EP1300631B1 - Combustion apparatus - Google Patents

Abstract

The combustion unit (1) has a fire grate (2) on which solid fuel, particularly wood (10), is placed and a flue gas evacuation (5) from the main combustion chamber (3) above the grate downwards through the grate to a secondary combustion chamber (4). Beneath the fire grate, nozzle tubes (6) are arranged in the flue gas evacuation system, which have outlet apertures (7a,7b) in their wall and serve to feed secondary gas into the primary gas evacuation system. <??>The grate bars with their lateral ends locate individually loosely on the side claddings (13) of the flue gas evacuation system and with which the housing (11) is lined. The nozzle tubes preferably have a pentagonal cross-section, with one corner upwards, preferably in the form of a diamond and the outlet apertures (7a,7b) are arranged at the other corners of the cross-section.

Description

I. field of use

The invention relates to firing devices, in particular firing devices for solid fuel.

II. Technical background

There are known combustion devices in which the combustion of the fuel, such as logs, takes place on a grate. In the present case, the rust is not only the falling through of the ash, but also the burn, so the flue gas removal is carried out by the rust down a flue gas removal to a reheat chamber in the burned in a second combustion stage, the still fuel-containing flue gases from the main combustion chamber or after-burned.

For this purpose, it is known in the flue gas removal or in the secondary combustion chamber, the primary extracted from the main combustion flue gases secondary gas, ie either secondary air or secondary to the main combustion chamber removed flue gas to feed to improve the afterburning.

For example, the secondary gases are supplied via nozzle pipes, which deliver the secondary gas into the primary flue gas discharge or directly into the afterburner via a plurality of lateral outlet openings.

When burning the fuel on a grate, it was already known to use these nozzle pipes directly as a grate for placing the fuel.

The nozzle tubes are usually made of steel, usually high-alloy stainless steel, since these nozzle tubes must withstand frequent and severe temperature changes or non-standard fuels and yet should not be formed too thick-walled. In contrast, there is the lining of the combustion chamber and / or the space for the flue gas removal to Nachbrennraum out mostly incombustible materials such as fireclay or silicon carbide (SiC), which are made as moldings and then precisely the lining of the housing of the heater, which also made of sheet steel, casting or fireclay exists.

In these known combustion devices, it was found that despite the use of high-alloy steels for the nozzle tubes, these by the laying and burning of fuel, for. As wood, especially logs, very quickly corroded and burned, which is probably due to the direct contact with the still acidic, wet firewood.

As a result, then designed the replacement of the nozzle tubes, which are usually firmly connected to a distribution box for the secondary air, in particular welded, were, consuming and expensive, since this sometimes even the lining of the combustion chamber and the exhaust gas recirculation had to be expanded.

Furthermore, DE 19531821 shows a firing device in which nozzle tubes with outlet openings for secondary gas are arranged lower than the firing grid, but not in the area below the firing grid.

A nozzle function do not meet these feed pipes. III, Presentation of the invention a) Technical task

It is therefore an object of the present invention to provide a combustion device and a method for replacing the nozzle tubes in such a burning device available, which in spite of simple and inexpensive construction of the burner only a small wear and a ensures long life of the individual components and still allows easy replacement of these nozzle tubes during wear of the nozzle tubes.

b) Solution of the task

This object is solved by the features of claims 1 and 18. Advantageous embodiments will be apparent from the dependent claims.

It has been found that the service life of the nozzle pipes to be arranged in the flue gas discharge drastically increases, as long as they do not come into direct contact with the still unburned firewood. Therefore, a separate combustion grate is placed above the nozzle tubes, on which rests the firewood, and therefore wears relatively quickly.

For this reason, no one-piece grate is used, but individual grate bars are arranged side by side in the firing device by simply placing them in corresponding pockets of the side liners made of chamotte or silicon carbide or similar refractories. In addition, the grate bars are not used as a hollow material, but as solid bars with a comparatively large cross-section of, for example, more than 2 cm in diameter, in particular more than 3 cm in diameter, wherein the grate bars also made of a steel-iron material, preferably of cast iron, preferably made of heat-resistant cast steel.

The nozzle tubes are located below this grate and not in contact with this grate, wherein the nozzle tubes preferably like the grate bars also horizontally, but viewed in the plan view transverse to them, in order to achieve optimum mixing of the flue gases down through the grate. In addition, this flue gas discharge below the grate is designed by tapered side surfaces of the side linings tapering to Nachbrennraum towards to achieve a nozzle effect and thus a good mixing. For the same reason are those in the flow path the flue gases through the flue gas outlet nozzle tubes arranged equipped with a cross section which has at least over a portion of its cross section in the direction of flow of the primary flue gases of increasing cross section, the outlet openings for the secondary gas are arranged near or at the location of the greatest width of the cross section. As a result, narrowing gaps between the nozzle tubes are again formed in the direction of flow of the primary flue gases, and thus a nozzle effect which accelerates the flow of the primary flue gases and thereby sucks in the secondary gas from the outlet openings of the nozzle tubes into the primary flue gases.

Preferably, the nozzle tubes have a triangular or pentagonal or round cross-section with an upwardly directed tip, and therefore can be made very easily because they are open at both ends.

These nozzle tubes are not welded or otherwise firmly connected on the side of the supply of secondary air with a transversely across all nozzle tubes extending distribution box, which is usually also made of sheet steel, but only the front side inserted into corresponding through holes in a wall of this distribution box and are with her other end on or in a corresponding part of the front lining of the flue gas discharge, which also consists of incombustible material (fireclay or SiC) on.

By a positive connection of the nozzle tubes to this end lining and / or the distribution box slippage of the nozzle tubes, also due to the constant stretching and contraction during temperature changes, reliably avoided. In this way, the entire interior of the heater can very easily form-fitting and without further assembly work composed by - after inserting the junction box into the housing - first the side linings, especially in a groove or recess provided there, and on the oblique Inner surfaces of the side liners at the one end aufsitzendes, trapezoidal lower end lining part are simply inserted. Subsequently, the hang up the nozzle tubes with their one end on the lower end-lining part and then inserting the other end face in the corresponding passages of the junction box. Now only the one hand, the upper end lining part must be placed on the ends of the nozzle tubes and then the grate bars are placed across the nozzle tubes, which in turn engage positively with their ends in corresponding pockets of the side linings and thereby positively secured in position.

c) embodiments

Fig. 1:

eine Aufsicht auf die erfindungsgemäße Brennvorrichtung und

Fig. 2:

eine Frontansicht der Brennvorrichtung.

An embodiment according to the invention is described in more detail below by way of example. Show it:

Fig. 1:

a plan view of the inventive combustion device and

Fig. 2:

a front view of the burning device.

In Fig. 2, in particular the area of the flue gas removal 5 can be seen in its construction, which is limited at the upper end by the combustion grate 2, on which rests the wood 10 or other combustible material, and thus represents the main combustion chamber 3. Below the flue gas discharge, the flue gases pass into a secondary combustion chamber 4, in which the afterburning of these flue gases and their removal takes place to the chimney, which is not shown.

As can be seen, the combustion device is arranged in a housing 11 made of, for example, sheet steel, from the vertical side walls transverse walls freely so far inwardly projecting that then the side linings 13 can be placed with its underside, the free passage between the side liners for the flue gases However, is not hindered by the transverse walls of the housing 11.

The moldings of the side lining 13, which may be formed identical to the vertical center plane due to the symmetry of the entire combustion device, sitting obliquely down and to the longitudinal center plane approaching inner surface 17, whereby the cross section is reduced in the flue gas discharge to Nachbrennraum out and thus the desired Nozzle effect occurs.

As shown in FIG. 1, in the front region on this inclined inner surface 17, the trapezoidally shaped lower end lining part 14, which has recesses for partially inserting the cross section of the nozzle tubes 6 in its upper side. After inserting the nozzle tubes can be placed on this an upper end lining 15, which is also trapezoidal shaped, which has been removed for the illustration of FIG. 1 in order to better recognize the position of the nozzle tubes 6 can.

At the upper end of the inclined inner surface 17 and / or at the transition to the upper end face of the side liners 13 have these inwardly and upwardly facing open pockets 16 for receiving the transverse, from one to the other side liner 13 extending, individual grate bars 2a, b, c. ., Which thus extend at a distance above the nozzle tubes 6. The nozzle tubes 6 are approximately halfway up the flue gas discharge.

The pockets 16 are also adapted to the cross-sectional shape of the grate bars 2a, b, which preferably have an L-shaped with the top pointing down and rounded top cross-section. Preferably, as can be seen in the plan view of FIG. 1, the pockets 16 are arranged at a smaller distance or partially overlapping each other than the thickness of the grate bars 2a, b, c .. in order not only to grate the grate bars predetermined, but to be able to arrange in a gradually selectable distance to each other, depending on the size of the parts of the fuel.

The nozzle tubes 6 are with their other, facing away from the frontal lining, end in the through holes of a wall of the over all nozzle tubes from one to the other side wall of the housing 11 preferably continuous, hollow distribution box 9 made of sheet steel, in the z. B. from an end face into an access opening 19, the desired secondary gas is supplied and from there flows into the open end faces of the projecting into the distribution box 9 nozzle tubes. From there, it is passed over the existing on both longitudinal edges of the nozzle tubes 6 outlet openings 7a, b and flows out of these into the flue gas outlet 5 of the primary flue gas. An outflow through the opposite, lining-side open end face of the nozzle tubes is almost completely avoided by these rest with their front side on the local housing wall on the inside

The outlet openings 7a, b are arranged on the two sides of the nozzle tubes, which have a cross-section in the form of an upright pointing with the top-facing diamond, at the two opposite and furthest points of the cross section and in the longitudinal direction of the nozzle tubes. 6 offset from one another such that in the region of an outlet opening z. B. 7a on the one hand on the opposite side just a gap between two outlet openings 7b is present. The gaps are preferably about as long as the outlet openings in the direction of the nozzle tubes. 6

In order to prevent a displacement of the nozzle tubes 6 in the device in its longitudinal direction, a nose 12 may be bent, for example, down at the lining-side end of the nozzle tube, which then into a corresponding recess 18 in z. B. engages the lower end-lining part 14. As a result, movement of the nozzle tube 6 in the direction of the distribution box 9 is avoided. Also, the nose 12 and the corresponding recess 18 in the lower end lining 14 set back from the end face in the central region of the Stirnauskleidungsteiles 14 may be present as a blind hole or slot, whereby movement in both directions is prevented, even if the nozzle tube at a distance in front of the housing wall ends.

Fig. 1 shows that the nozzle tubes 6 only as small as possible protrude into the interior of the distribution box 9 in order to disassemble the nozzle tubes in Wear case does not have to take out the entire distribution box, but - after lifting the grate bars 2a and the upper end lining 15 - raise the nozzle tubes 6 at the lining-side end something and then be able to pull out of the distribution box 9.

2, it is also clear that the recesses for receiving the cross-section of the nozzle tubes 6, which are shown in FIG. 2 in the contact region between the upper and lower end lining 14, 15 in both lining parts, formed only in one of the two lining parts can be provided that the nozzle tubes 6 have a cross section which increases steadily from top to bottom.

LIST OF REFERENCE NUMBERS

1

burning device

2

burning rust

2a, b

Stainless rod

3

Main combustion chamber

4

secondary combustion

5

Flue gas extraction

6

nozzle tube

7a, b

outlet opening

8th

secondary gas

9

distribution box

9a, b

breakthrough

10

Wood

11

casing

12.12 '

nose

13

Side liner

14

Lower forehead lining

15

Upper forehead lining

16

bag

17

palm

18

recess

19

access opening

Claims (17)

1. A Combustion device (1) comprising

   - a combustion grate (2) for depositing a solid fuel, wood (10) in particular,

   - a flue gas extraction (5) from the main combustion chamber (3) above the combustion grate (2) through the combustion grate (2) downward into an after combustion chamber (4), wherein

   - below the combustion grate (2) expansion tubes (6) are located in the flue gas extraction (5), having exhaust orifices (7a,b..) in their walls for supplying secondary gas (8) into the primary flue gas extraction (5),

   characterized in, that
   the grate rods (2a, b) rest with their lateral ends, one by one, in a loose manner on the side fairings (13) of the flue gas extraction, lining the housing (11), and
   the expansion tubes (6) are spaced below the combustion grate (2) perpendicular to the direction of the grate rods (2a,b).
2. Combustion device according to one of the preceding claims,
   characterized in, that
   the expansion tubes (6) rest, one by one, in a loose manner, with one end on a front fairing, in particular the lower front fairing (14) of the flue gas extraction, and with the other end, one by one, in a loose manner, in the openings (9a) of a distributor box (9) for the secondary gas (8), placed over all expansion tubes in a perpendicular manner.
3. Combustion device according to one of the preceding claims,
   characterized in, that
   at the end, adjacent to the fairing, an upper front fairing (15) is placed over all expansion tubes (6) and the upper and lower front fairings (14, 15) are shaped in their contact surface, so that openings corresponding to the outer contour of the expansion tubes (6) are created.
4. Combustion device according to one of the preceding claims,
   characterized in, that
   the grate rods (2) are made from solid metal, cast material in particular, in particular heat resistant cast steel.
5. Combustion device according to one of the preceding claims,
   characterized in, that
   the side fairings (13), in the state, when installed in their housing (11), have a slant towards the middle of the flu gas extraction (5) from the combustion grate (2) downward with their interior surfaces (7), so that the space of the flue gas extraction decreases with increasing distance from the combustion grate (2).
6. Combustion device according to one of the preceding claims,
   characterized in, that
   the grate rods (2) rest with their ends in pockets (16) in the upper area of the side fairings (13), in particular in the upper area of the interior surfaces (17) of the side fairings in a flush manner, and in particular in the side fairings (13) the pockets (16) are spaced at a smaller distance behind each other, than corresponding to the width of the grate rods (2a,b), so that through inserting into different pockets, the distance of the grate rods (2a,b..) between each other can be changed in increments.
7. Combustion device according to one of the preceding claims,
   characterized in, that
   the expansion tubes (6) in their assembled state, extending preferably in a horizontal or slightly rising manner, have at least in a partial area from the upper end downwards an expanding cross section with lateral exhaust openings (7a,b) on both sides in their walls, preferably in the area of the maximum width of the expansion tubes (6).
8. Combustion device according to one of the preceding claims,
   characterized in, that
   the expansion tubes (6) preferably have a pentagonal cross section with one edge pointing upward, preferably shaped like a diamond, having exhaust openings (7a, b) at the outer edges of the cross section.
9. Combustion device according to one of the preceding claims,
   characterized in, that
   the exhaust openings (7a, b) along the longitudinal outer edges of the expansion tubes (6) are spaced in an equidistant manner, and in particular the length of the exhaust openings (7), seen in longitudinal direction of the expansion tubes (6) corresponds to the length of the distances between the exhaust openings (7).
10. Combustion device according to one of the preceding claims,
    characterized in, that
    in the expansion tubes (6) the exhaust openings of one longitudinal edge are located in longitudinal direction relative to the exhaust openings (7b) of the other longitudinal edge, so that in the longitudinal area of the gaps between the exhaust openings of the one side exhaust openings exist on the other side.
11. Combustion device according to one of the preceding claims,
    characterized in, that
    the expansion tubes (6) have at least one nose (12) protruding beyond the outer circumference of the expansion tube (6) at their end facing the fairing, and the front fairing, in particular the lower front fairing (14) has a groove (18) for the nose (12) in the respective position, in particular in the frontal end of the fairing (14), on the face pointing away from the flue gas extraction (5), or in a top view in the interior of the side fairing (14).
12. Combustion device according to one of the preceding claims,
    characterized in, that
    the expansion tubes (6) are open at both faces.
13. Combustion device according to one of the preceding claims,
    characterized in, that
    the fairing parts in particular the side fairing (13), the lower and the upper front fairing (14, 15) are made from chamotte, or silicone carbide (SiC), or cast steel as a shaped parts, in particular as a sintered shaped part.
14. Combustion device according to one of the preceding claims,
    characterized in, that
    the fairing parts (13, 14, 15), the particular grate rods (2a, b,..), the particular expansion tubes (6), and the distributor box (9) are assembled exclusively in a flush manner.
15. Combustion device according to one of the preceding claims,
    characterized in, that
    the front fairing (14, 15) rests in a groove or gap of the side fairing (13) with its front faces.
16. A process for replacing the expansions tubes of a combustion device, in particular according to one of the preceding device claims,
    characterized in, that

    • after removing the grate rods (2a,b..) and the upper front fairing, resting on the expansion tubes (6), the particular expansion tubes (6) are pushed towards the wall of the housing facing the fairing, until they are flush,

    • thereby they are disengaged from the distributor box (9) with their opposite ends,

    • they can be raised beyond the box (9) with this box sided end and extracted from the combustion device upward at oblique angle, in particular without removing the distributor box (9) and/or without tools.
17. A process according to claim (18)
    characterized in that,
    before displacing the expansion tubes (6) in longitudinal direction, the fairing side end of the respective expansion tube has to be raised far enough, so that a nose (12) of the expansion tube (6) is disengaged from the respective groove (18) in the lower front fairing (14).

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