DE2623033A1 - METHOD AND DEVICE FOR PURIFYING GASES - Google Patents

Description

Annex to the patent application for H 76/27

Klöckner-Humboldt-Deutz 2623033

Aktiengesellschaft _r ^fe

(O

dated May 18, 1976

Method and device for purifying gases

The invention relates to a method for reducing pollutants containing, in particular dust-laden gases, which are subjected to gas scrubbing by means of supplied liquid Formation of a floating bed consisting of floating droplets and a subsequent swirl separation of the droplets from the gas stream. The invention also relates to a device for carrying out the method.

In industrial technology, the problem of the cleaning of solid, liquid or gaseous pollutants increases Type of enriched exhaust gases that are to be discharged into the atmospheric air, an always important

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a more spacious room. In order to carry out the cleaning of the exhaust gases, it has been known for a long time that the Treat gases with a scrubbing liquid. However, so far it has not been possible in a satisfactory manner to carry out the cleaning of the exhaust gases with economic effort to the extent that the regulations of the stricter environmental protection conditions can always be fully taken into account.

From DOS 21 36 290 a method for gas cleaning is known with the help of a gas scrubber, the gas stream being washed and separated in stages, so that after each Separator stage the various removed from the gases ßoffarten classified together with the collected washing liquid should be deducted. In such a classifying and gas cleaning process, there is a washing effect and thus the cleaning effect is low. At the same time is the separation effect is insufficient, so that the gas polluting Particles of matter are carried to the next stage and there to a superimposition of the separation result to lead. Finally, the classifying and cleaning treatment of the exhaust gases involves considerable pressure losses connected, so that considerable energy is required to carry out the process.

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From DOS 21 15 710 is a vertical Uaßabscheider known to which the dusty gases are fed from above and are subjected to a washing water treatment before they are rotated 180 ° in the lower area of the Eaßabscheider be deflected, the dust-binding water droplets contained in the gas being ejected, collected and should be deducted. In addition to a low separation effect, this wet separator also has high pressure losses, so that this separator can only be used economically to a limited extent.

DT-PS 1 203 736 describes a gas scrubber based on the Yenturi principle known, which is followed by a centrifugal separator. With this gas scrubber there is a coarse separation the contaminating constituents contained in the gases are economically feasible, however, the degree of purification achieved does not always meet the current environmental conditions with regard to the degree of purity of industrial exhaust gases.

In this prior art, it is the object of the invention to provide an improved method for gas cleaning and to create a gas scrubber that can handle even the finest dust

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particles or droplets of liquid as well as gaseous impurities "Can separate with little pressure loss and is largely insensitive to contamination. In addition, the gas scrubber should also have economically justifiable manufacturing and operating costs as well small structural dimensions can be achieved.

This object is achieved by the method in that the gas of a further scrubbing in a stream of droplets is subjected and that then an impingement separation of droplets from the gas stream. As a result, the roughly pre-cleaned gases are rewashed, whereby the ! "purification of the gases by means of an impact separation of the E liquid droplet occurs. The exhaust gases to be cleaned can therefore be largely dry and almost completely freed from contaminating pollutants from the gas scrubber subtracted from. With low pressure losses and low gas velocities, a high liquid throughput is required and thus a high washing or cleaning effect is possible.

In an embodiment of the invention it is provided that the gas in the stream of droplets with fine drops of liquid in

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Is brought into contact. In this way, after a quick coarse cleaning of the exhaust gases, the already pre-cleaned gases then with fine drops of liquid in Brought contact, which are distributed as mist-like as possible, so that the remaining gas-polluting pollutant particles meet with a high degree of certainty a drop of liquid in the stream of droplets and from these be bound. The residual droplets of the swirl separation can also be mixed with the liquid droplets in the droplet stream agglomerate and as larger droplets in the subsequent impact separation with certainty of the Gases are separated. This is done with simple measures the fine cleaning of the gases achieved.

In a further embodiment of the invention it is provided that the washing liquid to form the droplet stream is injected into the gases and in the opposite direction of the flowing gases. This makes a statistical Particularly homogeneous distribution of the fine droplets of the post-wash in the gas flow and an even better fine cleaning achieved.

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In a special embodiment of the invention it is provided that the liquid droplets separated from the gas by impingement separation are at least partially formed again of the stream of droplets are returned to the gas stream. This way you can always be a part of the secluded Drops of liquid as washing liquid for as long be reused until this liquid is so enriched with contaminants that a Cleaning is required, for example in a settling basin. This is an optimal use of the washing effect also possible with small amounts of liquid.

The device according to the invention for carrying out the gas cleaning process consists of a gas scrubber with a lower cone-shaped flow tank based on the Venturi principle, which has a cyclone separator is connected downstream and is characterized in that the gas outlet of the cyclone separator with at least is connected to an upper flow channel, which in turn is guided into at least one impact separator is, wherein at least one liquid inlet is arranged in the flow channel. This becomes a wet scrubber created, the finest dust particles or

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Drops of liquid and gaseous impurities separates completely from the raw gases with a low pressure loss and is largely insensitive to contamination is. In addition, the gas scrubber according to the invention can be produced at economically justifiable costs and operated economically due to low energy losses The small seam requirement due to the compact design is an additional advantage.

In an embodiment of the device according to the invention it is provided that in the lower region of the flow container behind the liquid inlet seen in the direction of flow of the gases a tear-off edge is arranged. Through the tear-off edge behind the narrowest cross-section of the Venturi tube is arranged, the eddy and floating bed training is effectively supported.

In an embodiment of the invention it is provided that the liquid introduction in the flow channel approximately on half the channel length is arranged. This ensures that the "further liquid injection against the carrier

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gas direction can be made and a largely mist-like distribution of the droplets is achieved in the flow channel, so that this finely distributed droplet stream with the droplets emerging from the cyclone separator into the flow channel over a longer distance agglomerate and at the same time bind the remaining free pollutant particles.

In a further embodiment of the invention it is provided that discharge lines in the bottom area of the impact separator are arranged, which are in connection with the devices for introducing the liquid into the flow channel stand. In this way, at least a portion of the scrubbing liquid can circulate in the gas scrubber and their economic utilization can be improved.

In a further preferred embodiment of the invention it is provided that the flow container, the cyclone separator, the flow channel and the impact separator are arranged axially in alignment with one another and standing vertically and are connected to one another to form a single structural unit. This measure creates a gab washer,

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its manufacturing costs and tree requirements are low is. At the same time, a high degree of inclination becomes a low Pressure loss and high liquid throughput achieved.

In an embodiment of the invention it is proposed that the flow channel viewed in the direction of flow of the gases is tapered at the end of the channel. A high pressure zone is formed in the flow channel, in which due to the opposite the gas velocity at the scrubber inlet, the lower gas velocities result in an extremely even distribution the fine drops of liquid sprayed into the flow channel takes place, so that the Vasche effect is favored.

In a further embodiment of the invention it is provided that the cross-sectional tapering of the flow channel a preferably square gas distribution chamber is connected, which is connected to the circumference of the transition piece arranged plate packs of the impact separator is formed and which is covered by a deflector. Through this the gas carrier flow passing through the flow channel is evenly divided without it Deposition processes within the distributor space koeat. It is useful here that on the side surfaces of the gas

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Distribution room at least one impact separator is arranged, which preferably consists of at least two lamellar tires with overlapping impact surfaces and There is collecting channels. In this way, the liquid droplets deflected by 90 ° from the flow channel are removed interspersed carrier gas directed onto the separation lamellae in such a way that flow gasses are formed that lead to are offset from certain angles to the direction of flow of the carrier gas, with the one impinging on the lamellae Liquid droplets are separated and conveyed into the collecting troughs, whereby an extremely good fine cleaning the exhaust gases is achieved and these are completely cleaned and drawn off dry from the Haßabscheider can be.

In a further embodiment of the invention it is provided that the flow channel is surrounded coaxially and at a distance by a pipe jacket, the diameter of which is that of the cyclone separator corresponds. This measure represents a particularly advantageous embodiment of the wet scrubber With regard to a compact structural unit, it is expedient that the impact separator is also coaxial and is surrounded at a distance by an outer jacket, the

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Diameter corresponds to that of the cyclone separator. This allows the from the individual impact separators cleaned gases escaping in the head of the wet scrubber are collected and through the fine gas outlet nozzle are discharged centrally from the wet scrubber.

The invention is illustrated in more detail with the aid of schematic drawings for an exemplary embodiment of a hate washer, further features and advantages of the invention, can be found. Show it:

Fig. 1 shows a wet scrubber according to the invention in the view,

Fig. 2 is a section through the wet scrubber

along the line II, II in Fig. 1 in an enlarged view,

Fig. 3 shows a further embodiment of the wet laundry rs.

In Fig. 1 to 3 a wet scrubber for gases is shown, which consists of a cone-shaped flow container based on the Venturi principle, which has a confusing

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like inlet nozzle 2 as well as a tubular nozzle 5 and a cyclone separator 4- placed on the flow container 1. In the passage from the flow container 1 to the cyclone separator 4-, a guide vane system 5 is provided in the narrowed cross section. At the foot of the cyclone separator an inclined plate 6, which covers the entire cross-section between the outer separator jacket and the guide vane wall, is welded in such a way that the separated liquid can flow off to the side. At the beginning of the flow container 1 in the flow direction of the gases behind the washing water _{inlet 7 5,} which consists, for example, of several inlet nozzles, through which the liquid enters the gas flow to be treated tangentially, an additional tear-off edge 8 is built in, which improves the formation of a fluidized bed and floating bed of the liquid droplets causes in the flow container 1.

The upper end of the cyclone separator 4 contains one Confusor-like closure 9 »into a flow channel is introduced so that a short end piece protrudes into the cyclone separator. The flow channel 10, in the middle of which is a liquid inlet halfway along the canal

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funning 11 is arranged, for example, a nozzle with a gas distribution chamber 12, which is of the. on the circumference of the transition piece 1 $ arranged plate packs of Impact separator is formed, connected. The flow channel 10 is tapered at the transition to the gas distribution space trained and at this point goes from the round, on angular cross-section across. The flow channel 10 is arranged coaxially and at a distance in an Eohrmantel 15, whose outer diameter corresponds to that of the outer pipe diameter of the cyclone separator 4-. The drill jacket 15 goes into a further outer jacket 16 in which the impact separators 17 are installed.

The impact separators 17 consist of several lamellae 18 with overlapping impact surfaces 19 and collecting channels The slats 18 together form a row. A disk pack consists of at least two such cells. the The lamellae of the impact separator are arranged vertically. The head of the flow channel 10 is tapered. This shape results in a change in cross-section from the round channel cross-section to the square cross-section of the gas distribution space 12 through the circumference The lamella packs of the impact separator 17 arranged in the cross section are carried out. On the side surfaces 21 of the gas distribution space 12 an impact separator is connected to each

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sen. The gas flow is after. Exit from the flow channel 10 before entering the separation lamellae 18 each deflected 90 °. This deflection is achieved by a deflection body 22 which forms the gas distribution space 12 "Covered. Below the liquid collector 23 the impact separator 17 and a sheet 14 is attached to the outer jacket 16 for covering the cross-section. This becomes a Prevents the purified gas from flowing back into the outer jacket 16 and the tubular jacket 15. The one at the bottom of the impact separator 17 attached liquid collector 23 are formed by different heights so that a slope is maintained up to a drain line 24 ·. The common discharge line 24 of the impact separator 17 leads to a settling basin 25 into which the drain line from the cyclone separator 4 is also led. From the sedimentation tank 25 lead liquid lines 27, 28 to the inlet nozzles of the Eohr nozzle 3 of the flow container 1 and for introducing liquid 11 into flow channel 10.

According to FIG. 3, the cross-sectional tapering follows of the flow channel 10 an impact separator 29, the lamellae, however, are slightly inclined to the horizontal also provided with baffles 19 and collecting channels 20 are.

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During operation, the gas to be cleaned flows into the flow container 1 and is accelerated in the confuser-like inlet nozzle 2. Both in the confuser-like Inlet stub as well as in the Eohrdüse 3, the narrowest cross section of the flow container 1, is Washing liquid supplied and atomized. The high relative speed of the drops of liquid causes an agreement through inertial forces, since with liquid drops, which are injected into an aerosol, a flow around the droplets until the Relative speed takes place. By deflecting the flow Inertial forces arise at the impurities, which cause a displacement into the liquid.

In the subsequent cone-shaped flow container 1, the speed senergy is converted back into pressure energy. The shape of the flow container 1, the injected I ¹ IUssigkeitsmenge as well as the speed of the to be cleaned carrier gas are matched to one another that in the upper region of the flow container 1 in a kind of floating bed an equilibrium condition between the weight of the droplets and from the kinetic energy of the gas re-

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resulting upward drag force adjusts. The fluidized bed formation of the liquid droplets can be achieved through an inlet behind the washing liquid 7 arranged additional tear-off edge 8, which is arranged at the foot of the flow container, essential raise.

The gas flowing through the flow container 1 draws some of the liquid droplets out of the fluidized bed in the direction of the downstream cyclone separator, whereby due to the liquid supply in the confuser-like inlet nozzle 2 or in the tubular nozzle 3 sets a constant renewal of the droplets. The droplets carried along by the carrier gas are in the the cyclone separator 4 downstream of the Sfcrömungsbehälter 1 separated from the carrier gas. In the cyclone separator 4 a sudden relaxation of the gases occurs. In addition, a strong centrifugal field is created by the stationary Guide vane system 5 generated. As a result of turbulence, many droplets combine on the way to separation to larger droplets that reach the walls of the cyclone separator 4 from the guide vane system 5 and deposit there. From there the liquid flows

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on the inclined plate 6, which covers the entire cross-section between the outer separator jacket and the guide vane system "and from there over the
Closing line 26 into the settling basin 25. The clarified liquid is fed again to the inlet connection 2 or the Eohrdüse 3 of the flow container 1, for example via a pump (not shown in detail) or by the action of gravity.

From the cyclone separator 4- the gas, which is still loaded with finely distributed droplets, flows into the flow channel. Depending on the gas composition and gas density, as well as the density and viscosity of the scrubbing liquid, there are additional, finely distributed liquid droplets, dust particles or gaseous impurities in the carrier gas before it enters the flow channel.
Within the flow channel 10, further scrubbing liquid is added about half the length of the channel in countercurrent to the carrier gas direction via the liquid inlet 11, for example a nozzle. The liquid droplets distributed like a mist agglomerate with the finely distributed liquid droplets that have not yet been separated out in the carrier gas and flow through the cross-section

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Fertilization 13 of the ßtrömungskanals 10 to the gas distributor space 12. In the gas distribution space 12, the gases are deflected by 90 ° and flow into the impact separator 17. The lamellae 18 of the impact separator 17, which are provided with baffles 19 and collecting channels 20, form flow lanes which are offset at certain angles to the flow. The gas impinging on the lamellae 18 is deflected in accordance with the flow paths. While the carrier gas follows the change of direction with almost no delay, the liquid droplets are not able to follow the flow deflection due to their inertia. The droplets move against the baffles 19, are separated from the carrier gas and conveyed into the collecting channels 20 by the gas flow. The liquid collectors 23 arranged at the foot of the impact separator are designed with different heights so that a gradient up to the drainage line 24 is maintained. The common discharge line 24 of the impact separator 17 also leads to the settling basin 25, from which the clarified liquid is fed to the liquid inlet 11 in the flow channel 10 in the circuit, for example via a pump not shown in detail. The cleaned and dry gases pass over the tapered one

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Outer jacket 16, which includes the impact separator 17, in the ambient atmosphere.

According to IPig. 5 are the gases to be cleaned from the Cyclonic separator 4 and the flow channel 10 in the impact separator 29 passed, with the agglomerated droplets separated from the gases in the horizontal Collect inclined downwardly open collecting channels 20 and flow into the liquid collector 23. The mode of action of the impact separator 29 corresponds, as described above, to that of the impact separator 17

The treatment of an exhaust gas with the device according to the invention for cleaning dust-laden gases can both in the dedusting or separation of solid, liquid and gaseous impurities as well as in a chemical one There is a reaction between the liquid and a harmful element in the gases.

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Readers page

Claims (18)

1W3Q33 Claims qJ Process for cleaning gases containing pollutants, in particular dust-laden gases, which are subjected to gas scrubbing by means of supplied liquid to form a floating bed consisting of floating droplets and a subsequent swirl separation of the droplets from the gas flow, characterized in that the gas is subjected to further washing in a droplet flow and then an impingement separation of droplets from the gas flow follows. 2. The method according to claim 1, characterized in that that the gas in the stream of droplets with fine liquid droplets is brought into contact. 3. The method according to claim 1 or 2, characterized in that that the liquid to form the stream of droplets in the gases and the direction of the flowing Gas is injected in the opposite direction. - 21 - 709849/0175 ORlGfNAL INSFECTiED 4-. Process according to Claim 1, 2 or 3, characterized in that the I ¹ liquid droplets separated from the gas by impingement separation are at least partially returned to the gas flow to form the droplet flow. 5 · Device for carrying out the method according to a of claims 1 "to 4" consisting of a gas scrubber with a lower cone-shaped flow tank based on the Venturi principle, which has a cyclone separator is connected downstream, characterized in that the gas outlet of the cyclone separator (4-) with at least a flow channel (10) is in connection, which in turn in at least one impact separator 19) (17 »is guided, with at least one liquid inlet (11) being arranged in the flow channel (10). 6. Apparatus according to claim 5? characterized, that in the lower region of the flow container (1) - seen in the direction of flow of the gases - behind the Washing water inlet (7) a tear-off edge (8) is arranged. - 22 - 7Ö9849 / Q17S 26X3033 7. Device according to claim 5 or 6, characterized in that that the liquid inlet (11) is arranged in the flow channel (10) approximately at half the length of the channel is. 8. Apparatus according to claim 5, 6 or 7 _? characterized in that drain lines (24) are arranged in the bottom area of the impact separator (17, 29) and are connected to devices (11) for introducing the liquid into the flow channel (10). 9. Device according to one of claims 5 to 8, characterized characterized in that the flow container (1), the cyclone separator (4-), the flow channel (10) and the Impact separator (17 »29) axially aligned with one another and are arranged vertically and are connected to one another to form a single structural unit. 10. Device according to one of claims 5 to 9 »thereby characterized in that the upper region of the cyclone separator (4) with a frustoconical cover hood (9) is provided, into which the flow channel (10) is immersed. - 25 - 709849 / 017S 11. Device according to one of claims 5 hiß 10, characterized characterized in that the flow channel (10) - seen in the direction of flow of the gases - tapers at the end of the channel is trained. 12. Device according to one of claims 5 to 11, characterized characterized in that the impact separator (29) adjoins the cross-sectional tapering of the flow channel (10), whose lamellae are arranged to run approximately horizontally. 13. Device according to one of claims 5 to 12, characterized characterized in that the cross-sectional tapering 13 of the flow channel (10) is preferably a square Gas distribution chamber (12) is connected, which is of the arranged on the circumference of the plate packs of Impact separator (17) is formed and which is covered by a deflection body (22). 14. The device according to claim I3, characterized in that that at least one impact separator (17) is arranged on each of the side surfaces (21) of the gas distribution space (12) is. - 24 - 709849 / 017S 15. Apparatus according to claim 13 or 14, characterized in that that the lamellae (18) of the impact separator (17) are arranged vertically. 16. Device according to one of claims 5 "to 15» thereby characterized in that the impact separator (17, 29) consists of at least two rows of lamellae (18) with overlapping There is baffle surfaces (19) and collecting channels (20). 17 · Device according to one of claims 5 to 16, characterized characterized in that the flow channel (10) is surrounded coaxially and at a distance by an Eohrmantel (15), whose diameter corresponds to that of the cyclone separator (4). 18. Device according to one of claims 6 to 17, characterized characterized in that the impact separator (17) is surrounded coaxially and at a distance from an outer jacket (16) whose diameter corresponds to that of the cyclone separator (4). 709849/0176