DE3023807C2 - Device for burning corrosive residues - Google Patents

Description

The invention relates to a device for burning of corrosive or corrosive substances Residues according to the preamble of claim 1.

Large-scale production of chlorinated organic Compounds, the amount of which is constantly increasing in the world, inevitably leads to significant amounts Residues that often contain chlorine or chlorine compounds. These residues can either be gaseous be like in the production of vinyl chloride or polymers or Copolymerlsaten des Vlnylchlorlds, or liquid and / or tarry solids, as in the production of .aliphatic, eycloallphatlschen and / or aromatic chlorinated hydrocarbons. The composition of these chlorine-containing residues varies depending on their origin, certain residues include tarry substances containing chlorine which at least some of the components more than Carbon atoms contained in the molecule. Other chlorine-containing residues include chlorinated C ^ compounds

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65 gene and / or chlorinated Q compounds. These chlorine-containing residues may be accompanied by other compounds containing chlorinated ^ - ^ - compounds.

For ecological reasons, this waste is to be dumped into or burned to rivers or lakes or in or by the sea not permitted. For burning off such residues are high temperatures - above 600 "C, for example 900 to 1450 ° C - necessary; at the same time hydrogen chloride or hydrochloric acid is formed needs expensive ones because of the high flame temperatures and the aggressiveness of the combustion products Investments.

Various devices are already known for the combustion of products with well-defined properties, such as refined hydrocarbons, for the production of thermal energy. However, such systems are unsuitable for burning off the above residues because of their changing properties and quantities, since the stability of the combustion and, as a result, the flame is not guaranteed; the burners and atomizing nozzles clog up when processing viscous residue and it is difficult. Conditions for a complete combustion to hydrogen chloride with only a minimal amount of free chlorine must be met, without carbon being formed at the same time to an appreciable extent. In addition, there are considerable corrosion problems and high maintenance costs, since the burners in particular wear out quickly despite complex protective measures. This applies in particular to large-scale plants for He processing of around 3 t / h residues.

From DD-PS i 31 959 is a device for the joint combustion of exhaust gases containing hydrogen chloride and liquid residues of chlorinated hydrocarbons are known. In this known device works a burner in a combustion chamber. The burner is set up from an annular burner plate on an annular rim, the slth in the inwardly conical widening circular opening of the masonry of the combustion chamber is located. The burner himself consists of four concentrically nested supply pipes of different lengths, with the inner tube for the supply of the residues to be burned serves, which with the help of atomizing air and / or steam through a with a side Elntritlsstuizen provided ring jacket can be atomized. This ring jacket is covered by another inner jacket surrounded, to which combustion air is supplied via a side connection. After all, the encloses front part of the second ring jacket has an outer third ring jacket, to which exhaust gas via a lateral nozzle is fed. In the front part of the first two ring mantles swirl plates are arranged and all three ring jackets are bent conically inwards at their outlet opening, so that a nozzle-shaped constriction is formed this results in three annular spaces. This arrangement is intended to result in a misty mixing of Exhaust gas, liquid residue and combustion air can be achieved. It should be noted that with the known Device All Concentric Pipes In One Level In the combustion chamber open and thus only in this the Smell of the supplied streams can take place,

The object of the invention is now a device create for the complete incineration of liquid, paslenformlgen, solid or loaded with solids, but also gaseous residues, which lead to halogen

Exhaust gases containing, in particular, hydrogen chloride fOliren, In such a catfish that a flexible Operational management with flame stabilized as far as possible worldwide and thus complete combustion of the residues is made possible, even if the composition and supply of residues to be destroyed is considerable fluctuates. In addition, it should be achieved with the device that exhaust gases arise, which on the materials the system no longer have a corrosive effect and from which the hydrogen halide acid, in particular Remove hydrochloric acid, through a simple conventional wash and a targeted one Can be used.

Based on the above prior art, as set out in the preamble of claim 1, the above Problem solved by the combination of features specified in the characterizing part of claim 1.

Due to the flame formed due to the structural design of the device according to the invention If the thermal stress on the components of the burner and its surroundings is low, so that for these components no special alloys or heat-resistant materials are required. Because the different air currents are concentric to the axis of rotation of the flame, the mixture formation with the atomized residues is optimal. Due to the high stability of the flame, there are also variations in the composition of the to be processed Residues, especially with regard to their halogen content and additional fuel requirements, perfect controlled. In the combustion chamber itself is an adjustable negative pressure between 1.3 and 53 mbar maintained under normal pressure, so that the burner itself gets its combustion air from the environment sucks in and thus no energy-consuming fans or the like for supplying the combustion air are needed. If liquid or pasty residues are to be processed, the Atomizing air with positive pressure, namely in the Order of magnitude of, for example, 2 to 10 bar (absolute). The combustion chamber itself is convenient formed vertically and rotationally symmetrical.

Delivering the corrosive or corrosive products As already mentioned, residues can be liquid, possibly loaded with solid particles, paste-like, be solid or gaseous; the liquid, pasty ones or solid industrial waste »* or residues can usually> 40% by weight, even> 75% by weight chlorine and the gaseous residues at room temperature other than nitrogen and / or oxygen Contain> 50% by weight and mostly between 55 and 73% by weight of chlorine. Of course, the device according to the invention is also used useful for the incineration of corrosive products that contain significantly less than 40% by weight of halogen contain, for example 5 to 35 wt .- * halogen.

Essential is be! Operation of the device according to the invention a narrow or slim flame. The formation of the desired flame shape is initiated by the atomizing air. In order to prevent the flame from spreading too much, the atomizing air is constricted in an adjustable manner; Air speed and thus the distribution effect as well as the constriction are Vefanderbafi

The flame stabilization in the device according to the invention is achieved by rotating vortex air, which is constricted with the help of deflector structures in order to prevent the flame from spreading. " half the atomizer for the corrosive residues to be removed.

The device according to the invention also enables the secondary air flows to be constricted and deflected (-Current), which gives the flame the desired shape. The stabilization device for the flame is cooled.

In the device according to the invention, there is a regulation or shutdown of the supply of excess air provided. To create and maintain the Underpressure In the combustion chamber, for example, a Venturi tube or a fan is used.

The components for flame stabilization and for constricting and deflecting the secondary air have a same axis of symmetry and this is the axis of rotation of the flame.

The invention is based on a device for combustion of chlorine-containing liquid or pasty residues with or without suspended solid particles and the production of hydrochloric acid is explained later. It shows:

FIG. 1 shows, in section, a combustion system according to the invention; FIG.

Flg. 2 in section an atomizer for the residues with central injection nozzle;

Fig. "In section an introduction and diversion for Vortex air;

Flg. 4 In section, the flame stabilizes Constriction of the secondary air flow, combined with a support plate of the burner at the base of a combustion chamber, and

Fig. 5 In section, the assembly of the components Flg. 2 to 4 (in the device according to the invention.

After Flg. 1 is a burner 1 with a circular one Support plate 2 connected with bolts or screws with nuts 3 on a flat bottom plate 4 of a cylindrical Combustion chamber 5 is attached, soft to the downstream part (not shown) the system is connected. The discharge / or the combustion gases 6 is on the side in the upper part of the combustion chamber 5 arranged. The cremation chamber! 5 is closed at the top with a hinged cover 7, which fulfills two functions: opening the lid after combustion to cool down and deflecting the flow of heat Into the atmosphere in case of disturbances In downstream located parts of the entire facility.

The device is under an adjustable negative pressure held, preferably 4 to 26.6 mbar below atmospheric pressure. This negative pressure creates air sucked in by the burner, necessary for atomization and combustion of the product to be burned, for adjustment the desired flame shape and to cool the burner.

With the help of an In Flg. In the injector 21 shown in FIGS. 2 and 5, the residues are atomized. It consists of an inner tube 22 for dk, residues and a tube 23 for any additional fuel and between a concentric annular space 24 α and an annular space 24 b for the atomizing air (primary air). Tubes 22 and 23 end in the plane on which the flame should sit. A double bevel 25 allows the air to be constricted in order to prevent the flame from becoming too thick and thus too much thermal stress on the stabilizing ring shown in Fig. 4. With the help of a thread 26, a Breririergehäuse 27 is adjustable so that the width of the annular slot 28 between the two bevels 25 can be adjusted to the desired width.

This allows the airing speed and thus the Adjust the atomizing effect through the constriction effect. The injector 21 can slide in a guide 29 to the to achieve the desired adjustment.

After Flg. 3 and 5 comprises a cylindrical box 31 four peripheral tangential feed lines 32 for suction the outside air, which is a swirl device. The belt stream generated in this way then passes through two frustoconical deflector parts 33 and 34 arranged one behind the other (as an example of deflector elements for the Eddy air flow ') to the FJammenbasls.

The vortex air flow has a multifaceted task. He causes turbulence through which the droplets formed by the atomizing air will; it supplies the main part of the combustion air! 5 (oxygen); he shapes the flame to be narrow should, and completes the one introduced by the atomization line Atomization and leads to a pre-settling of the hammer by giving it a regulating movement

The extent of these effects can be measured with the help of (not shown) shutters or diaphragms on the four tangentlalen Supply lines 32 are regulated.

After Fl g. 4 and 5 is the base of the using Flame set in rotation over a cylinder jacket 41, whereby the stability of the flame Is ensured. A truncated cone concentric to it 42 forms the constriction to stabilize the flame and allows the supply of secondary air the edge of the cylinder jacket. The secondary or additional air is used for the final shaping of the Flame, additional oxygen and constantly the upper part of the cylinder jacket to avoid it to cool from excessive heat stress.

The cylinder jacket 41 and the truncated cone 42 for the Stabilizers are mounted on a support plate 43 which has two concentric rows of openings 44 and 45 and although in the embodiment shown it has six openings 44 and four openings 45 -. The inside Row of openings 44 is used to introduce air into the space between the cylinder jacket 41 and Truncated cone 42 and the outer row of openings 45 allows a more or less large excess of air In the combustion chamber. These openings can be partially or completely closed.

The support plate 43 is with (not shown) bolts or Screws and nuts (see component 4 in Fig. 1) attached to a base plate 46 of the combustion chamber, wherein an annular space 47 is left free, the height of which is limited by means of Bellagenschelbe 48 and the like will. This creates an air jacket through the Combustion chamber is formed by the prevailing negative pressure, which is particularly useful for thermal insulation and cooling of the burner contributes. This eliminates any deformations, tension and bending that may occur due to overheating of the generally metallic Material avoided.

The hydrogen chloride escaping from the combustion chamber with the exhaust gases is quickly quenched and then taken up in dilute hydrochloric acid; the concentrated hydrochloric acid obtained may be a desired one Use are supplied.

The device according to the invention enables a very extensive atomization of the residues to be destroyed, so that rapid evaporation of the droplets is favored - evaporation is known to be necessary for good combustion - sufficient air supply in and around the flame, high stability of the flame, great flexibility of the Operation - since the burner provided according to the invention can be regulated within very wide ranges of the throughput , oeispieisweisc uis aui ucn viciiuuiicn new üiiu uu start-up does not cause any difficulties - the use of several combustible substances at the same time such as light heating oil, heavy heating oil or natural gas - if the to the residues to be removed contain too little energy; In this way, the temperature of the flame can be brought to the desired level - a simple construction of the system without moving parts - the wear and tear of which would require excessive maintenance, so that a great robustness of the device is ensured - and ultimately does not lead to corrosion, because that Due to the large volume of air, the highly diluted hydrogen chloride gas is no longer corrosive under the operating conditions. Corrosion could only occur if poorly evaporated residues drain off. However, the geometric configuration of the burner makes it possible to keep such a risk very low. Because there is no fear of corrosion in the burner, no special materials such as tantalum and inconel need to be used. Heat-resistant steel is very suitable. Finally, the energy consumption is extremely economical.

The device according to the invention is very flexible and can easily be attached to the residues to be burned adjust. Solid residues are atomized and fed in pneumatically via the inner tube 22 (FIG. 2); it Therefore, no air is required for atomization and the annular space 24 6 (Fig. 2) and the openings 45 (Fig. 4 and 5) closed, thereby interrupting the supply of excess air.

Even when gaseous residues are burned, the annular space 24 6 (Fig. 2) is closed, but remains In this case the openings 45 (Flg. 4 and 5) open.

The application of the device according to the invention will be explained in more detail using the following examples.

Examples I to

The chlorine-containing residues indicated in the following table were below those listed in the table Process conditions to a harmless smoke ω burned gas- The combustion took place in a clear, completely stable flame, the smoke gases of which were quickly quenched and fed into an absorber. In This can wash out the hydrogen chloride content, for example with demineralized water, and the hydrochloric acid obtained is added to another use or neutralized with sodium hydroxide solution or is the Flue gas washed out with a washing solution containing soda or caustic soda. This is how you get catfish a residual gas with no detectable amounts of carbon, free chlorine or any organic compounds. Due to the air flow in the device according to the invention, there was always the burner and its support plate adequately cooled. In Example 6, the residue B had to be preheated to 180 ° C, since this highly viscous liquid had a crystallization point of 150 ° C. and blocked the supply lines had to become.

Tabel 30 23 example 1 C ₂ H ₃ OO ₀₁ S ₂ N ₁₀₁₄₂ 488.7 kg / h example 1 Composition of 2.6 - Example 4 ??>; 807 8th Example 3 Example 6 230236/480 PVC exhaust gas ^ Smoke gases 71.85 Hexachlorobenzene, liquid mixture A liquid, B high- Product to be burned Manufacturing 98% propane 5 NmVh Wt% 14.5 ^ Hexächlorbütadlen ,. from 30 wt. viscous liquid ~ < 28.9% PVC QQ
8.8 O ₂ 0.05 Hexachlorethane, Example 2 ijS ^ DIchlofpröpart, C ₂ H ₂ Cl ₂ 67.3KN ₂ ' N ₂ 6.4 Chlorethylene, solid mixture of 31% by weight A + B: C ₂ H ₂₁ J ₆ Cl ₂₁ Oj 3.8% O ₂ CO ₂ 4.6 Chloropropane Stereosofnefen des l, 2.2 ^ Trlchlorpropari Residue A: CI ₂ Hexachlorocyclohexane and 39% by weight C ₂ H ₂ Cl ₂ 180 HCl from the extraction Perchlorethylene +
B: hexachlorobenzyl, H ₂ O of lindane, 625 kg / h Hexachlorobutadlene, Product quantity and 300 Continuation table 80 μm 30 mVh at 4 bar Hexachlorethane, Atomizing air) 25 kg / h heavy fuel oil Perchlorethylene Fuel·) 180 Product to be burned 125 kg / h 350 kg / h 9.7 1395 kg / h 500 kg / h Negative pressure in the chamber 10 nV / h 140 mVh at +0.1 bar : 40ai / h (based on 110 In the chamber 25 kg / h heavy fuel oil 65 kg / h furnace oil 20 kg? H of heating oil Atmospheric pressure) 60 burner base plate 11.7 mbaf 700 Vortex air flow *) mVh Continuation table 175 (44) + 330 (45) Secondary air flow *) 2800 mVh 470 Air through annulus 47 *) mVh Product quantity and 42 on the support plate temperature Atomization: ^{5 years} 1500 1180 flames ⁰ C Fuel*) temperature 35 on the support plate *) Standard conditions 1220 flames temperature Example 3 Example 2 3.0 52.7 16.3 14.1 0.2 74.1 18.2 5.6 9.6 0.1 4.6 1.5 Example 5 ^ Residues; 487 kg / h 25 fir / h 25 kg / h heavy fuel oil 7th

9 Negative pressure in the chamber *) 30 23 Example 4 6.9 807 10 For this purpose 3 sheets of drawings - (based on 7.8 60.7 continuation Atmospheric pressure) 12.7 Example 5 Example 6 mbar 0.07 6.0 10.8 Vortex flow ») 9.33 mVh 240 10.3 Secondary air flow) RiVh 30 (44) +180 (45) 1030 3280 Air through annulus 47
RiVh temperature 120 570 (44) + 460 (45) 1650 (44) + 800 (45) • c 60 on the support plate Continuation table ί 160 In the chamber 570 1200 30 on the support plate 35 on the support plate Composition of Example 4 Example 5 1240 In the chamber 1190 In the chamber Smoke gases Weight K Example 6 O ₂ N ₂ 5.9 CO ₂ 62.5 Cl ₂ 16.4 3.1 HCl 0.4 52.3 H ₂ O 11.9 17.1 2.9 0.2 17.7 9.6

Claims (2)

Patent claims: 1.Device for incinerating corrosive or corrosive substances supplying residues, especially halogenated hydrocarbons and such containing or supplying residues from a combustion chamber (5) and a burner (1), which with the help of a circular support plate (2) and a flat base plate ( 4) is attached to it, as well as an outlet for the combustion gases (6) and a cover (7) for the combustion chamber and the burner is formed from an injector (21) with a concentric fuel pipe (23) and a concentric inner pipe (22), between which there are annular spaces (24 α and ^{| 5} 24 b) , the latter merging into an annular slot (28) at the mouth end, and a cone-shaped deflector with a swirl device for supplying the combustion air to the flame base, characterized by the grain size questioning Characteristics: a) the injector is provided with a thread (26) on which a housing (27) is screwed in such a way that the width of the longitudinal cover (28) is adjustable and the housing is held in an ^{axially slidable manner in a guide M} (29); b) the swirl device is & .s cylindrical box (31) with tangential feed lines (32) for drawing in the outside air through the negative pressure Formed in the combustion chamber; c) a support plate (43) is provided on the box (31), on which a cylinder jacket (41) and a truncated cone (42) concentrically aligned with it are supported so that an opening (44) In the support plate (43) you: h the narrowed opening secondary air between the truncated cone (42) and the upper end of the cylinder jacket (41) Can be fed to the flame base, and d) In the support plate (43) are openings (45) for Entry of dilution air into the combustion chamber intended. 2. Device according to claim 1, characterized in that that the openings for the entry of the Vc-thinning air can be covered 30th