Note: Descriptions are shown in the official language in which they were submitted.
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1
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.
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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
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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.
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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
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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
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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
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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
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+/- 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
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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.
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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
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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.
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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.
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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
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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
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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
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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
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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
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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
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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.
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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
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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
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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.
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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
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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.
5
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.
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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
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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
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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
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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
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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
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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.
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