Grate for firing

Abstract

A grate (1) for furnaces comprises grate bars (5, 6, 8, 9) and grate rods (4, 7) engaging in receptacles (3) of grate bars (5, 6, 8, 9), by which grate bars (5, 6, 8, 9) can be moved back and forth in the direction of their longitudinal extent. Adjacent grate bars (5, 6, 8, 9) are moved relative to each other during the back-and-forth movement in order to clean the air gaps between grate bars (5, 6, 8, 9). The direction of the relative movement between adjacent grate bars (5, 6, 8, 9) is essentially horizontal, parallel to the longitudinal extent of the grate bars (5, 6) and / or essentially perpendicular, transverse to the longitudinal extent of the grate bars (8, 9).

Description

[0001] The invention relates to a grate for furnaces.

[0002] Grates for furnaces are known which have several grate bars which are seated with downward-facing receptacles on grate rods which extend essentially transversely to the longitudinal extent of the grate bars.

[0003] The ends of the grate bars that are remote from the receptacles in the grate bars rest on grate bars that are adjacent in the direction of the longitudinal extension of the grate bars in the area of the ends that have the receptacles for the grate bars, so that the grate bars that follow one another in the longitudinal direction of the grate bars are arranged so as to overlap one another.

[0004] In grates, the grate bars are arranged in several adjacent rows extending in the direction of their longitudinal extension, so that several grate bars are arranged next to each other in the grate, perpendicular to the longitudinal extension of the grate bars. Between the grate bars arranged next to each other, perpendicular to the longitudinal extension of the grate bars, gaps are provided to allow the passage of (combustion) air ("air gaps").

[0005] Such grates can be designed as pusher grates, with the overlapping grate bars forming a stepped upper surface of the grate.

[0006] To perform advance movements of the grate bars, the grate bars or individual grate bars are adjustable along their longitudinal extension. By moving the grate bars back and forth, and thus the grate bars coupled to them, the material to be burned is conveyed further along the sloping grate.

[0007] The problem with conventional grates is that the air gaps between the grate bars become clogged, for example, due to combustion residues, and impede the passage of air to a greater or lesser extent. Obstruction of the passage of air through the grate in the area of the air gaps between adjacent grate bars impairs the effectiveness of the combustion process.

[0008] DE 10 2008 056 468 B3 discloses a method for cleaning grates, comprising grate bars and grate bars arranged on the grate bars, between which air gaps are provided. The grate bars engage in receptacles in the grate bars. To clean the air gaps, the grate bars are moved relative to one another. The relative movements between grate bars arise because there is varying degrees of play between the grate bars and the receptacles of the grate bars. DE 10 2008 056 468 B3 also describes a grate for carrying out this method. In the known grate, the play of the grate bars in the receptacles in adjacent grate bars varies, resulting in relative movements. DE 10 2008 056 468 B3 also discloses bringing about vertical movements of grate bars perpendicular to the feed direction by providing wedge-shaped contact surfaces on the grate bars.

[0009] Similar methods for cleaning the air gaps between grate bars and corresponding grates are known from DE 911 317 C and GB 2 503 319 A.

[0010] The invention is based on the object of proposing a grate in which the relative movements of the grate bars are brought about in a simple manner.

[0011] This object is achieved with a grate having the features of claim 1.

[0012] The features provided in the grate according to the invention bring about the relative movements of adjacent grate bars in a simple manner, so that the air gaps between the grate bars are cleaned reliably and effectively.

[0013] It is taken into account that the grate bars are moved relative to each other both in the direction of their longitudinal extension and relative to each other, in particular by pivoting, transversely to the direction of their longitudinal extension.

[0014] The relative movement between adjacent grate bars in the direction of their longitudinal extent is achieved by the grate bars engaging in receptacles of adjacent grate bars - viewed transversely to the direction of the grate bars' longitudinal extent - with different amounts of play. This design has the effect that when the grate bars move back and forth, only those grate bars are moved into which the grate bars engage in the receptacles with less play, whereas the grate bars into which the grate bars engage in the receptacles with greater play are (initially) not moved, i.e. remain stationary at least temporarily. Only when the grate bars rest against the front end of the receptacles in the direction of movement of the grate bars, into which the grate bars engage with greater play, are these grate bars also moved if the amount of movement of the grate bars is greater than the play.

[0015] The difference in play between the grate bar receptacles and the grate bars - and thus the relative movement of adjacent grate bars - is achieved by the grate bars engaging in the grate bar receptacles having areas of different thickness, in particular of different diameters, in the area of the receptacles.

[0016] Further details and features of the invention will become apparent from the following description of preferred embodiments with reference to the partly schematic drawings. It shows: Fig. 1 in side view a moving grate, Fig. 2 a grate bar with different thickness areas, Fig. 3 in plan view a part of a grate comprising three grate bars and with the grate bar with different thickness areas according to Fig. 2 and Fig. 4the position of the grate bars of the part of the grate of Fig. 3 after moving the grate bar.

[0017] One in Fig. 1 The grate 1 shown comprises a plurality of grate bars 5. The grate bars 5 are arranged next to one another in accordance with the desired width of the grate 1, seen transversely to the direction of their longitudinal extent, with air gaps being provided between adjacently arranged grate bars 5. Fig. 1 shows that the grate bars 5 in the grate 1 are arranged overlapping one another, so that a stepped upper side of the grate 1 results.

[0018] Each grate bar 5 has on its underside a downwardly open receptacle 3 in which a grate bar 4 is received. By means of the grate bars 4 received in the receptacles 3 of grate bars, grate bars can be moved back and forth by moving grate bars 4 in the direction of the longitudinal extension of the grate bars.

[0019] The end of each grate bar 5 opposite the holder 3 rests on the grate bar 5 adjacent in the longitudinal direction of the grate bars 5 from above, for example approximately in the area of its holder 3.

[0020] At Fig. 1 Fixed grate bars 4 and adjustable grate bars 4 that can be moved back and forth in the direction of the longitudinal extension of the grate 1 are provided. The movable grate bars 4 are mounted on a grate carriage 2. A drive (not shown) is assigned to the grate carriage 2, with which the grate carriage 2 can be moved back and forth. The grate carriage 2 is moved in the direction of the Fig. 1 The grate is moved back and forth along the double arrow 15 shown in the drawing – essentially horizontally. Moving the grate bars 4 back and forth results in a movement of the grate 1 like a reciprocating grate, so that the firing material is gradually conveyed downwards over the steps of the grate 1.

[0021] It is also considered to drive all grate bars 4 and not just individual grate bars 4 back and forth.

[0022] Within the scope of the invention, it is provided that the play between grate bars 4 and receptacles 3 of the grate bars is different for grate bars 5 arranged adjacent to one another.

[0023] According to the invention, it is provided that grate bars 7 have alternating stronger and less strong areas, in particular areas with a larger and areas with a smaller diameter ( Fig. 2 ). The grate bar 7 with stronger and less strong areas, for example, engages in receptacles 3, which are dimensioned such that in areas of the grate bar 7 with a smaller diameter there is a greater play between receptacle 3 and grate bar 7 than in areas of the grate bar 7 with a larger diameter ( Fig. 3 ) is present. This allows the use of uniform grate bars 6 in the grate 1. Thus, as in Fig. 4indicated - when the grate bars 7 move back and forth, the relative movement according to the invention between adjacent grate bars 6 is achieved.

[0024] Due to the relative movement between adjacent grate bars 5 and 6, the air gaps between adjacent grate bars 5 and 6 are cleaned by removing combustion residues and / or unburned material from the (downward) air gaps.

[0025] Since grate bars are mounted on the grate bars 4 by engagement of the grate bars 4 in the receptacles 3 in such a way that grate bars can be pivoted up and down about the axis of the grate bars 4, in addition to the (horizontal) relative movement between adjacent grate bars in the direction of the longitudinal extent of the grate bars, a relative movement between adjacent grate bars transverse to their longitudinal extent (vertical), namely for example by pivoting up and down, can also be achieved.

Claims

1. Grate (1) for furnaces, comprising a plurality of grate bars (5, 6) and grate rods (4) aligned parallel to one another, wherein grate rods (4, 7) engage in receptacles (3) in the grate bars (5, 6), wherein the grate rods (4, 7) are received in receptacles (3) with play, and wherein the play of the grate rods (4, 7) in the receptacles (3) in mutually adjacently arranged grate bars (5, 6) is of different sizes, characterized in that that grate rods (7) engaging in the receptacles (3) of grate bars (6) have regions with differently large thickness, in particular differently large diameter, in the region of the receptacles (3) of mutually adjacently arranged grate bars (6).

2. Grate according to claim 1, characterized in that grate rods (7) have alternating regions of greater thickness and regions of lesser thickness.

3. Grate according to claim 2, characterized in that grate rods (7) with regions of greater thickness engage with lesser play and with regions of lesser thickness engage with greater play in receptacles (3) of grate bars (6).

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