Device for cleaning exhaust gas

 

(57) Abstract:

The invention concerns a device for cleaning exhaust gas, in particular gaseous waste CVD process, a plasma etching or a similar process, with at least one zone of combustion vertical location within the outer pipe, which at the top is limited to a dome-shaped casing, and a burner internal or external mixing nozzle fuel gas which juts into the zone of combustion, and is supplied to the burner fuel gas, oxygen or air and waste gases, and means to supply and exhaust oxidant and/or sorbent in the wash zone above the zone of combustion. The burner is fixed in the center of the dome-shaped casing has a nozzle combustible gas and at least one nozzle supplying gaseous waste directed vertically downward into the zone of combustion. Arising in combustion gases are directed along the inner side of the outer pipe from the Foundation up to the washing area, and possible removal of the sorbent after its distribution in the wash zone and the enrichment of the reaction products along the inner side of the outer pipe through the base. The technical result - the creation of a cleaning device hazoor the

The invention concerns a device for cleaning exhaust gas, in particular gaseous waste CVD processes, i.e. processes of chemical deposition from the vapor (gas) environment, as well as processes of plasma etching or a similar process with at least one zone of combustion vertical location within the outer pipe, which at the top is limited to a dome-shaped casing, and a burner internal or external mixing nozzle fuel gas which juts into the zone of combustion, and is supplied to the burner fuel gas, oxygen or air and waste gases, and means to supply and exhaust oxidant and/or sorbent to the washing area outside the zone of combustion.

Purification of such waste gases occurs, as a rule, in two stages so that the gaseous waste is first burned and then cleaned in washing installation (installation of a wet gas purification). The burning of waste gases and, accordingly, the oxidation is performed by means of burners within the combustion chamber.

From EP 0 346 893 B1 is known a similar device treating the waste gases, which comprises a closed bottom and an open top base with a circular cross secene wall, bounding the combustion chamber. In this base juts out from the bottom burner for combustion together with combustible gaseous waste gas supplied into the combustion chamber. The combustion chamber is limited from above by a splash guard, which is the washing chamber. In this wash chamber is centrally located nozzle, through which is formed a cone of spray cleaners vamiali aerosols and solid components from burned gaseous wastes. The splash guard prevents splashing of the washing means in the combustion chamber and, accordingly, contact with the burner or flame.

Washed residues are carried away by the flushing means along the inner side of the cylindrical outer wall down and discharged through located at the base of the drain.

The disadvantage of this device by treating the waste gases is that the processes of cleaning devices are very expensive and that, in particular, it is difficult to clear the zone of combustion. In addition, it is almost inevitable contamination of the fuel gas nozzles and jets of gaseous waste, so to guarantee reliable operation requires regular maintenance of the burner.

US 5,123,836 then describes the device signorina burner, forming a flame downward into the combustion chamber. Along with the combustible gas to the burner is served combusted toxic gas. Lower flame burners are nozzle spray producing water mist, which washed away resulting in the combustion of microparticles. This combusted gas simultaneously cools quickly. Additionally, on the inner wall of the combustion chamber in the tangential direction is formed flowing down from the top of the water film. This film of water prevents the deposition of particles on the inner wall of the combustion chamber.

The design of this device is very expensive and it is only intended to remove particulate matter from gas flared.

Therefore, the object of the invention is a device treating the waste gases, which requires less cost to manufacture and which eliminates the disadvantages of the modern state of the art.

Underlying the invention the task is solved by a device treating the waste gases of the above-mentioned type so that the burner is fixed in the center of the casing and has a nozzle combustible gas and at least one nozzle supplying gaseous waste, which is directed vertically downward into the zone of combustion, which area is which extends to the base and ends at some distance from the bottom of the base, that occur in the combustion process, the reaction products along the inner side of the outer tube base go up in the wash zone and that the sorbent after the distribution in the wash zone and the enrichment of the reaction products is given along the inner side of the outer tube through the base.

With such a simple device that you will sell treating the waste gases leads to higher reliability of operation, as well as a significant improvement in the cleaning of waste gases. In particular, it is possible to avoid the influence of combustion products, which are deposited on the burner in the combustion zone or on the inner side of the outer tube and, respectively, on the bottom of the combustion zone. Also avoid a possible narrowing of the cross section or the clogging of nozzles of the fuel gas.

In order to achieve a particularly good mixing of fuel gas with the gaseous waste burner has several nozzles supplying gaseous waste, which is concentrically surrounded by a combustible gas nozzles.

In order to avoid possible overheating of the burner attached to the cooling unit. For this purpose in the outer tube and over the burner nozzle is spraying cortopassi waste and on the other hand, simultaneously cooling the burner housing. The spray nozzle may be made in the form of rings, nozzles, solid or hollow cone, so that the burner gets a sufficient amount of washing liquid.

The annular nozzle is fixed on top of the casing on the inner wall of the outer tube. Formed as a result of this ring splashing in this case parallel to the inner wall of the outer pipe and is directed to the burner housing so that overlaps all of the cross-section of the outer pipe.

A significant improvement in the cooling of the burner is achieved in the case when the spray nozzle is connected with the chamber in the burner supply line, through which the nozzle of the spray can be submitted sorbent or a flushing agent.

In this way the burner is cooled inside, so that may be permitted a higher combustion temperature. This version is particularly suitable for hydrogen burner, and the camera must be placed between the fuel gas nozzles and nozzle supplying gaseous waste, concentrically surrounding it.

To prevent the excessive heating of the casing and the burner, between the zone of combustion and cat heat shield prevents too strong cooling combusted gaseous waste.

To limit the combustion zone laterally provided by the inner tube surrounding the heat shield.

Between the heat shield and the inner wall of the inner tube has a ring gap, and the space between the casing and the heat-shielding screen via hole is connected with the space outside the outer pipe. Because of this, along with the reduced pressure in the zone of combustion is achieved by constant flushing the space between the heat-shielding screen and casing.

In the development of the invention, the space between the housing and the heat-shielding screen is a ring of nozzles with nozzles supply of cleaning materials that are directed to the inner wall of the inner tube. Consequently, during pauses in the operation of the device can be cleaned combustion zone water or sorbent without opening it.

To ensure the permanent removal of the sorbent or flushing means, without disturbing the combustion process, the bottom of the base in the deepest place is provided with a drain.

In special design of the inner and outer tubes are composed, respectively, of the upper and lower parts connected to each other with the possibility of separation, and the base can be separated from the services, which further improves even due to the fact that the upper part of the outer pipe with the attached burner casing, the upper part of the inner tube, the heat-shielding screen, opening and ring of nozzles can be moved axially up and the base is axially down.

In the next version of the invention the upper part of the inner tube at the lower end has a narrowing cross-section, with which the upper end of the lower part forms an annular gap. This is achieved by improving the efficiency of the combustion process, as it occurs recirculation of already burned gaseous waste, which is why they are re-exposed to the combustion process. In addition, this is to wash the inner side of the inner pipe and the reduction of sediment.

In order to prevent the entry of wash funds or sorbent in the combustion zone, between the upper part of the outer pipe and the upper part of the inner tube is a protective tube that covers the upper edge of the lower part.

In the following development of the invention the zone of combustion associated with the space outside the pipe through the inputs, which are the ignition device or counter Enna side of the outer pipe next is the edge with a brush, which takes a flushing agent or sorbent on the inner side of the outer pipe and at the same time contributes to a more intensive hydration of gaseous waste.

The outer pipe above the casing is attached through one or more separators to exhaust installation for the formation of low pressure in the combustion zone and the washing zone. As a result of formation of low pressure is achieved, on the one hand, the suction of gaseous waste from the combustion zone and, on the other hand, prevents the possibility of gaseous wastes through the flush holes and plums.

The invention is explained more by the example of execution. In the respective drawings are shown:

Fig. 1 is a schematic representation in cross section corresponding to the invention the cleaning unit gaseous wastes;

Fig.2 - device according to Fig. 1 with a plug-in zone of combustion;

Fig.3 - device cleaning of waste gases with a return of gaseous wastes;

Fig.4 is a simplified device treating the waste gases without a separate combustion zone;

Fig. 5 is a schematic representation in cross section of the burner with an additional cooling device;

Fig. 6 is a cross - section of the burner, snabi.

The list of signs:

1 - Outer tube.

1a - Upper part of the outer pipe.

1b is the lower part of the outer pipe.

2 - Basis.

3 - the Bottom.

4 - Plums.

5 - Cover.

6 - Zone combustion.

7 - Wash area.

8 - the Element of communication.

9 - Hole.

10 - the Gap.

11 - the Edge with a brush.

12 - Burner.

13 - Nozzle fuel gas.

14 - Nozzle supplying gaseous waste.

15 - the Heat shield.

16 - the Inner pipe.

16a - Upper part of the inner pipe.

16b - the lower part of the inner tube.

17 is an Annular gap.

18 - Nozzle spray.

19 - Ring injectors.

20 - Separator.

21 - Enter.

22 - Narrowing cross-section.

23 is an Annular gap.

24 - Protective pipe.

25 - the Lead pipe.

26 Camera.

27 - Pipeline.

28 - enter the gaseous waste.

29 - oxygen Flow.

30 - Egalitarian Luggage.

In accordance with Fig. 1, the cleaning device of gaseous waste status is eat conical or convex bottom plate 3, which in the deepest place is provided with a drain 4.

In the outer pipe 1 is expanding down the dome-shaped casing 5, which separates the lower zone of the combustion chamber 6 from above her washing zone 7. This fastening of the casing 5 into the outer pipe 1 is made by means of connection elements 8, provided with holes 9, for example, pieces of pipe, which is fixed to the casing 5. To ensure the passage of gas from the combustion zone 6 to the washing zone 7, the diameter of the casing 5 is smaller than the inner diameter of the outer pipe 1. Consequently remains free annular gap 10 in the area of the inner wall of the outer pipe 1, which overlaps mounted on the casing 5 edges with a brush 11.

Next, in the center of the dome-shaped casing 5 fortified burner 12 with the nozzle pointing downwards fuel gas 13 and nozzle supplying gaseous waste 14. Mount the burner 12 in the casing 5 may be a threaded connection or a clamping ring. In order to achieve good mixing of waste gases supplied to the nozzle supplying gaseous waste 14, with a combustible gas, a nozzle supplying gaseous waste 14 is designed as a Central nozzle surrounded by an annular nozzle fuel gas 13 or NESCO is hemy excess amount of oxygen, or hydrogen, also burned with excess oxygen.

Below the casing 5 is surrounding the burner 12 and, accordingly, the nozzle of the fuel gas supply 13 and the nozzle supplying gaseous waste 14 heat shield 15, which is the cone extends downwards and, in particular, serves to reduce thermal load of the casing 5. To separate the combustion zone 6 down from the casing 5 extends a fixed inner tube 16, which surrounds the heat shield 15. However, with a heat shield 15 and the inner wall of the inner tube 16 left annular gap 17, so that the space between the casing 5 and the heat-shielding screen 15 through the opening 9 communicates with a space outside the outer pipe 1. Thereby flushing the space between the casing 5 and the heat-shielding screen 15, if the zone of combustion 6 dominates reduced pressure.

The inner pipe 16 extending to the base 2, also serves to separate the flame in the combustion zone 6 from the fed in the area of thermal reactions of gaseous wastes that are sent as reaction gases from the base 2 on the inner side of the outer tube 1 up to the washing zone 7.

In the washing zone 7 of the smallest drops of sorbent. This sorbent is used for leaching occurs when combustion of gaseous waste gaseous and solid reaction products. When this cone spray nozzle 18 is obtained in the form of a solid cone and extends to the inner side of the outer pipe 1. At the same time thus the cooling of the burner 12.

Sorbent evenly, as the aerosol is distributed by the spray nozzle 18 in the washing zone 7 and then plays the casing 5 and secured on the edge of the brush 11 on the inner side of the outer pipe 1 and flows from there to the base 2 and then through the drain 4, not shown in the collection.

To clean the inner side of the inner tube 16 at its upper end to the casing 5 there is a ring of nozzles 19, which during pauses in the operation of water or sorbent can be sprayed on the inner side of the inner tube 16, thus there are deposits can be removed or reduced.

The upper part of the washing zone 7 forms a separator 20 for holding solid or liquid aerosols, coupled with a not shown exhaust installation, simultaneously producing the necessary negative pressure.

To ignite the flame of the mountains is the first input may be the ignition device and/or UV flame sensor.

Fig. 2 shows essentially the same device treating the waste gases, and the outer tube 1 and inner tube 16 is made detachable, so that the device can particularly easily disassembled and serviced. This outer tube 1 consists of the upper part 1a and a lower part 1b and the inner tube 16 from the upper portion 16a and a lower portion 16b connected to each other with the possibility of separation. Additionally, the base 2 may also be separated from the outer tube 1 or the lower part 1a of the outer pipe 1.

The upper part 1a of the outer tube 1 with a fixed burner 12, the casing 5, the upper part 16a of the inner pipe 16, with a heat shield 15, the hole 9 and the ring of nozzles 19 can move in the axial direction up or base 2 can be moved down in the axial direction. This allows you very easy to clean the combustion zone 6.

It is evident from Fig. 3 follows a special variant of the invention, which is implemented internal return gaseous wastes and internal flushing of the inner tube 16. Under this principle, the design corresponds to the variant shown in Fig. 2, with the upper portion 16a of the inner pipe 16 at the lower end has a narrowing cross-section 22, including the 23 part of the gaseous waste transported upward between the lower part 16b and the inner side of the lower part 1b, again supplied to the combustion zone 6 and fed back to a hot flame. Further, this return is provided by rinsing the inside of the lower portion 16b, so that there is, at least in part, prevents the deposition of particles.

To avoid sorbent through the annular gap 23 into the combustion zone, between the upper part 1a of the outer tube 1 and the upper part 16a is protective tube 24 that overlaps the upper edge of the lower portion 16b.

This protective tube 24 at the same time prevents excessive cooling of the upper part of the combustion zone 6.

Fig. 4 shows a simplified version of the invention, in which the area of the combustion chamber 6 is surrounded by only the outer tube 1. In order to achieve the best cooling of the burner 12, the flow of the sorbent to the spray nozzle 18 is made through the burner 12 so that the supply line 25 is conducted to the burner housing 12, which is explained below.

Particularly efficient cooling of the burner 12 is derived from Fig. 5. For this purpose between the nozzle supplying gaseous waste 14 and the nozzle or nozzles of the fuel gas 13 is a camera 26, concentrically with obroncow spray 18 and on the other hand, with feeder cleaners or sorbent. Thus is achieved a particularly intensive cooling of the burner, without affecting the temperature of the combustion processes. Therefore, this option is particularly suitable for hydrogen burner or combustion processes with a high temperature.

In Fig. 6, 7 shows a device for the simultaneous combustion of waste gases from various processes. For this purpose, as shown in Fig. 6, directly next to the burner 12 has two nozzles gaseous wastes 14, 14', and gaseous wastes produced through separate inputs gaseous wastes 28, 28'. The fuel gas nozzle 13 is surrounded by a nozzle supplying gaseous waste 14, 14' and are supplied with a combustible gas not shown on the entry of combustible gas through the annular surge chamber 30. Additional oxygen supply 29 provides combustion with particularly high excess of oxygen.

With this design you can burn the waste gases, which when mixed outside of the combustion chamber would become uncontrollable to react with each other, resulting simultaneously achieved much more efficient use of the mouth is not limited to, moreover, only the amount of burners 12 limits the number of nozzles supplying gaseous waste 14, 14'. For reliable operation with multiple inputs gaseous wastes only need to pay in order to reliably prevent a reverse flow of waste gases into the inputs of the gaseous waste 28, 28'.

1. Device for cleaning exhaust gas, in particular of waste gases from the CVD process, plasma etching, with at least one zone of combustion of vertical location in the outer pipe, limited internal pipe extending up from the base of the outer tube and terminating at a certain distance from the bottom of the base, and the top is dome-shaped casing, and a burner internal or external mixing nozzle fuel gas which juts into the zone of combustion, and to the burner provided with a supply of combustible gas, oxygen or air and gaseous wastes, as well as by means of feed and withdrawal of the sorbent to the washing area outside the zone of combustion, characterized in that the burner (12) is fixed in the center of the dome-shaped casing (5), equipped with nozzles combustible gas and at least one nozzle supplying gaseous waste directed vertically downward into the zone of combustion (6) arising ¡area and possible removal of the sorbent after its distribution in the wash zone and the enrichment of the reaction products along the inner side of the outer pipe through the base.

2. The device under item 1, characterized in that the fuel gas nozzle (13) are arranged concentrically around the nozzle supplying gaseous waste (14).

3. The device under item 1 or 2, characterized in that the burner (12) is attached to the cooling device.

4. Device according to one of paragraphs.1 to 3, characterized in that the means for supplying sorbent or cleaners - spray nozzle (18) is made in the form of an annular nozzle, nozzle solid or hollow cone and placed in the outer pipe above the stove.

5. The device according to p. 4, characterized in that the spray nozzle (18) through line (27) is connected with the chamber (26) in the burner (12), through which the spray nozzle (18) is provided to feed sorbent or washing facilities.

6. The device under item 5, characterized in that the chamber (26) is located between the fuel gas nozzles (13) and a nozzle supplying gaseous waste (14) concentrically around the last.

7. Device according to one of paragraphs.1 - 6, characterized in that between the combustion zone (6) and cover (5) is located concentrically surrounding the burner (12) and extending from top to bottom heat shield (15).

8. Device according to one of paragraphs.1 to 7, characterized those is different, however, between the heat-shielding screen (15) and the inner wall of the inner tube (16) is made annular gap (17) and that the space between the casing (5) and with a heat shield (15) through hole (9) is connected with the space outside the outer tube (1).

10. Device according to one of paragraphs.1 to 9, characterized in that the space between the casing (5) and with a heat shield (15) is a ring of nozzles (19) with nozzles for supplying a flushing means, directed to the inner wall of the inner tube (16).

11. Device according to one of paragraphs.1 to 10, characterized in that the bottom (3) of the base (2) in the deepest place is provided with a drain.

12. Device according to one of paragraphs.1 - 11, characterized in that the outer and inner pipe (1, 16) made of composite of the upper and lower parts (1A, 16A; 1b, 16b) connected to each other with the possibility of separation.

13. The device according to p. 12, characterized in that the base (2) is connected with the outer pipe (1) or part (1b) of the outer pipe (1) with the possibility of separation.

14. The device under item 12 or 13, characterized in that the upper part (1A) of the outer pipe (1) with a casing (5) and secured on the burner (12), the upper part (16A) of the inner tube (16), with a heat shield (15)15. The device under item 12 or 13, characterized in that the base (2) is installed with the possibility of axial movement down.

16. Device according to one of paragraphs.12 to 14, characterized in that the upper part (16A) of the inner tube (16) at the lower end is made with narrowing cross-section (22) and installed with the formation of the annular gap (23) with the upper end of the lower part of the inner pipe (16b).

17. The device according to p. 16, characterized in that between the upper part (1A) of the outer pipe (1) and the upper part of the inner tube is a protective pipe (24) overlying the upper edge of the lower part (16b).

18. Device according to one of paragraphs.1 to 17, characterized in that the zone of combustion (6) through the input (21) is connected to the space outside the outer tube (1) and that in the input (21) are devices for ignition or control of the burner (12).

19. Device according to one of paragraphs.1 to 18, characterized in that the burner (12) contains a device for the ignition and control.

20. Device according to one of paragraphs.1 to 19, characterized in that between the cover (5) and the inner side of the outer tube (1) is the edge with the brush (11).

21. Device according to one of paragraphs.1 to 20, characterized in that the outer tube (1) over shell & the combustion (6) and in the wash zone (7).

 

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