EP0581918B1 - Process for melting down combustion residues in slag - Google Patents

Abstract

Instead of burning rubbish completely up, which has long been the aim, the material to be processed is first merely carbonised in a low temperature unit (2) and then, with the addition of carbonising agents or gases, taken to a high temperature unit (7) to reach the temperature needed to melt the slag and achieve complete combustion. It is thus possible that foreign substances (heavy metals) are absorbed in the slag and bind permanently therein. Concerning the equipment, the original, conventional combustion region is replaced by a generator for combustible carbonising gases so that, instead of being burned, the material introduced is merely gasified. Gasification or carbonisation may be controlled in any manner. The residues from the carbonisation process contain more combustion energy than the ordinary burned residues and may be subjected to a slag liquefaction process in the high temperature unit; a rotary kiln is proposed there. The end product is a completely burned, liquefied slag which may be allowed to set in any shape.

Description

The invention relates to a method and a device for degassing, Gasification, burning and melting of waste as well as melting of solid residues, for example from domestic waste incineration plants using garbage as an energy source.

The fly ash, filter cake and slag from conventional waste incineration plants today contains, in addition to unburned carbon, washable Heavy metal compounds and organic hydrocarbons. The legislation is now increasingly moving around the world, striking reductions to prescribe the amount of such pollutants (in a relatively short time), so reduce the eco-toxic potential of the slags and safe storage and / or to make use of the width. In parallel, the Requirements for other solid residues (airborne dust and RGR residues) just as aggravated; Residues that are no longer used should be able to be processed into as inert residues as possible.

As a rule, at least one tries today by reducing the volume The spatial extent of the unusable components is the final one Rest of the whole effort to encounter unavoidable landfills to keep it as small as possible. For highly toxic residues is one space-intensive, environmentally safe residual landfill very expensive, especially if if legal requirements regarding long-term security are met must become.

So far, it is not in the usual grate furnaces for household waste possible to carry out the combustion at such a high temperature aside from unwanted local heating that during combustion also a process-related melting of the combustion slag for the permanent integration of heavy metals and burning out of organic, highly toxic connections could be made. It would based on current experience with liquefaction of slag during combustion the grates would stick or the liquefied slag would get through the Rust crevices flow. In other words, neither the combustion process known today the systems in service are still suitable for such a Action. In the few plants that consist of a combination of grate firing and rotary tube, there has been melting of the slags so far also not possible, as usually the most possible in the firing zone total incineration of the waste is sought and also takes place and in Rotary tube therefore no longer has enough combustion energy to melt down the slag is available. Apart from that, they have rotary kilns not the required properties and facilities for deduction the molten slag. Such rotary kilns serve the purpose only the complete burning out of the slag. With hazardous waste disposal the waste in special waste rotary kilns at very high Temperatures burned with the help of external energy. The problem of Slag is very subordinate here.

In the process according to the document EP-0'302'310 waste is in a pyrolysis tube swollen and the pyrolysis residues are sieved and separated, so that landfill is excreted in a less harmful form to get and so only part of the waste in a rotary tube Use a burner to melt slag.

In the process according to DE-3'815'187 waste is in a pyrolysis furnace obscured, the pyrolysis residues are suitably processed, transferred into a combustion chamber and there with carbonization gases Burnt out slag. Excess heat is generated via heat exchangers removed from the heating circuit.

In the process according to DE-2'946'774 waste is on a Rust pyrolysis-like, burnt gas. The resulting slag and unburned residues are separated from the combustion gas in an afterburning chamber led and they are completely to slag there burned out. The afterburner is heated with the combustion gas and dusts in the combustion gas are separated and closed Slag melted.

In the process according to the document WO-A-9 201 197 waste is on a Rust melted to incompletely burned out slag and this Slag together with separated ash in a subsequent rotating pipe completely melted down with the help of a gas burner.

In the process according to the document FR-2'175'914 waste is in a pyrolysis reactor not scorched but largely burned. This creates Ash and combustion gases are led into a high temperature chamber. The ash is batched there with the help of a burner Slag melted.

The aim of the invention is to contribute to the relief of the environment. It sets itself the task of a process for the effective inerting of Specify slag, fly dusts, boiler ash and similar toxic substances and to create a facility with which to carry out this procedure can be. The condensed and environmentally harmful according to the inventive process Material that effectively binds materials is supposed to be an environmental one harmless landfill form (e.g. as a TVA inert residue according to the Swiss Requirements of the technical regulation for waste) or can be put to a useful purpose instead of being deposited.

Figur 1

zeigt schematisch eine Gesamtanlage gemäss Erfindung, den mit Abfällen betreibbaren Reaktor mit Kessel und Rauchgasreinigung. An diesem Reaktor können das erfinderische Verfahren sowie auch die wesentlichen Teile einer Vorrichtung gemäss Erfindung diskutiert werden.

Figur 2

zeigt den Temperaturverlauf im Reaktor, gemessen in einer Versuchsanlage.

Figur 3

zeigt ein Diagramm des bspw. Verlaufes einer Fremdstoffzugabe zur Einschmelzung in die Schlacke, hier ist es rezirkulierter Filterstaub der eigenen Anlage, es können aber auch Fremdstoffe aus anderen Anlagen sein.

Figur 4

zeigt im Diagramm eine beispielhafte Zusammensetzung der Reststoffe aus einer Tonne Abfall (Literaturangabe Vehlow).

With the method according to the invention, slags, dusts and boiler ash can be melted down solely by the energy content of the waste. The heavy metal compounds are immobilized, the loss on ignition is reduced to a minimum, the organic hydrocarbon compounds are reduced below the current detection limit and the specific volumes are greatly reduced. The basic idea of the invention is that instead of a complete incineration of waste, as has been sought up to now, only a substoichiometric carbonization of the process material is carried out beforehand in a low-temperature unit and then using the sulfurized materials or gases obtained at a high temperature -Unit a complete combustion (e.g. in a rotary kiln) with subsequent slag liquefaction is carried out. The material remaining from the charring (residues) contains more combustion energy than the usual, burnt-out residues and can be fed to a slag liquefaction process in the high-temperature unit, for example a rotary kiln. Part or all of the energy obtained from the gasification can be supplied to the slag liquefaction in gas form, so that the process can be controlled or regulated in a relatively simple manner. The end product of the process is a completely burned-out, liquefied slag that can be solidified in any form.

Figure 1

schematically shows an overall system according to the invention, the waste-operated reactor with boiler and flue gas cleaning. The inventive method and also the essential parts of a device according to the invention can be discussed in this reactor.

Figure 2

shows the temperature profile in the reactor, measured in a test facility.

Figure 3

shows a diagram of, for example, the course of an addition of foreign matter for melting into the slag, here it is recirculated filter dust from the own plant, but it can also be foreign matter from other plants.

Figure 4

shows in the diagram an exemplary composition of the residues from a ton of waste (literature reference Vehlow).

On the basis of these four figures, the invention in its idea and in its Execution shown down to the details.

The reactor according to FIG. 1 is constructed using tried and tested plant components available on the market. In terms of process engineering, the components are coupled and connected in series so that the desired process can be carried out. The reactor points in the process direction, that is from left to right, the essential parts of the device: a feed point 1, for receiving the process material with devices for placing it on the smoldering grate (for example a feed grate); a generator 2 in which garbage is gassed or gasified with an under-stoichiometric air supply; In this generator, the following are essential components: a feed grate 3, nozzles 4 and addition devices 5 and 6; then follows a rotary kiln 7 with a gas / air hood 8, for the combustion of the generated generator gases and for the burning out and melting of the slag; This is followed by an afterburning chamber 9 with an addition device 10, for example air supply for lingering and afterburning still combustible components, and then an empty draft for the flue gases to be discharged, which leads into a boiler group 11 for lowering the temperature and using the flue gases for heat; This is followed by an electrostatic filter 12 and a flue gas cleaning system 13 for cleaning the flue gases and finally the chimney 14 for discharging the cleaned flue gases into the atmosphere. A whole number of process paths labeled with letter groups intervene in the process at various process points, the meaning of which is explained in connection with the function discussion.

First, the waste is fed into a generator via a feed device transported on a moving grate. Here you will find a substoichiometric Partial degassing and gasification as well as partial combustion take place. The garbage is soaked and preheated. Because the processes in the generator (Rust), in contrast to the most widespread rust systems, with a lot smaller amounts of air, especially with a smaller amount of downwind resp. smaller (substoichiometric) excess air run out in the micro or Local area much fewer so-called "hot combustion nests" (hot spots) educated. This causes a sharp reduction in NOx emissions (probably 50% -70%).

The rotary kiln is connected to the generator for the melting of Own and foreign substances in the slag. At the transition of the generator under controlled conditions, air is well distributed into the rotary tube Rotating tube injected. In the same region, the foreign substances, recirculated dusts, dusts and slag from other plants and such be abandoned. There is then a combustion in the generator generated carbonization gases and a burnout of the solid feed. The energy released in the process increases the temperature in the rotary tube increases the slag melting point, and the total solids (self-slag and foreign matter) are liquefied. The circulation of the slag in the Rotary tube leads to thorough mixing, homogenization and a good burnout. The slag flows out of the slightly inclined rotary tube into a pre-cooler and then into a detoxifier.

The complete combustion of the flue gases is carried out in the afterburning chamber Secondary air supplied during the same dwell time causes a perfect burnout of the gases. Instead of secondary air flue gases can also be recirculated or vapors injected The boiler of the reactor presented here must be at the higher flue gas temperatures of this method. By means of large radiation areas and a long gas path, the flue gas temperature is up to first convection part lowered below the air traffic jam softening point.

After the boiler, the reactor can be used with those on the market today Gas cleaning components such as dust filters, laundry, denox and dioxin separation be equipped. However, these components can compared to the conventional waste incineration plants significantly lower Gas volume flows can be designed. As with a standard system the final temperatures of the combustion process are lower than Accordingly, the process discussed here results in larger amounts of gas. For this reason, in the method according to the invention Efficiency of the plant higher than with conventional waste incineration plants.

Trials on a modified plant

Plants of this size cannot simply be set up on a trial basis or existing systems can be converted on a trial basis. However, it is also with an aim of the invention, the method for the use of as many as possible Align proven and commercially available plant components.

A specially selected system was modified to test the process procedurally adjusted to a reactor according to the invention. Various Defects were accepted, which are: the amount of waste, that is, the energy source required for liquefaction of slag difficult to regulate; the ratio between smoldering and combustion air could only be approximated; the injection of the combustion and Burnout air was only partially and properly distributed in the right amount respectively. In addition, the operational safety of the system had to be guaranteed will.

Despite these restrictions, it was possible during several attempts to reach the temperatures required for the slag melting in the rotary tube. The calorific value was measured on average at H _u = 10,890 kJ / kg. Based on the knowledge gained, the minimum calorific value for the process according to the invention with controllable air supply can be operated at an estimated 7,500 kJ / kg. By preheating the combustion air and adding additives that lower the melting point of the slag and increase the inclusion of heavy metals, it should be possible to process waste with an even lower calorific value. The trials were not pre-sorted and shredded for the trials. In any case, it would make sense to separate certain fractions such as metals.

Something has to be considered especially. It is with the inventive Process possible, e.g. foreign slag, that is slag from incineration plants, where melting is not possible, or dusts, Melt ash from other plants, in short foreign substances, in the same process. The smelting reactor, the foreign slag, ashes, dusts and the like is melting and operated with garbage as an energy source the necessary amount of energy however, preferably in the form of garbage.

The foreign matter application and melting was based on a recirculation task tested. After household trash alone during a trial was melted down and this experiment gave positive results in a further investigation the melting of filter dusts from the The system's electrostatic precipitator was examined in the slag. From an addition of Residues from the flue gas cleaning (filter cake) became available aside. However, it is possible to remove such residues according to the invention Process reactor. It is believed that if the most essential Proportion of heavy metals that occur during waste incineration, permanently (the scale for this is, for example, an eluate test) melted down in slag can relieve all landfills intended for this purpose and their capacities. One could go over to polluting substances to be disposed of by melting in accordance with the invention by Includes slag.

The filter dust was added as recirculate via a specially made water-cooled lock construction, which is attached close to the rotary tube was (posting point 6, Figure 1). The filter dust was in batches introduced the facility. There were during a certain period in Average approx. 10%, later 20% of those given during the main test Put the amount of waste into the system and melt it down (see Figure 3).

During the test, it was caused by too much waste to a slight increase in the dust load in front of the electrostatic precipitator. Even if, which is unlikely to result in the total increase in the dust concentration in the Depending on the temperature, flue gas could be traced back to the recirculate at least 91% of the recirculate is incorporated into the molten slag. This corresponds to around 82 kg to 182 kg of filter dust per ton of burned Garbage. In contrast, there is an "own" dust accumulation at the Incineration of one ton of waste of approximately 33 kg, which corresponds to approximately 3%. In other words, you can get significant amounts of toxic Rubbish that comes from other plants and is deposited under expensive conditions would have to be with the melting process according to the invention Dispose of additional garbage. Figure 6 shows approximately the composition the amount of residues from burning 1 ton of waste.

The question of pollutant emissions in the method according to the invention can The following are carried out: Several samples of those melted in this process Garbage slag with and without recirculation addition resp. with and without adding filter dust were tested with an eluate test (CH-TVA test). The melted rubbish slag without the addition of recirculate not only fulfilled the eluate test according to TVA for an inert substance; she also has a loss on ignition of only <0.1%. All declared highly harmful hydrocarbon compounds such as dioxins, furans etc. are below the detection limit. The evaluations show that the TVA limit values for inert substances (Eluate test) of all samples examined were not exceeded. The TVA limit values for inert substances were determined in both eluates (Test 1 and Test 2) not exceeded. The slag thus fulfills the tested Parameters the requirements of the regulation.

During the experiment with adding filter dust, in addition to the regular ones Measurements on the system in addition to the temperatures and moisture contents also determines the concentration of the most important exhaust emissions.

The dust concentration in the raw gas after the boiler, that in normal operation is in the middle of the usual range during the test phase slightly increased. This is due to a lack of control to bring back increased waste. The clean gas, however, fulfills that Claims by the TVA of the 17th BImSchV.

The nitrogen oxide or NOx emissions during the test with the addition of filter dust were 2.5 times lower than in normal operation and below the regulation in Switzerland. The daily mean value reached was approx. 141 mg / m ³ _n based on 11% O ₂ . The sulfur oxide or SOx concentration in the clean gas rose during the experiment. This is probably due to temperature-related decomposition of metal sulfates.

The inventive method discussed here offers the possibility of without slag, ashes and fly dusts to melt away from the outside. As the eluate tests show, heavy metal compounds are in the Slag is practically insoluble. The melted slag has also a very low loss on ignition and the dioxin values are below the detection limits. Unlike other processes, this is done Melt not only without external energy supply; it is even a higher one Plant efficiency is to be expected than with conventional incineration plants. The Plant offers the possibility of incineration residues in one dissipate environmentally friendly form and reduce the cost of disposal.

The diagram in FIG. 2 shows the temperature profile measured in the test in the reactor. The low temperature range from 600 ° C to 1000 ° C of the generator and the high temperature range from 1000 ° C to 1400 ° C of the rotary tube can be seen. In the afterburning chamber and the idle draft, the temperature control is reduced to lower temperatures in order to lower it completely in a subsequent boiler group for the purpose of heat recuperation and recirculation. The solid line shows the thermal curve of a theoretical (ideal) combustion and the dashed line shows the temperature curve of the system in standard operation. The course shown with dots shows the melting operation.

Furthermore, two flow diagrams are shown in FIGS. 3 and 4 which, based on the process, essentially show the mass flow and the associated energy flow. It is clear that these diagrams with absolute numbers indicate a very specific course and composition which is dependent on the plant and combustion material, but essentially show the effectiveness of the method according to the invention.

Discussion :

The reactor presented here essentially consists of a combination of a closed gas generator 2 with a mechanical Feed grate 3 and a downstream rotary kiln 7 and one Plenty of process-engaging connections (e.g. additions, returns) Etc.). The usual flue gas cleaners and a device are connected downstream for the discharge of the liquid slag. Lead out of these assemblies Process interventions (feedbacks) to the generator / rotary tube group back.

According to FIG. 1, the process path begins at entry 1, in which fixed and liquid waste RG, additives AD, recycled rust diarrhea RD as well Foreign substances FR (e.g. slag from other domestic waste incineration plants for Melting). These substances get on the feed grate 3, where they add other substances such as rust air RL, vapors BR, polluting air VL, foreign substances FR and oxygen-containing gases O2 is carbonized, but not gassed, burned. This is achieved in the after heating up through the grate, a substoichiometric amount of grate air RL is blown in very slowly. Through a plurality of air nozzles 4 can recirculated flue gas RR, vapors BR and pollution air VL be added. By two further addition devices 5, 6, namely a solids feeder 5 for solids from boiler ash KA, filter dust FS and foreign matter FR and an addition device 6 to a preheated gas / air mixture VV from the area of Collection hood 8 above the rotary tube, vapors BR, combustion air (better Gasification or smoldering air) VL, and oxygen-containing gas O2, air for example, to add.

With this system there is no additional energy supply for the actual process in addition to the solid waste, the air supply and for the drive units required. Via the additional feed device 5 the solid residues kettle ash KA and filter dust FS can be recycled RZ or from household waste incineration plants as foreign matter FR close to Put the rotary tube in the system and with the residues of the generator be melted down. Such foreign substances and residues can, as above already mentioned, also as fiber for the targeted change of the composition of the char can be added at the entry. By the melting of residues and recirculate, as well as foreign substances FR will immobilize their pollutants, especially heavy metals reached. For this, the device points to the side walls of the generator Addition points 4 for the supply of combustion air VL, vapors BR or recirculated flue gas RR. In the area of the transition from the grate combustion zone a system 6 is provided for the rotary tube, which the addition of a preheated gas / air mixture from the area of a (provided) Hood 8 above the rotary tube, and of combustion air VL, vapors BR or of oxygen O2 is used. Furthermore, in the afterburning chamber 9 after the rotary tube another system 10 for adding combustion air VL or brothers BR provided. Through these measures, in addition to the Process control also minimizes heat loss, especially in the with vacuum operated rotary tube that practically always leaks having. With the consistent and targeted return of unprocessed, Energy containing substances and heat energy, can be a very achieve high process yield.

In addition, in the area of the transition from the generator to the rotary tube Via the device 5, an addition of kettle ash KA and filter dust FS of your own plant or external incineration plants FR respectively. An addition is advisable at this point so that the dust does not from the generator air led through the grate is immediately discharged into the flue gas will.

The preheated and partially degassed solid residues of the generator arrive into the rotary tube. By in the area of the transition from the generator Air VL, O2 introduced to the rotary tube causes combustion in the rotary tube the generator gases. The temperature reached in the rotary tube leads to complete burnout and melting of the solid reaction products, which are melted away from the rotary tube. By the melting will be all at the temperature of 1300 ° C - 1400 ° C organic compounds destroyed and heavy metals in the glass structure of the Slag permanently integrated. The glazed slag only indicates the surface removes little of the bound heavy metals.

In the afterburning chamber 9 behind the rotary tube, a supply of Combustion air VL or vapors. The combustion air leads to the greatest possible Final combustion of the combustible substances in the flue gas as well as the temperature control of the flue gases. From boiler group 11 to the afterburning chamber can generate thermal energy by utilizing the energy content the flue gases in the form of steam (electricity) and district heating be won.

Most of the known slag and residue melting processes require an external energy supply, for example by means of fossil fuels or through electricity. This is not necessary in the process according to the invention. By the special structure and the special air flow of the system is enough Energy content of the solid waste completely from the reaction products of the generator and the other residues added in addition will melt down. Compared to conventional household waste incineration plants without smelting slag, it does not become less but more energy for other purposes (such as electrical energy, district heating) dissipated. But above all, there is a noteworthy fact here in the foreground: the energy for melting comes from waste, which should have been burned either way and slag, as well as residues would have produced, and the inventive method does not melt only their own slags and residues, but still has capacity, Process foreign substances with.

Since it is the largest with household waste and household-like waste Part of the feed of this facility represent a very inhomogeneous Is a mixture, the described reaction sequences in the generator not delimit spatially. The supply of the different gases to the different ones Positions should be matched as best as possible to ensure that different calorific value of the feed material and its composition correspond to.

Figure 2 shows the approximate temperature profile of the process in the reactor. The process begins with task 1, where the temperature is still that of the environment. Seen in the process direction, in the generator at the beginning of the grate, the temperature is a few 100 ° C and increases with increasing charring (gasification) at the end of the grate to about 1000 ° C, but without forming significant heat or hot spots. The temperature of the charring is controlled by the targeted addition of rust air RL underneath the rest and by the addition of vapors BR and / or charring air VL. At the beginning of the rotary tube, in which the burnout and slag liquefaction take place, the temperature rises quickly to the high temperature range between 1200 ° C and 1400 ° C due to ignition of the carbonization gases.

Burning out and melting take place at this temperature. On the transition point to the afterburner chamber remains the temperature through the Effect of further supplied combustion air essentially the same and then falls through the targeted addition of additional (cooling) combustion air VL and / or vapors BR successively again in the direction of the low temperature range to 1100 ° C. In the boiler 11, the flue gases are cooled to 200 ° C.

This diagram shows that the very high temperatures over 1000 ° C, at which the slag begins to melt and at which system parts not designed for this temperature begin to be damaged, For example, from the grate into a rotary kiln designed for these temperatures be relocated. These high temperatures in a suitable place, the first can be achieved in a targeted manner by the process according to the invention can, so to speak, in the better interpretable for high temperatures Rotary kiln delegated. With delegation is not just the burning of one other place but also the transfer of the energy carriers to them Location meant. Here there are flammable gases from the smoldering on the rust and which now in the rotary tube together with the flammable, but degassed residues the desired high temperatures enable. The substoichiometric charring is caused by recuperated, recirculated thermal energy from the area of the rotary kiln (hood 8) largely to completely supported.

FIG. 3 shows a diagram for the addition of filter dust within the test series, which was briefly discussed above. For a little over two hours, the fractions were added in two proportions: initially about 10% based on the amount of rubbish, then about 20%. With automated addition, the task can be staggered in finer steps.

FIG. 4 shows, in the form of a pie chart according to Vehlow, an exemplary composition of the residues from a ton of waste. This composition is of course largely dependent on the initial composition of the waste. It denotes: A = burned and evaporated portion; B = rust discharge; C = RGR residues, salts; D = filter dust; E = kettle ash; F = rust diarrhea.

Claims (19)

1. Process for burning waste (RG) in a combustion plant having a gas generator (2) equipped with a travelling grate (3) and a following rotary kiln (7), having the following sequence: applying the waste (RG) to the travelling grate (3), heating and low-temperature carbonization of the waste (RG) on the travelling grate (3) in such a manner that still-combustible pyrolysis residues and combustible low-temperature carbonization gases form from the waste (RG), with the combustion energy content of the waste (RG) being essentially retained, continuous introduction of air into the gas generator (2) in the region of the transition from gas generator (2) to the rotary kiln (7), which air mixes with the low-temperature carbonization gas and is displaced together with this into the rotary kiln (7) so that the pyrolysis residues continuously passing into the rotary kiln burn with the low-temperature carbonization gas/combustion gas mixture at high temperature in the rotary kiln (7).
2. Process according to Claim 1, characterized in that flue gas (RR) and solid residues (KA,FS,RZ) of the combustion plant are recirculated to the gas generator (2).
3. Process according to Claim 1, characterized in that the low-temperature carbonization is carried on the travelling grate (3) with a substoichiometric amount of grate air (RL) which is forced through the low-temperature carbonization material as underfeed air at low pressure.
4. Process according to Claim 1, characterized in that low-temperature carbonization air (VL) and/or a preheated gas/air mixture (VV) is/are fed to the gas generator (2) via a feed apparatus (6).
5. Process according to Claim 1 or 4, characterized in that oxygen-containing gas (O2) and/or vapours (BR) is/are fed to the gas generator (2) via a feed apparatus (6).
6. Process according to one of Claims 1 to 5, characterized in that the heat energy which is released in process steps which follow the low-temperature carbonization is recirculated to the same.
7. Process according to one of Claims 1 to 6, characterized in that complete combustion of the combustible portions of flue gas (RR) is carried out in an afterburning chamber (9) downstream of the rotary kiln (7).
8. Process according to Claim 7, characterized in that low-temperature carbonization air (VL) and vapours (BR) are added to the afterburning chamber (9) for afterburning of flue gas (RR) under temperature control.
9. Process according to Claim 1, characterized in that the gas/air mixture (VV) comprises firstly gases which escape from leaks at transition points of the rotary kiln (7) and secondly air which is preheated by waste heat from the rotary kiln (7).
10. Process according to Claim 1, characterized in that the vapours (BR) originate from a wastewater treatment and/or sewage sludge incineration and have contents for conversion into heat energy, which decrease the nitrogen oxide content of the flue gas (RR).
11. Process according to Claim 1 or 2, characterized in that solid residues such as boiler ash (KA), filter dust (FS) and recirculated material (RZ) from the present process and foreign matter (FR) from external processes are introduced via a special feed apparatus (5) into the gas generator (2) and in that, on the one hand, these are fused together with solid pyrolysis residues of the gas generator (2) and on the other hand are used as ballast for controlling the process.
12. Process according to Claim 11, characterized in that foreign matter (FR) is used from domestic refuse incineration plants.
13. Process according to Claim 1, characterized in that waste (RG) and recirculated material passing through the grate (RD) are fed via an intake (1) to the gas generator (2).
14. Apparatus for burning waste (RG), in particular for burning domestic refuse and for fusing combustion residues, such as slag, ash and the like, having the following features: a gas generator (2) having a travelling grate (3) for heating and low-temperature carbonization of the waste (RG); a rotary kiln (7) immediately downstream of the gas generator (2) for the high-temperature combustion of these heated and low-temperature carbonized waste (RG) and low-temperature carbonization gases to form slag and flue gas (RR); a feedpoint (1) in the gas generator (2) for introducing the waste (RG); an apparatus in the gas generator (2) for feeding grate air (RL), which forces grate air (RL) as underfeed air through the low-temperature carbonization material in such a manner that still-combustible pyrolysis residues and combustible low-temperature carbonization gases are formed from the waste (RG) and the combustion energy content of the waste (RG) is retained; and a plant apparatus (6) above the travelling grate (3) in the gas generator (2) for feeding preheated air in the region of the transition point from the gas generator (2) to the rotary kiln (7) to make this high-temperature combustion possible, which air mixes with the low-temperature carbonization gas and passes together with this into the rotary kiln.
15. Apparatus according to Claim 14, characterized in that it has, in the gas generator (2), a feed apparatus (5) for adding solid residues (KA, FS, RZ, FR) to support this high-temperature combustion, which added solid residues can be recirculated material (RZ) of the apparatus, boiler ash (KA) of an afterburning chamber (9) and/or a boiler group (11) and filter dust (FS) of an electrostatic precipitator (12).
16. Apparatus according to Claim 14 or 15, characterized in that it has feedpoints (4) for feeding flue gas (RR) of the apparatus formed in the high-temperature combustion and/or feedpoints (4) and a feed apparatus (6) for feeding vapours (BR) into the gas generator (2).
17. Apparatus according to Claim 14 or 15, characterized in that it has an afterburning chamber (9) downstream of the rotary kiln (7) for complete combustion of the combustibie materials of the flue gas (RR).
18. Apparatus according to Claim 17, characterized in that it has a further plant apparatus (10) for adding low-temperature carbonization air (VL) and/or vapours (BR) into the afterburning chamber (9).
19. Apparatus according to Claim 15, characterized in that the added solid residues are foreign matter (FR) from domestic refuse incineration plants.

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