DE19852954A1 - Recombiner for the effective removal of hydrogen from hazardous atmospheres - Google Patents

Abstract

The invention relates to a recombiner for removing hydrogen from air contaminated by accidents, which comprises a housing (10) which defines a longitudinal direction for a through-flow and at both ends, in the longitudinal direction, has at least one opening. Said recombiner further comprises at least one catalyst element (11) arranged inside the housing (10). The aim of the invention is to solve the technical problem of reacting in a controlled and efficient manner and at a wide range of concentrations both small and large quantities of hydrogen with the atmospheric oxygen present in the containment vessels. To this end the at least one catalyst element (11) is configured in modular form and filled with a porous substrate which is coated with a catalytic material. The catalyst element (11) at least partly fills the cross-section of the housing (10).

Description

The invention relates to devices with which hydrogen released or caused by accidents from non-inertized rooms, e.g. B. security containers of pressure and non-inertized boiling water reactors that In addition to hydrogen, water vapor, air, aerosols and white Contain tere gases, effectively eliminated without reignition can be. The hydrogen can be present in the presence of the existing atmospheric oxygen, e.g. B. by means of catalytic Method to recombine within the device to water vapor be kidneyed.

In the course of serious accidents, large amounts of hydrogen are generated in water-cooled nuclear reactors (LWR) due to the reduction of water vapor, which get into the containment. The maximum amounts of hydrogen can both compressive and boiling water reactors about 20,000 m _n ³ gen Betra. Because of that are available in the safety containers (containment) air oxygen, there is the risk of formation of flammable mixtures, their uncontrolled inflammations dung with subsequent detonation severe dynamic compressive stress of the containment walls. In addition, water vapor and hydrogen always lead to pressure and temperature increases in the accident atmosphere. This is in particular sondere in boiling water reactors significant because the volumes m _n ³ as compared to 70,000 m _n be their only about 20,000 container ³ for pressurized water reactors. Increases in pressure and temperature lead to additional static stress on the containment walls. In addition, there is a risk of leakage of radiotoxic substances in the event of leakage due to the excess pressure.

Preventive safety measures are in place at Inerti Sizing the gas volumes with nitrogen, as in the case of Boiling water reactors have already been made. Further Countermeasures already implemented represent catalytic re combiners. With their help the resulting what hydrogen both inside and outside the ignition limits exothermic catalytically recombined, d. H. under development converted from heat into water vapor. Hydrogen content with Concentrations within the ignition limits can be shown also burn conventionally after spark ignition. However, the processes that occur are not controlled l barable, so that it may be one of the above mentioned reactions that could endanger the system.

To eliminate the normal operation and accidents resulting hydrogen were both thermal as well Catalytic recombiners developed the hydrogen recombine with the oxygen of the air in water vapor. Preferred are catalytic systems that are passive, i. H. self-starting and without external energy supply, work, to ensure availability during an incident  is steady. There are two types of recombiner, the substra te both metallic plates or foils as well as highly porous These granules are used on the platinum or palladium is applied as a catalyst. Several foils and granules lat packets - the granules are flat from wire nets Parcels held together - are vertical and parallel to each other other arranged in a housing. The hydrogen / air mix enters the bottom of the case and the catalytic coated surfaces set the reaction on. The mixture or the reaction products overflow in however, only the resulting thermal buoyancy Surfaces of the films or the granulate packages.

Therefore, especially in the case of the granule packages, only one ge small part of the total existing catalytic surface surface and used to convert the hydrogen. Despite the large free surface of the recombiner, the Porous granules used as the substrate is the effectiveness significantly less than the other Sy also developed systems for which plates or foils are used. The Fuel gas / air mixture reached when overflowing the be layered substrates not all catalytic centers because the reaction only takes place on the package surfaces. The reaction is incomplete in both systems. About that in addition results from the vertical arrangement of the foils or the granule packages that a large proportion of the cross section of the housing is freely flowing and therefore not is used for the recombination.

Another disadvantage is the fact that a targeted Premixing not possible before entering recombiners is. The reactants become oxygen and hydrogen fed to the recombiners as they arise or locally available. The maximum degradation rates or thermal The performance of existing systems is limited due to the Overflow of the surfaces and the associated ge  wrestle cross exchange. In addition, the possibility of heat memory storage low.

The heat of reaction is also removed from the systems problematic. It takes place almost exclusively as a result of Kon vection from the solid surfaces to the flowing past Gases and heat radiation to neighboring structures. To Large amounts of hydrogen can cause the be lead stratified substrates so that the ignition temperature he is sufficient or exceeded and it is consequently too homo gene gas phase reactions with deflagration or detonation can come. Another disadvantage is the additional on heating of the surroundings.

The available systems see the entry of the the hydrogen-containing mixture at the bottom. Due to the reaction on the catalytically active surfaces Chen there is a buoyancy, so that the depleted Mixture emerges at the top. Therefore, to increase buoyancy in the prior art constrictions of the outer housing see. Another variant of the prior art would depend gen has a constant cross-section over the entire height on. In the upper area, however, the mixture is reversed by 90 ° directs. It leaves the housing through an outlet grille. In order to these systems are preferably only for a vertical one Flow from bottom to top is suitable.

In the large security containers, however, it is the outer walls also to a downward flow come, so that recombiners arranged there at least for flows through from top to bottom for a certain time and due to the internal buoyancy and the resulting ge blocked flow directions for a long time can be. In addition, it is likely to would come to a reversal of the flow, so that for these cases and mining equipment effective for these conditions  who needs improved start-up behavior the.

The technical problem of the present invention exists hence in both small and large amounts of hydrogen with the air acid present in the security containers controlled in a wide range of concentrations and implement efficiently.

The technical problem outlined above is caused by a Recombiner for removing hydrogen from accidents spheres with a housing that has a longitudinal direction for a Flow specifies and at both ends in the longitudinal direction each has at least one opening, and with at least a catalyst element which is arranged in the housing, solved, wherein the at least one catalyst element module is formed like and made with a porous substrate is filled, which is coated with a catalyst material is, and wherein the at least one catalyst element Cross section of the housing essentially completely fills.

According to the invention, it has been recognized that the efficiency of the Recombiners can definitely be improved by that the gas mixture flowing through the recombiner Incident atmosphere not only on the surfaces of the Kataly flows past the catalyst elements, but the catalyst elements must flow through, so that the largest possible proportion of ka surfaces with a catalytic effect within the catalyst mo duls is overflowed by the gas mixture. Thus, higher order Settling rates reached, so that from the recombiner emerging gas mixture is sufficiently emaciated to an un controlled combustion of the gas mixture outside the re avoid combiners efficiently. By the present Invention is therefore achieved in that the hydrogen in the Containment of a pressurized water reactor at a cat  layered surfaces is implemented in a controlled manner, whereby the risk of ignition of the hydrogen-rich mixture is largely avoided. The elimination is also ongoing of hydrogen so effective that it may be the beginning the high hydrogen concentrations present in the accident quickly to concentrations below the lower ignition limit be lowered and thus the risk of major explosion Amounts of hydrogen can be avoided with certainty.

At least two catalyst modules are preferred provided that side by side and / or one above the other in Ge are arranged. You can choose between two next to each other of the arranged catalyst modules at least one free one Flow channel may be provided. Furthermore, is more preferred Way between two superimposed catalyst mo or two layers of several catalyst modules each have at least one intermediate provided space, the catalyst modules symmetrical or are arranged asymmetrically in the housing. By this variable arrangement of the catalyst modules due to the modular properties of the catalyst elements in the first place is possible, it is ensured that in addition to the flow the catalyst modules also a free flow of the gas mixture is possible through the recombiner. Here does the free cross section in the layers in which Kata are arranged only a small part of the entire cross section. Overall, however, is based on this Way generated an internal circulation, so in particular then when the flow is within the containment changes direction, also the flow direction within the Recombiner through the main flow direction of the Gasge mixed current can be reversed. The spaces between each two catalyst modules or layers of Catalyst modules also serve one each Mixing of the gas mixture resulting from the previously flowed catalyst modules into the space.  Therefore, several layers of catalyst modules match arranged differently, each from a space ge are separated, because of the mixing of the gas mix in each space in the flow that follows th catalyst module a more uniform implementation of what achieved.

In a further preferred embodiment of the present Er plates or foils are provided which cover the housing of the recombiner in the longitudinal direction in flow channels share, with the flow channels at least partially Catalyst modules are filled. This will add Lich surfaces to the catalyst modules in the Housing of the recombiner provided with a cataly table material are coated. The off also serves Formation of the flow channels, the flow distribution the gas mixture by the recombiner evenly form. Finally, the additional surfaces serve the Sheets and foils that are created by recombination also absorb heat within the recombiner and either to the longitudinal openings of the Deriving the housing or the housing itself.

The porous catalytic substrate is preferably that is contained in the catalyst modules, as granules or as an arrangement of nets, strips and / or Expanded metals formed. There is also a combination from a granulate and an arrangement of nets, strips and / or expanded metals possible. In doing so, one is as possible even distribution of the catalytically active surface of the porous substrate. Furthermore, the Distribution of the catalytic substrate within the kata analyzer module the flow resistance is set in such a way that the due to the flow conditions in the containment predetermined flows of the gas mixture through the recom binator cannot be prevented. The natural train through the  Recombiner must therefore be sufficient to flow through to ensure the recombiner. Therefore, the Flow resistance caused by the catalyst modules inside half of the housing of the recombiner is built, one do not exceed the upper threshold.

Due to the increased efficiency of implementation according to the invention of hydrogen is required within the recom binators to ensure adequate heat dissipation. To serve the plates already mentioned in the housing or foils. Furthermore, can also be used in a Catalyst module a combination of a coated, catalytic substrate and an uncoated, non-catalytically active substrate can be provided. To the then catalytically active substrate is implemented Hydrogen instead of heat release, the unbe layered substrates absorb and give the thermal energy can not forward. The uncoated, non-catalytically active substrates in a preferred manner with external structures in heat-conducting contact.

The modular structure of the catalytic converter elements The present invention is particularly by the design of the catalyst module reinforced with a housing that too is open at least on two sides to a through To allow flow of the catalyst module. Because of the On the one hand, housings are easily manageable or modules, on the other hand, by a suitable arrangement free flow of the catalyst modules with their housings mation channels are formed in the housing of the recombiner. Furthermore, the catalyst modules can be sized and Designing the corresponding circumstances very easily be adapted due to the training with a housing. In this case, the housing of the catalyst is preferred module completely filled with catalytic substrate, while in further training in the housing at least  a flow channel is formed which is not catalytic schematic substrate is filled. Like the case of the Recombiner can also be the housing of a catalyst module Have plates or films that the housing of the catalyzer door module divided in the longitudinal direction into flow channels. These flow channels are then at least partially filled with catalytic substrate. They also serve here Plates and foils to improve the flow and a possible better derivation of that through the recombina tion generated heat.

As has already been stated, it is necessary that a recombiner arranged in the containment in both directions can be flowed through. For this purpose, be preferably the housing of the recombiner is so constructed det that it has a substantially same cross section has the entire length. Therefore there are no crosses changes in section that flow through the recombina would prefer tors in either direction.

To better implement the gas mixture through the recom To achieve binator, it is advantageous if the gas mixture is sufficiently mixed, that is, the oxygen and the Hydrogen is distributed as evenly as possible in the gas tank mixed. For this purpose, at least are preferred at least one of the two open ends inside the housing of the recombiner a calming and mixing zone provided before the inflowing gas mixture the first Ka Talysatormodul or the first layer of catalyst modules reached. A more efficient and even implementation of the The result is hydrogen.

In a further preferred manner, the divide in the interior of the Ge plates and foils arranged in the recombiner's house Calming and mixing zone in partial volumes. The It serves the one hand that the entering gas mixture  more calmed and geared towards the catalyst modules can be. On the other hand, by dividing the Volu mens achieved that the size of the partial volumes is so small that a possible ignition of the gas mixture is prevented when leaving the recombiner, because the free spaces between the plates and foils are small are smaller than the size of the detonation cells.

Furthermore, there is an ignition of the gas mixture in the area the calming and mixing zone at the entrance and exit The gas mixture is prevented by the plates or foils are at least partially uncoated. This will make one further recombination and warming up the recombiner in Prevents entry and exit area of the housing, and the uncoated areas can be those present in the gas mixture Absorb and dissipate heat.

They serve the same goal in a preferred manner arrange at least one of the two open ends of the housing th cooling devices that the entering or exiting Cool the gas mixture sufficiently to ensure that the Ignition temperature within the gas containing hydrogen to avoid mixing.

To cool the recombiner itself are further ahead draft inside the housing of the recombiner cooling devices released in the catalyst modules arranged volumes. This can free flow channels or the spaces between each two other arranged catalyst modules or layers of Ka be analyzer modules. The cooling devices are ins especially in the form of radiation sheets or in the form of with Coolant flows through cooling tubes.

Finally, the gas mixture is ignited by Non-return locks prevent at least one of the  Both open ends of the housing are provided. The back Impact barriers have openings with a size which allow the gas mixtures to enter and exit. Because of the heat dissipation by means of these locks is the Prevents passage of the flame.

The aforementioned and the claimed and in the Ausfü tion examples described to use according to the invention the components are subject to their size, shape, dimensions Material selection and technical conception are not special Exceptional conditions, so that the be known selection criteria apply without restriction can. Further details, features and advantages of the Ge subject of the invention emerge from the following Description of the accompanying drawing, in the - example liable - preferred embodiments of the invention Recombiners are shown. The drawing shows:

Fig. 1 a containment of a reactor plant in a schematic representation, is in the right half recombiners of the prior art and in the left half of an inventive recombiner Darge are

Fig. 2 shows a first embodiment of a recombiner OF INVENTION to the invention,

Fig. 3a, b the recombiner shown in Fig. 2 in cross section,

Fig. 4a, b, a second embodiment of a recombiner OF INVENTION to the invention in longitudinal section and in cross-section,

Fig. 5 ac a third embodiment of an inventive recombiner in longitudinal section and

Fig. 6 different configurations of the catalyst modules in cross section.

Fig. 1 shows schematically a safety container of a reactor system. It shows an example of the flow processes within the containment during an accident.

For the sake of simplification, the illustration of the reactor and other components which are arranged within the security container 1 has been omitted. In the lower loading area 2 , hydrogen forms after an accident from the reaction of the water vapor with the fuel element casings. The consisting of steam, air, hydrogen, and aerosols mixture rises due to the density differences - high temperature of the mixture, and low density of hydrogen - upwards, as with the dotted line 3 a is shown. As a result of heat transfer to the cooler external walls occurs due to higher density to a downward movement, as shown by the arrow b. 3

In the right side of FIG. 1, two combinators 4 a and 4 b known from the prior art are also schematically and exemplarily indicated, which are generally fastened to the walls according to the prior art. They consist of a housing 10 'and catalytically active elements 11 ', which consist of plates or foils in the recombiner 4 a and 4 b of granulate packages in the recombiner.

As described above, all known systems are designed for a flow from bottom to top, as shown by arrow 5 a. The indicated convection roller, however, allows the conclusion that a flow in the direction of gravity is possible. The assumption of the arrow 5 a marked upward flow certainty applies with Si in the event that the recombiners 4 located in either the upward flow or the gas mixture is located within the containment vessel first at rest and after start of the reaction the catalyst elements, a flow opposite the earth's gravity begins. But even in this case, there should be a downward flow through the recombiners or circulation in them after a certain time. For this operation, however, the systems known from the prior art are not laid out.

In the left half of FIG. 1, a recombiner 6 according to the invention, also consisting of housing 10 and catalyst modules 11 , is shown, in which the inflow is possible both from above and from below. The cross section of the housing 10 is the same over the entire height. In addition, the catalytic catalyst modules 11 are arranged symmetrically or asymmetrically in the housing, so that internal circulations can be generated in this way.

Coolers 7 are arranged at the inlet and outlet to absorb the heat of reaction or to cool the atmosphere. The heat absorbed by the coolers 7 is released through risers 8 to higher water basins. The cooled water flows back through the lines 9 into the cooler 7 .

In FIG. 2, an embodiment of the recombiner 6 is shown in more detail. In a housing 10 catalytic catalyst modules 11 are arranged side by side and one above the other.

A continuous flow channel 13 is provided, which enables a flow in both directions. Between the catalyst modules 11 there are spaces 14 in which the emaciated gas can mix and cool. Further calming or mixing zones 15 are provided at the entry or exit of the housing 10 .

In the case of an upward flow, the mixture enters at the bottom, as shown by arrow 16 . As a result of the exothermic reaction, the mixture in the flow channel 13 is heated up and rises to the top, as shown by the arrow 17 . Above the mixture leaves, depleted and heated, the recombiner 6 , as shown by the arrow 18 Darge. The case of a downward flow is also indicated. Entry 19 and exit 20 are marked with dashed lines.

The released in a catalyst module 11 amount of heat is either dissipated convectively from the other gases, as shown by the arrow 21, or through the Rekombina goal wall 10 to the outer containment atmosphere 22 or to the middle flow channel re 13 by flowing atmosphere, a discharged 23rd This prevents additional heating and possibly overheating of the subsequent catalyst modules 11 .

There are check valves 12 at the inlet and outlet which are intended to prevent the flame from spreading into the containment when the mixture is ignited. These barriers can be designed as nets, expanded metals or grids for dissipating the heat, the free distances between the wires, webs or bars are smaller than detonation cells. This means that they can also prevent detonations from occurring.

Two embodiments shown in Figs. 3a and 3b are of the shown prior-described recombiner 6 showing in cross-section, the outer wall 10, Catalyst modules 11 and a flow channel 13 for cooling, which is shown here as a single and common channel. But there are also other, not symmetrically arranged flow channels conceivable that support the formation of internal circulation flows in downward flow. The representations of the cross sections in Fig. 3 shows that the catalyst modules 11 are modular and on the other hand essentially fill the cross section of the housing 10 , wherein only one flow channel 13 is formed, which only a small part of the cross section of the housing 10 one takes.

In FIGS . 3a and 3b, the catalyst modules 11 have arrangements of granules on the left as porous substrates and nets or expanded metals on the right. Numerous modifications are possible for both, e.g. B. size (edge length, diameter, effective heights), materials (ceramic, metal), grain or wire diameter (granulate shape, porosity), arrangement of the individual layers to each other (rotation), layer thicknesses and catalyst materials and amounts. Combinations of nets and granules are also provided and produce advantageous effects. The amount of porous substrate is dimensioned so that it does not lead to high pressure losses when flowing through the porous substrate, which prevents a flow due to natural draft. Furthermore, to avoid overheating and ignition, a combination of catalytically active elements with uncoated nets, expanded metals, granules or plates for the purpose of heat storage or dissipation is possible. When using the aforementioned plates or foils, only one side can also be coated.

FIG. 4a shows a longitudinal section through a recombiner 6 modified in comparison to FIG. 2. In this embodiment, plates or foils 24 are arranged in parallel in the housing 10 . At the entry and exit there are the anti-kickback devices 12 described above . The catalyst modules 11 are net angeord in the longitudinal direction in the middle of the housing. In the cross section shown in Fig. 4b, the different flow channels can be seen. The previously described networks, expanded metals or granules come into consideration as catalytically active material. In Fig. 4b it can also be seen that the catalyst modules 11 completely fill the cross section of the housing 10 .

To increase or better control sales, the plates or foils 24 can be coated over the entire length or only in sections with catalyst materials. The turnover is only in sectors. In the subsequent uncoated section, heat is stored and dissipated. This leads to cooling of the flowing mixture and thus overheating in the following coated section is avoided. Another possibility is to use short plates or foils that are coated on one or both sides and between which spaces are provided. In the empty spaces between adjacent plate or film sections, the gas can mix and cool down.

In Fig. 5a-c show three embodiments of the recombiner 6 described above are shown. Fig. 5a shows several side-by-side catalyst modules 11 which are separated from each other by plates 24 and the cross section of the housing 10 substantially completely fill. Between the individual superimposed catalyst modules 11 there are spaces 14 for swirling, mixing and cooling of the atmosphere.

In FIG. 5 b, individual zones lying one above the other and next to one another are not filled with porous substrate, so that they act as flow channels 13 and are freely flowed through and can contribute to cooling the catalyst modules 11 . The width of the catalyst modules 11 and the free zones is dimensioned such that the buoyancy in the reaction zones does not completely obstruct a downward flow from the free zones, the catalyst modules 11 of each layer essentially completely filling the cross section of the housing 10 .

The embodiment shown in Fig. 5c provides alternate catalyst modules 11 and free flow channels 13 in each position, in which the hydrogen-containing mixture is either implemented or used for cooling. In the following layer catalyst modules 11 and flow channels 13 are arranged offset from the previous position. As in the other exemplary embodiments, calming and mixing zones are also provided in the intermediate spaces 14 between the individual modules 11 . A great advantage of these arrangements is the flexibility and adaptability to the respective circumstances, ie height, cross-section and number of modules are freely selectable.

The overview of FIG. 6 shows the arrangement of possible individual catalyst modules in a recombiner housing 10 . Each catalyst module 11 has a separate housing 33 . This arrangement offers the advantage that in the free spaces between the housings 33 of the individual catalyst modules and between the housings 33 of the catalyst modules and the recombiner wall 10, a hydrogen-rich containment atmosphere flows and part of the heat of reaction generated in the catalyst modules 11 can be removed. The number and arrangement of the catalyst modules 11 are adapted to the circumstances, the catalyst modules 11 of a layer of catalyst modules 11 essentially completely filling the cross section of the housing 10 and the free spaces only making up a small part of the cross section.

The catalyst module 25 has the entire cross section either of the nets or granules, both coated with catalyst material.

To cool the catalyst module 26 , a flow channel 34 , arranged centrally in the example, is additionally provided.

In the catalyst module 27 , the cross section is divided into smaller channels by means of inserted plates or foils 35 , the cross sections of which are each filled with networks of the same or different wire diameters or mesh sizes.

In the catalyst module 28 , both sides of the plates or foils 35 for hydrogen recombination are also coated at the edges of the individual cross sections with catalyst material.

The catalyst module 29 provides for heat dissipation free flow channels 36 , the cross sections of which are not filled with nets. This creates zones in which free convection can form and contribute to cooling. These zones make up only a small part of the overall cross-section. The plates or foils 35 are coated only on the sides that are in contact with the catalyst elements.

In the catalyst module 30 , porous granules are provided in all cross sections. Material, porosity and catalyst coating can be the same or vary in all channels.

In the catalyst module 31 , both sides of the plates or foils 35 are coated. The channels are filled with granules as before.

The catalyst module 32 again provides free flow channels 36 to create convection zones and thus heat dissipation. The porous granules in the catalyst elements can, as described above, be the same or have different porosities. The plates or foils 35 are coated on one side only.

The symmetrical arrangement is shown in Fig. 6 of the Ka talysatormodule in the Rekombinatorgehäuse 10th When also shown in FIGS. 5a and 5b shown asymmetric location of one or more catalyst module 11 is in the housing 10 even with downwardly directed flow of the hydrogen-rich mixture through the free gaps or by the Ka talysatormodule 11 itself due to the pressure differences Zvi's free cross-sections and channels of the modules filled with porous catalyst elements, which lead to the cross exchange of the mixture strands, an internal circulation with upward flow through the catalyst module and thus a starting of the reaction possible.

In order to avoid heating up the containment atmosphere, the recombiners shown can be operated with upstream and downstream coolers 7 , as shown in FIG. 1. Combinations with self-starting the turbocompressor units are also conceivable, so that the flow is forced and, due to higher flow speeds and thus also higher heat and mass transfer coefficients, their catalytic effectiveness is increased. In this case, the recombiners no longer have to be arranged vertically. Your inclination to the vertical axis can be arbitrary.

Reference list

1

Security container

2nd

lower area

3rd

Flow gas mixture

4th

Recombiners

5

Flow

6

Recombiner

7

cooler

8th

Riser

9

Downpipe

10th

casing

11

Catalyst module

12th

Non-return lock

13

Flow channel

14

Space

15

Calming and mixing zone

16

Upward flow

17th

Upward flow

18th

Upward flow

19th

Downward flow

20th

Downward flow

21

convection

22

Heat dissipation in a containment atmosphere

23

Heat dissipation in the containment atmosphere of the Strö channel

13

24th

Plates or foils

25th

to

32

Catalyst module

33

Housing of

11

34

Flow channel

35

Sheets / foils

36

Flow channel

Claims (22)

1. Recombiner to remove hydrogen from sturgeon atmospheres

• 1. with a housing ( 10 ) which specifies a longitudinal direction for a flow and has at least one opening at both ends in the longitudinal direction, and
• 2. with at least one catalyst element ( 11 ) which is arranged in the housing ( 10 ),

characterized by

• 1. that the at least one catalyst element ( 11 ) is modular and is filled with a porous substrate which is coated with a catalyst material, and
• 2. that the at least one catalyst element ( 11 ) essentially completely fills the cross section of the housing ( 10 ).

2. Recombiner according to claim 1, characterized in that at least two catalyst modules ( 11 ) are provided, which are arranged side by side and / or one above the other in the housing ( 10 ). 3. Recombiner according to claim 2, characterized in that at least one free flow channel ( 13 ) is provided between two catalyst modules arranged side by side ( 11 ). 4. Recombiner according to claim 2 or 3, characterized in that between two stacked catalyst modules ( 11 ) at least one space ( 14 ) is provided. 5. Recombiner according to one of claims 2 to 4, characterized in that the catalyst modules ( 11 ) are arranged symmetrically or asymmetrically in the housing ( 10 ). 6. Recombiner according to one of claims 1 to 5, characterized in that plates or foils ( 24 ) the hous se ( 10 ) in the longitudinal direction in flow channels untertei len, the flow channels are at least partially filled with catalyst modules ( 11 ). 7. Recombiner according to one of claims 1 to 6, characterized characterized in that the porous catalytic substrate as granules or as an arrangement of nets, strips fen and / or expanded metals is formed. 8. Recombiner according to one of claims 1 to 6, characterized characterized in that the porous catalytic substrate as a combination of a granulate and a type order of nets, strips and / or expanded metals is trained. 9. Recombiner according to one of claims 1 to 8, characterized in that in a catalyst module ( 11 ) a combination of a coated, we catalytic substrate, in particular plates or foils, and an uncoated, non-catalytically active substrate, in particular plates or foils , is provided. 10. Recombiner according to one of claims 1 to 9, characterized in that the catalyst module ( 11 ) has a Ge housing ( 33 ). 11. Recombiner according to claim 10, characterized in that the housing ( 33 ) of the catalyst module ( 11 ) is arranged spaced from the housing ( 10 ). 12. Recombiner according to claim 10 or 11, characterized in that the housing ( 33 ) of two catalyst modules ( 11 ) spaced from each other in the housing ( 10 ) of the recombiner ( 6 ) are arranged. 13. Recombiner according to one of claims 10 to 12, characterized in that the housing ( 33 ) of the catalyst module ( 11 ) is completely filled with catalytic substrate. 14. Recombiner according to one of claims 10 to 12, characterized in that at least one flow channel ( 34 ) is formed in the housing ( 33 ). 15. Recombiner according to one of claims 10 to 14, characterized in that plates or foils ( 35 ) divide the housing ( 33 ) in the longitudinal direction into flow channels ( 36 ), wherein the flow channels ( 36 ) are at least partially filled with catalytic substrate. 16. A recombiner according to one of claims 1 to 15, characterized in that the housing ( 10 ) has a substantially same cross-section over the entire length. 17. Recombiner according to one of claims 1 to 16, characterized in that a calming and mixing zone ( 15 ) is provided on at least one of the two open ends within the housing ( 10 ). 18. Recombiner according to claim 17, characterized in that in the interior of the housing ( 10 ) arranged plates or foils ( 24 ) divide the calming and mixing zone ( 15 ) into partial volumes. 19. Recombiner according to claim 18, characterized in that the plates or foils ( 24 ) in the region of the calming and mixing zone ( 15 ) are at least partially uncoated. 20. Recombiner according to one of claims 1 to 19, characterized in that cooling devices ( 7 ) are arranged on at least one of the two open ends of the housing ( 10 ). 21. Recombiner according to one of claims 1 to 20, characterized in that in the housing ( 10 ) from the catalyst modules ( 11 ) released Volumnia cooling devices are arranged, in particular in the form of radiation sheets or with coolant flow through cooling tubes. 22. Recombiner according to one of claims 1 to 21, characterized in that non-return locks ( 12 ) are provided on at least one of the two open ends of the housing ( 10 ).