DE2149648A1 - Method and device for the smokeless incineration of waste products - Google Patents

Description

The limited availability of land for landfills and garbage dumps creates an urgent need for improved methods of incinerating a wide variety of waste and other undesirable materials. There is a particular need for incineration processes in which non-combustible solids are placed in the incinerator remain while at the same time all volatiles oxidize as completely as possible and converted into a gaseous and smokeless state will.

The incinerator according to the invention is particularly suitable for the incineration of difficult to burn material, in particular lumpy materials, materials with a high ash content and organic waste in

ORIGINAL INSPECTED

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liquid, semi-solid and solid form.

In particular, the incinerator according to the invention is suitable to burn combustible substances in such a way that incombustible components contained therein remain substantially in the incinerator.

The incinerator according to the invention is essentially one in two stages and without a grate working device · In the first stage of the device, the substances to be burned are thereby vaporized or That volatilizes a flame from a first burner along with a flow of air in a generally downward direction going direction acts on the surface of a solid or semi-solid filling, in this First chamber vaporizable substances and, to a certain degree, combustion occurs. After that will be all gaseous substances are transferred to an adjacent second stage, in which with the help of a second burner and one further air flow a further oxidation and combustion is carried out.

Since it is essentially in the evaporation zone of the first stage If surface evaporation occurs, the filling of waste material to be incinerated is not, as is the case with conventional, with a fire grate working incinerator is the case, flowed through by gases. It will therefore be very little moved so that only to a very small extent particulate non-evaporable substances and components in the second stage trespass. According to the invention, the evaporation of solid and semi-solid waste is essentially from above down in front of you. In this way, the non-evaporable substances accumulate in the first stage of the incinerator and can use it from time to time, such as the course of the

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driving it permitted or required to be removed. Of course can be combustible liquid or powder Substances are injected either continuously or at intervals directly into the evaporation zone forming the first stage will.

The vaporized material and the products of combustion of the first Step step, possibly together with excess air coming from the first fan or one on another Way supplied air flow, into the combustion chambers of the second stage over, in with the flame of a second burner and optionally with the supply of further air, the combustion process is brought to an end, the developed gaseous products completely and essentially smokeless burn.

In the drawing shows

FIG. 1: In elevation, an embodiment of the invention Incinerator in its essential parts with a side-mounted filling device for the supply of waste materials to be incinerated the first stage;

Figure 2: also in elevation, another embodiment of the incinerator with a conveyor chute for the Supply of the waste materials and an optionally arranged one of the vaporous combustion products flow through a heat retention zone, for example a waste heat boiler for the generation of steam. As I said, the installation of the waste heat boiler can be decided in each special case, since the Vapors emerging from the two-stage incinerator are simply diverted to the outside without generating heat can be.

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In the embodiment of the incinerator according to Figure 1, the waste materials 2 can through an inlet device, for example a filling device 3 is introduced directly, either in batches or continuously, into the first stage forming evaporation zone 1 will. In the evaporation zone 1, the waste materials the action of an introduced by at least one burner 5 strong fuel flow 4- and also a strong one Air flow 6 subjected. The fuel can be, for example, fuel gas, heating oil or a finely divided solid fuel, use like coal or coke dust.

If it is solid waste, evaporation will occur in the filled waste material layer 7 in the step 1 essentially from top to bottom. This is an important feature of the invention. As in level 1 without fire grate is being worked, the layer 7 is moved in its mass only to a very small degree. Hence the mass of the to be burned Waste materials 7 not from air or other gaseous Components flowing through. It follows from this that solid and relatively non-evaporable particles of the first stage 1 are only very small less and in any case unattractive amount through the system be funneled. The non-evaporable components therefore remain in their entirety in zone 1. the Vaporizable components occur as vapor stream 8 together with combustion products of the one introduced by the burner 5 Fuel and excess air into the second stage 9, where complete combustion with very little smoke he follows.

You can find the burner or the burners 5 in the upper part of the the first stage 1 forming evaporation zone optionally in at an angle or at angles, provided that the flame is mainly directed downwards to the area to be burned Material 7 is directed. An air flow 6 can be introduced through the burner 5 or around the burner 5. If desired, you can add more air from the first air supply

2 0 9 8 1 j / 0 9 5 6

separated by a separately arranged inlet opening or blow the supply line or several such openings or supply lines into the first stage 1 or onto others Press in the way. The one according to the drawing for the air supply after the first stage 1 in particular and actually certain supply line 6 is generally, although not necessarily, arranged above the air supply line, those for the simple burning of the fuel in the first burner or burners is required, although the excess, if desired, is supplied separately can be. The supply of the first air stream 6 can include at least one partial combustion in the first stage 1 forming Create an evaporation zone. Primarily, however, the first stage should be a zone with high heat input be, in which the vaporizable components of the material to be burned 7 are vaporized.

The gaseous products, i.e. the products of fuel combustion, the excess air, the evaporated waste and any products from partial incineration in stage 1, form a total of a gas stream 8 which is passed through a pipe into the combustion zone of the second stage 9, in the main combustion takes place.

In the combustion zone forming the second stage 9 is further fuel 11 is supplied to at least one burner 12, through which and / or with which a further air stream 13 is also introduced will. This separate second air supply 13 should take place above the supply point for the air is required for the combustion of the fuel 11 entering the second burner 12 and compared to that The amount of air required for the incineration of the evaporated waste products is preferably introduced in a large excess will. This second air stream 13 supplied in excess is, for example, into the second stage 9 forming combustion zone blown in.

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It can also enter the combustion zone other than through the burner 12 of the second stage. In the combustion zone of the second stage 9, all of the first stage 1 coming vaporizable components and all oxidizable components oxidized as much as possible, so that the from the combustion zone of the second stage 9 in one Outlet nozzle 15 withdrawing gases 14 essentially are smokeless and only have a very minor air pollutant effect.

FIG. 2 shows a second embodiment, similar to the embodiment according to FIG. 1, of a fire rust-free, two-stage Incinerator according to the invention, in which the waste to be incinerated through a hopper 16 via a conveyor 17 »For example a screw conveyor for solids, introduced into the first stage 1 evaporation zone will. FIG. 2 shows in particular that the gases 14 flowing off from the combustion zone of the second stage 9 are one Exhaust gas preheaters, for example a waste heat boiler 18 with a steam coil 19, are fed into the water 21 enters and steam exits at 22. The exhaust gases escape through the outlet port 15 to the outside.

FIG. 2 also shows that the second burner 12 does not necessarily as shown in Figure 1, arranged perpendicular to the combustion chamber forming the second stage 9 needs to be. Rather, it can also be other than vertical, for example at an angle or, as shown in Figure 2, be arranged horizontally to the combustion chamber 9. In this case you can put one or more burners in vertical position and at the same time arrange one or more burners in a more or less horizontal position. The flame of the Burner can be in the combustion chamber, in or entirely or partially tangential, as recommended for maximum combustion.

If necessary, the combustion chambers of each stage, the pipe between the combustion chambers and the outlet

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can be provided with fireproof cladding.

The temperatures in the combustion zones depend on the materials to be burned. They can go from 93 degrees up 1316 degrees Celsius or more in the evaporation zone of stage 1 and still in the combustion zone 9 of stage 2 be higher. You can control the temperatures in stage 1 and stage 9 by making an appropriate measurement the amount of fuel 4 and 11 and air 6 and 13 to be fed to the burners 5 and 12, the flame exposure regulated. Components or substances that can evaporate more easily evaporated in zone 1 at lower temperatures and then burned in zone 9. Materials that are more difficult to vaporize naturally require higher temperatures in Zone 1.

In general, one carries out the process according to the invention preferably at a volume ratio of the first to the second zone of about 1: 3, with a ratio of about 1: 2.5 euLs lowest limit and a ratio of 1: 3 as is desirable to look at. The ratio can, if larger dimensions are desired for the second stage and the outlet connection or official regulations for the outlet nozzle require larger dimensions, going up to 1: 6.

According to another and very useful embodiment, which, however, is not shown in the drawing, the evaporation chamber of the incinerator according to the invention as Digging be formed in a layer of earth or rock or a rock. The ditch is at its end with a Equipped gas outlet pipe, which is lined in a suitable manner refractory and lined with a refractory Trigger nozzle is connected. The trench is made of a metallic, ceramic or double-walled lid metallic-ceramic material covered. Inside the double-walled lid, air is kept circulating under pressure, which cools the lid and preheats it.

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The preheated air is then used for combustion, and for this purpose both the first and the second Stage supplied as excess air. The first burner generally gives its heat down through the lid of the trench into the evaporation zone. The second burner is arranged in the lower part of the interior of the flue pipe serving as a combustion chamber, where also a Part of the air passed through the cover of the trench and thereby preheated is passed. In it become tangential with or with the flame pointing upwards, additional amounts of fuel burned. In these trench-type incinerators, the waste products to be incinerated are transported with the Truck pulled up and tipped in or pushed in with a bulldozer. The resulting ash also becomes mechanical removed. Liquid waste products can be pumped or blown into the first stage, while finely divided ones Solid substances can be introduced with a conveyor device or also blown in.

In contrast to the two-stage incinerator after Figures 1 and 2, the trench-type incinerator does not require a refractory lining for the first stage forming evaporation zone. Serves as an evaporation zone instead, the trench covered with a double-walled lid, which is cooled by circulating air. The hot combustion gases the first stage and the controlled flame application in the second stage create favorable draft conditions, that no smoke escapes from the open end of the first stage can.

example

The substances listed in the table below were used for the tests according to this example. The one for the incineration The furnace used for this material had a diameter of about 30 cm in its first zone and a height of about 4-6 cm and a capacity of about 0.0334- m and in his second stage with inclusion of the discharge nozzle a diameter of about 15 cm a height of about 51 ca and a frame

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assets of about 0.109 Hr. As fuel were used by everyone the tests used natural gas and air in accordance with the information given in the table.

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Tabel

Try material

Amount of test sample (kg)

Henge amount of the combustion Verminpro kg per kg ma- ma- nungsge- alteration TERIAL comparable TERIAL ver-speed Running From the

turned natural gas

turned air

^{ s $ jr <- ⁵ ^>

speed per m2 floor area of zone 1 (kg / h / m2)

falling materials in
Weight %

maximum temperature reached

rc)

Ratio of the zone and zone 2 air supplied

NJ O CO CXJ

cn era

Soot and waste tires 5.2

solid polypropylene in tablet form

Kraft paper

0.6

0.175

30.2

116

78.3

1204

472 73

100

85

1335

1010

1.58

0.32

2.33

Penalty in tablet form 4.5

Polyethylene in chunks

27.5

3.0

32.3

22.8

12.5

100

1468

147

100

1316

only air to zone 1; no air by zone

0.67

"request material

Amount of test sample

(kg)

Henge des

per kg of material used natural gas

(8899 kgcal / m3)

Tabel

Amount of air used per kg of material

(m ³ / kg)

Incineration reduction dwindling waste per waste material m2 of soil in
area of weight %
Zone 1

(kg / h / a ² )

Reached ratio maximum- zone 1 and zone 2 supplied air

temperature

( ⁰ C)

from refines rien originated asphalt emul sion

0.22

15.8

311

98.4

1449

0.50

liquid Tetraethyl anhydride

0.6

10.4

483

92.6

1554

0.65

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The Ibis 7 experiments include a wide variety of substances in the two-stage incinerator that works without fire grate according to the invention can be consumed oxidatively smokeless in an effective manner

Certain waste materials such as paper, soot, garbage and the like can be burned completely or almost completely in the first stage · Substances of this type usually burn slow and require the addition of a fuel to get the evaporation going. With such substances one sets a oxidizing atmosphere usually in the first stage thereby from introducing a larger amount of air.

Other waste materials such as rubber, water-in-oil emulsions and the like cannot be completely burned in the first stage will. On the other hand, they vaporize easily and require little additional fuel to vaporize them begins and lasts. In the case of easily combustible substances of this type, the first stage is a reducing one Atmosphere, since even at high air supply rates the Oxygen consumption is so high that a reducing atmosphere must be expected. The vaporized material of the first Step enters the oxidative combustion zone of the second together with combustion products of the fuel used Stage above, in which further oxygen, usually in the form of air, and, if necessary, further fuel is introduced so that all substances are completely oxidized. With substances of the type mentioned are common in the second stage very little or no fuel additives required. One can do the desired oxidative combustion with a cause additional airflow.

The burners for the first and second stages of the incinerator according to the invention can be any high-pressure burner Use type and suitable construction.

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With the incinerator according to the invention, usual solid waste (trash) and other waste materials to 5% their original weight and volume are reduced. From the example of this description it can be seen that the problem of garbage and waste disposal can be largely defused by incineration. Organic too Substances and the old smells associated with them can be removed by incineration. As an example of fabrics, that can be burned without developing smoke are polyethylene in tablet form and other polyolefins and polyolefins with an ash content or a content of catalyst components, newspapers, garbage, rubber waste, tire casings, oils as well as oils and pesticides with a content of radioactive substances Components and bodies called.

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Claims (2)

Patient calls; a) Evaporation of the evaporable components of the waste materials in a first stage with retention the non-evaporable components of the waste materials in this first stage, b) passing these vaporized components out of the stage (a) in a second stage, c) Combustion of these vaporized components in this second stage in the presence of excess oxygen at an elevated temperature and d) removal of the products of oxidative combustion this level (c) to the open air, characterized in that the waste products in non-evaporable components, which are essentially in the first Level, and into essentially smokeless and essentially fully oxidized products, which are discharged from the second stage are converted by the evaporation in the first stage by only acting downwards on the waste materials Flame is brought about. 2. A smokeless two-stage incinerator for performing the method according to claim 1 with a) one of an evaporation zone with at least one first burner, at least one compressed air inlet device, a filling device for the waste materials and a first stage consisting of an outlet device for the gaseous products; 209815/0956 b) one of a combustion zone with at least one second burner, at least one compressed air inlet device, an inlet device for receiving the gaseous coming from the first stage Products and an outlet device for the burned gaseous products and consisting of a second stage c) a connecting pipe between the first and the second stage for passing over the vaporous products4 characterized in that at least one burner is arranged in the first stage in such a way that it does the in
material brought in at this stage in the downward direction
flames and that the first stage is not equipped with a fire grate.