EP0790464B1 - Combustion grate, especially for waste incinerators - Google Patents

Abstract

A fire grate has tensioning devices (3) inserted in recesses (2) of an oven wall (1), with each device acting upon one grate side plate. The tensioning device (3) includes a cylinder (4) inserted into the oven wall, a hollow piston (7) guided therein and a spring (26), which can be adjusted in its tension. The grate side plate has a carrying plate (12) directly fastened to the piston bottom (10) with a grate border plate (13) suspended, or hanging, on the carrying plate (12). The piston (7) has diameter and length dimensions such that it can support and guide the grate side plate without further guiding devices. Neighboring pistons (7) are connected flexibly to each other by guiding bars (36), so that the pistons (7) can influence each other reciprocally. An upper edge of the grate side plate, particularly the grate border plate (13), has a flange (17) extending toward the oven wall. The flange (17) sealingly engages an elastical seal (19), fastened onto the oven wall. An additional covering ledge (21) covers the flange (17) and includes a shaped part or angle (22) which bounds a hollow space (23) between these two parts, just like a labyrinth seal.

Description

The invention relates to a firing grate, in particular for waste incineration plants, with partially overlapping Rows of grate bars, with the rows of grate bars alternating fixed and movable in the longitudinal direction of the grate bars are and with the grate bar rows by grate side plates are limited, which are movably supported transversely to their longitudinal direction and by clamping devices that are held in the furnace wall against which rows of grates can be pressed, whereby the tensioning devices comprise pressure members which in to Firebox open guides are guided.

In a known grate of this type (DE-C-41 05 331) are the grate side plates on grate bar signs, i.e. special guides that are U-shaped to the guided above and below edges, the grate bar signs are attached to the grate bar supports. As tensioners serve hydraulic cylinders at the ends of the Grate side plates are provided, each hydraulic Unit on both ends of adjacent grate side plates presses. The grate bars, which are immobile in the longitudinal direction, lie thereby directly on the grate side plates, while for the longitudinally movable grate bars in the Grid side plates slider is provided on the an additional hydraulic cylinder unit acts with their plunger reaches freely through the grate side plate. This relatively high effort is intended to different relationships between the movable and the immovable rows of grate bars result to be able to compensate. Another disadvantage this configuration is that the close management of the Rust side plates in the U-shaped guides, in particular with exposure to dust, which is unavoidable in the combustion chamber Canting and jamming can lead so that Malfunctions occur during rust operation.

From DE-A-14 51 519 it is known to compensate for Thermal expansion of the grate bars by two inside each other sliding half shells by springs or weighted levers are instructed to strain the To be able to record heat play. These half shells are but supported on a firm surface and thus one Subject to friction, even by foreign bodies Deadlocks can occur that cause a shift in the Half shells and thus hinder the thermal expansion compensation.

The object of the invention is to provide a grate according to the The preamble of claim 1 to further design that relatively little design effort largely trouble-free operation of the grate and the Clamping devices including the grate side plates is guaranteed.

This task is based on a rust of the above specified type according to the invention solved in that each Grate side plate firmly with the pressure element of the clamping device connected and supported solely by this and is that the guide is guided as one on the firebox side opposite side of the closed cylinder and the pressure member are designed as a hollow piston guided in the cylinder, the by a spring element accommodated in the hollow piston is loaded, its counterforce on the cylinder bottom acts, and with its piston crown with the grate side plate firmly connected and with its piston shirt in the cylinder is guided sealed.

This configuration enables those necessary in the prior art additional guides for the grate side plates are omitted because the Management and support tasks by the clamping device itself is carried out, with which the grate side plate is firmly connected. Canting and jamming and related Malfunctions in the grate operation are thus avoided. Because additional Guides for the grate side plates are also eliminated Reduced effort.

So that the hollow piston of the clamping device performs the management tasks assigned to it can perform particularly reliably, points out further Embodiment of the invention the piston shirt a length that is greater than the cylinder depth. So is with all lifting movements that this clamping device in Rust operation must always have a sufficient guide length of the piston inside the cylinder.

Another measure according to the invention, which is good Piston guide and thus for a tilt-proof guide the grate side plate is advantageous is that in the Cross section of circular piston whose diameter is larger than half the grate plate height. Because of this large size the cylinder and the piston of the clamping device, which is also the guide for the Grate side plate is, with little design effort safe guidance of the grate side plates, even in the event of faults in grate operation, guaranteed by the penetration of Solids caused between adjacent grate bars can be.

According to an advantageous further embodiment of the invention are adjacent pistons with each other by guide rods connected with their free ends articulated to each attack adjacent pistons. These guide rods not only act as an anti-twist device in cross-section circular pistons, but also serve adjacent ones To influence the pistons of adjacent clamping devices that a certain entrainment of a piston the neighboring pistons. This results in a Connection of the individual clamping devices in the manner of a Link chain, the impact on each neighboring Brings piston so that the grate side plates different states of expansion of the roof tiles rows of grate bars in the manner of a serpentine line can adjust. This allows the additional Clamping devices according to the state of the above Technology that reaches directly through the grate side panels act on the movable rows of grate bars, whereby the enormous technical effort of the known Rust formation can be largely avoided.

According to a development of the invention it is provided that the Articulated connection between the piston and the guide rod and the guide rod at right angles to the piston longitudinal axis encompassing hinge pin, which in fixed arranged on the piston and the guide rod between receiving retaining tabs is held. This will a robust and structurally simple connection between neighboring pistons created a mutual balance cause different expansion of rows of grate bars can.

Since additional management facilities are eliminated, not only are structurally complex, but also a considerable one Requiring space is the prerequisite for an advantageous Created further development of the invention, which consists in that the cylinders with their open ends are flush with the floor a stove wall recess or a stove wall recess are attached, the depth of which is such that the Grate side plates at operating temperature of the grate bars with the Align the furnace wall. Larger rooms to accommodate additional ones Guide devices for the grate side plates are not necessary, so that a greater effort the design of the furnace wall due to the small space requirement is not required, but in the known embodiments with additional guidance facilities is necessary.

To the grate side panels, which of course as simple Plates can be made to withstand the very high heat can protect better in a further design of the invention, the grate side plates are double-walled be and a support plate connected to the piston and a rust limitation plate made of high-temperature resistant Include material on their, the support plate facing side transverse to the longitudinal direction Has support ribs. In this embodiment, the grate side plate its dimensions are smaller than usual because it is covered by the rust control plate, the correspondingly larger dimensions in height and if necessary can also have in length.

Preferably, the grate limiting plate can have several in Longitudinal direction of the support plate with little play to each other arranged sub-panels include, the total length of the Length of the support plate corresponds.

A further advantageous embodiment of the invention exists in that the grate side plates or the grate limiting plates at its top edge one towards the furnace wall have protruding flange which from one to the Oven wall attached cover strip covered with little play is. This will provide some protection against intrusion Dust and coarser particles brought about without such a cover get behind the grate side plates could.

In order to improve this sealing effect even more advantageously Development of the invention between the free edge the flange of the grate side plate or the grate limiting plate and the furnace wall is elastic on the furnace wall yielding sealing body can be used. Such Sealing bodies consist of mineral in a known manner Materials that are correspondingly heat-resistant and one have sufficient elasticity to accommodate the movements of the Sealing the grate side plate or the grate limiting plate to be able to follow.

Another improvement in the seal is that on the back of the grate side plate or the support plate arranged in the longitudinal direction of the same extending web is, which engages sealingly in a groove of the sealing body.

To protect the sealing body from excessive loads caused by dust to protect, can in further development of the invention side of the cover strip facing the flange an offset of the cover strip upward cavity have, whereby between the flange of the grate side plate or the grate limiting plate and the cover strip a kind of labyrinth seal with relaxation space for the penetrated Air is formed so that the passage of dust between the upper edge of the grate side plate or the grate limiting plate and the cover strip largely prevented and thus the sealing body is less burdened with dust. As a result, the sealing body can perform its sealing function exercise for a longer period of time.

To adapt the clamping device to the prevailing conditions to be able to, in a further development of the invention The spring element can be adjustable in its preload.

Figur 1:

Einen Vertikalschnitt durch eine Spannvorrichtung mit Tragplatte und Rostbegrenzungsplatte;

Figur 2:

Eine Ansicht in Richtung der Schnittlinie II-II in Figur 1;

Figur 3:

Einen Schnitt nach der Linie III-III in Figur 2; und

Figur 4:

Eine der Figur 1 entsprechende Schnittdarstellung einer abgeänderten Ausführungsform.

The invention is explained below with reference to an embodiment shown in the drawing. The drawing shows:

Figure 1:

A vertical section through a clamping device with a support plate and grate limiting plate;

Figure 2:

A view in the direction of section line II-II in Figure 1;

Figure 3:

A section along the line III-III in Figure 2; and

Figure 4:

A sectional illustration corresponding to FIG. 1 of a modified embodiment.

A furnace wall labeled 1 has a grate height Return 2, in which several, labeled 3 in total Clamping devices are arranged. Any jig includes a cylinder open to the combustion chamber side 4, which is flush with the bottom 5 of the Recess 2, for example, fixed by a weld 6 is. In the cylinder 4 is a hollow piston 7 with its Piston shirt 8 guided and sealed by a seal 9, so that no dust can enter the interior of the cylinder 4 can. The piston skirt 8 is longer than the cylinder depth executed so that it is always safe with all lifting movements is led. With the piston crown 10 of the piston 7 is by screws 11 a support plate 12 firmly connected to the individual rust control plates to protect them against the effects of heat 13 are attached, for which the grate limiting plate 14 ribs in the area of its upper bent end 15 with hanging grooves 16. The rust control plate 13 has at its upper edge one directed towards the open wall Flange 17, the free end 18 against one elastic sealing body 19 presses by means of a bracket 20 held at the bottom 5 of the recess 2 of the furnace wall 1 is. A cover strip 21 is also provided on the furnace wall, with an upward bend 22 over the flange 17 of the grate limiting plate 13 with little Distance lies, whereby a cavity 23 through the offset 22 arises, which largely covers the flange 17 is so that a relaxation room like a labyrinth seal arises. So in the example shown is the grate side plate through the support plate 12 and the grate limiting plate 13 formed. In the event that these two parts are in one piece are executed, the one-piece grate side plate the same outer shape as the grate limiting plate 13 on.

The individual grate limiting plates 13, which with little Gap 24 are attached to each other on the support plate 12, have an overall length that is the length of a support plate 12 corresponds, whereby no overlaps at the gap 25 between adjacent support plates 12 exist. This can the grate limiting plate assigned to a support plate 12 13 together with the support plate 12 across Longitudinal grate direction due to the rust expansion or due to the action of the clamping device 3 move.

So that the tensioning device 3 can perform its function a compression spring 26 is provided in the interior of the hollow piston 7, with one end on the piston crown 10 and with is supported at its other end on a replacement bearing 27, which in Shape of the inner diameter of the hollow piston 7 essentially matched plate and at the end of an adjusting screw 28 is seated, which is attached to the cylinder base 29 Nut 30 screwed in and through a lock nut 31 is secured. The set screw 28 points to its outside the end of the cylinder 4 a handle 32 in the form of a head with a through hole 33 into which a correspondingly thick rod for turning the set screw 28 is insertable to adjust the bias of the compression spring 26 to be able to.

The piston 7 is so far beyond the cylinder 4 that the Rust control plates 13 essentially with the furnace wall 1 align. Within the free space caused by the return 2 is formed, are adjacent pistons 7 by guide rods 34 connected in an articulated manner. For this are on the piston skirt 8 of each piston 7 on both sides of the same Retaining tabs 35, for example fastened by welding, which receive the respective guide rod 34 between them, one through the retaining tabs 35 and the guide rod 34 hinge pin 36 inserted through the hinge connection manufactures. Since all pistons 7 are adjacent Clamping devices 3 articulated to the piston by such attacking guide rods 34 are connected on the one hand a rotation of the pistons 7 in their cylinders 4 and thus prevents rotation of the support plates and on the other hand a mutual influence takes place through these guide rods 34 of the jigs, in such a way that different Extensions of successive rows of grate bars be largely balanced. Such different On the one hand, expansion can be caused by different thermal loads on the grate bar rows or through between slag particles reaching the grate bars.

A tensioning device 3 is assigned to each support plate 12, through which the support plate is held and guided, with the Achieving good guidance of the pistons 7 and the associated ones Cylinders 4 have the largest possible diameter, the piston diameter being almost the height of the support plate 12 corresponds. The large length of the piston shirt 8 carries also for a stable guidance of the piston and thus the Support plate 12 at. Each support plate 12 can either be one Grate bar row can be assigned or the support plates can also have a greater length so that they are part of the subsequent row of grate bars or even several rows of grate bars can spread. So that the support plates the occurring Can withstand pressures are on the back of the same Web 37, for example, fixed by welding. For Show increase in the stability of the grate limiting plates 13 these on their rear ribs 38, which are transverse to the longitudinal direction of the support plates, i.e. essentially in the vertical direction run, creating voids 39 into which of below in the area of that formed by the recess 2 Cracked fresh air for cooling the grate limitation plates or the support plate can penetrate. This from the underwind box Coming air can because of the sealing body 19th Do not flow around the grate laterally. Because from the underwind box if there is practically no dust pollution, that is enough provided seal 9 to prevent dust from entering to avoid the cylinder 4.

Figure 4 shows a variant in the seal between the Rust control plates and the furnace wall. The change is that the sealing body 19 'has a greater height and is provided with a groove 40 into which an extended Web 37 'penetrates to achieve an additional seal.

Otherwise, the configuration according to FIG. 4 coincides with that according to Figures 1 to 3.

Claims (13)

1. Furnace grate, especially for waste incinerators, with partly interengaging rows of grate bars, the rows of grate bars being alternately stationary and movable in the longitudinal direction of the grate bars, and the rows of grate bars being bounded by grate side plates (12, 13), which are supported such that they can be moved transversely with respect to their longitudinal direction and can be pressed against the rows of grate bars by clamping devices (3) which are held in the furnace wall (1), the clamping devices (3) comprising pressure elements (7) which are guided in guides (4) that are open with respect to the combustion chamber, characterized in that each grate side plate (12, 13) is firmly connected to the pressure element (7) of the clamping device (3) and is supported and guided only by the said pressure element (7), in that the guide is formed as a cylinder (4) closed on the side facing away from the combustion chamber, and the pressure element is formed as a hollow piston (7) which is guided in the cylinder (4) and is loaded by a spring element (26) which is accommodated in the hollow piston (7) and whose opposing force acts on the cylinder base (29), and is firmly connected to the grate side plate (12, 13) by its piston head (10) and is guided in a sealed manner (9) in the cylinder (4) by its piston skirt (8).
2. Furnace grate according to Claim 1, characterized in that the piston skirt (8) has a length which is greater than the cylinder depth.
3. Furnace grate according to Claim 1 or 2, characterized in that in the case of a piston (7) with a circular cross section, its diameter is greater than half the height of the grate side plates.
4. Furnace grate according to one of Claims 1 to 3, characterized in that adjacent pistons (7) are interconnected via guide rods (34) which, at their free ends, act in an articulated manner on respectively adjacent pistons (7).
5. Furnace grate according to Claim 4, characterized in that the articulated joint between piston (7) and guide rod (34) comprises a hinge pin (36) which is at right angles to the piston longitudinal axis and reaches through the guide rod (34) and is held in retaining lugs (35) which are firmly arranged on the piston (7) and accommodates the guide rod (34) between them.
6. Furnace grate according to one of Claims 1 to 5, characterized in that the cylinders (4) are fixed with their open ends flush with the bottom (5) of a furnace niche or recess (2) in the furnace, whose depth is dimensioned such that the grate side plates (12, 13) are aligned with the furnace wall (1) at the operating temperature of the grate bars.
7. Furnace grate according to one of Claims 1 to 6, characterized in that the grate side plates are of double-walled design and comprise a support plate (12) joined to the piston (7) and a grate boundary plate (13) which is suspended on the latter and, on its side facing the support plate (12), has supporting ribs (38) running transversely with respect to the longitudinal direction.
8. Furnace grate according to Claim 7, characterized in that the grate bounding plate (13) comprises a number of part plates which are arranged in the longitudinal direction of the support plate (12) with slight play (24) in relation to one another and whose overall length corresponds to the length of the support plate (12).
9. Furnace grate according to one of Claims 1 to 8, characterized in that the grate side plates (12, 13) and the grate bounding plates (13) have, at their upper edge, a flange (17) which projects in the direction of the furnace wall and is covered with slight play by a covering strip (21) fixed to the furnace wall.
10. Furnace grate according to Claim 9, characterized in that between the free edge (18) of the flange (17) of the grate side plate (12, 13) and/or the grate bounding plate (13) and the furnace wall (1), a sealing element (19) is inserted which is held on the furnace wall (1) and is resiliently compliant.
11. Furnace grate according to Claim 10, characterized in that on the rear of the grate side plate (12, 13) and/or the support plate (12) there is arranged a web (37') which extends in the longitudinal direction of the same and engages in a sealing manner in a groove (40) in the sealing element (19').
12. Furnace grate according to one of Claims 9 to 11, characterized in that that side of the covering strip (21) which faces the flange (17) has a cavity (23) which is formed by bending over a portion (22) of the covering strip (21) at the top.
13. Furnace grate according to one of Claims 1 to 12, characterized in that the prestress of the spring element (26) can be adjusted.

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