EP0674134B1 - Combustion method for pulverous materials - Google Patents

Abstract

An assembly to incinerate contaminated dust has an incineration chamber (2) with an inlet (4) for the material to be destroyed, and an outlet (6) for the incineration product gases. Primary combustion air (P) is introduced to the chamber through another inlet (12) located close to the first. Secondary combustion air (S) is introduced to the chamber through a third inlet (14) located close to the incineration gas discharge outlet. The secondary air is directed against the oncoming flow of dust from the first inlet. The third inlet imparts a twisting vortex flow-motion to the secondary air, which rotates about an axis (8) running between the dust inlet and the incineration gas outlet. The incinerator outlet discharges from the incinerator to an afterburner zone (32) with an inlet (34) for tertiary air (T). The secondary air inlet has a blower-ring (22) surrounding the gas outlet (6) whose inner (24) surface widens conically and incorporates a number of air inlet slits (26). The slits extend from the external circumference (28) to the inner surface and pass secondary air, generating the vortex motion within the incineration chamber.

Description

The present invention relates to a method for burning of dusty materials, especially with Activated coke dust contaminated with pollutants from filter systems, Sewage sludge dust and the like.

Today there are materials in many areas that are very heavily contaminated with extremely harmful toxins. This is the case, for example, with sewage sludge from sewage treatment plants, but also especially with filter plants in which pollutants are separated by activated carbon adsorbers. Such activated carbon adsorbers are used in the separation of nitrogen oxides (NO _x ; so-called denitrification), sulfur oxides (SO _x ), dusts, hydrocarbons and even dioxins and furans. With NO _x , SO _x and dusts, they are often used as "police filters" behind other types of separating devices (eg catalytic converters or electrical separators). Hard coal active coke (SAK) is generally used for denitrification, while brown coal coke (hearth furnace active coke HOK) is generally used for the other substances or compounds. For PCB, PCT, dioxins and furans, which occur mainly in flue gases from waste incineration plants, such activated coke filters are currently the only safe separation option. Because the partially extremely low pollutant limit values stipulated by legal provisions (in particular the Federal Immission Control Act) can hardly be achieved by firing technology alone. For dioxins and furans in particular, emission limit values of <0.1 ng / m ³ must be observed. There are also similarly low limit values for other pollutants (e.g. heavy metals, polychlorinated biphenyls (PCB), polychlorinated terphenyls (PCT) as precursors of dioxins and furans).

Now, of course, the disposal of those with pollutants contaminated materials is a major problem safe destruction of toxic substances and compounds Usually only combustion is possible, however require some pollutants, such as in particular Dioxins, combustion conditions that have not yet existed or can only be managed with extremely great technical effort are. So is to destroy harmful organic Compounds a combustion temperature of anyway more than 850 ° C with a dwell time of at least two seconds required. The legislator is asking Hazardous waste incineration plants even a temperature level of over 1200 ° C with a two-second dwell time.

A procedure for burning rod-shaped materials from DE-B-1 024 191 known. This document describes "cyclone firing" where a fuel (fuel dust) air mixture via inlet slots with twist (rotary movement) in a cyclone muffle is introduced. Combustion air is also produced via slots (Primary air) also introduced with swirl, namely with same direction of rotation as the fuel-air mixture. On the Side of the opposite outlet opening are outlet slots arranged for secondary air (secondary air) in such a way that the secondary air also flows in with swirl, and indeed in the opposite of the fuel-air mixture Direction of the opposite inlet and either with the same or with the opposite direction of rotation as that Air-fuel mixture. With this configuration the Known furnace is said to improve combustion through more complete contact with the fuel Air can be reached, however, is the special problem the combustion of special pollutants contaminated substances (dusts) not addressed.

EP-A-0 409 037 describes a different combustion chamber in that than doing no counterflow of primary and Secondary air, but only rectified, moving towards of an output described swirling flows are. In addition, this publication is also not concerned with the special problem of thermal destruction of Pollutants. This publication describes one initially substoichiometric combustion with primary and Secondary air and a subsequent complete combustion by means of excess air achieved by tertiary air, however, the substoichiometric combustion must according to the overall disclosure of this document with an extremely serious lack of air (λ << 1) because the temperature is "below the ash softening point" should remain below 1100 ° C.

It is therefore a relatively lower temperature than in the subsequent complete combustion.

The present invention is based on the object Process for burning such to create contaminated materials, with which also with a constructive simple and compact device construction special, necessary for the safe destruction of pollutants Combustion conditions easily manageable are. It should preferably also a continuous material throughput be possible, so that an economical operation in particular possible in direct combination with such facilities in which the contaminated materials occur.

According to the invention, this is achieved by a method with the features of claim 1 or claim 3 reached. Advantageous developments of the invention are in the each contain dependent claims.

A suitable combustion device has one Combustion chamber with a one-sided inlet opening for the burning material and one opposite the inlet opening Exhaust port for through combustion resulting smoke gases, whereby in the area of the inlet opening a device for introducing yourself to the burning, dusty material mixing primary air and a device in the area of the outlet opening are provided for introducing secondary air such that the secondary air on the one hand counteracts the primary air Flows in the direction of the inlet opening and on the other hand in a swirl flow around an inlet and outlet opening extending combustion chamber axis is offset. According to the Invention connects to the outlet opening a post-combustion zone to which - in addition to the primary and secondary air - tertiary air is introduced.

The arrangement of the inlet opening and - in the direction of flow or seen in the throughput direction - opposite Exhaust opening with subsequent post-combustion zone enabled a continuous, continuous combustion process, but due to the division of the Combustion air and the counter-swirl flow of the Secondary air is the dwell time of the material or the dust-air mixture is long enough, especially because of very intensive swirling and mixing, i.e. through education one practically homogeneous over the entire firing distance Mixture, an extraordinarily high firing temperature of 1200 ° to 2000 ° C or even higher can be achieved. The increase in the residence time leads to the advantage that the combustion chamber is relatively short and therefore the Overall, the device is very compact can be.

The combustion can advantageously be carried out by metering Supply of primary, secondary and tertiary air like this control that overall at least approximately a stoichiometric Combustion is achieved. This means that the so-called excess air number λ at least approximately the same 1 is. For security reasons - to always be complete To be able to ensure combustion - lies λ according to the invention on the order of about 1.02. This extremely small excess air is of decisive advantage in that as a fire temperature drop due to too big Excess air is avoided, i.e. the firing temperature can be kept very high and permanent. It is complete combustion with thermal destruction of all pollutants occurring in practice, in particular also of dioxins. In this context the term "complete combustion" means that by the invention in the flue gas only an extraordinary low percentage of unburned substances, namely <0.1% is included. The one usually required here The limit value of a maximum of 5% unburned is therefore advantageously far below. Furthermore, the preferred near-stoichiometric combustion also a new formation of dioxins and the like advantageously avoided because of such reactions because of the low Air excess of around 2% in particular is not enough Oxygen is available.

Due to the turbulence according to the invention and the achieved with it Homogeneity of the dust-air mixture also becomes also achieved a very stable flame (flame stabilization), i.e. "Tearing off" the flame is advantageous avoided. Therefore, it is advantageously sufficient a so-called ignition and Arrange support torch, which is usually only for the first time Igniting the combustion "turns on" then but be switched off during further operation can, because the combustion stabilizes itself. Indeed it can be advantageous to use the pilot and auxiliary burner automatically controlled by a controller so that in the event an irregularity of those running within the combustion chamber Burning the pilot and auxiliary burners automatically is switched on for a certain time.

Through the tertiary air supplied in the afterburning zone can be substoichiometric according to the invention within the combustion chamber are burned, then a total of i.e. by primary, secondary and tertiary air, preferably achieved an approximately stoichiometric combustion with λ ≈ 1.02 becomes. The substoichiometric combustion in the Combustion chamber leads to a higher combustion temperature and thereby an even safer removal of the pollutants, especially dioxins. The by feeding Post-combustion caused by tertiary air practically leads to a completion of the combustion such that overall achieved the intended complete combustion becomes.

But it should be mentioned at this point that according to the invention basically also overall stoichiometric, e.g. with λ ≈ 1.9, can be burned, for example if a lower temperature e.g. reached about 1200 ° C shall be. But it also becomes a very stable combustion due to the homogeneity of the mixture reached.

It is also particularly advantageous if the primary air too is set in a swirl flow, the swirl directions of primary air and secondary air opposed to each other are directed. Preferably, too Tertiary air swirled; are here then the swirl directions of secondary air and tertiary air facing each other. In this preferred embodiment it is thus a "multi-stage counter-swirl burner". Especially in this embodiment, the residence time spectrum of the material to be burned increased significantly.

This is practically completely homogeneous over the entire firing path Dust-air mixture can be almost without excess air (λ = 1) be burned. It is noteworthy that a Control range of 1:20 can be achieved without that Influencing stability of the flame. This means that optimal, complete combustion over a control range guaranteed from full load to 1/20 of full load can be. For example, the device is for 1000 kg Designed for full load, even at 1/20, i.e. 50 kg, a complete, optimal combustion can be achieved, even at a temperature of around 1800 ° C.

Further advantageous design features of the invention are explained in more detail in the following description become.

Fig. 1

einen Längsschnitt durch eine Verbrenn-Vorrichtung in einer ersten Ausführungsform,

Fig. 2

eine Teilansicht in Pfeilrichtung II gemäß Fig. 1 (vgl. auch Fig. 4),

Fig. 3

eine Teilansicht in Pfeilrichtung III gemäß Fig. 1 (vgl. auch Fig. 4),

Fig. 4

einen Längsschnitt analog zu Fig. 1, jedoch in einer besonders vorteilhaften Weiterbildung der Vorrichtung,

Fig. 5

einen Teilbereich der Vorrichtung im Querschnitt in der Schnittebene V-V gemäß Fig. 4,

Fig. 6

eine vereinfachte Prinzipdarstellung einer mit der erfindungsgemäßarbeitenden Vorrichtung ausgestatteten Müllverbrennunganlage und

Fig. 7

eine blockschaltbildartige Darstellung der Vorrichtung mit dieser vorgeordneten Zusatzkomponenten zur Aufbereitung und zum Transport des zu verbrennenden Materials.

The invention will be explained in more detail below with reference to preferred exemplary embodiments and application examples of a device suitable according to the invention, which are illustrated in the drawing. Show:

Fig. 1

2 shows a longitudinal section through a combustion device in a first embodiment,

Fig. 2

2 shows a partial view in the direction of arrow II according to FIG. 1 (cf. also FIG. 4),

Fig. 3

2 shows a partial view in the direction of arrow III according to FIG. 1 (cf. also FIG. 4),

Fig. 4

2 shows a longitudinal section analogous to FIG. 1, but in a particularly advantageous development of the device,

Fig. 5

4 shows a partial area of the device in cross section in the sectional plane VV according to FIG. 4,

Fig. 6

a simplified schematic diagram of a waste incineration plant equipped with the device according to the invention and

Fig. 7

a block diagram representation of the device with this upstream additional components for processing and transporting the material to be burned.

The same in the different figures of the drawing Parts always have the same reference numerals so that any description of a Partly analogous with regard to the other drawing figures applies, in which this part with the corresponding reference numerals can also be seen.

1, there is one Device 1 for burning dust Materials mainly from a combustion chamber 2 with a one-sided inlet opening 4 for the material to be burned and also for supplied combustion air as well as with a the inlet opening 4 opposite in the throughput direction Outlet opening 6 for combustion Flue gases. The inlet and outlet openings 4, 6 are preferred arranged coaxially to each other, i.e. a combustion chamber axis 8 runs in particular centrally through the Inlet and outlet openings 4, 6.

The material to be burned is in dust form, i.e. in ground state, supplied via a pipeline 10, this pipeline 10 in the area of the inlet opening 4 flows. For the purpose of transporting the dusty This material is a certain percentage of air attached so that a dust-air mixture is already from the pipe 10 exit. However, this mixture becomes additional Combustion air supplied.

The combustion air is initially in primary air P and Secondary air S divided, in the area of the inlet opening 4 a device 12 for introducing the primary air P and material to be burned in the area of the outlet opening 6 a device 14 for Introducing the secondary air S are provided such that the secondary air S on the one hand the primary air P or the resulting dust-air mixture in Direction of the inlet opening 4 flows and on the other hand in a swirl flow around the combustion chamber axis 8 becomes. Through this in Fig. 1 and also in Fig.4 using Flow lines illustrated swirl flow of the secondary air S will increase the residence time of the flammable Mixtures reached within the combustion chamber 2 as well such an intense swirling and mixing that a almost homogeneous fuel mixture is generated. Result from this optimal combustion conditions.

In the embodiment according to FIG. 1, the device is 12 to introduce the primary air P only in the form of a short, preferably cylindrical, the inlet opening at the same time 4 tube piece 16 formed such that the primary air P with the entrainment of the combustion Material initially essentially straight, i.e. as approximately homogeneous flow, through the inlet opening 4 in the direction the outlet opening 6 is blown. Within the Combustion chamber 2, the fuel mixture is then the opposite Swirl flow of the secondary air S intensive swirled.

In the case of the particularly advantageous embodiment according to 4 is the device 12 for insertion the primary air P is formed such that the primary air P taking the material to be burned on the one hand the secondary air S in the direction of the outlet opening 6 flows and on the other hand also in a swirl flow is displaced about the combustion chamber axis 8. Here is the swirl direction of the primary air P or of the dust-air mixture the swirl direction of the secondary air S opposite. Through this particularly advantageous measure becomes an extraordinarily intensive mixing and therefore achieved a practically absolutely homogeneous firing mixture. This results in thermal destruction sufficiently long dwell time of pollutants as well as a extraordinarily high combustion temperature of anyway more than 1200 °, especially about 1800 to 2000 ° C. It can a practically stoichiometric combustion with one extremely small excess air (λ ≈ 1.02) reached become.

4 and 5, is to generate the Swirl flow of the primary air P, i.e. as a device 12 for Introducing the primary air P within the inlet opening 4 a swirl flap device 18 with in particular for changing the swirl inclination-adjustable swirl flaps 20 are arranged. This swirl flap device 18 is in the manner of a Turbine wheel or an axial fan, wherein the swirl flaps over the circumference of the inlet opening 4 evenly spaced around radial axes are in particular continuously pivotable, namely between an axially aligned arrangement and one approximately vertical arrangement, the opening 4 then almost closed is. This can also have a certain Regulation of the air volume can be achieved. In any case serves the swirl flap device 18 for the variability of Swirl effect or swirl intensity of the primary air-dust mixture.

In both embodiments according to FIGS. 1 and 4 there is Device 14 for introducing the secondary air S essentially from a surrounding or the outlet opening 6 to the outlet opening 6 concentric blowing ring 22, the one expanding conically in the direction of the combustion chamber 2 Inner surface 24 and several arranged distributed over the circumference Has louvers 26. These louvers 26 extend from the outer circumference 28 of the blowing ring 22 to to the inner surface 24 and are oriented such that the secondary air S supplied from the outside through the louvers 26 flows and thereby into the combustion chamber 2 directed swirl flow is offset. How in particular 2, the blowing ring 22 is expedient formed by several individual ring elements 30, which each form the louvers 26 between them or limit. These ring elements 30 are Positioning means not described in detail in their position fixed or clamped. The blowing ring is preferably made 22 from about twenty-four individual elements, so that also a total of twenty four louvers in one the scope is evenly distributed. The Number of ring elements 30 or the louvers 26 can however vary widely, depending on the Interpretation of the burner output and the respectively required Air volume.

In this regard, it is particularly advantageous if the Louvers 26 of the blowing ring 22 in terms of their effective flow cross-section formed in such a nozzle-like manner are that the outside with a certain, i.e. by that required for complete combustion at λ ≈ 1 Air volume specified, inlet pressure supplied secondary air S through the narrowed louvers 26 one such high flow rate maintains that it penetrates of fuels in the louvers 26 prevented. Thus, self-cleaning is advantageously practical or self-maintenance of the louvers 26 achieved by the injected secondary air S.

In the illustrated embodiments is a "tripartite division" of the total combustion air required provided by in addition to primary and Secondary air P, S still tertiary air T is supplied. Conveniently for this purpose connects to the outlet opening 6 in the direction facing away from the combustion chamber 2 is a post-combustion zone 32 with a device 34 for feeding the Tertiary air T on. Here the combustion takes place within the combustion chamber 2 sub-stoichiometric with an excess air number or "lack of air" λ <1. It becomes thereby a particularly high temperature to absolute safe destruction of pollutants, especially dioxins, reached. A completion of the combustion then takes place in the afterburning zone 32 Supply of the tertiary air T, the tertiary air T with a volume per unit time is supplied that preferably the overall combustion is approximately stoichiometric (λ about 1.02). Of course, could also with higher excess air e.g. λ ≈ 1.9 are driven, taking advantage of good and stable combustion remains.

As can now be seen from Figs. 3 reveals the device 34 for supplying the tertiary air T is such trained that the tertiary air T on the one hand in the the combustion chamber 2 opposite direction of the post-combustion zone 32 flows, but on the other hand also in a swirl flow is displaced, whereby the dwell time within the post-combustion zone 32 is increased. According to the invention are the swirl directions of tertiary air and secondary air opposed to each other. This will make a repeat Mixing and swirling of the fuel mixture reached. The device 34 also expediently exists for supplying the tertiary air T from a to the outlet opening 6 concentric blowing ring 36, which in its constructive Design basically that for the secondary air S provided blowing ring 22 corresponds, so that on this For the sake of simplicity, refer to the above explanations is referred. To this end, the same or functional corresponding parts with the same reference numerals. Of particular note, however, is that the conical inner surface 24 of the blowing ring 36 into the Combustion chamber 2 extends in the opposite direction. Also are the air slots 26 are also formed in the blowing ring 36, that the tertiary air T has such a high flow rate maintains that it penetrates substances effectively prevented from the flue gases. As tertiary air T cold fresh air is expediently used (with Outside or ambient temperature).

In contrast, the primary air P and preferably also the secondary air S before it is introduced into the combustion chamber 2 expediently heated. For this it is advantageous if the combustion chamber 2 is delimited by a chamber wall 38 , which in turn is enclosed by an outer jacket 40 in this way is that between the chamber wall 38 and the Sheath 40 a cavity enclosing the chamber wall 38 42 is formed. In this cavity 42 opens into one of the Outlet opening 6 near area an air inlet 44, and the cavity 42 goes on that facing away from the outlet opening 6 Side in the inlet opening 4 over. It is preferred within the cavity 42 between the chamber wall 38 and the outer jacket 40 a helical extending partition 46 arranged such that the Air supplied via the air inlet 44 to the chamber wall 38 flows around helically in the direction of the inlet opening 4. This ensures good and effective heat absorption or heat transfer from the combustion chamber 2 via the Chamber wall 38 reached on the air (heat exchanger). This also contributes to the fact that within the combustion chamber 2 very high firing temperatures can be achieved. At the same time the chamber wall 38 is advantageously cooled. The air preferably flows completely at least twice around the chamber wall 38, i.e. it is a flow of at least 2 x 360 ° = 720 °.

As is common practice with the Device 1 the combustion chamber 2 with an inner jacket 48 lined with a refractory material. The for this are commonly used refractory materials however only up to an average temperature of about Resistant at 1600 ° C. Therefore, it is due to the very high Combustion chamber temperatures of up to 2000 ° C are particularly advantageous, if between the chamber wall 38 and the refractory Inner jacket 48 a cavity enclosing the latter 50 formed for a cooling medium cooling the inner jacket 48 is. It is then particularly advantageous if the secondary air S is used as the cooling medium, for which purpose preferably the via the air inlet 44 and between the Chamber wall 38 and the outer shell 40 formed hollow Air 42 supplied in the room is in front of inlet opening 4. divided the area into the primary air P and the secondary air S. becomes. The secondary air S then flows through the Coolant cavity 50 towards that at the outlet opening 6 arranged feed device 14. Appropriately the coolant cavity 50 directly into the blow ring 22 enclosing annular chamber 52, from which the Secondary air S flows through the air slots 26. By this particularly advantageous measure is therefore on the one hand effective cooling of the inner jacket 48 achieved, on the other hand the secondary air S is heated up at the same time.

As can now also be seen from FIGS. 1 and 4, in Area of the inlet opening 4, in particular with light oil Ignition and support burner 54 to be operated Burner 54 is used on the one hand for the first ignition in start-up mode the combustion device 1. Once a regular combustion inside the combustion chamber 2 is reached, this burner 54 can be switched off become. On the other hand, the pilot and auxiliary burner 54, preferably controlled automatically by a controller, that in the event of an irregularity within the Combustion chamber 2 running combustion of the pilot and auxiliary burners 54 automatically switched on for a certain time becomes. For this function it has the burner 54 switching control for monitoring the one hand in the Combustion chamber 2 running combustion and on the other hand the Flame of the burner 54, in particular photocells or the same sensors.

6 is a particularly advantageous application of the Device 1 illustrates. Here the combustion chamber 2 is thus directly on a combustion boiler 56 in particular a waste incineration plant arranged that exiting through the outlet opening 6 Flue gases directly into the combustion chamber 58 of the combustion boiler 56 can be initiated. This is preferably Arrangement of device 1 on the combustion boiler 56 chosen such that the flue gases in one Enter the area of the combustion chamber 58 in which one Operating temperature ≥ 1200 ° C. This is advantageous undercooling the combustion chamber flame Edge influences and streak formation in the firebox are excluded. In this application, the Device 1 in particular for burning the in the Waste incineration system of activated coke, advantageously a steady throughput, i.e. a steady Disposal is possible. It also provides thermal support the one running inside the combustion boiler 56 Combustion reached. That from the Device 1 originating flue gas is then together with the Flue gases from a conventional incinerator Flue gas cleaning supplied.

7, the combustion chamber 2 is a processing device 60 upstream for the material to be burned, which in particular from a grinding device 62 and transport devices 64 exists. In detail, the one that arises Activated coke from an intermediate silo 66 via a pneumatic one Conveyor system 64a in particular with nitrogen to the Grinding device 62 promoted and there for a secured Burning down the necessary fineness. Of the Ground coke dust is then passed through a rotary valve 64b carried out and further by means of the combustion air dosed fed. Each unit is separate advantageously designed to have a maximum Active coke can be disposed of continuously. This means, that each combustion boiler with its own combustion device is equipped so that by this Amount of activated coke directly in the boiler can be disposed of again.

However, it is an alternative to this preferred application also possible, which via the outlet opening 6 from the Device 1 escaping smoke in particular via a flue gas cooling system ("Quenche") Feed flue gas cleaning (flue gas scrubber).

Claims (6)

1. Process for the combustion of powdered materials using an apparatus, which has a combustion chamber (2) having a unilateral inlet opening (4) for the material to be burned and an outlet opening (6) opposite the inlet opening (4) for flue gases produced by the combustion, an arrangement (12) being provided in the area of the inlet opening (4) for the introduction of primary air (P) mixing with the material to be burned, and an arrangement (14) being provided in the area of the outlet opening (6) for the introduction of secondary air (S) in such a way that the secondary air (S) on the one hand flows counter to the primary air (P) in the direction of the inlet opening (4), and in so doing is, on the other hand, turned into a swirled flow about a combustion chamber axis (8) running through inlet and outlet opening (4, 6), a post-combustion zone (32) with an arrangement (34) for the feeding of tertiary air (T) adjoining the outlet opening (6) in the outlet direction of the flue gases loading from the combustion chamber (2), the combustion inside the combustion chamber (2) occurring sub-stoichiometrically with λ < 1 in such a way that an increased combustion temperature of at least approximately 1200°C is attained for the removal of pollutants such as dioxins, and further tertiary air (T) being fed into the post-combustion zone (32) with a volume per unit time such that the combustion, on the whole, occurs approximately stoichiometrically with λ ≥ 1.
2. Process according to claim 1, characterised in that, on the whole, approximately stoichiometric combustion occurs with λ = 1 to 1.05, especially approximately λ = 1.02.
3. Process for the combustion of powdered materials using an apparatus, which has a combustion chamber (2) having a unilateral inlet opening (4) for the material to be burned and an outlet opening (6) opposite the inlet opening (4) for flue gases produced by the combustion, an arrangement (12) being provided in the area of the inlet opening (4) for the introduction of primary air (P) mixing with the material to be burned, and an arrangement (14) being provided in the area of the outlet opening (6) for the introduction of secondary air (S) in such a way that the secondary air (S) on the one hand flows counter to the primary air (P) in the direction of the inlet opening (4), and in so doing is, on the other hand, turned into a swirled flow about a combustion chamber axis (8) running through inlet and outlet opening (4, 6), a post-combustion zone (32) with en arrangement (34) for the feeding of tertiary air (T) adjoining the outlet opening (6) in the outlet direction of the flue gases leading from the combustion chamber (2), the combustion inside the combustion chamber (2) occurring sub-stoichiometrically with λ < 1 in such a way that an increased combustion temperature of at least approximately 1200°C is attained for the removal of pollutants such as dioxins, and further tertiary air (T) being fed into the post-combustion zone (32) with a volume per unit time such that the combustion, on the whole, occurs superstoichiometrically with λ up to approximately 1.9.
4. Process according to one of claims 1 to 3, characterised in that the combustion inside the combustion chamber (2) occurs in a temperature range from 1800°C to 2000° or higher.
5. Process according to one of claims 1 to 4, characterised in that cold, fresh air is used as tertiary air (T).
6. Process according to one of claims 1 to 5, characterised in that the primary air (P) and preferably also the secondary air (S) are heated before introduction into the combustion chamber (2).

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