CA3149974A1

CA3149974A1 - Gastight container

Info

Publication number: CA3149974A1
Application number: CA3149974A
Authority: CA
Inventors: Michael GOEGGERLE; Manuel Lipp
Original assignee: Goeggerle Michael; Xl Beteiligungen & Co KG GmbH
Current assignee: Xl Beteiligungen & Co KG GmbH
Priority date: 2019-09-04
Filing date: 2020-08-20
Publication date: 2021-03-11
Also published as: DE102020116333A1; CN114641560A; WO2021043590A1; EP4025682A1; DE102020119254A1

Abstract

The invention relates to a gastight container (1), in particular a silo for storing organic substances, having a receiving chamber (2), a floor (3), a peripheral wall (4) and a roof device (5). The roof device (5) has a gastight cover (8) formed from flat metal profiles (6) and/or flat metal plates (7). The roof device (5) has a supporting structure (9) arranged above the cover (8) and a suspension device (10). The suspension device (10) is fixed to the cover (8) and to the supporting structure (9). The suspension device (10) is designed to brace the cover (8) upwardly in the direction of the supporting structure (9).

Description

Gastight container The invention relates to a gas-tight container, in particular a silo for the storage of organic substances, having a receiving chamber, having a base, 5 having a peripheral wall and having a roof device, wherein the roof device has a gas-tight cover which is formed from flat metal panels and/or from flat metal plates.
The gas-tight container is preferably a gas-tight large-capacity container.
The invention also relates to an apparatus for obtaining a gaseous energy source from organic substances, in particular a biogas reactor, having a gas-tight container.
15 A generic gas-tight container is known for example from DE 42 32 318 Al.
Furthermore, an apparatus for obtaining a gaseous energy source from organic substances is known from DE 199 54 904 Al.
20 Generally, from the prior art, it is known to use gas-tight containers for receiving liquid, gaseous or solid substances for various applications.
In particular in industry and also in municipalities, there is a need for large-capacity containers or for large-volume containers, which may have for 25 example volumes of 100 to 50 000 m3, for receiving liquids, for example also wastewater and sludges or intermediate and end products of the chemical, pharmaceutical and food-processing industries. Furthermore, there is also a need for gas stores, in particular for storing biogas, sewage treatment plant gas or landfill gas.
Furthermore, there is a need for containers, in particular for silos, for the storage of organic substances or for the storage of plant products.

2 Also known are so-called biogas reactors, also referred to as fermenters, which are containers in which microorganisms, cells or small plants are cultivated. Known here in particular are biogas reactors of biogas plants in which the biomass is degraded in an anaerobic process to form biogas and 5 fermentation residue. Such containers are closed off in an air-tight or gas-tight manner and have an agitator and various measurement and control devices for process control.
DE 197 56 485 Al has disclosed an apparatus in which for example fecal 10 matter is stored in a fermentation chamber on average for several days at a temperature of for example approximately 35 , and the fermentation gas formed is collected in a gas chamber which is arranged above the fermentation chamber. The gas chamber is upwardly delimited by a gas-tight covering which is, within the gas chamber, fixed to a wall which forms the 15 fermentation chamber.
One particular requirement in the production of large-volume containers, in particular when these are used as biogas reactors of biogas plants or as fermenters is that the construction is to be of gas-tight form. This 20 requirement applies here correspondingly also to the roof device or to the roof construction of such a container.
The conventional roof devices known from the prior art, for example a cone roof, as is shown for example in DE 199 54 904 Al, cannot, or can, 25 technically, only with great effort, be produced in a gas-tight manner.
This is due inter alia to the required screwing of the cone roof itself or to the attachment thereof to the wall of the container.
In this respect, it is proposed for example in DE 199 54 904 Al to use an 30 additional inner covering.
It is furthermore known from the prior art that the roof device has a cover which is formed from flat metal panels. Such a structure is also referred to

3 as a membrane cover. The metal panels from which the cover is formed are in this case welded to one another in a gas-tight manner, so as to form a unitary, gas-tight cover. For cost and weight reasons, the cover formed in this manner is normally formed from metal panels which have a relatively 5 small thickness. In order to protect the cover from weather influences and also from damage, it is additionally known from the prior art that a cone roof, which itself is not gas-tight, is formed above the cover.
Such a construction has proven to be effective in practice.
It has however been shown that the cover formed from the flat, thin metal panels, that is to say the membrane roof, has to tendency to "flutter" if the receiving chamber of the container is subjected to pressure.
15 The present invention is therefore based on the object of improving the gas-tight containers known from the prior art, in particular of avoiding undesired movements of a cover of the container.
The present invention is also based on the object of providing an apparatus 20 for obtaining a gaseous energy source from organic substances, in particular a biogas reactor, which is improved in comparison with the prior art.
With regard to the gas-tight container, the object is achieved by the features of claim 1.
With regard to the apparatus for obtaining a gaseous energy source from organic substances, the object is furthermore achieved by the features of claim 22.
30 Provision is made of a gas-tight container, in particular a silo for the storage of organic substances. The container has a receiving chamber, a base, a peripheral wall and a roof device. The roof device has a gas-tight cover which is formed from flat metal panels and/or from flat metal plates.

4 The gas-tight container is preferably a large-capacity container.
According to the invention, it is provided that the roof device has a supporting

5 structure arranged above the cover and has a suspension device, wherein the suspension device is fixed to the cover and to the supporting structure and the suspension device is designed to brace the cover upwardly in the direction of the supporting structure.
10 It should be pointed out that the indications "top" or "bottom" or "above" or "below" refer to a container which is mounted correctly on a base, in particular a concrete base or the like.
The inventor has realized that bracing of the cover results in an undesired 15 movement, in particular a fluttering of the cover, being avoided. In particular for gas-tight containers designed as a biogas reactor or as a fermenter, undesired "fluttering" of the cover formed from the thin metal panels or metal plates has been possible in the case of the prior-art containers.
20 The solution according to the invention now makes possible the use of the cover formed from the metal panels or metal plates for gas-tight containers without the disadvantages encountered previously, specifically the "fluttering", having to be accepted.
25 The solution according to the invention improves the construction and makes possible in particular the use of a relatively thin cover.
In the prior art, such a cover is also referred to as a "membrane cover" or "membrane roof".
The cover may preferably be formed from flat metal panels, although it is also possible for the cover to be formed from flat metal plates or a combination thereof. The metal plates may in particular also be in the form of an annulus or part of an annulus or in the form of a disk.
Insofar as reference is made below to a cover composed of metal panels, this is to be understood in such a way that, alternatively, the cover may also 5 be produced from metal plates or a combination thereof.
The cover according to the invention closes off the wall of the container at the top side and, for this purpose, is preferably connected to the upper end of the peripheral wall of the container.
It is advantageous if the suspension device braces the cover upwardly in such a way that the cover is convexly curved upward.
In principle, it would also be possible for the suspension device to be 15 configured in such a way that it braces the cover downwardly, that is to say exerts a pressure force on the cover. However, it has turned out to be more suitable for the suspension device to pull the cover upward or to brace it upwardly.
20 It is advantageous if the cover is of self-supporting design.
The inventor has realized that, in the case of the gas-tight container according to the invention, a cover can be realized particularly advantageously by being of self-supporting design. This is to be understood 25 within the context of the invention as meaning that the cover is supported only by the wall and no additional supports, in particular no central supports in the center, are provided. Within the context of the solution according to the invention, it is however provided that the cover is braced upwardly by the suspension device. Here, within the context of the invention, the cover is still 30 considered to be self-supporting, in particular since said cover has no additional load-bearing supports or the like between the edge regions.
The self-supporting, light cover composed of high-grade steel allows both

6 existing gas-tight containers to be retrofitted with the cover and new containers to be produced in a corresponding manner.
The cover may have a peripheral edge region, which preferably extends 5 between the cover and the wall.
It is advantageous if the cover is connected at its peripheral edge region in a gas-tight manner to the wall.
10 A gas-tight connection of the edge region of the cover to the wall can be achieved for example by way of welding or else by way of another material-bonding method, for example adhesive bonding. However, the inventor has realized that it is particularly advantageous if the cover is screwed or riveted or connected in a force-fitting manner in some other way to the edge region 15 of the wall. Here, it is preferably provided that the peripheral edge region of the cover has bores by way of which a screw connection to the wall is made possible, preferably with the aid of further connecting elements, for example flanges or other profiles.
20 According to the invention, it may furthermore be provided that the roof device is designed in such a way that a gas-tight connection between the wall and the cover is released if the pressure in the receiving chamber exceeds a defined burst pressure, wherein the burst pressure corresponds to a positive pressure of 100 mbar, particularly preferably 80 mbar and very 25 particularly preferably 60 mbar.
The aforementioned configuration, according to which the connection between the wall and the cover is released if the pressure in the receiving chamber exceeds a defined burst pressure, significantly increases the level 30 of safety of gas-tight containers, in particular where these are used as biogas reactors or fermenters. With the production of gas or biogas, there may be a risk of explosion given exceptional circumstances. The inventor has realized that a hazardous situation due to the risk of a gas explosion can be

7 mitigated considerably if the gas-tight connection between the wall and the cover is released if a positive pressure of greater than 100 mbar is built up in the receiving chamber. A particularly high level of safety can occur if the build-up of a positive pressure of greater than 80 mbar, very particularly 5 preferably of greater than 60 mbar, is enough to release the connection.
The release of the connection or the bursting of connecting parts allows the pressure to be released from the receiving chamber into the atmosphere, that is to say to the outside, so that a normal pressure or only a slight positive 10 pressure is essentially established again in the receiving chamber. The normal pressure is typically 1.01325 bar. That is to say, if the burst pressure corresponds to a positive pressure of 100 mbar, the connection between the wall and the cover is, or the parts incorporated in the connection are, configured in such a way that the gas-tight connection between the wall and 15 the cover is released if an absolute gas pressure of greater than 1.1325 bar prevails in the receiving chamber.
It may, in particular in the case of the operation of a biogas reactor or a fermenter, be provided that the operating pressure in the receiving chamber 20 is selected in such a way that it corresponds to a positive pressure of 2 to 25 mbar. It has been shown that this is particularly suitable for the operation of gas-tight containers, in particular of biogas reactors and fermenters.
Firstly, the low positive pressure results in improved generation of biogas, and secondly, a positive pressure in the receiving chamber assists with the 25 removal of the gas from the receiving chamber for feeding the gas for example to an external gas tank. For this purpose, the receiving chamber has, in a known manner, a gas outlet opening. This is known from the prior art, in the context of which reference is made for example to DE 197 56 485 Al. A positive pressure in the receiving chamber of 30 preferably 2 to 25 mbar has also turned to be suitable for avoiding entry of oxygen into the receiving chamber from the outside.
The low positive pressure in the receiving chamber of 25 mbar, also possibly

8 +/- 20 mbar, that is intended for the operation of the fermenter or of the biogas reactor or, in general, of a gas-tight container has turned out to be advantageous. At the same time, it has turned out to be advantageous if a low burst pressure is enough to release the gas-tight connection between 5 the wall and the cover, in order to reduce a risk of explosion or the damage which can occur in the event of an explosion.
It may be advantageous to ensure that the difference between the desired operating pressure, that is to say the positive pressure desired for operation, 10 and the burst pressure, that is to say the positive pressure from which the gas-tight connection between the wall and the cover is released, is selected in such a way that the burst pressure is not already reached during operation for tolerance-related reasons.
15 The above-stated values, in particular an operating pressure of 25 mbar or less, possibly even 30 mbar or less, and a burst pressure which corresponds to a positive pressure of 60 mbar, have turned out to be particularly suitable.
The roof device may be preferably be designed in such a way that, if the 20 burst pressure is exceeded, the cover is lifted off from the wall.
According to the invention, it may furthermore be provided that use is made between the peripheral edge region of the cover and the wall of the container of a burst ring which, in the event of the burst pressure being reached, 25 releases a gas-tight connection between the cover and the wall.
The fact that the gas-tight container additionally has a burst ring means that the burst pressure from which the gas-tight connection between the cover and the wall is to be released can be set in a defined manner. Here, it may 30 be provided that the burst ring is blown off. Preferably, the burst ring is designed in such a manner that, from a defined burst pressure, it opens up a connection from the receiving chamber to the outside, preferably being at least partially annularly peripheral with respect to the wall (in particular in a

9 symmetrical manner), preferably being completely annularly peripheral, so that the positive pressure can be released to the outside from the receiving chamber.
5 It is advantageous for the burst ring to be designed in such a way that, in the event of the burst pressure being reached, the cover is lifted off from the wall. Alternatively, it may also be provided that the connection between the burst ring and the cover and/or between the burst ring and the wall is partially or completely released.
According to the invention, it may furthermore be provided that the peripheral edge region of the cover is provided on a bottom side with a lower flange ring and/or on a top side with an upper flange ring.
15 The use of a lower flange ring and/or of an upper flange ring has turned out to be particularly suitable for reinforcing the cover in the edge region and for connecting the edge region in a stable and gas-tight manner to the wall.
In a structural configuration of the invention, it may be provided that the 20 peripheral edge region of the cover is fixed in a force-fitting manner between the lower flange ring and the upper flange ring.
It has turned out to be particularly suitable for the peripheral edge region of the cover to be clamped in a force-fitting manner between the lower flange 25 ring and the upper flange ring. For this purpose, a screw connection may preferably be provided. In this way, a particularly stable and also re-releasable connection between the two flange rings and the cover can be produced.
30 According to the invention, it may be provided that the lower flange ring is connected to the burst ring and the burst ring is connected to the wall of the container.

The inventor has realized that a release of the connection between the wall and the cover can be achieved particularly advantageously in that the lower flange ring is connected to the burst ring and the burst ring is connected to the wall of the container. By way of a suitable design or arrangement of the 5 burst ring, it may be achieved here that the burst ring releases the connection between the wall and the lower flange ring and thus the cover.
This may be realized for example in that the burst ring is lifted off from the wall or the connection provided there breaks. This may additionally or alternatively also be achieved in that the connection between the burst ring

10 and the lower flange ring is released, for example in that the cover is lifted up or the connection between the burst ring and the lower flange ring is released in another way, for example breaks.
Preferably, the connection between the flange ring and the burst ring or 15 between the burst ring and the wall is released in an at least partially annularly peripheral, preferably in a completely annularly peripheral, manner.
According to the invention, it may furthermore be provided that at least the 20 majority of the flat metal panels and/or of the flat metal plates of the cover have a thickness of 0.2 mm to 5 mm, preferably 0.3 mm to 2 mm, more preferably 0.4 mm to 1.5 mm, particularly preferably 0.5 mm to 1.2 mm, and very particularly preferably 0.6 mm to 1.2 mm, in particular 1 mm.
25 The above-stated values have turned out to be particularly suitable for providing a light, flexible cover. Such a cover is also referred to as a membrane cover.
Such a cover makes it possible for containers having a diameter of up to 30 50 m to be freely spanned. Here, the cover can withstand snow loads and strong wind without supports or struts for supporting the cover being required in the receiving chamber. The cover resulting from such a metal panel is particularly suitable for gas-tight containers, in particular also for storage

11 containers for fermentation residue.
The metal panels or the metal plates are preferably welded, wherein a formation of the cover by metal panels or sheet-metal panels that are welded 5 to one another is particularly suitable.
It has been shown that a cover which, as seen in plan view, is round or circular is particularly suitable for closing off a gas-tight container.
Accordingly, it is particularly suitable if the wall of the gas-tight container is 10 likewise of circular form or if the wall is a cylindrical wall.
It has furthermore turned out to be particularly suitable if the cover is in the form of a flat roof.
15 It is advantageous if the cover, after the metal panels or the metal plates have been welded to one another, is wound up on a roller or roll and, in such a wound state, is transported to the building site. The cover can then, on the building site, be unrolled again on the top side of the wall and be connected in a gas-tight manner to the top side of the wall in the manner already 20 described.
A cover composed of the aforementioned metal panels or metal plates, in particular made of high-grade steel, has the advantage that the cover is corrosion-resistant, is impermeable with regard to diffusion of gas and is 25 insensitive to UV radiation. The cover may be used for any containers, preferably for metal containers, in particular steel containers, and also for concrete containers as well as for metal-reinforced concrete containers, in particular for steel-reinforced concrete containers. The wall on whose upper end the cover is mounted may be formed from any material, preferably 30 metal, in particular steel, concrete, metal-reinforced concrete, in particular steel-reinforced concrete, or may have one of the materials as a main constituent.

12 The cover may preferably be completely prefabricated in the production factory and mounted on the building site at a later stage. In particular if, in a preferred embodiment, a force-fitting connection between the wall and the cover is provided, on-site welding work can be dispensed with.
According to the invention, it may be provided that the receiving chamber has a volume of 100 to 50 000 m3, preferably of 1,000 to 10 000 m3, particularly preferably of 2,000 to 8,000 m3.
The inventor has realized that the solution according to the invention is suitable in particular for receiving chambers having the above-stated volumes.
The height of the gas-tight container may preferably be 2 to 50 m and the width or the diameter may preferably be 4 to 50 m.
The gas-tight container may be provided in particular for sewage treatment plant gas, landfill gas or biogas.
It is advantageous if the supporting structure is in the form of a cone roof and/or in the form of a skeleton structure.
The formation of the supporting structure, to which the suspension device is then also fixed, as a cone roof and/or as a skeleton structure has turned out to be particularly suitable. In this way, a structure which, on the one hand, can accommodate large forces and, on the other hand, can be realized in a reliable and process-safe manner by known measures is selected.
It may be provided in particular that the supporting structure of the cone roof or the skeleton structure is correspondingly fixed to the wall, preferably on the top side of the wall, so that the forces can be introduced directly into the wall and, from there, dissipated downward to the base on which the wall stands.

13 It is advantageous if the supporting structure itself is not of gas-tight design.
In principle, it would be possible for the supporting structure, that is to say 5 for example the cone roof and/or the skeleton structure, to likewise be of gas-tight form. This, however, increases the construction costs significantly and, owing to the cover formed in a gas-tight manner, is not necessary in the present case.
10 As an alternative to the configuration of the supporting structure as a cone roof and/or as a skeleton structure, according to the invention, it may also be provided that the supporting structure is formed by horizontally extending bars. Here, the bars are preferably fastened to the top side of the wall or placed thereon.
However, the formation of a supporting structure as a cone roof and/or as a skeleton structure has turned out to be advantageous, in particular for being able to fix the suspension device above the cover in a stable manner.
20 It is also advantageous here if the supporting structure has a walk-on platform, which is preferably also arranged above the suspension device. In this way, operation of the suspension device can be facilitated.
According to the invention, it may furthermore be provided that the 25 suspension device is arranged centrally above the cover, preferably coaxially with respect to the vertically extending central axis of the container.
An arrangement of the suspension device centrally above the cover has turned out to be particularly suitable for being able to brace the cover 30 upwardly in the direction of the supporting structure. It has turned to be advantageous in particular if the cover is braced upwardly primarily in a central region. Here, a particularly symmetrical arrangement of the suspension device proves to be effective for introduction of the forces into

14 the cover in as uniform a manner as possible.
The suspension device may be fixed directly to the cover. It is however advantageous if the suspension device is fixed to a flange ring or a ring 5 segment or a fastening element or a fastening plate, which itself is in turn fastened to the cover. A flange ring having a diameter which corresponds approximately to the diameter of the suspension device is particularly advantageously suitable.
10 It is advantageous if the suspension device is fixed to fastening points of the cover, and if the distance of the fastening points from the center point of the cover is less than 70%, preferably less than 60%, more preferably less than 50%, particularly preferably less than 40%, and very particularly preferably less than 30%, of the distance of the center point of the cover from the edge

15 of the cover.
The aforementioned fixing of the suspension device to the cover has turned out to be particularly suitable for bracing the cover upwardly. Here, it is particularly preferable if the suspension device is arranged symmetrically or 20 centrally around a center point of the cover.
The fastening points of the cover to which the suspension device is fixed may in this case also be formed on a fastening ring, a flange ring of a fastening plate, or a ring segment, that is fixed to the cover.
According to the invention, it may furthermore be provided that the suspension device has a plurality of chains. Here, the chains may be fixed directly or via one of the aforementioned connecting elements to the cover so as to brace the cover upwardly in the direction of the supporting structure.
It has turned out to be particularly suitable for the suspension device to have a plurality of chains which are fixed directly or via a connecting element, for example the aforementioned flange ring, to the cover. Here it may also be provided that the suspension device is designed to lift and to lower the cover within a defined travel. For this purpose, provision may be made for example of a setting device, for example in the form of threaded rods, which allow the suspension device to be loosened or retightened in order for the travel or the 5 bracing of the cover in the direction of the supporting structure to be set.
Here, it is particularly suitable if the threaded rods each interact with a chain or another suspension member of the suspension device.
10 According to the invention, it may be provided that an agitator is arranged in the receiving chamber.
It has turned out to be particularly suitable if the agitator is introduced from above or from the side (as illustrated for example in DE 199 54 904 Al).
In principle, it is also possible for more than just one agitator to be provided in the receiving chamber.
Insofar as it is provided to introduce the agitator from above, it is 20 advantageous if the cover has an agitator leadthrough, which preferably extends coaxially with respect to the vertical central axis of the container.
Here, the agitator leadthrough may be provided with seals in such a way that the agitator leadthrough ends in a gas-tight manner with respect to the 25 agitator.
The agitator may be designed in a fundamentally known manner.
It may be particularly suitable if the agitator or the shaft of the agitator 30 extends from above over at least 50% of the height of the receiving chamber.
Furthermore, it may be advantageous for blades to be provided on the shaft of the agitator at regular or irregular intervals, by way of which blades the material, in particular an organic substance, introduced into the receiving

16 chamber can be moved. Preferably, the blades can be folded in or are correspondingly flexible such that the radius of the blades can be reduced for the purpose of mounting or dismounting the agitator.
5 It is advantageous for the gas-tight container to have a heating device in the wall.
In particular if the gas-tight container is used as a bioreactor or fernnenter, it may furthermore be suitable if the wall is insulated. Preferably, the roof 10 device is insulated too.
Preferably, the gas-tight container, in particular the receiving chamber of the gas-tight container, is connected to a gas store via a gas outlet.
15 The receiving chamber may furthermore have further elements, for example of the type as described in DE 199 54 904 Al. A filling connector for introduction of fresh organic substances into the receiving chamber, which in this case may also be referred to as a fermentation chamber, should be mentioned, for example.
The gas-tight container according to the invention may, in particular in a configuration as a fernnenter or biogas reactor, also be designed as a combination of a digester and a gas store. In this case, the gas store may be positioned above the cover, preferably so as to be situated within the 25 supporting structure, in particular if the latter is in the form of a cone roof and/or in the form of a skeleton structure.
However, the solution according to the invention is particularly suitable if a gas store is positioned outside the gas-tight container and is connected via 30 piping to a gas outlet of the gas-tight container.
According to the invention, it may be provided that the cover has at least one outer cover ring with an inner opening, and the cover furthermore has an

17 inner cover disk which closes off the inner opening of the outer cover ring in a gas-tight manner.
The aforementioned solution provides a particularly suitable construction for 5 ensuring the possibility of accessing the receiving chamber without the entire cover having to be removed again. In this way, for example, a so-called "manhole" may be provided. In order to pass into the receiving chamber, for example in order to introduce or to remove an agitator, it is sufficient for the inner cover disk to be dismounted. By doing this, the inner opening of the 10 outer cover ring is opened up, said inner opening preferably being dimensioned in such a way that an agitator can be introduced into the receiving chamber and can be removed from there again.
Here, the inner cover disk may have an agitator leadthrough for the agitator.
If the agitator is introduced laterally into the receiving chamber, an agitator leadthrough in the inner cover disk may be dispensed with.
In a particularly advantageous configuration of the invention, it may be 20 provided that the inner cover disk has bores through which screws may be inserted for the purpose of screwing the cover disk to the outer cover ring.
Here, it may be provided that, on the inner side, facing the receiving chamber, of the cover disk, the screw heads, after the through-passage, are in each case welded to the cover disk to ensure captive retention thereof.
The present invention also relates to an apparatus for obtaining a gaseous energy source from organic substances, in particular a biogas reactor, having a gas-tight container with one or more of the features presented above.
Possible configurations and also the advantages of such an apparatus for obtaining a gaseous energy source, which apparatus has a gas-tight container, correspondingly emerge from the statements above and also from

18 the statements below.
The figures each show preferred exemplary embodiments, in which individual features of the present invention are illustrated in combination with 5 one another. The features of an exemplary embodiment are also realizable separately from the other features of the same exemplary embodiment, and may accordingly be combined by a person skilled in the art with features of other exemplary embodiments to form further meaningful combinations.
10 In the figures, in each case schematically:
figure 1 shows a longitudinal section through a gas-tight container according to the invention;
15 figure 2 shows a detail illustration of a section of a roof device of the gas-tight container according to the invention;
figure 3 shows a plan view of a cover of the gas-tight container in a first embodiment;
figure 4 shows a plan view of a cover of the gas-tight container in a second embodiment;
figure 5 shows an illustration of a possible connection between a cover 25 and a wall in a first embodiment; and figure 6 shows an illustration of a possible connection between a cover and a wall in a second embodiment, with use being made of a burst ring.
The exemplary embodiments in figures 1 to 6 show a gas-tight container 1 which may in principle be suitable for various applications. The gas-tight container 1 may be used in particular for the storage of solid, liquid and

19 gaseous media, in particular also for the storage of organic substances.
In the exemplary embodiment, it is provided that the gas-tight container 1 is designed as a fernnenter or as a so-called biogas reactor. Here, the gas-tight 5 container 1 may be part of an apparatus for obtaining a gaseous energy source from organic substances. The apparatus may additionally have further devices, for example a gas store. In the exemplary embodiment below, the gas-tight container 1 is illustrated only to the extent which is essential for explanation of the present invention.
In a preferred embodiment, in which the gas-tight container 1 is designed as a fernnenter, it may be provided in particular that this has further elements, for example a gas outlet, heating devices, feed openings for introducing organic substances, and the like, as is known for example from 15 DE 199 54 904 Al or DE 197 56 485 A, the respective content of which is fully incorporated by reference in the present description.
In particular also with regard to the construction of the wall 4, described in more detail below, of the container 1, use may be made of features from the

20 two aforementioned documents.
It should be pointed out that, although the gas-tight container 1 in the exemplary embodiment is preferably designed as a fermenter, the exemplary embodiment is not to be understood as being restricted thereto.
As can be seen from the exemplary embodiments, the gas-tight container 1 has a receiving chamber 2, a base 3, a peripheral wall 4 and a roof device 5.
30 In the exemplary embodiment, the receiving chamber 2 is enclosed in a gas-tight manner by the base 3, the wall 4 and the roof device 5. Here, the receiving chamber 2 may be designed in particular as a fermentation chamber, in particular for receiving organic substances.

The wall 4 may be formed from any material, for example from metal, concrete or metal-reinforced concrete, in particular steel or steel-reinforced concrete, or comprise the aforementioned materials as main constituents.
5 Preferably, the wall 4 is formed by sheet-metal strips which are welded to one another. Provision may also be made of a double folding system, as is used by Lipp GmbH Tannhausen, to form the wall from sheet-metal strips.
The base 3 may be formed in any manner, the base 3 preferably being 10 formed by steel plates and/or by concreting.
In the exemplary embodiment, the receiving chamber 2 may have a volume of 100 to 50 000 m3, preferably of 1,000 bis 10 000 m3, particularly preferably of 2,000 to 8,000 m3.
Furthermore, for the invention, it is particularly suitable if the gas-tight container 1 has a height of 2 to 50 m and a width of 4 to 50 m.
The roof structure 5 has, as can be seen from the exemplary embodiments, 20 a gas-tight cover 8 which is formed from flat metal panels 6 and/or metal plates 7. In principle, it is possible for the cover 8 to be produced from metal panels 6 or metal plates 7 or a combination of metal panels 6 and metal plates 7. In the exemplary embodiment, figure 3 illustrates a plan view of a cover 8 which is formed from metal panels 6, whereas figure 4 shows a plan 25 view of a cover 8 which is formed from metal plates 7.
Insofar as reference is made in the exemplary embodiment to a design of the cover 8 from metal panels 6 or metal plates 7, this is to be understood in such a way that the in each case other design may alternatively also be 30 selected.
In the exemplary embodiment illustrated in figure 4, it is provided that the metal plates 7 are designed as metal rings, as will subsequently be

21 illustrated in even more detail.
The cover 8 is fixed to the top side of the wall 4 and connected in a gas-tight manner to the wall 4.
Here, in the exemplary embodiment, it is provided that the cover 8 is connected at its peripheral edge region in a gas-tight manner to the wall 4.
In the exemplary embodiment, it is furthermore provided that at least the majority of the flat metal panels 6 and/or of the flat metal plates 7 of the cover 8 have a thickness of 0.2 mm to 5 mm, preferably 0.3 mm to 2 mm, more preferably 0.4 mm to 1.5 mm, particularly preferably 0.5 mm to 1.2 mm, and very particularly preferably 0.6 mm to 1.2 mm, in particular 1 mm.
The metal panels 6 being in the form of thin and flat metal panels results in a light cover, a so-called membrane structure, which makes it possible for even large diameters to be spanned freely or in a self-supporting manner by the cover 8, that is to say that no further supports below the cover 8 are required. The cover 8 can nevertheless accommodate high loads.
A particular advantage of a cover 8 formed in this way is also that said cover can be wound up on rollers or rolls and then, on site, that is to say on the building site, unwound again and connected to the wall 4. Here, the wall 4 may be constructed or formed in particular from the materials already mentioned above (metal, in particular steel, concrete, metal-reinforced concrete, in particular steel-reinforced concrete) .
In the exemplary embodiment, the flat metal panels 6 or the metal plates 7 are preferably formed from high-grade steel.
As can be seen from figures 1 and 2, above the cover 8, the roof device 5 has a supporting structure 9 and a suspension device 10. Here, the suspension device 10 is fixed to the cover 8 and to the supporting structure

22 9. The suspension device 10 is designed to brace the cover 8 upwardly in the direction of the supporting structure 9. As can be seen from figures 1 and 2, the cover 8 is braced upwardly by the suspension device 10 in such a way that the cover 8 is convexly curved upward, that is to say in the direction of 5 the supporting structure 9.
In the exemplary embodiment, the supporting structure 9 is in the form of a cone roof and/or in the form of a skeleton structure. For this purpose, the supporting structure 9 has for example rafters 11, which are preferably fixed 10 to the top side of the wall 4 in order that the weight forces can be introduced into the wall 4.
What is important with the supporting structure 9 is that this is designed as a supporting element of the gas-tight container 1, that is to say that the 15 supporting structure 9 of the roof device 5 can accommodate weight forces, in particular also in such a way that the cover 8 can be braced upwardly by the suspension device 10.
As can be seen from figures 1 and 2, the supporting structure 9 has a 20 platform 12. Here, the platform 12 is preferably arranged in the region of the tip or the upper end of the gas-tight container 1 or of the tip of the roof device 5. Preferably, the platform 12 is situated in the center of the roof device 5 in relation to the horizontal extent of the roof device 5. The platform 12 may in particular serve for maintenance and for operation of the suspension device 25 10. The platform 12 may additionally also be used for mounting, for dismounting, for maintenance and for operation of an agitator 13 (which is optionally arranged at this position).
In the exemplary embodiment, the agitator 13 is also supported by the 30 supporting structure 9. Agitators 13 are in principle known from the prior art for gas-tight containers, in particular for ferrnenters. In this respect, reference is made for example to DE 199 54 904 Al, which discloses an agitator introduced laterally into the receiving chamber 2.

23 Within the context of the present exemplary embodiment, too, it is also possible for an agitator to be introduced laterally into the receiving chamber 2 as an alternative on in addition to an agitator 13, as is illustrated in figures 5 1 and 2.
In the exemplary embodiment, it is provided that the agitator 13 extends from the roof device 5, from above the platform 12 in the exemplary embodiment, into the receiving chamber 2. Here, the agitator 13 preferably extends along 10 the central axis, extending in a vertical direction, of the container 1, preferably coaxially with respect to the vertically extending central axis of the container 1.
The agitator 13 may have, in a known manner not described in more detail, 15 a motor. In the exemplary embodiment, it is furthermore provided that the agitator 13 has one or more blades 14 in order for the material, preferably an organic substance, that is introduced into the receiving chamber 2 to be stirred or set in motion. In the exemplary embodiment, the blades 14 are preferably able to be folded in, so that the agitator can be removed through 20 corresponding openings in the roof device 5.
In the exemplary embodiment, it is provided that the cover 8 has an agitator leadthrough 15, which preferably extends coaxially with respect to the vertical central axis of the container 1. The agitator leadthrough 15 is 25 illustrated by way of example in figures 3 and 4. The agitator leadthrough 15 has seals (not illustrated in more detail), in order that the agitator leadthrough 15 ends in a gas-tight manner with respect to the agitator 13 or the shaft thereof.
30 In the exemplary embodiment, it is provided that the supporting structure 9 itself is not of gas-tight design. However, this would in principle be possible.
As can be seen from the exemplary embodiments, the suspension device

24 is arranged centrally above the cover 8, preferably coaxially with respect to the vertically extending central axis of the container 1. The suspension device 10 is designed to lift the cover 8, and possibly to lower it again, within a defined travel.

The suspension device 10 is provided in particular for bracing the cover 8 upwardly in such a way that fluttering of the cover 8, for example owing to varying pressures in the receiving chamber 2, is avoided.
10 In principle, the suspension device 10 may be of any construction and act at any points of the cover 8. The exemplary embodiment is not to be understood as being restricted to a specific construction. However, it has turned out to be particularly suitable for the suspension device 10 to be fixed to fastening points 18 of the cover 8, and for the distance of the fastening points 18 from the center point of the cover 8 to be less than 70%, preferably less than 60%, more preferably less than 50%, particularly preferably less than 40%, and very particularly preferably less than 30%, of the distance of the center point of the cover 8 from the edge of the cover 8.
The suspension device 10 preferably acting in an inner circle of the cover 8 and bracing the cover upwardly results in particularly suitable bracing of the cover 8, by way of which bracing "fluttering" of the cover 8 is reliably avoided.
The suspension device 10 may have devices (not illustrated in more detail) for varying the travel by which the cover 8 is lifted. For this purpose, provision may be made for example of threaded rods which are rotated in a suitable manner so as to shorten or to lengthen the vertical length of the suspension device 10 and thereby to lift or to lower the cover 8.
As can be seen from figures 1 and 2, in the exemplary embodiment, it is (optionally) provided that the suspension device 10 has a plurality of chains 16 which are fixed directly or via a connecting element to the cover 8 so as to brace the cover 8 upwardly in the direction of the supporting structure.

For this purpose, the use of chains 16 has turned out to be particularly suitable, in particular also in combination with the threaded rods (not illustrated in more detail) by way of which the chains 16 can be lifted or, 5 further, lowered.
In the exemplary embodiment in figures 1 to 3, it is provided that the cover 8 is provided with a fastening ring 17 on which the suspension device 10 acts. Preferably, the fastening ring 17 has here a plurality of fastening points 10 18 to which the suspension device 101 preferably the chains 16, can be fixed, said fastening points preferably being arranged uniformly spaced apart from one another. This configuration has turned out to be particularly suitable, although it is optional within the context of the exemplary embodiment. The fastening ring 17 may be fixed in a gas-tight manner to the cover 8, which is 15 formed by the metal panels 6 (or metal plates 7), by way of known measures, for which purpose corresponding seals (not illustrated in more detail) may also be provided.
Figure 4 illustrates a design of the cover 8 that is an alternative to that in 20 figure 3. Here, it is provided that the cover 8 has an outer cover ring 19 with an inner opening 20. The cover 8 furthermore has an inner cover disk 21 which closes off the inner opening 20 of the outer cover ring 19 in a gas-tight manner. However, here, in the exemplary embodiment, there remains an agitator leadthrough 15, which is closed off in a gas-tight manner only after

25 the insertion of the agitator 13.
In the exemplary embodiment in figure 4, the inner opening 20 of the outer cover ring 19 is illustrated by a dashed line since, in the illustrated view, this is concealed by the inner cover disk 21. The inner cover disk 21 is connected 30 in a gas-tight manner to the outer cover ring 19, for which purpose corresponding seals may be used. In principle, it would be possible for the inner cover disk 21 to be welded to the outer cover ring 19. In the exemplary embodiment, however, a screw connection is provided. The design

26 illustrated in figure 4 has the advantage that, if the agitator 13 is intended to be removed from the receiving chamber 2, it is not necessary for the entire cover 8 to be dismounted, but rather it is sufficient for the inner cover disk 21 to be dismounted from the outer cover ring 19. The inner opening 20 of 5 the outer cover ring 19 is thereby exposed, so that the agitator 13 can be removed. Here, the inner opening 20 may also be in the form of a so-called manhole cover, in order, generally, to provide access to the receiving chamber 2.
10 The inner cover disk 21 may have bores through which the screws 22 are inserted. Here, it may be provided that the screw heads of the screws 22 are welded captively to the inner cover disk 21. By means of the screw 22, it is particularly advantageously possible for the inner cover disk to be connected to the outer cover ring 19.
Figure 4 furthermore illustrates fastening points 18 at which the suspension device 10, in particular chains 16 of the suspension device 10, can act.
In principle, the cover 8 illustrated in figure 4 may also have multiple cover 20 rings. This is illustrated in figure 4 by the dot-dashed line.
Figure 4 furthermore illustrates bores in the outer edge region of the cover 8 or in the outer edge region of the outer cover ring 19, which bores serve for fixing of the cover 8 to the wall 4. For this purpose, use may preferably be 25 made of screws 27 (subsequently illustrated in more detail). The cover 8 illustrated in figure 3 also has corresponding bores 23.
Figure 4 illustrates a suitable possible way of fixing the cover 8 to the top side of the wall 4. For this purpose, it is provided that the peripheral edge 30 region of the cover 8 is provided on its bottom side with a lower flange ring 24 and on a top side with an upper flange ring 25. Here, the flange rings 24, may preferably be screwed to one another. Another force-fitting connection and/or a materially bonded connection, for example a welded

27 connection, are/is also possible. A screw connection, however, has turned out to be particularly suitable, in particular in order for the need for local welding on the building site to be avoided and in particular in order for it to be possible for the cover 8 to also be detached again. Provision may be 5 made of a seal 26 between the bottom side of the cover 8 and the lower flange ring 24 in order to produce a gas-tight connection at this position.
In the embodiment illustrated in figure 5, it is furthermore provided that the lower flange ring 24 is preferably screwed to a wall 4. At this position, too, 10 another force-fitting connection or else a materially bonded connection, for example a welded connection, may be provided. However, at this position too, a screw connection is particularly suitable. Provision may in turn be made of a seal 26 which is arranged between the lower flange ring 24 and the wall 4, in order, at this position too, to produce a gas-tight connection.
The screws used for producing the screw connection bear the reference sign 27 in figure 5.
For the connection of the lower flange ring 24 to the wall 4, it may be 20 provided that the screws 27 are screwed through the wall 4, this being suitable in particular for walls 4 composed of metal, in particular steel.
Alternatively, it may also be provided that the screws 27 are screwed only into the wall 4, this being suitable in particular for walls 4 composed of concrete or metal-reinforced concrete, in particular steel-reinforced 25 concrete.
The container 1 illustrated in the exemplary embodiment is not restricted to that embodiment of the connection between the cover 8 and the wall 4 which is illustrated in figure 5, although this embodiment has turned out to be 30 particularly suitable.
In the exemplary embodiment, it is (optionally) provided that the roof device 5 is designed in such a way that a gas-tight connection between the wall 4

28 and the cover 8 is released if the pressure in the receiving chamber 2 exceeds a defined burst pressure, wherein the burst pressure corresponds to a positive pressure of 100 mbar, particularly preferably 80 mbar and very particularly preferably 60 mbar.
Such a configuration has turned out to be suitable for safety reasons. Here, different measures may be adopted to ensure that the gas-tight connection between the wall 4 and the cover 8 is released if the pressure in the receiving chamber 2 exceeds a defined burst pressure.
The releasable connection between the cover 8 and the wall 4 can particularly advantageously be released if use is made between the cover 8 and the wall 4 of the container 1 of a burst ring 28 which, in the event of the burst pressure being reached, releases a gas-tight connection between the cover 8 and the wall 4.
In principle, the burst ring 28 may be used at any suitable position of the roof device 5, in particular in such a way that the burst ring 28 is situated between the cover 8 and the wall 4. A particularly advantageous design is illustrated in figure 6, to which the exemplary embodiment is not restricted.
In the exemplary embodiment illustrated in figure 6, it is provided that the lower flange ring 24 is connected to the burst ring 28. It is furthermore provided that the burst ring 28 is connected to the wall 4 of the gas-tight container 1.
In order to connect the burst ring 28 to the lower flange ring 24 or to the wall 4, a screw connection is provided in the exemplary embodiment illustrated in figure 6. Screws 27, for example, may be used for the screw connection.
Alternatively, it is also possible for provision to be made for another force-fitting connection or else a materially bonded connection, for example a welded connection. A screw connection, however, has turned out to be

29 particularly suitable, in particular in order for the connection to also be released again.
For the connection of the burst ring 28 to the wall 4, it may be provided that 5 the screws 27 are screwed through the wall 4, this being suitable in particular for walls 4 composed of metal, in particular steel. Alternatively, it may also be provided that the screws 27 are screwed only into the wall 4, this being suitable in particular for walls 4 composed of concrete or metal-reinforced concrete, in particular steel-reinforced concrete.
The burst ring 28 may be formed in such a way that the connection between the burst ring 28 and the wall 4 and/or the connection between the burst ring 28 and the lower flange ring 24 are/is released if the burst pressure is exceeded. Furthermore, it may also be provided that the burst ring 28 is 15 destroyed if the burst pressure is exceeded.
In the exemplary embodiment illustrated in figure 6, there is furthermore also illustrated an upper flange ring 25, which is in principle suitable for producing a stable connection, although this is in principle optional within the context 20 of the exemplary embodiment in figure 6. In figure 6, it is provided that use is made of seals 26 at the connecting positions in order for the receiving chamber 2 to be closed off in a gas-tight manner.
The flange rings 24, 25, as viewed in cross section, are preferably in the 25 form of U-profiles.
In the exemplary embodiments, it is provided that the peripheral edge region of the cover 8 is fixed, that is to say clamped, in a force-fitting manner between the lower flange ring 24 and the upper flange ring 25 in such a way

30 that a gas-tight connection is the result.
The exemplary embodiments illustrated by way of example in figures 5 and 6 are suitable for walls 4 composed of any materials, preferably for walls 4 composed of metal, in particular steel, concrete, metal-reinforced concrete, in particular steel-reinforced concrete. In particular, it is possible for the cover 8 to be mounted onto the already existing wall 4 at a later stage (on site). The solution according to the invention furthermore also allows already 5 existing containers to be retrofitted with a new cover 8 or a roof device 5 at a later stage.

Claims

Patent claims

1. A gas-tight container, in particular a silo for the storage of organic substances, having a receiving chamber, having a base, having a peripheral wall and having a roof device, wherein the roof device has a gas-tight cover which is formed from flat metal panels and/or from flat metal plates, wherein the roof device has a supporting structure arranged above the cover and has a suspension device, wherein the suspension device is fixed to the cover and to the supporting structure and the suspension device braces the cover upwardly in the direction of the supporting structure, wherein at least the majority of the flat metal panels and/or of the metal plates of the cover have a thickness of 0.2 mm to 5 mm.

2. The gas-tight container as claimed in claim 1, wherein the suspension device braces the cover upwardly in such a way that the cover is convexly curved upward.

3. The gas-tight container as claimed in any one of claims 1 and 2, wherein the cover is self-supporting.

4. The gas-tight container as claimed in any one of claims 1 to 3, wherein the cover is connected at its peripheral edge region in a gas-tight manner to the wall.

5. The gas-tight container as claimed in any one of claims 1 to 4, wherein the roof device is designed in such a way that a gas-tight connection between the wall and the cover is released if the pressure in the receiving chamber exceeds a defined burst pressure, wherein the burst pressure corresponds to a positive pressure.

6. The gas-tight container as claimed in claim 5, wherein the positive pressure is 100 mbar.

7. The gas-tight container as claimed in claim 5, wherein the positive pressure is 80 mbar.

8. The gas-tight container as claimed in claim 5, wherein the positive pressure is 60 mbar.

9. The gas-tight container as claimed in any one of claims 5 to 8, wherein use is made between the peripheral edge region of the cover and the wall of the container of a burst ring which, in the event of the burst pressure being reached, releases a gas-tight connection between the cover and the wall.

10. The gas-tight container as claimed in any one of claims 4 to 9, wherein the peripheral edge region of the cover is provided on a bottom side with a lower flange ring and/or on a top side with an upper flange ring.

11. The gas-tight container as claimed in claim 10, wherein the peripheral edge region of the cover is fixed in a force-fitting manner between the lower flange ring and the upper flange ring.

12. The gas-tight container as claimed in any one of claims 10 and 11, wherein the lower flange ring is connected to the burst ring and the burst ring is connected to the wall of the container.

13. The gas-tight container as claimed in any one of claims 1 to 12, wherein at least the majority of the flat metal panels and/or of the metal plates of the cover have a thickness of 0.3 mm to 2 mm.

14. The gas-tight container as claimed in claim 13, wherein at least the majority of the flat metal panels and/or of the metal plates of the cover have a thickness of 0.4 mm to 1.5 mm.

15. The gas-tight container as claimed in claim 14, wherein at least the majority of the flat metal panels and/or of the metal plates of the cover have a thickness of 0.5 mm to 1.2 mm.

16. The gas-tight container as claimed in claim 15, wherein at least the majority of the flat metal panels andfor of the metal plates of the cover have a thickness of 0.6 mm to 1.2 mm.

17. The gas-tight container as claimed in claim 16, wherein at least the majority of the flat metal panels and/or of the metal plates of the cover have a thickness of 1 rnm.

18. The gas-tight container as claimed in any one of claims 1 to 17, wherein the flat metal panels and/or the flat metal plates of the cover are formed from high-grade steel.

19. The gas-tight container as claimed in any one of claims 1 to 18, wherein the receiving chamber has a volume of 100 to 50 000 m3.

20. The gas-tight container as claimed in claim 19, wherein the receiving chamber has a volume of 1,000 to 10 000 m3.

21. The gas-tight container as claimed in claim 20, wherein the receiving chamber has a volume of 2,000 to 8,000 m3.

22. The gas-tight container as claimed in any one of claims 1 to 21, wherein the supporting structure is in the form of a cone roof and/or in the form of a skeleton structure.

23. The gas-tight container as claimed in any one of claims 1 to 21, wherein the supporting structure is formed by horizontally extending bars.

24. The gas-tight container as claimed in any one of claims 1 to 23, wherein the supporting structure itself is not of gas-tight design.

25. The gas-tight container as claimed in any one of claims 1 to 24, wherein the suspension device is arranged centrally above the cover.

26. The gas-tight container as claimed in claim 25, wherein the suspension device is arranged coaxially with respect to the vertically extending central axis of the container.

27. The gas-tight container as claimed in any one of claims 1 to 26, wherein the suspension device is fixed to fastening points of the cover, and the distance of the fastening points from the center point of the cover is less than 70% of the distance of the center point of the cover from the edge of the cover.

28. The gas-tight container as claimed in claim 27, wherein the distance of the fastening points from the center point of the cover is less than 60% of the distance of the center point of the cover from the edge of the cover.

29. The gas-tight container as claimed in claim 28, wherein the distance of the fastening points from the center point of the cover is less than 50% of the distance of the center point of the cover from the edge of the cover.

30. The gas-tight container as claimed in claim 29, wherein the distance of the fastening points from the center point of the cover is less than 40% of the distance of the center point of the cover from the edge of the cover.

31. The gas-tight container as claimed in claim 30, wherein the distance of the fastening points from the center point of the cover is less than 30% of the distance of the center point of the cover from the edge of the cover.

32. The gas-tight container as claimed in any one of claims 1 to 31, wherein the suspension device has a plurality of chains which are fixed directly or via a fastening element to the cover so as to brace the cover upwardly in the direction of the supporting structure.

33. The gas-tight container as claimed in claim 32, wherein the fastening element is a fastening ring.

34. The gas-tight container as claimed in any one of claims 1 to 33, wherein the suspension device is designed to lift and to lower the cover within a defined travel.

35. The gas-tight container as claimed in any one of claims 1 to 34, wherein an agitator is arranged in the receiving chamber, and the cover has an agitator leadthrough.

36. The gas-tight container as claimed in claim 35, wherein the agitator leadthrough extends coaxially with respect to the vertical central axis of the container.

37. The gas-tight container as claimed in any one of claims 1 to 36, wherein the cover has at least one outer cover ring with an inner opening, and the cover has an inner cover disk which closes off the inner opening of the outer cover ring in a gas-tight manner.

38. An apparatus for obtaining a gaseous energy source from organic substances, in particular a biogas reactor, having a gas-tight container as claimed in any one of claims 1 to 37.