Apparatus and method for treating exhaust gas of a main process

Abstract

The invention relates to an apparatus (1) for treating exhaust gas (2) of a main process (3), comprising a filter unit (4), which has a first and a second filter stage (5, 6), and a gas feed line (11) for feeding the exhaust gas (2) from the main process (3) to the filter unit (4). The first filter stage (5) comprises a first filter (7) and a second filter (8); the second filter stage (6) comprises a third filter (9). The third filter (9) is disposed in the filter unit (4) between the first filter (7) and the second filter (8). The gas feed line (11) has a device (12) for dividing the incoming exhaust gas (2) among a first and a second gas feed line (13, 14). A gas transfer system (18) is used to transfer the partial gas flows (16, 17), after flow through the first and second filters (7, 8), to the third filter (9). The gas transfer system (18) has a main-additive feed device (21) for feeding a main additive (22) to the exhaust gas. Discharge devices (23, 25, 27) are provided for discharging filter products (24, 26, 28) removed by the filters (7, 8, 9). The invention also relates to a method for treating exhaust gas of a main process by means of the apparatus according to the invention.

Description

[0001] Description

[0002] Apparatus and method for treating exhaust gas from a main process

[0003] The invention relates to a device for treating exhaust gases from a main process, comprising a filter unit for cleaning the exhaust gases and a gas supply line for supplying the exhaust gases from the main process to the filter unit. The invention further relates to a method for treating exhaust gases from a main process using this device.

[0004] The main process can, for example, be a primary process in a sintering plant, pelletizing plant, coking plant, power plant, or similar facility. This main process generates process gases, hereinafter referred to as exhaust gases, which must be cleaned by appropriate treatment before being released into the environment.

[0005] In exhaust gas purification, it is common practice to add adsorbents and absorbents to the exhaust gas as additives. These adsorbents and absorbents bind and subsequently remove components of the exhaust gas. Fabric filters are used for this removal.

[0006] WO 2006 / 099948 A1 discloses methods and devices for treating exhaust gas from sintering plants, which comprise fabric filters for cleaning the exhaust gas.

[0007] In known devices and methods for exhaust gas purification, filtering is carried out in a single stage. The addition of adsorbents and absorbents in combination with dust from the main process in the fabric filters thus produces a filter product which is removed from the exhaust gas and in which dust, adsorption products and absorption products are mixed together. In most cases, due to the pollutant content of this mixed filter product, the only option is to dispose of it in landfill. In some applications, partial recycling of the product is possible, but depending on the additives used, this requires complex processing of the mixed filter product, for example by leaching. One such processing method is known, for example, from WO 2022 / 048965 A1.In this way, valuable components can be extracted from the mixed filter product, which can then be added to the main process or other processes.

[0008] A disadvantage of the known devices and methods is that the addition of additives with different effects occurs before the single-stage filter unit, resulting in the various products and dusts contained in the exhaust gas only being collected together as a mixed filter product. Separation of the various products and dusts after filtration is not possible or only possible with additional, complex treatment processes.

[0009] The invention is based on the object of specifying a new device and a new method for treating exhaust gas from a main process, in particular a device and a method in which different filter products can be discharged from the filter unit, preferably without significantly increasing the space requirement for the filter unit of the device in comparison with known devices.

[0010] This object is achieved with regard to the device by the features of the device according to claim 1 and with regard to the method by the features of the method according to claim 10. Embodiments and further developments are specified in the respective dependent claims.

[0011] The device according to the invention for treating exhaust gas from a main process comprises a filter unit for cleaning the exhaust gas and a gas feed line for supplying the exhaust gas from the main process to the filter unit. The invention provides that the filter unit comprises a first filter stage and a second filter stage. The first filter stage in turn comprises a first filter and a second filter. The second filter stage comprises a third filter. The first filter, the second filter and the third filter are each a fabric filter, wherein each fabric filter can comprise one or more filter elements. The fabric filters serve to dedust the exhaust gas flowing through it. The fabric filters can be, for example, pulse-jet filters, i.e. fabric filters in which compressed air flows through the fabric filter elements in countercurrent for cleaning purposes.During cleaning, the filter products collect in appropriate collecting devices and can be discharged.

[0012] According to the invention, the third filter is arranged in the filter unit between the first filter and the second filter. The gas supply line has a device for dividing the incoming exhaust gas into a first gas supply line and a second gas supply line, the first gas supply line being designed to supply a first partial gas flow of the exhaust gas to the first filter and the second gas supply line being designed to supply a second partial gas flow of the exhaust gas to the second filter. The first and second filters are therefore arranged parallel to one another in the exhaust gas flow with regard to the exhaust gas flow. For example, the first and second filters can be at least substantially identical in construction. It can also be provided that the first and second filters in the filter unit are arranged and / or designed symmetrically to a central surface of the second filter.

[0013] The invention further provides that the exhaust gas treatment device comprises a gas transmission system for transmitting the first partial gas stream after flowing through the first filter and the second partial gas stream after flowing through the second filter to the third filter. According to the invention, the gas transmission system comprises at least one main additive supply device for supplying at least one main additive to the exhaust gas.

[0014] According to the invention, the device for treating exhaust gas has a first discharge device for discharging a first filter product separated by the first filter and a second discharge device for discharging a second filter product separated by the second filter and a third discharge device for discharging a third filter product separated by the third filter from the filter unit.

[0015] The advantages of the invention lie in the fact that the two-stage filtration and the addition of the main additive between the filter stages result in at least two different filter products being created directly through filtration, without any further treatment steps: the first and second filter products, and the third filter product, which are discharged separately from the filter unit. The different filter products can be recycled and / or disposed of independently of one another.

[0016] In principle, this advantage could also be achieved by two independent filter units connected in series. However, this would significantly increase the space required for the entire filter device. A further advantage of the invention is that the combination of the two filter stages in one filter unit enables spatially compact two-stage filtration. The space requirement of the two-stage filter unit provided according to the invention does not differ significantly from the space requirement of a single-stage filter unit known from the prior art with comparable filter performance. This is made possible by dividing the first filter stage into two filters connected in parallel with regard to the exhaust gas flow, the first filter and the second filter, and the second filter stage with a further, third filter which is spatially arranged in the filter unit between the first and second filters.This allows exhaust pipes and / or discharge devices for filter products to be arranged in a compact and therefore space-saving manner.

[0017] A further advantage of the single-stage filter unit is the lower investment and operating costs compared to two filter units connected in series. These costs do not differ significantly from the investment and operating costs of a conventional single-stage filter unit with comparable filter performance.

[0018] According to a further development of the invention, the gas supply line can have at least one primary additive supply device for supplying at least one primary additive to the exhaust gas. The separate supply of the primary additive and the main additive before different filter stages supports the aforementioned advantage that at least two different filter products are produced directly by filtration, without further treatment steps.

[0019] One embodiment of the invention provides that the filter unit has a common housing for the first filter, the second filter, and the third filter. For example, the housing can have a cuboid shape with a length, a width, and a height, the length being greater than the width and the height. In this case, the third filter can be arranged in the housing in the longitudinal direction between the first and the second filter. In particular, the first and second filters are located at opposite ends of the cuboid housing, and the third filter is arranged centrally in the cuboid housing.

[0020] One embodiment provides that the gas forwarding system between the first and second filters on the one hand and the third filter on the other hand has a first gas forwarding line for forwarding the first partial gas stream after it has flowed through the first filter, a second gas forwarding line for forwarding the second partial gas stream after it has flowed through the second filter, a device for combining the first partial gas stream and the second partial gas stream to form a total gas stream and a third gas forwarding line for forwarding the total gas stream to the third filter. In this case, at least two main additive feed devices can be provided for feeding at least one main additive to the exhaust gas, one of these main additive feed devices being arranged on the first gas forwarding line and another of these main additive feed devices being arranged on the second gas forwarding line.Alternatively or additionally, one of the at least one main additive supply devices for supplying at least one main additive to the exhaust gas can be arranged on the third gas forwarding line.

[0021] It can also be provided that the gas supply line arranged between the main process and the filter unit has one of the at least one primary additive supply devices for supplying at least one primary additive in a third gas supply line, which, from the perspective of the exhaust gas flow, is arranged upstream of the device for dividing the incoming exhaust gas. Alternatively or additionally, at least two primary additive supply devices can also be provided for supplying at least one primary additive, one of these primary additive supply devices being arranged on the first gas supply line and another of these primary additive supply devices being arranged on the second gas supply line.

[0022] The primary additive and / or the main additive can be added, for example, by means of injection.

[0023] The primary additive can be, for example, an absorbent, such as activated carbon or hearth furnace coke. The resulting first and second filter products can then be fed, for example, to the main process from which the exhaust gas is generated, and / or to another main process and / or to another recycling process. In some embodiments, no further processing steps are required.

[0024] The main additive can be an absorbent, for example Ca(0H)2 or NaHCO3. If Ca(0H)2 is used as the main additive, the resulting third filter product can be fed directly to a recycling process, for example cement production, without any further processing steps. If NaHCO3 is used as the main additive, the resulting third filter product can be fed to a further treatment, for example leaching. If suitable second additives are used, the gas transmission system with the main additive feed device, if necessary in conjunction with a gas conditioner described in more detail below, can be used for flue gas desulfurization.

[0025] A further development of the invention provides that a gas conditioner is arranged in the gas transmission system between the first filter and the second filter on the one hand, and the third filter on the other. For example, the gas conditioner can be configured to cool the exhaust gas stream. Alternatively or additionally, the gas conditioner can be a gas conditioning reactor and, for example, provide a reaction chamber for added additives.

[0026] One embodiment provides that the first discharge device and the second discharge device are designed to supply the first filter product and the second filter product to the main process from which the exhaust gas originates and / or to another main process and / or to a further utilization process.

[0027] The third discharge device can be designed to supply the third filter product at least partially to a further treatment device and / or at least partially to the main process and / or at least partially to the gas supply line and / or at least partially to the gas transmission system and / or at least partially to a further main process and / or at least partially to a further utilization process.

[0028] From the perspective of the flowing exhaust gas, the purified exhaust gas exits the filter unit after passing through the second filter stage and the third filter. For this purpose, a clean gas line is assigned to the third filter, which receives the purified exhaust gas after passing through the first and second filter stages and feeds it to a gas aftertreatment and / or exhaust device, for example, a flue gas denitrification system and / or a blower and / or a chimney.

[0029] The method according to the invention for treating exhaust gas from a main process uses the device according to the invention described above. The method comprises the following steps: a) The exhaust gas from the main process is fed to the filter unit by means of the gas feed line, the exhaust gas being divided in the device for splitting the incoming exhaust gas and a first partial gas stream of the exhaust gas being fed to the first filter by means of the first gas feed line and a second partial gas stream of the exhaust gas being fed to the second filter by means of the second gas feed line; b) the first partial gas stream is passed on to the third filter after flowing through the first filter and the second partial gas stream is passed on to the third filter by means of the gas forwarding system, at least one main additive being fed to the exhaust gas by means of the at least one main additive feed device;c) a first filter product separated by the first filter is discharged from the filter unit by means of the first discharge device and / or a second filter product separated by the second filter is discharged by means of the second discharge device and / or a third filter product separated by the third filter is discharged by means of the third discharge device;

[0030] The advantages of this method and embodiments and further developments of this method emerge from the above explanations of the device according to the invention.

[0031] According to a further development of the method, in step a) at least one primary additive can be supplied to the exhaust gas by means of the at least one primary additive supply device.

[0032] One embodiment of the method provides that in step b) the first partial gas flow, after flowing through the first filter, is first fed via the first gas forwarding line and the second partial gas flow, after flowing through the second filter, is first fed via the second gas forwarding line to the device for combining the first partial gas flow and the second partial gas flow to form a total gas flow, and then the total gas flow is fed via the third gas forwarding line to the third filter.

[0033] A further development of the method provides that the exhaust gas is conditioned between the first filter and the second filter on the one hand and the third filter on the other hand, in particular by means of the gas conditioner described above.

[0034] One embodiment of the process provides for the first filter product and the second filter product to be fed into the main process and / or another main process and / or another recycling process. In some embodiments, no further processing steps are required.

[0035] Alternatively or additionally, it can be provided that the third filter product is fed at least partially to a further treatment device and / or at least partially to the main process and / or at least partially to the gas supply line and / or at least partially to the gas transmission system and / or at least partially to another main process and / or at least partially to a further utilization process.

[0036] According to one embodiment of the process, the primary additive may comprise an adsorbent and / or the main additive may comprise an absorbent. Examples of this have already been explained above.

[0037] One embodiment of the invention provides that the primary additive comprises an inert substance, for example CaCO3, for controlling the carbon content in the first filter product and / or in the second filter product.

[0038] The invention will be explained in more detail below with regard to further features and advantages by means of the description of an embodiment and with reference to the enclosed schematic drawing. It shows

[0039] FIG 1 shows an embodiment of a device according to the invention for treating exhaust gases from a main process.

[0040] FIG. 1 shows a schematic representation of a device 1 according to the invention for treating exhaust gas 2 of a main process 3. The main process 3 can be, for example, a primary process in a sintering plant, pelletizing plant, coking plant, power plant or comparable plant.

[0041] The device 1 comprises a filter unit 4 for cleaning the exhaust gas 2 and a gas feed line 11 for supplying the exhaust gas 2 from the main process 3 to the filter unit 4. The filter unit 4 is designed as a two-stage filter unit 4 with a first filter stage 5 and a second filter stage 6. The first filter stage 5 is divided into two parts and comprises a first filter 7 and a second filter 8, which are spatially separated and spaced from one another in the filter unit 4. The second filter stage 6 comprises a third filter 9, which is arranged in the filter unit 4 between the first filter 7 and the second filter 8.

[0042] The filter unit 4 has a common housing 29 for the first filter 7, the second filter 8 and the third filter 9. The housing 29 has a cuboid shape (not shown completely in FIG. 1), i.e. the housing has a greater length than its width and height. The three filters 7, 8, 9 are arranged one behind the other in the housing 29 in the longitudinal direction thereof, with the third filter 9 being arranged between the first filter 7 and the second filter 8. For example, the filter unit 4 can have a length of the order of magnitude of 15 to 20 meters and a width and height of the order of magnitude of 7 to 8 meters.

[0043] The first filter 7, the second filter 8, and the third filter 9 are each a fabric filter 10. Each fabric filter 10 can comprise one or more filter elements (not shown). The fabric filters 10 can be, for example, pulse-jet filters.

[0044] The gas supply line 11 has a device 12 for dividing the incoming exhaust gas 2 into a first gas supply line 13 and a second gas supply line 14. The first gas supply line 13 is designed to supply a first partial gas stream 16 of the exhaust gas 2 to the first filter 7 and the second gas supply line 14 is designed to supply a second partial gas stream 17 of the exhaust gas 2 to the second filter 8. The gas supply line 11 has, in a third gas supply line 15 between the main process 3 and the device 12 for dividing the incoming exhaust gas 2, a primary additive supply device 19 for supplying at least one primary additive 20 to the exhaust gas 2. The primary additive 20 can be supplied, for example, by means of injection.

[0045] The device 1 for treating exhaust gases 2 further comprises a gas forwarding system 18 for forwarding the first partial gas stream 16 after flowing through the first filter 7 and the second partial gas stream 17 after flowing through the second filter 8 to the third filter 9. For this purpose, the gas forwarding system 18 has a first gas forwarding line 30 for forwarding the first partial gas stream 16 after flowing through the first filter 7 and a second gas forwarding line 31 for forwarding the second partial gas stream 17 after flowing through the second filter 8 and a device 32 for combining the first partial gas stream 16 and the second partial gas stream 17 to form a total gas stream 33 and a third gas forwarding line 34 for forwarding the total gas stream 33 to the third filter 9.

[0046] The illustrated device 1 for treating exhaust gas 2 has two main additive supply devices 21 for supplying at least one main additive 22 to the exhaust gas 2, one of these main additive supply devices 21 being arranged on the first gas line 30 and another of these main additive supply devices 21 being arranged on the second gas line 31. The supply of the main additive 22 can be effected, for example, by means of injection.

[0047] In the gas transmission system 18, a gas conditioner 35 is arranged between the first filter 7 and the second filter 8 on the one hand and the third filter 9 on the other hand, in the example shown downstream of the device 32 for combining the first partial gas stream 16 and the second partial gas stream 17 from the perspective of the exhaust gas stream. This can be a gas conditioning reactor which, for example, provides a reaction space for added additives. The device 1 for treating exhaust gas 2 has a first discharge device 23 for discharging a first filter product 24 separated by the first filter 7 and a second discharge device 25 for discharging a second filter product 26 separated by the second filter 8. The first discharge device 23 and the second discharge device 25 are designed to feed the first filter product 24 and the second filter product 26 to the main process 3.

[0048] Furthermore, a third discharge device 27 is provided for discharging a third filter product 28 separated by the third filter 9 from the filter unit 4. The third discharge device 27 is designed to supply the third filter product 28 partially to a further treatment device 36, for example a so-called leaching device, and partially to the gas transmission system 18. It is also possible for the third filter product 28 to be supplied directly to a recycling facility, for example, cement production, without further processing steps (not shown).

[0049] The primary additive 20 may, for example, be an adsorbent, and the main additive 22 may be an absorbent. The primary additive 20 may include an inert substance, for example, CaCO3, for controlling the carbon content in the first filter product 24 and the second filter product 26.

[0050] From the perspective of the flowing exhaust gas, the cleaned exhaust gas 37 exits the filter unit 4 after flowing through the second filter stage 6 with the third filter 9. For this purpose, a clean gas line 38 is assigned to the third filter 9 (shown only schematically in FIG. 1), arranged for example above the third filter 9 (this arrangement is not shown in FIG. 1), which receives the cleaned exhaust gas 37 after flowing through the first filter stage 5 with the first filter 7 and the second filter 8 and the second filter stage 6 with the third filter 9 and feeds it to a gas aftertreatment and / or blow-out device 39, for example a flue gas denitrification system and / or a blower and / or a chimney.

[0051] Reference symbol list

[0052] 1 device for the treatment of exhaust gases

[0053] 2 exhaust gas

[0054] 3 Main process

[0055] 4 filter unit

[0056] 5 first filter stage

[0057] 6 second filter stage

[0058] 7 first filter

[0059] 8 second filter

[0060] 9 third filter

[0061] 10 fabric filters

[0062] 11 Gas supply line

[0063] 12 Device for dividing the incoming exhaust gas

[0064] 13 first gas supply line

[0065] 14 second gas supply line

[0066] 15 third gas supply line

[0067] 16 first partial gas flow

[0068] 17 second partial gas flow

[0069] 18 Gas transmission system

[0070] 19 Primary additive feed device

[0071] 20 Primary additive

[0072] 21 Main additive feeding device

[0073] 22 Main additive

[0074] 23 first discharge facility

[0075] 24 first filter product

[0076] 25 second discharge facility

[0077] 26 second filter product

[0078] 27 third distribution facility

[0079] 28 third filter product

[0080] 29 housings

[0081] 30 first gas transmission

[0082] 31 second gas transmission line

[0083] 32 Device for combining the first and second part gas stream

[0084] 33 Total gas flow

[0085] 34 third gas transmission line 35 gas conditioner

[0086] 36 additional treatment facilities for the third filter product

[0087] 37 purified exhaust gas 38 clean gas line

[0088] 39 Gas aftertreatment and / or blow-out device

Claims

Patent claims 1. Device (1) for treating exhaust gas (2) of a main process (3), comprising a filter unit (4) for cleaning the exhaust gas (2) and a gas supply line (11) for supplying the exhaust gas (2) from the main process (3) to the filter unit (4), characterized in that the filter unit (4) comprises a first filter stage (5) and a second filter stage (6), wherein the first filter stage (5) comprises a first filter (7) and a second filter (8), wherein the second filter stage (6) comprises a third filter (9), wherein the first filter (7) and the second filter (8) and the third filter (9) are each a fabric filter (10), wherein the third filter (9) is arranged in the filter unit (4) between the first filter (7) and the second filter (8), wherein the gas supply line (11) has a device (12) for dividing the incoming exhaust gas (2) between a first gas supply line (13) and a second gas supply line (14),wherein the first gas supply line (13) is designed to supply a first partial gas flow (16) of the exhaust gas (2) to the first filter (7) and the second gas supply line (14) is designed to supply a second partial gas flow (17) of the exhaust gas (2) to the second filter (8), wherein the device (1) for treating exhaust gas (2) has a gas forwarding system (18) for forwarding the first partial gas flow (16) after flowing through the first filter (7) and the second partial gas flow (17) after flowing through the second filter (8) to the third filter (9), wherein the gas forwarding system (18) has at least one main additive supply device (21) for supplying at least one main additive (22) to the exhaust gas (2), wherein the device (1) for treating exhaust gas (2) has a first discharge device (23) for discharging a first filter (7) separated first filter product (24) and a second discharge device (25) for discharging a second filter product (26) separated by the second filter (8) and a third discharge device (27) for discharging a third filter product (28) separated by the third filter (9) from the filter unit (4).

2. Device (1) according to claim 1, wherein the gas supply line (11) has at least one primary additive supply device (19) for supplying at least one primary additive (20) to the exhaust gas (2).

3. Device (1) according to claim 1 or 2, wherein the filter unit (4) has a common housing (29) for the first filter (7) and the second filter (8) and the third filter (9), wherein the housing (29) has a cuboid shape with a length, a width and a height, wherein the length is greater than the width and the height, wherein the third filter (9) is arranged in the housing (29) in the longitudinal direction between the first filter (7) and the second filter (8).

4. Device (1) according to one of claims 1 to 3, wherein the gas forwarding system (18) has a first gas forwarding line (30) for forwarding the first partial gas stream (16) after it has flowed through the first filter (7) and a second gas forwarding line (31) for forwarding the second partial gas stream (17) after it has flowed through the second filter (8) and a device (32) for combining the first partial gas stream (16) and the second partial gas stream (17) to form a total gas stream (33) and a third gas forwarding line (34) for forwarding the total gas stream (33) to the third filter (9).

5. Device (1) according to claim 4, wherein at least two main additive supply devices (21) are provided for supplying at least one main additive (22) to the exhaust gas (2) wherein one of these main additive supply devices (21) is arranged on the first gas line (30) and another of these main additive supply devices (21) is arranged on the second gas line (31).

6. Device (1) according to claim 4 or 5, wherein one of the at least one main additive supply devices (21) for supplying at least one main additive (22) to the exhaust gas (2) is arranged on the third gas forwarding line (34).

7. Device (1) according to one of claims 1 to 6, wherein a gas conditioner (35) is arranged in the gas transmission system (18) between the first filter (7) and the second filter (8) on the one hand and the third filter (9) on the other hand.

8. Device (1) according to one of claims 1 to 7, wherein the first discharge device (23) and the second discharge device (25) are designed to feed the first filter product (24) and the second filter product (26) to the main process (3).

9. Device (1) according to one of claims 1 to 8, wherein the third discharge device (27) is designed to supply the third filter product (28) at least partially to a further treatment device (36) and / or at least partially to the main process (3) and / or at least partially to the gas supply line (11) and / or at least partially to the gas transmission system (18) and / or at least partially to a further utilization process.

10. Method for treating exhaust gas (2) of a main process (3) with a device (1) according to one of claims 1 to 9, in which a) the exhaust gas (2) of the main process (3) is fed to the filter unit (4) by means of the gas feed line (11), wherein the exhaust gas (2) in the device (12) for dividing the incoming exhaust gas (2) and a first partial gas flow (16) the exhaust gas (2) is fed to the first filter (7) by means of the first gas supply line (13) and a second partial gas stream (17) of the exhaust gas (2) is fed to the second filter (8) by means of the second gas supply line (14), b) the first partial gas stream (16) after flowing through the first filter (7) and the second partial gas stream (17) after flowing through the second filter (8) are passed on to the third filter (3) by means of the gas forwarding system (18), and at least one main additive (22) is fed to the exhaust gas (2) by means of the at least one main additive feed device (21), and c) a first filter product (24) separated by the first filter (7) by means of the first discharge device (23) and / or a second filter product (26) separated by the second filter (8) by means of the second discharge device (25) and / or a third filter product (28) separated by the third filter (9) is discharged from the filter unit (4) by means of the third discharge device (27).

11. The method according to claim 10, wherein in step a) at least one primary additive (20) is supplied to the exhaust gas (2) by means of at least one primary additive supply device (19).

12. The method according to claim 10 or 11, wherein in step b) the first partial gas stream (16), after flowing through the first filter (7), is first fed via a first gas forwarding line (30) and the second partial gas stream (17), after flowing through the second filter (8), is first fed via a second gas forwarding line (31) to a device (32) for combining the first partial gas stream (16) and the second partial gas stream (17) to form a total gas stream (33), and then the total gas stream (33) is fed via a third gas forwarding line (34) to the third filter (9).

13. Method according to one of claims 10 to 12, in which the exhaust gas (2) between the first filter (7) and the second filter (8) on the one hand and third filter (9) on the other hand.

14. Method according to one of claims 10 to 13, wherein the first filter product (24) and the second filter product (26) be fed into the main process (3) and / or another main process and / or another recycling process.

15. Method according to one of claims 10 to 14, in which the third filter product (28) is fed at least partially to a further treatment device (36) and / or at least partially to the main process (3) and / or at least partially to the gas supply line (11) and / or at least partially to the gas transmission system (18) and / or at least partially to a further utilization process.

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