DE8903706U1 - Device for treating flue gases from hazardous waste and clinical waste incineration plants - Google Patents

Description

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The invention relates to a device for treating the approximately 1000 ⁰ C - 1200 ⁰ C hot flue gases from hazardous waste and hospital waste incineration plants, with introduction of the flue gas into the combustion chamber of a waste incineration furnace for

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j Smoke from hazardous waste and clinical waste incineration plants [ raise the temperature of the combustion chambers to temperatures in the range of IC=UO ⁰ C up to a maximum of 12OO°C. For this reason, clinical waste incineration facilities in particular are preferably built in conjunction with waste incineration plants at a central location.

Plants have already been built in which the approximately 1000 ⁰ C hot flue gases from hospital waste incineration are they are introduced into the combustion chamber of a waste incineration plant.

This resulted in considerable difficulties, since the negative pressure of the waste incinerator in this procedure would cause the negative pressure of the hospital waste incinerator, which, due to completely different loading and partly completely different materials works unstably, controls.

The invention is based on the object of improving the handling of flue gases from hospital waste incineration in such a device and in such a method, increasing the efficiency and achieving structural savings

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especially since the flue gases from hospital waste incineration still contain combustible components such as carbon monoxide, hydrocarbons, dust, etc.

This is achieved in a device of the type mentioned above by means of air inlet devices in the brick flue gas duct and a fan in the path of the flue gas-air mixture.

The procedure is such that air is injected into the flue gases from the incineration of hazardous waste ⁱⁿ such a way that the temperature of the flue gas-air mixture is reduced to 200 ⁰ C - 350 ⁰ C, and the flue gas-air mixture is introduced into the combustion chamber of the furnace via a fan, in particular as secondary or tertiary air.

The device can be used in a variety of ways

be formed.
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Firstly, a heat exchanger can be arranged in the flue gas path, an air supply and a fan in front of the secondary or tertiary air inlet into the combustion chamber of the waste incineration furnace.

On the other hand, air inlet devices can be provided downstream of these, a heat exchanger, in particular an air preheater, in the flue gas path and a fan in the path of the flue gas-air mixture as a third alternative.

The air inlet devices can be designed as injectors with adjustable flaps in the bricked flue gas duct.

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Preferably, the injectors are arranged at an angle of up to 30° to the exhaust gas duct.

The damper HfJt can be conveniently controlled by the actual value of the temperature behind the fan.

Preferably, behind the injector inlet into the flue gas duct, this goes into a sheet metal duct of larger

cross-section with insulation, in which if necessary 10

Chicanes are built in.

The secondary and tertiary air supply can be provided via distribution bars with nozzles which are directed essentially towards the centre of the combustion chamber of the waste incineration furnace.

The fan for the flue gas air mixture can simultaneously be used as a suction fan for the hazardous waste or clinical waste incineration plant to control at a constant

Combustion chamber pressure must be developed.

According to the second procedure, the flue gases are first passed through a heat exchanger, in particular

Air preheater, to temperatures in the range of 200 ⁰ C to 2b

35O ⁰ C and, if necessary with the addition of air, introduced into the furnace combustion chamber as secondary or tertiary air via a fan.

Finally, it is still possible to get into the

To inject smoke air from hazardous waste incineration in such a way that the temperature of the smoke-air mixture is reduced to values of around 65O ⁰ C, then passed through a heat exchanger, in particular an air preheater, and then blown into the furnace combustion chamber via a fan, in particular as secondary air or tertiary air with a temperature of 200 ⁰ C - 350 ⁰ C.

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The air injection can be controlled based on the level of the temperature behind the fan.

The combination according to the invention therefore results in the

Possibility of removing the flue gases from such a plant after 5

previous temperature reduction for the purpose of a further

Afterburning of waste incineration. The fuel thus produced in a combustion chamber - namely the

Waste incineration chamber - mixed flue gases are in the iö

subsequent heat exchanger, which is usually Steam generator is cooled to 300 ⁰ C - 300 ⁰ C and cleaned together in the downstream flue gas cleaning system. This has the further advantage that a separate flue gas cleaning system for the hazardous waste or clinical waste plant becomes unnecessary.

The flue gases, which are cooled to temperatures of around 35O ⁰ C, for example, are then blown controlled into the combustion chamber of the waste incineration plant

and simultaneously burned. With the help of this Blower and a suitable negative pressure control can be used in the combustion chamber of the clinical waste or hazardous waste incineration plant even with different combustion behavior of the

The combustion chamber negative pressure must be kept constant. The 2b

Afterburning in the combustion chamber of the waste incinerator, the

Oxygen content of the injected flue gas-air mixture, which can be between 10% and 18%, depending on the selected process modification, in the corresponding

way. At the same time, the

combustible components such as CO _f C _n H _1n (hydrocarbons),

Dust, C etc. are burned and the NO _x content (nitrogen oxides)

in the waste incinerator.

This will significantly improve environmental conditions.

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For the process variants, it can be said that between 30% and 46% of the combustion air is supplied to waste incineration plants as secondary and tertiary air. The oxygen content in the flue gas-air mixture therefore corresponds roughly to the oxygen content of the secondary and tertiary air. If necessary, additional fresh air must be supplied in order to ensure the overall oxygen content of secondary and tertiary air in the combustion chamber of the waste incinerator.

The flue gas-air mixture, which has an oxygen content of 10% to 18% depending on the selected process technology, is circulated by means of a blower, which simultaneously

as induced draft fan for hazardous waste or 15

Hospital waste incineration plant is used specifically in the Injected into the combustion chamber of the waste incineration plant. The process technology presented thus offers, depending on

required oxygen demand of the secondary or

Tertiary air from waste incineration has several variants, namely

Version 1 ;

Temperature reduction only with air injection {(^-content up to

to 18%).

Variant 2:

Temperature reduction with heat exchangers ((^ content about

at 10%).

Option

Temperature reduction with air injection and heat exchangers ((^-content about 14% to 16%).

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This results in controlled combustion in the hazardous waste or clinical waste furnace through constant negative pressure in the furnace at different combustion speeds and calorific values.

Furthermore, a reduction of pollutants through ash combustion of CO, C _n H _m , dust in the form of C...

_in Also a reduction of the NO _x content in the waste incineration plant by injecting smoke gas

better energy use in the heat exchanger of the waste incinerator (of the flue gases as a whole) joint flue gas cleaning

,_ a reduction of the total flue gas flow through

Participation of the injected O2 in the combustion in the waste incinerator and finally

significant reduction in overall investment costs.

&ldquor;&Phi; Examples of embodiments of the invention will now be explained in more detail with reference to the accompanying drawings, in which

Figures 1 to 3 show three variants

Figure 4 shows a detail in the area of clinical waste incineration and Figure 5 shows a detail in the area of waste incineration.

The flue gases coming from the combustion chamber 10 for clinical waste and hazardous waste 3Q enter the flue gas duct 12 at about 100 ⁰ C. Air 16 is injected at 14. The flue gas-air mixture 18 exits at 200 ⁰ C - 350 ⁰ C and has an O ₂ content of about 18%. It is introduced as secondary or tertiary air via a fan 20 at 24 into the combustion chamber of the waste _incinerator 22. The smoke ash from

Both combustions take place in the MOll incinerator Heat exchangers and are fed to the flue gas cleaning system at 26.

In Fig. 2, like reference numerals designate like facilities. The combustion gases exit the combustion chamber for Hospital waste or hazardous waste 10 into the flue gas duct 12 with

a temperature of 1000 ⁰ C and flow through a

Heat exchanger of known design for heating Air or water 28. The flue gas-air mixture 30 enters

200 ⁰ C - 35O ⁰ C and has an O2~ content of approx. 10%. p &Idigr;

To achieve stoichometric or over-stoichometric conditions in % To obtain combustion chamber 23, air coming from 32 |

The fan 34 blows the mixture over the i

Injection 24 into the combustion chamber 22. M

The

According to Fig. 3, the flue gas exits the combustion chamber for j| Hospital waste or hazardous waste 10 with about 1000°C in the % Flue gas duct 12 and is heated by incoming air

36 cooled to 65O ⁰ C and then

Heat exchanger 38. This procedure has !

the advantage that the heat exchanger does not have to be exposed to particularly hot and aggressive gases.

The flue gas-air mixture 40 exits at 200 ⁰ C - 35O ⁰ C and a C^ content of 14% to 16% and is injected into the combustion chamber 22 via a blower 42 at 24.

The air injection 14 or 36 can be designed as shown in Fig. 4. Two injectors 54 are arranged at an angle OC of, for example, 15° to 30° to the axis of the flue gas duct 50. The conditions behind the fan control the air injection based on the temperature there.

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Adjustable flaps 56 ensure the necessary air supply. The flaps can be controlled by a motor.

In the example shown, the channel expands because larger fluid volumes have to be handled. The deep-water doors have cooled down. The bricked channel generally leads over a slum with insulation 52, in which chicages can be built.

According to one variant, the flue gas duct can be designed as a Venturi tube, with air inlets at the narrowest point.

Dez garbage oven 22 can be equipped with any grate 60, in

In the case shown, it should be equipped with a stepped grate, with a distributor 62 and slag discharge 64, molten metal feed 66 and flue gas discharge 68.

The previously mentioned secondary or tertiary air is

a distributor bar 70 with nozzles 72 into the post-combustion area in the combustion chamber 22. The flue gases 68 are fed to the common flue gas cleaning system (together

for hospital waste or waste incineration furnace). 25

On the other hand, it is known to cool the flue gases from the incineration of hospital waste in a steam boiler and to discharge the flue gases cooled to approx. 35O ⁰ C into the area

behind the Mtill boilers, where the flue gases 30

of different origin at approximately the same temperature at best mix.

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Claims (8)

·· · · I I It · · · · Il Il &bull; I 41· I I I I I III I I · » l|(l &bull; Il lilt Il I &bull;&bull;&bull;III Il ·· Il Il -1- CLAIM _c 1. Device for treating the approximately 1000 ⁰ C - 1200 ⁰ C &ogr; hot flue gases from waste incineration plants and hospital waste incineration plants», with the flue gas being introduced into the combustion chamber of a waste incineration furnace, through fan guides (6) in the brick flue gas duct (50) and a fan (20) in the path of the flue gas-air mixture. 2. Device for treating the approximately 1000 ⁰ C - 1200 ⁰ C hot flue gases from hazardous waste and Hospital waste incineration plant", with introduction of .15 flue gas into the combustion chamber of a waste incineration furnace, characterized by a heat exchanger (28), an air supply (32) and a fan (34) before the secondary or tertiary air inlet (24) into the Combustion chamber (22) of the waste incineration furnace. 20 3. Device for treating the approximately 1000 ⁰ C - 1200"C hot flue gases from hazardous waste and clinical waste incineration plants, with introduction of the Flue gases in the combustion chamber of a waste incineration furnace, 25 characterized by air inlet devices (36) and downstream of these a heat exchanger (38), in particular a plate heat exchanger, e.g. air preheater, in the flue gas path and a fan (42) in the path of the flue gas-air mixture. 4. Device according to one of claims 1 to 3, characterized in that the air introduction devices in a bricked flue gas duct (30) are designed as injectors (54) with an adjustable flap (56). »II» I I I I I · *·· Il I I Il · «·# i i "'.: i · f ! J : &iacgr; s &bull; III I ···,·»*· « II·· ·· · &bull;&bull;&bull;&bull;II ·· ·· ·· '· -2- 5. Device according to claim 4, characterized in that the injectors form an angle (oC) of 15° - 30° to the axis of the flue gas duct (50). 5 6. Device according to claim 4, characterized in that the flaps can be controlled by the actual value of the temperature behind the fan. 7. Device according to one of the preceding claims, characterized in that behind the injector inlet into the flue gas duct (50) this passes into a sheet metal duct (52) of larger cross-section with insulation, in which may have chicanes built in. 15 8. Device according to one of claims 1 to 7, characterized by distributor bars (70) with nozzles (72) which are directed essentially into the area above the burning garbage bed in the garbage incinerator. 20 Device according to one of the preceding claims, characterized in that the fan (20; 34; 42) for the flue gas-air mixture is simultaneously designed as an induced draught fan of the hazardous waste or clinical waste incineration plant for controlling constant combustion chamber negative pressure. · ff ffltfiM i * ■* &igr;# f * ii«· ft II * t ··!«