EP2314916B1 - Combustion grate assembly - Google Patents

Description

I. Field of application

In solid fuel burners, which are operated in particular in continuous operation or over long periods, the combustion grate, through which the combustion of the fuel usually takes place from top to bottom, is one of the most stressed components and is to be regarded as a wearing part. Such a grate is from document DE 10148686 C1 known.

II. Technical background

In order to achieve a good and complete combustion, the combustion grate is formed from adjacent, hollow nozzle tubes, which have in their flanks in the longitudinal extension side by side many outlet openings for combustion air, which the fuel gases when flowing through the combustion grate, which is usually from top to bottom, is fed to achieve the most complete combustion and a low pollutant and particulate matter content.

Since these nozzle tubes manufacturing technology usually can only be produced as steel pipes, they must be replaced from time to time.

So far, it was known, the surrounding receiving parts, which form the support area around the grate area, also made of sheet steel or However, due to the very large temperature differences at the beginning and end of the firing process to strong distortion, thermal expansion and thus permanently led to the destruction of these components.

In addition to the cost of spare parts then still high assembly costs were necessary to install these spare parts.

III. Presentation of the invention a) Technical task

It is therefore the object of the invention to provide a combustion grate which is simple and inexpensive to produce, in which as many parts have the highest possible life and in case of wear, the replacement of worn items as quickly and inexpensively feasible.

b) Solution of the task

This object is solved by the features of claim 1. Advantageous embodiments will be apparent from the dependent claims. By forming the grate area of juxtaposed nozzle tubes, which open at their ends into openings of the lateral, preferably common, receiving parts which simultaneously constitute the air supply channels, an extremely easy to install and maintain structure of the combustion grate is achieved, despite the necessary supply to secondary air in the grate area.

Since the air is supplied via the trained as a nozzle tubes rods of the combustion grate, so that the air is very evenly distributed in the afterburner and delivered directly at the transition from the main combustion chamber to Nachbrennraum and thereby achieves optimum combustion.

By on each side of the nozzle tubes only a single receiving part is present, and this receiving part consists of a lower part and a shell, between the z. B. half shells, the air supply channels are formed, the air supply channels are accessible at any time by the decrease in the intake tops. Also, the nozzle tubes can be easily removed in this way.

To complete the combustion grate also transversely to the direction of the nozzle tubes and there to provide a support surface for the solid to be burned, there is a spacer used between the receiving parts, which fill the distance between the opposite receiving parts, if not the last nozzle tube immediately at the end a spacer is arranged. In addition, at least the receiving upper parts are fixed positively in the running direction of the nozzle tubes by the spacer parts.

Of course, the air supply channels go through the entire area of the nozzle tubes and in particular over the entire length of the receiving parts. If the air supply channels have two open ends, one of the open ends of the air supply channels is closed by a closure piece, since the air supply is usually only from the one end side.

In this case, the receiving parts, the spacer parts and the closure pieces are usually made of a high-temperature fired material, such as silicon carbide, while the nozzle tubes are made of steel, and preferably folded and welded from a sheet metal Tubes with a polygonal cross section are to prevent twisting in the correspondingly shaped recesses of the receiving parts. In round nozzle tubes, an additional anti-rotation is necessary, for example, a radially projecting from the nozzle tube projection which projects into a corresponding recess of the surrounding receiving female part.

The nozzle tubes are therefore made of steel, as they must be able to withstand bending, even under high heat, as they sag freely in the middle and are only supported at the ends. In addition, the many, relatively small air outlet openings must be introduced in the steel tubes, which is not possible with burned and sintered particular material such as the other parts with this precision.

In addition, the air outlet openings in the nozzle tubes should be located very precisely just below the point of the largest cross section of the nozzle tubes, so the smallest distance between the nozzle tubes, which would also be difficult to achieve in the fired material.

In order to avoid a longitudinal displacement of the nozzle tubes relative to the receiving parts, these are positively connected to one another in the longitudinal direction of the nozzle tubes, for example by a longitudinal stop for the nozzle tubes formed in the receiving part, in particular the receiving upper part, or an outwardly protruding projection of the nozzle tubes which fits into a corresponding positioning recess of the receiving part.

In order to prevent air leaks in the wrong places, the nozzle pipes are sealed to the receiving parts by wrapping with a heat-resistant sealing tape in the area where the nozzle pipes are enclosed by the receiving parts.

In the same way, the stacked upper and lower parts of the receiving parts are sealed against each other, which instead or additionally may be formed as a labyrinth seal on the contact surfaces, as well as the inserted into the receiving parts closure pieces.

In the same way as the frontal openings of the air supply channels can be closed by plugs, not required openings for nozzle tubes in the receiving parts can be sealed by appropriate fittings, for example, the first and last opening at the beginning and end of a receiving part, if there used instead a spacer shall be.

Furthermore, the receiving upper part contains a positive fixation with respect to the receiving base in all transverse directions, e.g. by correspondingly shaped projections, which can also be part of the labyrinth seal at the same time.

Likewise, the spacer will also have a positive connection with the components underneath, so that it can not be moved unintentionally in the direction transverse to its longitudinal extent relative to the receiving parts.

Preferably, the spacer locked by simply inserting between the receiving parts form-fitting manner with respect to these, and thereby also fixed the receiving shell positively between the spacer and the surrounding housing.

Frequently, such a combustion grate will only have a grate area formed by nozzle tubes, but in special constructions several such grate areas formed by nozzle tubes may be arranged side by side, which are then interrupted by receiving parts running therebetween.

In this way can be created by means of always the same length of nozzle tubes very different lengths of burners whose extension in one direction can be a multiple of the length of the nozzle tubes.

In this way, the components described can be used as a modular system for producing burner grids of different sizes, the modular system comprising in the simplest case only one type of nozzle tube, and at least one type of spacer element.

Further, when receiving parts with different distances between the openings for the nozzle tubes in the kit are present, and also the necessary fittings for closing openings for nozzle tubes, combustion grids with different spacing of the nozzle tubes, different numbers of nozzle tubes and with one or more grate areas from this very small number of items are created.

The combination options continue to increase greatly if the kit contains receiving parts that have not only on one, but also on both opposite sides openings for nozzle tubes, so both the kit has both one-sided and two-sided receiving parts.

The same applies if additional additional spacers in different dimensions in the longitudinal direction and / or transverse direction of the nozzle tubes, or receiving parts with different numbers of openings for nozzle tubes, and / or different lengths and / or different thickness nozzle tubes.

c) embodiments

Fig. 1:

den Brennrost im zusammengebauten Zustand,

Fig. 2:

das Aufnahmeunterteil,

Fig. 3:

das Aufnahmeoberteil,

Fig. 4:

das Abstandsteil,

Fig. 5:

das Düsenrohr, und

Fig. 6:

einen Brennrost mit mehreren Rostbereichen 3.

Embodiments according to the invention are described in more detail below by way of example. Show it:

Fig. 1:

the combustion grate in the assembled state,

Fig. 2:

the receiving base,

3:

the receiving shell,

4:

the spacer,

Fig. 5:

the nozzle tube, and

Fig. 6:

a grate with several grate areas 3.

FIG. 1a shows the grate 1 in the assembled state in perspective view, while FIG. 1b a vertical section transverse to the direction 10 of the nozzle tubes 2 and Figure 1c a vertical section in the direction 10 of the nozzle tubes 2 shows.

FIG. 1a shows that viewed in the plan view in the center of a grate area 3 is formed, which consists of spaced apart side by side, hollow nozzle tubes 2, so that in the space between the nozzle tubes 2 through - as best in FIG. 1b to recognize - the combustion gases of the combustion of resting on the grate area 3, not shown, burning material can be removed down.

In this case, the combustion gases through air outlet openings 13 in the nozzle tubes 2 additional air, the so-called secondary air, fed to the To optimize combustion in the afterburner 4 below the grate area 3.

How best FIG. 5b shows are for this purpose along the course direction 10 of each nozzle tube 2 a plurality of periodically spaced air outlet openings 13 present, which penetrate the wall of the nozzle tube 2, in accordance with FIG. 5b just below the point of the greatest width of the cross-section 14 of the nozzle tube 2, which in this case is a pentagonal, center-symmetrical cross-section, which is directed with the tip upwards.

The nozzle tubes 2 have a polygonal cross section so that they can not be unintentionally rotated in the likewise polygonal, precisely fitting recesses 22, whereby the position of the air outlet openings 13 would change.

As FIG. 1b can be seen, is formed by two oppositely directed, convex bulbous, in this case angled side walls of two adjacent nozzle tubes 2, a passage from top to bottom, which - viewed from top to bottom - initially greatly narrowed and then expands again, so a nozzle shape forms.

This creates a negative pressure in the region below the narrowest point of this nozzle for the fuel gases flowing from top to bottom, so that secondary air from the fuel gases is automatically drawn in from the air outlet openings arranged there without this secondary air having to be supplied with overpressure.

So it is no fan or the like in the air supply line for the secondary air necessary.

As the Figures 5 show, the nozzle tubes 2 are folded from a sheet metal and at one point, here the center of the flat bottom, welded together, in particular Laserverschweißt.

The air outlet openings 13 can be introduced very inexpensively and quickly before edging and welding in the still flat sheet in this way, be it by punching, drilling or cutting by laser or water jet, which is much faster and cheaper possible than the introduction z. B. in the rounding of a drawn tube, quite apart from the fact that the deformation of a drawn tube to a polygon is also not without problems.

This central grate area 3 is surrounded by a non-permeable support area 13, on which the firing material can also rest, but preferably forms a firing point only above the grate area 3, since only there are the combustion gases discharged downwards.

• Zum einen sind dies die beiden auf jeder Stirnseite der Düsenrohre 2 in Querrichtung 11 zu den Düsenrohren 2 durchgehenden Aufnahmeteile 6 für die Düsenrohre 2, die jeweils aus einem Aufnahmeunterteil 6a und einem darauf aufgelegten Aufnahmeoberteil 6b bestehen.

The support region 13 is formed by the upper side of the components surrounding the grate region 3 and receiving the ends of the nozzle tubes 2:

• On the one hand, these are the two on each end face of the nozzle tubes 2 in the transverse direction 11 to the nozzle tubes 2 continuous receiving parts 6 for the nozzle tubes 2, each consisting of a receiving base 6a and a receiving top part 6b thereupon.

In the region of the joint 7 between the upper part 6b and lower part 6a, the recess 22, ie in the upper part and lower part each about half of the recess 22, formed, which corresponds to the outer periphery of the nozzle tube 2, so that this with its end 2a, b in each case one of the recesses 22 rests.

Between receiving lower part 6a and receiving upper part 6b a circumferentially enclosed air supply channel 5a, b is formed, in which the lower part 6a is designed trough-shaped and the upper part 6b closes this tub as an applied cover.

In this case, the lower part 6a protrudes upwards at the outer end remote from the nozzle tubes 2 next to the upper part 6b and together with the latter forms the support region 13.

As Figure 1c shows, the ends 2a, b of the nozzle tubes 2 do not or only slightly into the free space of the air supply channels 5a, b in order to hinder the air flow as little as possible, from which the nozzle tubes 2 relate their secondary air. In each case, a stop 24 for the upper tip 15 of the front end of the nozzle tube 2 is formed in the receiving upper parts 6b in order to positively prevent a longitudinal displacement of the nozzle tube 2.

The receiving parts 6, which usually pass through all the nozzle tubes 2 of the grate area 3 and even protrude beyond this grate area 3, as in FIG. 1a shown, have at the end faces usually no one-piece closure for the air duct 5a, b, which, however, is supplied only from one end face with air.

Therefore, the other, unnecessary open end of the supply channel 5a, b is usually through a closure piece 12, as in Figure 1c indicated, closed.

The upper side of the receiving parts 6, in the illustrated case only the receiving upper part 6b, is sloping inclined towards the center, ie the nozzle tubes 2 and the grate area 3, in order to allow the firing area lying on this supporting area 13 to slip better in the direction of the grate area 3 during the burnup ,

Often it is desired for the spatial limitation of the ember bed that - as in the case illustrated - the grate area 3 is surrounded on all sides by a dense support area 13.

In this case, the nozzle tubes 2 are not arranged side by side up to the ends of the receiving parts 6, but in the region of the front ends of the receiving parts 6 there are no more nozzle tubes 2 between them, but there is the distance 9 between the receiving parts 6 by a suitable , solid spacer 8 closed.

Because of the obliquely sloping outer, pointing to the center of the combustion grate side wall of the receiving parts 6, the receiving part is wedge-shaped with a decreasing from top to bottom cross section, so that it can be used in a simple manner from above between the receiving parts.

In this case, the spacer 8 protrudes beyond the joint between receiving lower part 6a and receiving upper part 6b, and thereby locks the receiving upper part 6b in a form-fitting manner in at least one horizontal direction.

In this case, a groove-shaped positioning recess 17 can be seen in the underside of the spacer 8, which extends in the direction 10 of the nozzle tubes 2 and into which a component of the surrounding combustion device engages to prevent displacement of the spacer 8 on the nozzle tubes 2 to or away from them ,

Likewise, the nozzle tubes 2 may have, for example, from the bottom downwardly projecting projection 16 in a corresponding recess 20 of the z. B. receiving lower part 6a engages and a displacement of the nozzle tubes 2 in their direction of travel relative to the Prevents receiving parts or even with round pipes would provide a backup against unwanted rotation.

If such a projection is present on both sides at the end of the nozzle tube 2, this can protrude into the air supply channel 5, which then serves as positioning recess.

FIG. 2 shows separately the receiving base 6a in a perspective view, with the in its longitudinal direction, the transverse direction 11 of the grate 1, continuous and both sides end-like open trough-shaped channel which forms the air supply channel 5a in the nozzle tubes 2.

In the outer wall of the trough to the grate towards the lower halves of the adjacent recess 22 for inserting the nozzle tubes 2 can be seen in the opposite wall, the shoulder for inserting the Aufnahmoberteiles 6b, which serves as the air supply channel 5a on the top occlusive lid and in FIG. 3 is shown in perspective.

There are again in the transverse direction 11 adjacent to each other in the lower edge of the downwardly directed leg of this L-shaped receiving upper part 6b, the upper halves of the recesses 22 for the nozzle tubes 2 to recognize, including the upstanding tip 15 'in the right recess 22nd additionally the stop 24 is located, which serves as a longitudinal stop for the nozzle tubes 2 in the receiving upper part 6b and thus in the receiving part 6 total.

The upper part 6b is not displaceable relative to the lower part 6a in the transverse direction 11 due to the positive engagement, which then cause the inserted nozzle tubes 2 between these two components.

A positive connection between the upper part 6b and lower part 6a in the direction 10 of the nozzle tubes 2 can be provided by the contact surface between the upper part 6b and lower part 6a is formed as a labyrinth seal with zigzag cross-section, ie consist of tongue and groove, which is not shown in the drawings ,

A displacement of the receiving lower part 6a in its longitudinal direction, the transverse direction 11 of the burner grate 1, with respect to the surrounding components is positively prevented by each transverse to its longitudinal direction, ie in the direction 10 of the nozzle tubes 2, shoulder 23 in the bottom of the receiving part 6a, with it is held positively in a surrounding component.

How best that FIGS. 1 show, the components of the support area 13, so receiving base 6a, receiving shell 6b, spacer 8 and optionally the closure pieces are massive, at least very thick-walled, components, which consist of a fired at high temperature material, in particular silicon carbide.

The contrast, a much smaller wall thickness having hollow, open on both sides of the front side, nozzle tubes 2 are made of steel, are also exposed to a higher temperature load due to the immediately above ember bed, and therefore form a wearing part in the grate 1, which one on simple Must be able to change way.

As FIG. 1a shows, this is possible in a few steps, for this purpose only the spacers 8 and receiving tops 6b must be lifted upwards, whereupon you can also remove the nozzle tubes 2 upwards and replace them with new ones.

In order to prevent the leakage of secondary air in wrong places, by means of a resilient, heat-resistant sealing strip 18, the ends of the nozzle tubes 2 may be wrapped on the outside, in the region in which they are received between receiving upper part 6b and receiving base 6a, so that these two parts lie close to the nozzle tube 2.

If the receiving upper part 6b rests not by means of labyrinth seal, but by means of a flat support surface on the receiving part 6a, such a sealing tape 18 is recommended between these two components, which at the same time serves as the adhesion and thus displacement of the two components against each other, non-positive retaining element.

In the same way, the closure pieces 12 arranged in the ends of an air supply channel 5a, b can be wound around and sealed by sealing tape 18 and likewise a fitting piece 19 in a recess 22, not required for a nozzle pipe 2, of a receiving part 6.

Fig. 6 shows - in the same direction as Fig. 1c This is made possible by the fact that the outer receiving parts 6 are designed as described above, whereas the middle receiving part is formed on both sides for receiving the ends 2b of the nozzle tubes 2 projecting there.

In this way - ie with the help of these special, in particular mittsymmetrisch formed receiving parts 6 - can be prepared with a plurality of spaced grate sections 3 spaced apart grate sections 1.

LIST OF REFERENCE NUMBERS

1

burning rust

2

nozzle tube

2a, b

The End

3

grate area

4

secondary combustion

5a, b

Air supply channels

6

receiving part

6a

Recording base

6b

Recording shell

7

parting line

8th

spacer

9

distance

10

Verlaufsichtung

11

transversely

12

closing piece

13

Air outlet opening

14

cross-section

15

top

16

head Start

17

Positioning recess

18

sealing tape

19

spud

20

recess

21

head Start

22

recess

23

shoulder

24

attack

Claims (8)

1. A combustion grate (1) for solid material combustion devices, the combustion grate comprising:

   - nozzle tubes (2) arranged adjacent to each other, forming a grate portion (3) and characterized in that

   - the nozzle tubes (2) protrude with their ends (2a, b) into one of two receiver elements (6) respectively which form a portion of a contact portion (13) and which are secured against rotation in a form locking manner therein,

   - wherein the receiver elements (6) respectively include at least one air intake channel (5a, b),

   - the nozzle tubes (2) are connected with the air feed channels (5a, b) in the receiver elements (6),

   - the receiver elements (6) are configured in a transversal direction (11) relative to an extension direction (10) of the nozzle tubes (2) longer than the grate portion (3), and

   - wherein spacers (8) in addition to the nozzle tubes (2) fill a distance (9) between the two receiver elements (6) that are arranged opposite to each other.
2. The combustion grate according to claim 1, characterized in that the analog end portions (2a, b) of all nozzle tubes (2) are received in a common receiver element (6) and in particular each receiver element (6) includes a receiver element base (6a) and a receiver element top (6b) and the nozzle tubes are arranged in a portion of a separation gap (7) there between in openings (22).
3. The combustion grate according to one of the preceding claims, characterized in that

   - the air intake channels (5a, b) extend over an entire length of the receiver elements (6) and an inlet is closed in a face of the receiver elements (6) in particular by a closure (12), and/or

   - the receiver elements (6), the closures (12) and the spacers (8) are made from a material that is fired at high temperature, in particular silicone carbide (SIC) and the nozzle tubes (2) are steel tubes, in particular tubes that are made from sheet metal, creased and welded together.
4. The combustion grate according to one of the preceding claims, characterized in that

   - the air outlet openings (13) are arranged in the nozzle tubes (2) below a largest portion of a cross section (14) of the nozzle tubes and/or

   - the nozzle tubes (2) have a non-circular cross section, in particular a pentagonal cross section with an upward oriented tip (15) of the cross section.
5. The combustion grate according to one of the preceding claims, characterized in that

   - the nozzle tubes (2) include a radial protrusion (16) in an extension direction of the nozzle tubes at least at a location wherein the protrusion fits into a corresponding positioning recess (17) of the receiver element (6) and fixates the nozzle tube at one end in the longitudinal direction and/or against rotation relative to the receiver element (6) and/or

   - the nozzle tubes (2) are sealed relative to the receiver elements (6) by envelopment with a heat resistant seal tape (18).
6. The combustion grate according to one of the preceding claims, characterized in that

   - the receiver element bases and receiver element tops include at least as many recesses (22) as nozzle tubes (2) are provided, in particular more recesses and non-essential recesses (22) are sealed tight by plug elements (19), and/or

   - the receiver top element (6b) is fixated in a form locking manner in all horizontal directions in space by simple placement onto the receiver base (6a).
7. The combustion grate according to one of the preceding claims, characterized in that

   - the spacer includes a recess (20) where a protrusion (21) of a component arranged thereunder can engage in order to position the spacer element in a direction transversal to the longitudinal direction (2) of the nozzle tubes (2) and/or,

   - the spacer element (8) interlocks in a form locking manner in the receiver elements by insertion between the receiver elements (6) and protrudes in an upward direction beyond the gap between the receiver base element (6a) and the receiver top element (6b).
8. The combustion grate according to one of the preceding claims, characterized in that the receiver element (6) includes between the grate portions on both sides openings (22) for inserting nozzle tubes (2) when plural grate portions (3) are arranged adjacent to each other in a longitudinal direction of the nozzle tubes (2).

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