EP0770821B1 - Method and apparatus for simultaneous disposal of finely divided bulk goods and other waste in thermal treatment plants - Google Patents

Abstract

Separate input devices (2,21) feed the fine granular material and the other waste into a combustion chamber of a rubbish burning plant. The input device (21) for the fine granular material is connected with a burner (11) inside the treatment plant (1) or at least one lance ending within the treatment plant. The lance is connected to a supply unit for technically clean oxygen or a gas such as air with a high oxygen content. The burner is arranged in the vicinity of the input device (2) for the other waste in the treatment plant or the lance ends in the vicinity of the input device. The input device (21) for the fine granular material is connected with a pneumatic conveyor unit.

Description

The invention relates to a method for the simultaneous disposal of fine-grained, in particular dusty, bulk and other waste in a thermal Treatment stage, especially in the furnace of a waste incineration plant, the fine-grained bulk goods separated from all other waste via one separate supply to a burner arranged in the treatment stage and / or at least one lance ending in the treatment stage, and a device for performing the method.

Fine-grained, in particular dusty, pollutant-containing bulk goods fall into many production processes. Such dusts arise, for example, in Dust separators from flue gas cleaning systems, such as B. plastic dusts and Wood chips, or as a used adsorbent in flue gas cleaning processes, such as z. B. activated carbon, lime and activated carbon-lime mixtures. Characteristic of this type of Waste is the fact that it is considered a secondary product of each large-scale process occur in relatively small quantities and therefore predominantly in containers (usually 200 I-drums, maximum silo vehicle) be handled. The majority of these bulk goods must be due to their Degree of contamination can be disposed of thermally (by burning or gasification). For this purpose, the bulk goods are usually placed in a storage bunker Waste treatment plant emptied and with others in the storage bunker Waste into the respective incinerator via a gripper (e.g. rotary tube or grate firing). That is only with great technical effort Occurrence of dust-like emissions when emptying the containers in the Storage bunker and the transfer of the bulk goods into the incinerator to avoid.

From document DE-A-41 07 200 is a thermal waste treatment plant, known, which is equipped with a carbonization reactor, the waste in carbonization gas and formed solid smoldering residue, and especially for the treatment of waste is suitable with a low calorific value. In the document EP-A-0 192 025 a Process for the combustion of dusty fuels described, in which the Fuel is fed into the combustion chamber using an oxygen-containing gas stream becomes. A satisfactory avoidance of dust emissions is, however, with not achieved the known method.

The present invention has for its object a method of the beginning mentioned type and a device for performing the method for To make available with which an economical disposal of the bulk goods largely avoiding dust emissions.

On the process side, this object is achieved in that the Burners with technically pure oxygen or a higher proportion of oxygen is operated as air-containing gas, and / or the lance with technically pure Oxygen or a gas with a higher oxygen content than air is applied, and the fine-grained bulk materials directly into the flame of the Brenners and / or the lance are introduced, the fine-grained bulk goods in the entrance area of the thermal treatment stage into the flame of the Brenners and / or the lance are introduced, in which the other waste in the thermal treatment level can be entered, which already in this area high temperatures can be reached.

Since the fine-grained, in particular dust-like, bulk goods are not simply by means of a Gripper together with the other waste in the thermal treatment stage can be entered, but via a separate feed directly into the Flame of a burner and / or a lance introduced and burned and / or are melted, there are no significant dust emissions. Moreover this ensures safe disposal of the bulk goods. Since a lot of dusts, such as B. plastic dust, have a high calorific value, is by the location of the Entry of the dusts reaches that already at the beginning of the thermal treatment of the Fabrics are at high temperatures, causing overall thermal treatment works more effectively.

Bulk goods with a grain size of less than 0.5 mm preferably less than 0.1 mm, particularly preferably less than 0.05 mm used.

The bulk goods are preferably pneumatically fed into the Flame of the burner and / or the lance conveyed.

The bulk materials are expediently blown in by means of a gas the flame of the burner and / or the lance is introduced. To be favoured Low nitrogen gases are used, which prevents excessive nitrogen oxide formation becomes. It can also be a fuel gas, especially natural gas, propane or butane be used.

According to a further development of the inventive concept, contaminated gas is e.g. B. from landfills or polluted exhaust air z. B. from tank systems for blowing the bulk goods are placed in the flame. Such gases have to be disposed of anyway so that by simultaneous treatment with the bulk goods two Disposal problems or when using materials to be disposed of as Additives such as B. sewage sludge or pyrolysis residues, even three Disposal problems can be solved at the same time.

For blowing the bulk goods into the flame of the burner and / or the lance preferably used a dispersing and metering device, as in the DE 42 25 483 C2 is described.

A small one is sufficient for the combustion and / or melting of the bulk goods Oxygen or an oxygen-enriched gas powered burner a serious shift in the temperature profile in the thermal treatment stage is excluded. Because of the use of oxygen or of an oxygen-enriched gas produces only low exhaust gas volume flows at high combustion temperatures. This means that the cleaning of the exhaust gases removed from the thermal treatment stage thanks to the integrated dust treatment is hardly burdened in the thermal treatment stage.

By using technical oxygen or one with oxygen enriched gas, especially oxygen-enriched air, is compliance the required high temperatures are guaranteed The technical oxygen is expediently in an air separator or a pressure swing adsorption system (PPE system) manufactured on site or provided in a storage tank.

The bulk materials are preferably in the flame of the burner and / or Lance at temperatures from approx. 1,250 to approx. 1,500 ° C and at ambient pressure completely burned. The bulk goods can only partially in the flame oxidized, e.g. B. be subjected to gasification. There is also the possibility the bulk materials melt in the flame or thermal changes in the Bulk goods.

Bulk materials with a high calorific value, in particular activated coke, are preferred. Plastic dust or shredder waste.

According to a further development of the inventive concept, the bulk goods low calorific value waste or residues, especially lime, to be disposed of or activated carbon-lime mixtures. By using technically pure oxygen or an oxygen-enriched gas and use Bulk goods with high calorific value in the burner can also be low-energy fine-grained, preferably contaminated waste or residues burned in the flame or melted down.

A device for carrying out the method consists of a thermal treatment device, in particular a furnace of a waste incineration plant, those for fine-grained bulk goods on the one hand and other waste on the other hand, has separate feed devices, the feed device for the fine-grained bulk goods with one inside the treatment facility arranged burner and / or at least one within the Treatment device ending lance is connected.

On the device side, the task is solved in that the burner or the lance with a supply device for technically pure oxygen or a a higher oxygen content than air-containing gas is connectable, and the Burner is arranged near the feeder for other waste and / or the lance ends near the feeder for the other waste, thus high temperatures already in the entrance area of the treatment facility can be achieved. Because the bulk goods (e.g. plastic dust or activated carbon) often have a high calorific value, are already in the entrance area of the Treatment facility reaches high temperatures, reducing the effectiveness of the thermal treatment is increased overall.

The feed device for the fine-grained bulk goods is expediently as Formed line, which is connected to a pneumatic conveyor, which the bulk goods without dust emissions through the line directly into the Flame of the burner carried.

The thermal treatment device is preferably an incinerator educated. The incinerator expediently has grate firing on, for example, the incineration plant as a conventional waste incineration plant be trained to work on the steam power process. The treatment facility can also be designed as a rotary kiln or as a combustion chamber his.

In a particularly preferred embodiment of the invention, the burner and / or the lance a metering device according to DE 42 25 483 C2 upstream. With this dosing device it is achieved that even on delivery constantly changing dusty bulk goods with different properties and reliable disposal is guaranteed in small quantities.

According to a further development of the inventive concept, the feed device stands for bulk goods with a storage container for low calorific value waste or Residue in connection. Basically suitable as low heating waste or All non-combustible dusts that have to be treated.

The method according to the invention and that provided for carrying out the method Device are suitable for the treatment of all conceivable fine-grained Bulk goods, especially dusts contaminated with pollutants, e.g. B. plastic dusts, Wood chips or used adsorbent from flue gas cleaning processes such as B. activated carbon, lime, lime-activated carbon mixtures, etc. With the invention can handle such bulk goods without significant dust emissions on economic Disposed of way. In addition, the calorific value increases when used Bulk goods simultaneously increase the effectiveness of the thermal Waste treatment, e.g. B. achieved in waste incineration plants. This is special advantageous because the usually delivered waste is increasing have a very low calorific value, so the incineration of such waste is becoming increasingly difficult.

There are a number of advantages associated with the proposed method. By the use of technical oxygen or oxygen-enriched gas the exhaust gas volume flow generated in the thermal treatment stage becomes insignificant increased. In addition, the often existing calorific value of the dusts targeted use.

The device according to the invention can be easily integrated into existing ones Plants for the thermal treatment of substances, especially conventional ones Waste incineration plants to be installed later. For retrofitting existing ones Plants are particularly suitable for waste incineration plants, the one Have grate firing and work according to the steam power process. Also Rotary kilns e.g. B. of special waste incineration plants are suitable for a Retrofitting. Furthermore, use of the invention is special Combustion chambers conceivable.

In the following, the invention is to be illustrated schematically in FIG illustrated embodiment are explained in more detail:

In the figure is the flow diagram of a waste incineration plant with integrated activated carbon disposal shown.

In Figure 1, a furnace of a waste incineration plant is shown, which after the usual steam power process works. A feeder 2 becomes burning waste, especially hazardous waste, the combustion chamber 1 of the Waste incinerator fed. The furnace 1 Waste incineration plant has a grate furnace, not shown in the figure. When the waste is burned in the combustion chamber 1, solid and / or Molten combustion particles that are in one of the waste feed 2 deposit the part of the combustion chamber 1 facing away as slag. The slag will via a trigger 3 together with the other solid combustion residues discharged from the combustion chamber 1. When burning the waste materials in the Combustion chamber 1 combustion gases are generated via an exhaust pipe 5 fed a flue gas cleaning 6. The flue gas cleaning 6 acts as Pollutant sink in the entire combustion process. Then the exhaust gas via exhaust pipe 8 fed to an adsorption stage 9 acting as a police filter, in the fine-grained activated carbon for the adsorption of environmentally relevant gas substances is used. The cleaned exhaust gas finally leaves the system via line 10.

After adsorption, the loaded activated carbon is drawn off via line 7 and placed in a storage container 15. A screening device 16 provides for Separation of coarse-grained constituents, which together with the over line 17 Supply 2 waste supplied directly into the combustion chamber 1 of the Waste incineration plant can be introduced.

The fine-grained fractions are transferred to a screw conveyor 19 by means of a funnel 18 abandoned, the fine-grained bulk goods of a bulk material throttling device 20, which is constructed according to DE 42 25 483 C2, feeds. The Bulk throttle device 20 doses the fine-grained bulk goods in a Supply line 21 through which the bulk goods to the combustion chamber 1 of the Waste incineration plant to be directed.

A solid fuel burner 11 is arranged on the waste entry side of the combustion chamber 1. The solid fuel burner 11 is with technically pure oxygen, which in one Provided liquid oxygen tank, not shown, and via an oxygen line 12 is supplied to the burner, supplied.

In the flame of the oxygen-operated solid fuel burner 11, the dusts become a temperature of approx. 1,350 ° C and ambient pressure within the furnace 1 of the incinerator completely burned. This creates molten combustion particles and combustion exhaust gas, which is the exhaust gas volume flow only slightly increased from the combustion chamber 1. The molten Combustion particles are stored in a cool part of the combustion chamber 1 Waste incineration plant and are together with the other solid combustion products carried out from 1. The contained in the activated carbon Pollutants are destroyed as a result of the combustion process in the flame or transferred into the gas phase and with the other combustion gases Flue gas cleaning 6 supplied.

Additional, preferably contaminated dusts are supplied via line 13 the storage container 15.

With the described method, a reliable disposal of the contaminated fine-grained activated carbon ensures without essential Dust emissions occur. At the same time, the effectiveness of the waste incineration plant increased because of the combustion of the fine-grained, high calorific value Activated carbon by means of the oxygen-operated solid fuel burner 11 in the entrance area of the combustion chamber 1 a need-based adjustment of the temperature profile additionally takes place within the combustion chamber 1. By setting a high The temperature in the entrance area becomes the incineration of the waste in the furnace 1 improved. In addition, conventional energy sources (e.g. heating oil) in the Comparison to the conventional achievement of a correspondingly high combustion chamber temperature be saved.

Claims (14)

1. Process for the simultaneous disposal of fine-grained, in particular dust-like, bulk materials and other wastes in a thermal treatment stage (1), in particular in the combustion chamber (1) of a refuse incineration plant, the fine-grained bulk materials being fed separately from all the other wastes, via a separate feed (21), to a burner (11) arranged in the treatment stage (1) and/or to at least one lance which ends in the treatment stage, characterized in that the burner is operated with technical grade oxygen or a gas which has a higher oxygen content than air, and/or the lance is acted on by technical grade oxygen or a gas which has a higher oxygen content than air, and the fine-grained bulk materials are introduced directly into the flame of the burner (11) and/or the lance, the fine-grained bulk materials being introduced into the flame of the burner (11) and/or the lance in the entry region of the thermal treatment stage (1), in which the other wastes are introduced into the thermal treatment stage (1), with the result that high temperatures are reached even in this region.
2. Process according to Claim 1, characterized in that the bulk materials are conveyed pneumatically into the flame of the burner (11) and/or the lance.
3. Process according to Claim 1 or 2, characterized in that the bulk materials are introduced into the flame of the burner (11) and/or the lance by means of a low-nitrogen gas.
4. Process according to one of Claims 1 to 3, characterized in that the bulk materials are introduced into the flame of the burner (11) and/or the lance by means of a gas which is to be disposed of.
5. Process according to one of Claims 1 to 4, characterized in that the bulk materials are completely burnt in the flame of the burner (11) and/or the lance at temperatures of approx. 1250 to approx. 1500°C.
6. Process according to one of Claims 1 to 4, characterized in that the bulk materials are partially oxidized, in particular gasified, in the flame of the burner (11) and/or the lance.
7. Process according to one of Claims 1 to 4, characterized in that the bulk materials are melted in the flame of the burner (11) and/or the lance.
8. Process according to one of Claims 1 to 7, characterized in that bulk materials with a high calorific value, in particular activated coke, plastics dust or shredder wastes, are predominantly used.
9. Process according to one of Claims 1 to 8, characterized in that waste or residue materials with a low calorific value, in particular lime or activated carbon/lime mixtures, are admixed with the bulk materials.
10. Apparatus for carrying out the process according to Claim 1, having a thermal treatment device (1), in particular a combustion chamber (1) of a refuse incineration plant, which has separate charging devices (2, 21) for the fine-grained bulk materials, on the one hand, and the other wastes, on the other hand, the charging device (21) for the fine-grained bulk materials being connected to a burner (11) arranged inside the treatment device (1) and/or to at least one lance which ends inside the treatment device, characterized in that the burner (11) or lance can be connected to a supply device for technical grade oxygen or a gas which has a higher oxygen content than air, and the burner (11) is arranged in the vicinity of the charging device (2) for the other wastes and/or the lance ends in the vicinity of the charging device (2) for the other wastes, with the result that high temperatures are reached even in the entry region of the treatment device.
11. Apparatus according to Claim 10, characterized in that the charging device (21) for the fine-grained bulk materials is connected to a pneumatic conveying device.
12. Apparatus according to Claim 10 or 11, characterized in that the treatment device has a grate firing.
13. Apparatus according to one of Claims 10 to 12, characterized in that the treatment device is designed as a rotary kiln.
14. Apparatus according to one of Claims 10 to 13, characterized in that the charging device for the bulk materials is in communication with a storage container for a waste or residue material with a low calorific value.

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