 62, 63 and a nut 64, 65. Screw 62 has a screw head 66 with polygonal socket 67 and screw 63 has a mushroom shape as screw head 68. In both cases, latch 60, 61 has a latch head with a round cross section, which is either arranged in the wall of the adjacent grate bar (FIG. 3) or is arranged underneath underside 69 of the adjacent grate bar (FIG. 5). Undersides 6 and 69 of adjacent grate bars 1 and 23 are substantially flat between side walls 3 and 4 in the area of latches 60 and 61, so that screws 62 and 63 and nuts 64 and 65 are easily accessible.

[0081] Each grate bar 1, 23 has a latch window 70, 71 on a side wall 3 and a latch 60, 61 on opposite side wall 4, so that in the case of adjacent grate bars 1, 23, each latch 60, 61 may engage in latch window 70, 71 of the adjacent latch. Latch window 70, 71 may accommodate latch 60, 61 of the adjacent grate bar in the upper region, and have an opening (not shown) on its side opposite running surface 5.

[0082] The grate bar shown in FIGS. 18 to 21 has only one single latch 66 and a core rod 80 is embedded into grate bar 1. This embedded core rod 80 lies under the running surface in such a way that it does not contact the running surface. Embedded means that the core rod is preferably entirely surrounded by the remaining material of the grate bar, and is thus completely encased by the other material.

[0083] FIG. 21 shows how core rod 80 flexes in case of a break of grate bar 1, and how, in the case of a gap 81 occurring during the break, it bridges this gap 81 and holds broken parts 82, 83 of grate bar 1 together.

[0084] FIGS. 15 to 17 show a grate bar arrangement 90 with two fixed grate bars 91 and 92 and one grate bar 93 arranged moveably therebetween. It is clear in FIGS. 15 to 17 how movable grate bar 93 may be pushed between fixed grate bars 91 and 92 from the lower position, shown in FIG. 15, through the center position, shown in FIG. 16, to the upper position, shown in FIG. 17.

[0085] The arrangement and the shape of the grate bars are configured so that, regardless of the position of moveable grate bar 93, the opening cross section of all air slots 94 to 97 remains constant. For this purpose, grate bars 91 and 93 have a running surface 98, 99 and in each case a grate bar head 100, 101, and grate bar 93 with its grate bar head 101 is arranged as the upper grate bar to be movable relative to grate bar 91, which functions as the lower grate bar. When pushing upper grate bar 93 across lower grate bar 91, grate bar head 101 slides across a front area 102 and a rear area 103 of running surface 98 of grate bar 91. Air slot 95 in rear area 103 is thereby initially overrun by grate bar head 101 of grate bar 93, so that air slot 95 is subsequently covered by grate bar head 101 of grate bar 93, as shown in FIG. 16.

However, air slot 96 in grate bar 93 is thereby released, which was previously covered by grate bar 92. Thus, air slots 94 and 95 are open in the grate bar position shown in FIG. 15, while air slots 94 and 96 are open in the position shown in FIG. 16.

[0086] FIG. 17 shows grate bar 93 pushed completely upward, which now covers both air slot 95 and also air slot 94 of grate bar 91. Air slots 96 and 97 of moveable grate bar 93 are hereby released, so that two air slots are again open in this position of moveable grate bar 93 as well.

[0087] This example of a grate bar arrangement shows how the arrangement of air slots 94, 95, 96, 97 in the area of 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.

[0088] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.