EP4403827A1 - Method for cleaning grates and grate for carrying out the method - Google Patents

Abstract

A grate (1) for furnaces comprises grate bars (5, 6, 8, 9) and grate bars (4, 7) engaging in receptacles (3) of grate bars (5, 6, 8, 9), with 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 one another 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 vertical, transverse to the longitudinal extent of the grate bars (8, 9).

Description

The invention relates to a method for cleaning grates of furnaces on the one hand and to grates for carrying out the method for cleaning grates on the other hand.

Grates for furnaces are known which have several grate bars which rest with downward-facing mounts on grate rods which extend essentially transversely to the longitudinal extension of the grate bars.

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

In grates, the grate bars are arranged in several rows that lie next to each other and run in the direction of the longitudinal extension of the grate bars, so that several grate bars are arranged next to each other in the grate, transverse to the longitudinal extension of the grate bars. Between grate bars arranged next to each other, transverse to the longitudinal extension of the grate bars, gaps are provided that allow the passage of (combustion) air ("air gaps").

Such grates can be designed as feed grates, whereby the overlapping grate bars form a stepped upper side of the grate.

To carry out feed movements of the grate bars, the grate bars or individual grate bars are adjustable in the direction of the longitudinal extension of the grate bars. By moving the grate bars and thus the grate bars coupled to them back and forth, the material to be burned is conveyed further along the sloping grate.

The problem with the known grates is that the air gaps between the grate bars become filled, for example by combustion residues, and hinder the passage of air to a greater or lesser extent. If the passage of air through the grate is hindered in the area of the air gaps between adjacent grate bars, this impairs the effectiveness of the combustion process.

The invention is based on the object of proposing a method for cleaning grates and grates suitable for carrying out the method.

This object is achieved by a method having the features of claim 1.

As far as the grate is concerned, the object underlying the invention is achieved with a grate which has the features of one of the independent claims directed to the grate.

Due to the relative movement of adjacent grate bars occurring in the method according to the invention, air gaps located between the grate bars are cleaned reliably and effectively.

It is possible for the grate bars to be moved relative to one another in the direction of their longitudinal extension or for the grate bars to be moved, for example pivoted, relative to one another transversely to the direction of their longitudinal extension.

Within the scope of the invention, an embodiment of the method is also considered in which the grate bars are moved relative to one another both in the direction of their longitudinal extension and relative to one another, in particular by pivoting transversely to the direction of their longitudinal extension.

The relative movement between adjacent grate bars in the direction of their longitudinal extension can be achieved by engaging the grate bars in receptacles of adjacent grate bars with different amounts of play - viewed transversely to the direction of the longitudinal extension of the grate bars. This design has the effect that when the grate bars are moved back and forth, only the 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 not moved (initially), i.e. they 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.

The difference in clearance between the grate bar mounts and the grate bars can be achieved either by making the mounts larger or smaller and/or by providing areas of different thickness on the grate bars.

The relative movement of adjacent grate bars transverse to the direction of their longitudinal extension can also be achieved by pivoting grate bars about axes that are in the area of the receptacles in which the grate bars engage. The pivoting movement of the grate bars is selected such that pivoting movements of grate bars arranged adjacent to one another are of different sizes and/or are directed opposite to one another, so that the relative movements according to the invention arise between adjacent grate bars.

Fig. 1

in Seitenansicht einen Vorschubrost.

Fig. 2a

in Seitenansicht einen Roststab mit in seiner Aufnahme mit kleinerem Spiel angeordneter Roststange,

Fig. 2b

in Seitenansicht einen Roststab mit in seiner Aufnahme mit größerem Spiel angeordneter Roststange,

Fig. 3

in Draufsicht einen Teil des Rostes umfassend vier nebeneinander liegende Roststäbe und deren Roststange,

Fig. 4

die Lage der Roststäbe des Teils des Rostes von Fig. 3 nach dem Bewegen der Roststange,

Fig. 5

eine Roststange mit unterschiedlich starken Bereichen,

Fig. 6

in Draufsicht einen Teil eines Rostes umfassend drei Roststäbe und mit der Roststange mit unterschiedlich starken Bereichen gemäß Fig. 5,

Fig. 7

die Lage der Roststäbe des Teils des Rostes von Fig.6 nach dem Bewegen der Roststange,

Fig. 8

im Schnitt einen sich keilförmig verdickenden Roststab,

Fig. 9

im Schnitt einen sich keilförmig verjüngenden Roststab,

Fig. 10

einander überlappende sich keilförmig verjüngende und sich keilförmig verdickende Roststäbe,

Fig. 11

einander überlappende sich keilförmig verdickende und sich keilförmig verjüngende Roststäbe und,

Fig. 12

in Draufsicht einen Teil des Rostes umfassend einander überlappende Roststäbe gemäß Fig. 10 und Fig. 11.

Further details and features of the invention emerge from the following description of preferred embodiments based on the partly schematic drawings. It shows:

Fig.1

a side view of a feed grate.

Fig. 2a

in side view a grate bar with a grate bar arranged in its holder with a small amount of play,

Fig. 2b

in side view a grate bar with a grate bar arranged in its holder with greater play,

Fig.3

in plan view a part of the grate comprising four adjacent grate bars and their grate rod,

Fig.4

the position of the grate bars of the part of the grate of Fig.3 after moving the grate bar,

Fig.5

a grate bar with different thicknesses,

Fig.6

in plan view a part of a grate comprising three grate bars and with the grate bar with different thickness areas according to Fig.5 ,

Fig.7

the position of the grate bars of the part of the grate of Fig.6 after moving the grate bar,

Fig.8

in section a wedge-shaped thickening grate bar,

Fig.9

in section a wedge-shaped tapered grate bar,

Fig.10

overlapping wedge-shaped tapering and wedge-shaped thickening grate bars,

Fig. 11

overlapping wedge-shaped thickening and wedge-shaped tapering grate bars and,

Fig. 12

in plan view a part of the grate comprising overlapping grate bars according to Fig. 10 and Fig. 11 .

A in Fig.1 The grate 1 shown comprises several grate bars. The grate bars are arranged next to one another according to the desired width of the grate 1, transverse to the direction of their longitudinal extension, with air gaps being provided between adjacently arranged grate bars. Fig.1 shows that the grate bars in the grate 1 are arranged overlapping each other, so that a stepped upper side of the grate 1 results.

Each grate bar has a downwardly open receptacle 3 on its underside in which a grate bar 4 is accommodated. The grate bars 4 accommodated in the receptacles 3 of grate bars allow grate bars to be moved back and forth by moving grate bars 4 in the direction of the longitudinal extension of the grate bars.

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

In Fig.1 In the embodiment shown, fixed grate bars 4 and grate bars 4 that are adjustable - and move back and forth - in the direction of the longitudinal extension of the grate 1 are provided. In this embodiment of the grate 1, the movable grate bars 4 are mounted on a grate carriage 2. The grate carriage 2 is assigned a drive (not shown) 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 drawn double arrow 15 - i.e. essentially horizontally. By moving the grate bars 4 back and forth, the grate 1 moves like a feed grate, so that the fuel is gradually conveyed downwards over the steps of the grate 1.

Within the scope of the invention, a - preferred - embodiment of the grate 1 is also considered, in which all grate bars 4 and not only individual grate bars 4 are driven to move back and forth.

Within the scope of the invention, one embodiment provides that the clearance between grate bars 4 and receptacles 3 of the grate bars is of different sizes for grate bars arranged adjacent to one another.

In this embodiment, the grate 1 comprises grate bars 5, in whose seats 3 grate bars 4 are inserted with a smaller clearance ( Fig. 2a ) and grate bars 6, in whose seats 3 grate bars 4 with greater clearance ( Fig. 2b ) engage. Because grate bars 5 are provided with receptacles 3, into which the grate bars 4 engage with less play ( Fig. 2a ) and grate bars 6 are provided with holders 3, into which the grate bars 4 engage with greater clearance ( Fig. 2b ), it is achieved that when the grate bars 4 move back and forth between adjacent grate bars 5 and 6, a relative movement in the direction of the longitudinal extension of the grate bars 5 and 6 occurs, as Fig.4 The reason for this is that when the grate bars 4 are moved back and forth, the grate bars 6 with holders 3 with a larger clearance between the grate bar 4 and holder 3 are not moved (initially), but only the grate bars 5 with holders 3 with a smaller clearance between holder 3 and grate bar 4. This means that the grate bars 5 and 6 are moved by different distances in the direction of their longitudinal extension (horizontally or diagonally to the horizontal), i.e. a movement of the grate bars 5 and 6 occurs relative to one another.

Within the scope of the invention, an embodiment is also considered in which grate bars 7, which have alternating stronger and less strong areas, in particular areas with a larger and areas with a smaller diameter ( Fig.5 ). The grate bar 7 with stronger and less strong areas, for example, engages in mounts 3, which are dimensioned in such a way that in areas of the grate bar 7 with a smaller diameter there is greater play between mount 3 and the grate bar 7 than in areas of the grate bar 7 with a larger diameter ( Fig.6 This allows the use of uniform grate bars in the grate 1, for example grate bars 6 according to Fig. 2b to use. This is how - as in Fig.7 indicated - when the grate bars 7 move back and forth, the relative movement according to the invention between adjacent grate bars 6 is achieved.

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.

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, alternatively or in addition to the (horizontal) relative movement between adjacent grate bars in the direction of the longitudinal extension of the grate bars, a relative movement between adjacent grate bars transverse to their longitudinal extension (vertical) can also be achieved, for example by pivoting up and down.

For this purpose, in one embodiment it is provided that, viewed in the longitudinal direction and in the transverse direction of the grate bars, grate bars 9 ( Fig.9 ) are provided, which taper, in particular wedge-shaped (-ΔH) and grate bars 8 ( Fig.8 ), which thicken, particularly in a wedge shape (+ΔH). The grate bars 8 and 9 therefore have different heights at their ends remote from their supports 3 -ΔH (grate bar 9) or +ΔH (grate bar 8). The Fig. 10 and Fig. 11 show how grate bars 8 and 9 are arranged alternately in the direction of the longitudinal extension of the grate bars 8 and 9 so that a grate bar 8 always rests with its thinner (less high) end on a thickening grate bar 9 and vice versa a grate bar 9 rests with its thicker (higher) end on a tapering grate bar 8. For example, the arrangement of the grate bars 8 and 9 in the grate 1 is such that in Fig.10 shown rows of alternating tapered grate bars 9 (-ΔH) and thickened grate bars 8 (+ΔH) and the Fig. 11 shown rows of alternating thickening grate bars 8(+ΔH) and tapered grate bars 9 (-ΔH) are arranged next to each other as shown in Fig. 12 is shown.

In this embodiment of the grate 1 according to the invention, the grate bars 4, which engage in the receptacles 3 of grate bars 8 and 9, which are arranged adjacent to one another in the direction of the longitudinal extension of the grate bars 8 and 9, are moved differently from one another. The different movement of the grate bars 4 can be achieved by - see Fig.1 - only every second grate bar 4 is moved with the aid of the grate carriage 2. It is also possible to move adjacent grate bars 4 at different speeds, in different directions and/or with different sizes of the steps of the back and forth movement.

This ensures that in the grate 1, viewed in both directions (namely in the direction of the longitudinal extension of the grate bars 8 and 9 and transversely to the longitudinal extension of the grate bars 8 and 9), grate bars 8 (+ΔH) are always provided next to one another, which thicken away from the holder 3, and grate bars 9 (-ΔH) are provided, which thin away from the holder.

By moving the grate bars 8 and 9 with the help of grate rods 4 engaging in their receptacles 3, the ends of the grate bars 8 and 9 that are remote from the receptacles 3 slide on the upper side of grate bars 8 and 9 that are adjacent to each other in the direction of the longitudinal extension of the grate bars 8 and 9. When the ends of the grate bars 8 and 9 slide on a thickening grate bar 8 (+ΔH), they are pivoted upwards. When the ends of the grate bars 8 and 9 slide on a tapering grate bar 9 (-ΔH), they are pivoted downwards. Since grate bars 8, 9 with +ΔH and those with -ΔH are always arranged next to each other (cf. Fig. 10 to 12 ), due to the opposite pivoting directions, the relative movements according to the invention occur between adjacent grate bars 8 and 9, transversely (vertically, namely up and down) to the longitudinal extension of the grate bars 8 and 9.

When the grate bars 8 and 9 are moved back and forth by means of grate rods 4 engaging in their holders 3, the grate bars 8 and 9 move up and down (swing) relative to one another in different directions (vertical). In this way, the relative movements that clean the air gaps between the grate bars 8, 9 are achieved transversely to the longitudinal extension of the grate bars 8, 9.

Within the scope of the invention, it is also considered to move grate bars 5, 6, 8, 9 relative to each other not only in the direction of their longitudinal extension, but also transversely to the direction of their longitudinal extension. This can be achieved, for example, by moving one of the grate bars 5 and 6 with +ΔH (similar to Fig.8 ) and the other grate bar 5 or 6 with -ΔH (similar Fig.9 ) or one of the grate bars 8 and 9 with a holder 3 with a small clearance to the grate bar 4 (similar Fig. 2a ) and the other grate bar 8 or 9 with a holder 3 with greater clearance to the grate bar 4 (similar Fig. 2b ). Another possibility to move grate bars both in the direction of their longitudinal extension and transversely to it is to set a grate bar 7 in grate bars 8 and 9 according to Fig.5 to use.

In summary, an embodiment of the invention can be described as follows:
A grate 1 for furnaces comprises grate bars 5, 6, 8, 9 and grate bars 4, 7 engaging in receptacles 3 of grate bars 5, 6, 8, 9, with which grate bars 5, 6, 8, 9 can be moved back and forth in the direction of their longitudinal extension. Adjacent grate bars 5, 6, 8, 9 are moved relative to one another 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 substantially horizontal, parallel to the longitudinal extension of the grate bars 5, 6 and/or substantially vertical, transverse to the longitudinal extension of the grate bars 8, 9.

Claims (19)

Method for cleaning grates (1), comprising grate bars (4) and grate bars (5, 6, 8, 9) arranged on the grate bars (4), wherein grate bars (4) engage in receptacles (3) in grate bars (5, 6, 8, 9), and wherein air gaps are provided between grate bars (5, 6, 8, 9), characterized in that grate bars (5, 6, 8, 9) are moved relative to one another in order to clean air gaps present between them. Method according to claim 1, characterized in that the grate bars (5, 6) are moved relative to one another in the direction of their longitudinal extension. Method according to claim 1, characterized in that the grate bars (8, 9) are moved relative to one another, in particular by pivoting, transversely to the direction of their longitudinal extension. Method according to one of claims 1 to 3, characterized in that of two grate bars (5, 6) arranged next to one another, only one grate bar (5, 6) is moved, whereas the other grate bar (5, 6) of grate bars (5, 6) arranged next to one another remains stationary at least temporarily. Method according to one of claims 1 to 4, characterized in that grate bars (5, 6, 8, 9) are moved relative to one another by moving grate bars (4). Method according to claim 5, characterized in that grate bars (4) are moved back and forth transversely to their longitudinal extension. Method according to one of claims 1 to 6, characterized in that grate bars (4) engage with different amounts of play in receptacles (3) of grate bars (5, 6, 8, 9) arranged adjacent to one another. Method according to one of claims 1 to 6, characterized in that grate bars (8, 9) are pivoted during their movements in the direction of their longitudinal extension while resting on adjoining grate bars (8, 9) about an axis which lies in the region of the grate bar (4) which engages in its receptacle (3). Method according to claim 8, characterized in that adjacent grate bars (8, 9) carry out pivoting movements of different sizes and/or opposite to one another. Method according to one of claims 2 to 9, characterized in that grate bars (5, 6, 8, 9) are moved relative to one another both in the direction of their longitudinal extension and transversely to the direction of their longitudinal extension. Grate (1) for furnaces for carrying out the method according to one of claims 1, 2, 4 and 5 to 7, 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), characterized in that the grate bars (4, 7) are received in receptacles (3) with play, and that the play of the grate bars (4, 7) in the receptacles (3) in grate bars (5, 6) arranged adjacent to one another is of different sizes. Grate according to claim 11, characterized in that in the grate (1) alternately arranged next to each other are grate bars (5) with narrower mounts (3) and smaller clearance between the mount (3) and the grate bar (4) engaging therein and grate bars (6) with wider mounts (3) and larger clearance between the mount (3) and the grate bar (4) engaging therein. Grate according to claim 11, characterized in that grate bars (7) engaging in the receptacles (3) of grate bars (6) have areas of different thickness, in particular of different diameters, in the region of the receptacles (3). Grate according to claim 13, characterized in that grate bars (7) have alternating regions of greater thickness and regions of smaller thickness. Grate according to claim 14, characterized in that grate bars (7) with areas of greater thickness with smaller play and with areas of smaller thickness with larger play engage in receptacles (3) of grate bars (6). Grate (1) for furnaces for carrying out the method according to one of claims 1, 3, 4, 8 and 9, comprising a plurality of grate bars (8, 9) aligned parallel to one another and grate bars (4) aligned transversely to the grate bars (8, 9), wherein grate bars (4) engage in receptacles (3) in the grate bars (8, 9) and wherein the grate bars (8, 9) rest with their ends remote from the receptacles (3) on grate bars (8, 9) adjoining in the direction of their longitudinal extension, characterized in that adjacent grate bars (8, 9) are of different heights at their ends remote from the receptacles (3). Grate according to claim 16, characterized in that grate bars (9) which extend to their position from their holder (3) tapering towards the end remote from the holder (3) and grate bars (8) are provided which thicken towards the end remote from the holder (3). Grate according to claim 17, characterized in that in the grate (1) on the one hand grate bars (8) which thicken and grate bars (9) which taper are provided next to one another, and that on the other hand in the direction of the longitudinal extension of grate bars (8, 9) grate bars (8) which thicken and grate bars (9) which taper are provided in succession, alternating. Grate according to one of claims 15 to 17, characterized in that grate bars (8, 9) are mounted on the grate bars (4) so as to be pivotable about axes lying in the region of their receptacles (3).

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