Field of the Invention
[0001] The subject matter of the invention relates to a method of cleaning the bottom interstitial
space and/or wall interstitial space of a storage tank designed in particular for
the storage of liquid flammable, toxic and caustic materials.
Background of the Invention
[0002] Storage tanks, both underground and above ground storage tanks, should meet requirements
concerning non-pressurized and low-pressure tanks designed in particular for the storage
of liquid flammable, toxic and caustic materials. Such tanks must meet strict safety
standards; namely, they must be,
inter alia, equipped with monitoring and measurement devices signalling leakages of substances
to the ground and ground waters. Moreover, rigorous safety requirements compel both
the manufacturers and users of storage tanks to produce and use tanks having bottom
interstitial spaces and/or wall interstitial spaces.
[0003] Such spaces should basically prevent penetration of liquid flammable, toxic and caustic
materials directly to the ground and ground waters. They should thus form an additional
protective space located at the bottom of a storage tank in the case of a bottom interstitial
space, and an additional protective space located on the walls of a storage tank in
the case of a wall interstitial space. These spaces are made during the construction
of a storage tank or are added in the course of its operation. They are most frequently
delimited by a secondary steel bottom or a secondary laminated bottom made of 3D mats
and suitable resins.
[0004] Despite taking all due care and maintaining high quality safety standards, storage
tanks with a bottom interstitial space and/or wall interstitial space are subject
to damage due to sealing failure
(unsealing) of said spaces. This may be caused by improper operation or by operational wear of
the tank's parts when a sealing failure of the bottom interstitial space and/or wall
interstitial space occurs a result of which a product in the form of a liquid inflammable,
toxic and/or caustic material penetrates into those spaces.
[0005] If the presence of a product in detected in the bottom interstitial space and/or
wall interstitial space of the storage tank, it is necessary to take actions in order
to clean those spaces of a storage tank and subsequently repair them in order to seal
them and permit further operation thereof.
Description of Prior Art
[0006] Considering the above-described problem in order to eliminate damage caused by sealing
failure in the bottom interstitial space and/or wall interstitial space of a storage
tank, there is provided a method of cleaning the bottom interstitial space and/or
wall interstitial space of a storage tank in order to subsequently repair it and permit
further operation thereof.
[0007] In the prior art there are known such solutions that relate to a method of cleaning
storage tanks designed in particular for liquid flammable, toxic and caustic materials.
However, said method of cleaning applies only to the interior of a water tank, called
storage capacity or storage space of the storage tank, which method basically consists
in that a product remaining in the storage tank is drained and subsequently the storage
space of the storage tank is subjected to cleaning, washing and vaporization.
[0008] More specifically, the process consists in pumping out sediments from technological
and clean-out hatches through conduits forced into a tank for forcing in sediments.
If it is not possible to take off the covers of hatches due to remaining pumpable
and unpumpable sediments, starting removing residuals from the tank is performed through
open technological hatches of the main tank. After pumping out sediments to a level
that makes it possible to fully open technological and clean-out hatches cleaning
works are started using the addition of water (in the amount not greater than 2% of
the volume of sediments) and polymers which fluidize the residuals of liquid flammable
materials to the state allowing their easy pumping and which are added before and
while sediments move towards the vicinity of suction hosts of screw pumps.
[0009] When removing pumpable, unpumpable and solid sediments from the inside of the tank
has been finished, and a total lack of an explosive hazard area inside the tank has
been confirmed, the whole surface is washed by means of hot-water high pressure washers
with the addition of chemical substances making it possible to fully degrease the
surfaces being washed.
[0010] In the prior art there are also known techniques of automatic cleaning of storage
tanks that consist in dissolving accumulated sediments and cleaning large-size storage
tanks. Since the majority of cleaning processes are automatized, the system makes
it possible to eliminate the presence of workers inside the tanks, i.e. in the storage
space, during the main operations of dissolving sediments until the moment when the
operation of final cleaning and degreasing the storage tank and removing undissolved
solid elements is performed. The final operations with the participation of workers
in the working space are performed in the already safe space when the tank contains
only trace amounts of carbohydrates and the surrounding atmosphere does not pose a
threat to the life and health of people. Thanks to such solutions such systems fall
within the category of "NON MAN ENTRY" systems.
[0011] Compared with traditional methods of manual cleaning and desludging storage tanks,
the system of automatic cleaning is much more effective and safe for the health of
workers. An essential feature of the system is that the process is performed in a
closed-circuit system without the necessity to expose the product in open containers
outside a storage tank, which significantly reduces its adverse effect on the natural
environment.
[0012] Furthermore the prior art
U.S. Patent Application No. US 5 096 087 A which is considered as the closest prior art regarding claim 1, discloses a double
containment and leak detection apparatus and method including a tank having a bottom
and a surrounding shell, with a containment baffle above the bottom and a leak detector
in a containment space between the containment baffle and the tank bottom. The containment
baffle includes a baffle plate sealingly joined to the interior of the shell to form
a sealed containment space between the containment baffle and the bottom. The leak
detector is installed in the containment space to detect the presence of stored material
held in the tank in the event such material leaks into the containment space. The
leak detection means is connected, through a leak-proof access, to means external
to the tank for responding to such leaks of stored material so detected inside the
containment space. The invention further includes a primary containment, made of liner
material, located inside the tank above the containment baffle and within the shell,
capable of containing such stored material. A suitable flushing mechanism is provided
so as to remove any leaked fluids from the containment space.
[0013] Moreover in the prior art European Patent Application No.
EP 1 316 516 A1 is also known which also discloses a similar method to clean and refill the intermediate
space between the outer and inner shell of a double-shelled container or pipework.
The method comprises steps: fitting a service assembly onto the bottom of the container
which comprises couplers for the drilling assembly couplers for the service pipe and
couplers to access the intermediate space, connecting a service pipe onto the service
assembly, fitting a drilling assembly of the service assembly onto the coupler, with
which the drilling depth on the inner shell is adjusted respectively and with which
a hole is drilled on the inner shell through joint, removing the aged liquid mixture
and introducing a new liquid mixture or protective gas through the service pipe and
joint into the intermediate space.
[0014] The claimed method of the invention differs from this known prior art solutions in
that the emptied storage space of the storage tank is supplied in a continuous manner
with fresh air through at least one inspection hatch thus ventilating the storage
space of the storage tank by means of ventilators, and consisting in the continuous
monitoring of the storage space of the storage tank by means of sensors measuring
the level of an explosive atmosphere and determining the concentration of carbohydrates
as percentage with respect to the lower and upper explosive limit of gases and oxygen
content in the storage space of the storage tank, as well as the minimum admissible
concentration of toxic gases in the storage space of the storage tank. Furthermore
the concentration of explosive gases in the bottom interstitial space and/or wall
interstitial space of the storage tank is measured in a continuous manner, and in
the case the measurement is beyond the admissible range, the process of cleaning the
bottom interstitial space and/or wall interstitial space of the storage tank is repeated
until the concentration of explosive gases reaches the lower explosive limit, in accordance
with claim 1.
[0015] The above-described prior art solutions and, more broadly, solutions related to cleaning
the storage space of a storage tank fail to provide an answer to the basic question:
what measures should be taken while maintaining high safety standards in the process
of cleaning the bottom interstitial space and/or wall interstitial space of a storage
tank in the case the presence of a product is detected in those spaces due to sealing
failure.
Essence of the Invention
[0016] Thus, the subject matter of the present invention relates to providing a method of
cleaning the bottom interstitial space and/or wall interstitial space of a storage
tank, designed in particular for the storage of liquid inflammable, toxic and caustic
materials, which has been damaged due to sealing failure in the bottom interstitial
space and/or wall interstitial space.
[0017] The method must, on the one hand, ensure high efficiency of the whole cleaning process,
and on the other, guarantee high accuracy while maintaining strict safety standards.
[0018] To achieve the above purposes, the present invention provides a method of cleaning
the bottom interstitial space and/or wall interstitial space of a storage tank in
the event of a sealing failure in the bottom interstitial space and/or wall interstitial
space of a storage tank, which method consist in that the emptied storage space of
a storage tank is supplied in a continuous manner with fresh air through at least
one inspection hatch thus ventilating the storage space of the storage tank by means
of ventilators, the cleaning process being performed with the continuous monitoring
of the storage space of the storage tank by means of sensors measuring the level of
an explosive atmosphere and determining the concentration of carbohydrates as percentage
with respect to the lower and upper explosive limit of gases and oxygen content in
the storage space of the storage tank, as well as the minimum admissible concentration
of toxic gases in the storage space of the storage tank. The method is characterized
in that a fluid is sucked in, in the case of low-pressure function of bottom interstitial
space and/or wall interstitial space, or forced in, in the case of high-pressure function
of bottom interstitial space and/or wall interstitial space, into the bottom interstitial
space and/or wall interstitial space, and subsequently, after filling the bottom interstitial
space and/or wall interstitial space of a storage tank with the fluid, the sucked-in
or forced-in fluid, respectively, which has been mixed with the product remaining
in the bottom interstitial space and/or wall interstitial space, which product previously
penetrated into the bottom interstitial space and/or wall interstitial space of the
storage tank due to sealing failure, is respectively sucked off or drained from the
bottom interstitial space and/or wall interstitial space. In the course of, respectively,
sucking off or draining the fluid that was mixed with the product remaining in the
bottom interstitial space and/or wall interstitial space a neutral gas is forced into
the bottom interstitial space and/or wall interstitial space of the storage tank and
the concentration of explosive gases in the bottom interstitial space and/or wall
interstitial space of the storage tank is measured in a continuous manner. In the
case the measurement is beyond the admissible range, the process of cleaning the bottom
interstitial space and/or wall interstitial space of the storage tank is repeated
until the concentration of explosive gases reaches the lower limit explosive limit.
[0019] Preferably, the fluid being, respectively, sucked into or forced into the bottom
interstitial space and/or wall interstitial space of the storage tank is water or
water with washing agents in the form of surfactants that react with the product,
and corrosion inhibitors or reduced water vapour from a technological installation
or a steam generator.
[0020] Preferably, the fluid is sucked, through at least one inspection stub pipe of the
system monitoring leakages, into the bottom interstitial space and/or wall interstitial
space of the storage tank by means of a pump, in particular a low-pressure pneumatic
diaphragm pump or other Ex pump allowing suitable selection of low pressure within
the rage from 0 to -1 bar.
[0021] Preferably, the liquid is forced, through at least one inspection stub pipe of the
system monitoring leakages, into the bottom interstitial space and/or wall interstitial
space of the storage tank by means of a pressure installation with a suitable pressure
reducing valve allowing suitable selection of pressure within the rage from 0 to 1
bar.
[0022] Preferably, the fluid that has been mixed with the product remaining in the bottom
interstitial space and/or wall interstitial space is sucked out through at least one
inspection stub pipe of the system monitoring leakages from the bottom interstitial
space and/or wall interstitial space of the storage tank by means of a pump, in particular
a low-pressure pneumatic diaphragm pump or another Ex pump allowing suitable selection
of low pressure within the rage from 0 to -1 bar.
[0023] Preferably, the fluid that has been mixed with the product remaining in the bottom
interstitial space and/or wall interstitial space is drained through at least one
inspection stub pipe of the system monitoring leakages from the bottom interstitial
space and/or wall interstitial space of the storage tank by means of a pressure installation
with a suitable pressure reducing valve allowing suitable selection of pressure within
the rage from 0 to 1 bar.
[0024] Preferably, neutral gas is forced into the bottom interstitial space and/or wall
interstitial space of the storage tank through at least one inspection stub pipe of
the system monitoring leakages by means of gas regulators allowing suitable selection
of pressure within the range from 0 to 1 bar, from bottle bundles or a cryogenic tank
or a nitrogen generator or a technological installation.
[0025] Preferably nitrogen is used as a neutral gas to eliminate the explosive atmosphere
inside the bottom interstitial space and/or wall interstitial space of the storage
tank.
[0026] Preferably, the process of cleaning the bottom interstitial space and/or wall interstitial
space of the storage tank is repeated until the concentration of explosive gases reaches
the lower explosive limit which is below 10% for all types of carbohydrate mixtures,
below 4% for gaseous hydrogen, and oxygen content is below 5% for all types of gaseous
mixtures.
[0027] Preferably, in the case where the process of cleaning the bottom interstitial space
and/or wall interstitial space of the storage tank has been repeated at least twice
and the concentration of explosive gases in the bottom interstitial space and/or wall
interstitial space of the storage tank is outside the admissible range, inspection
holes having 1 mm to 50 mm in diameter are drilled in the upper surface delimiting
the bottom interstitial space and/or in the inner surfaces of walls delimiting the
wall interstitial space in the amount from several to several tens depending of the
size of the area of the bottom interstitial space and/or wall interstitial space of
the storage tank, and/or the number of inspection stub pipes of the system monitoring
leakages in the bottom interstitial space and/or wall interstitial space of the storage
tank and/or depending on the size of sections into which the bottom interstitial space
and/or the wall interstitial space of the storage tank has been divided.
[0028] Preferably, the concentration of explosive gases in the bottom interstitial space
and/or wall interstitial space is measured by means of gas meters on at least one
inspection stub pipe of the system monitoring leakages and/or in inspection holes
in the upper surface delimiting the bottom interstitial space or in inspection holes
in the inner surfaces of walls delimiting the wall interstitial space made for proper
cleaning of the bottom interstitial space and/or wall interstitial space of the storage
tank.
[0029] Preferably, after cleaning the bottom interstitial space and/or wall interstitial
space of the storage tank, inspection holes are plugged with magnet plugs with rubber
gaskets providing additional sealing around the inspection holes in order to lock
the outflow of a neutral gas into the storage space of the storage tank.
[0030] Preferably, neodymium magnet plugs are used as magnet plugs.
[0031] The solution presented according to the aspect proposed above ensures a suitable
method of cleaning the bottom interstitial space and/or wall interstitial space which
consists
inter alia in more efficient, more effective and more accurate cleaning of the bottom interstitial
space and/or wall interstitial space in accordance with strict safety standards.
[0032] Additionally, this method is very universal and may be used with various storage
tanks, in particular those in the form of both vertical and horizontal cylinders,
small and large tanks. Thus, the method may be used with many different storage tanks.
The proposed method according to the invention may also be used in the case of both
non-pressurized tanks and low-pressure ones as wells as many other tanks.
Brief Description of Drawings
[0033] The subject matter of the invention is presented in an example embodiment in relation
to the enclosed figures wherein:
- FIG. 1
- shows a cross-section of a storage tank which depicts, in a simplified way, the method
of cleaning the bottom interstitial space and/or wall interstitial space of a storage
tank according to the invention after the occurrence of a sealing failure in the bottom
interstitial and wall interstitial space;
- FIG. 2
- shows a cross-section of another storage tank which depicts, in a simplified way,
the method of cleaning the wall interstitial space of a storage tank in another embodiment
according to the invention, after the occurrence of a sealing failure in the wall
interstitial space;
- FIG. 3
- presents an exemplary pattern of inspection holes drilled in the inner surface delimiting
the wall interstitial space of a storage tank of FIG. 2 according to the invention.
Detailed Description of the Invention
[0034] The subject matter of the invention is described in detail below in relation to the
attached figures and embodiments. The present invention is not limited only to the
detailed embodiments described herein.
[0035] The embodiment presented in
FIG. 1 presents a cross-section of a storage tank 100 which depicts, in a simplified way,
a method of cleaning the bottom interstitial space 110 and wall interstitial space
120 of a storage tank 100. The tank has the shape of a cylinder with a vertical axis
and is designed for the storage of a product 150 in the form of a liquid flammable
material, which is crude oil in the present case.
[0036] In the presented embodiment the storage tank 100 is also equipped with a system monitoring
leakages in the bottom interstitial space 110 and wall interstitial space 120 to facilitate
detection of damage, in particular sealing failure of those spaces.
[0037] Such sealing failure causes passage of a product 150 - which is crude oil in the
present case - from the storage space 195 of a storage tank 100 to the bottom interstitial
space 110 of the storage tank 100. The bottom interstitial space 110 is a space located
at the bottom of the storage tank between the secondary bottom 105, laminated and
made of 3D mats and epoxy raisins, and the primary bottom 115 made of steel.
[0038] Before initiating the method of cleaning, according to the invention, the bottom
interstitial space 110 and the wall interstitial space 120 of a storage tank 100 that
has been damaged due to sealing failure of these spaces, first the storage space 195
is cleared of a product 150 remaining in the storage tank 100, and then the storage
space 195 of the storage tank 100 is subjected to cleaning, washing and vaporising
by methods known from the state of the art.
[0039] Subsequently, fresh air is supplied in a continuous manner through inspection hatch
170 thus ventilating the storage space 195 of the storage tank 100 by means of ventilators
160, which are located at the main shell 180 of the storage tank 100. In the case
of a storage tank 100 additionally placed in a protective shell (not shown), in order
to mount ventilators 160 on the shell and outside the protective shell, a special
air sleeve is made between the protective shell and the main shell 180 so as to limit
loss of fresh air forced into the storage tank 100.
[0040] The whole process of cleaning preceding the initiation of the proper process of cleaning
the unsealed bottom interstitial space 110 and wall interstitial space 120 is performed
with the continuous monitoring of the storage space 195 of the storage tank 100 by
means of sensors (not shown) measuring the level of explosive atmosphere and determining
the concentration of hydrocarbons as percentage relative to the lower and upper explosive
limit of gases and oxygen content in the storage space 195 of the storage tank 100,
and the lower admissible concentration of toxic gases in the storage space 195 of
the storage tank 100.
[0041] The operations defined above are performed in order to enable inner inspection of
the storage tank 100, i.e. of the storage space 195, by relevant services including
an authorised employee of the Office of Technical Inspection (UDT) and other competent
persons who will verify the condition of the bottom interstitial space 110 and wall
interstitial space 120 and determine whether a permission to operate the storage tank
100 may be issued.
[0042] If a sealing failure is detected, as in the presented example, the proper process
of cleaning the bottom interstitial space 110 and wall interstitial space 120 is initiated.
The method consists in that a fluid in the form of water with surfactants reacting
with a product 150 and corrosion inhibitors are forced through inspection stub pipe
130 of the system monitoring leakages to the bottom interstitial space 110 and wall
interstitial space 120 of the storage tank 100 by means of a pressure installation
with a pressure reducing valve allowing suitable selection of pressure, which is 0.5
bar in this case.
[0043] After filling the bottom interstitial space 110 and wall interstitial space 120 with
the fluid, which has been mixed with a product 150 remaining in said spaces, which
product penetrated earlier to said spaces due to sealing failure, the fluid is drained
through a inspection stub pipe 130 of the system monitoring leakages from said spaces
by means of a pressure installation with a pressure reducing valve allowing proper
selection of pressure, which is 0.5 bar in this case.
[0044] During drainage of a fluid that was mixed with a product 150 remaining in the bottom
interstitial space 110 and wall interstitial space 120, a neutral gas in the form
of nitrogen is forced in to eliminate explosive atmosphere inside the bottom interstitial
space 110 and wall interstitial space 120 of the storage tank 100. The above-mentioned
nitrogen is forced into the bottom interstitial space 110 and wall interstitial space
120 of the storage tank 100 through a inspection stub pipe 130 of the leakage monitoring
system by means of gas reducers allowing suitable selection of pressure, which is
0.5 bar in this case, from a technological installation.
[0045] Moreover, during drainage of the fluid the concentration of explosive gases in the
bottom interstitial space 110 and wall interstitial space 120 of the storage tank
100 is measured in a continuous manner by means of gas meters on two inspection stub
pipes 130 of the leakage monitoring system in order to properly clean those spaces.
In the case the measurement is outside the admissible range, the process of cleaning
the bottom interstitial space 110 and wall interstitial space 120 of the storage tank
100 is repeated until the concentration of explosive gases reaches the lower explosive
limit which is below 10% for all kinds of hydrocarbon mixtures, below 4% - for gaseous
hydrogen, and oxygen content below 5% for all types of gaseous mixtures. In the presented
embodiment the lower explosive limit of the concentration of explosive gases was obtained
after the process of cleaning the bottom interstitial space 110 and wall interstitial
space 120 of the storage tank 100 was repeated twice.
[0046] Another embodiment in
FIG. 2 shows a cross-section of a storage tank 200 which depicts, in a simplified way, a
method of cleaning the wall interstitial space 120 of a storage tank 200 after the
occurrence of a sealing failure in that space. The tank is a cylinder having a vertical
axis, which is designed for the storage of a product 150 in the form of a liquid flammable
material, which is unleaded petrol PB98 in this case.
[0047] As in the example described above for the storage tank 100, a sealing failure has
occurred and a product 150, which is unleaded petrol PB98 in this case, has penetrated
from the storage space 195 of the storage tank 200 into the wall interstitial space
120 of the storage tank 200.
[0048] It this case, despite the fact that the process of cleaning the wall interstitial
space 120 of the storage tank 200 has been repeated three times, the concentration
of explosive gases in the wall interstitial space 120 continued to be outside the
admissible range. Therefore, in order to improve the process of cleaning, inspection
holes 250 having a diameter of 20 mm have been drilled in the inner surface delimiting
the wall interstitial space 120, as illustrated in more detail in
FIG. 3 which presents a pattern of inspection holes 250 drilled in the inner surface delimiting
the wall interstitial space 120 of the storage tank 200 according to the invention.
[0049] The said inspection holes 250 are drilled by means of a pneumatically driven device
equipped with a holder for mounting a core drill bit, the number thereof being dependent
on the size of sections 280 into which the wall interstitial space 120 of the storage
tank 200 has been divided. In the embodiment presented in
FIG. 2 for a storage tank 200 in the form of a cylinder having a horizontal axis and the
capacity of 50 m
3, 20 inspection holes 250 should be drilled in the wall interstitial space 120. And
in the case of a storage tank 100 in the form of a cylinder having a vertical axis
and the capacity of 1000 m
3 as illustrated in
FIG. 1 it is assumed that 5 inspection holes 250 should be drilled in the wall interstitial
space 120 and 10 inspection holes 250 - in the bottom interstitial space 110. The
operation of drilling holes in the case of a storage tank 100 would be performed if
it was impossible to obtain a concentration of explosive gases within an admissible
range after the process of cleaning the bottom interstitial space 110 and the wall
interstitial space 120 of the storage tank 100 has been repeated twice.
[0050] Referring again to the embodiment shown in
FIG. 2, the inspection holes 250, after cleaning the wall interstitial space 120 of the storage
tank 200, are plugged with plugs of magnets with rubber gaskets providing additional
sealing around the inspection holes 250 in order to lock the outflow of a neutral
gas into the storage space 195 of the storage container 200. In the embodiment plugs
of neodymium magnets have been used as plugs magnets provided with rubber gaskets.
[0051] The above description of presented embodiment has been provided to enable any person
skilled in the art to carry out or use the invention. There are also possible various
modifications of this embodiment including all such changes, modifications and variants
that fall within the essence and scope of the attached patent claims. The basic principles
defined herein may thus be applied in other embodiments without extending the scope
of the invention. Therefore, the intention of the present invention is not to limit
it to the presented embodiment but to make it consistent with the broadest possible
scope corresponding to the principles and new features presented herein.
[0052] Thus, the solution according to the present invention uses the above specified technical
means as shown in the FIGURES from
FIG. 1 to
FIG. 3 to offer a method of cleaning the bottom interstitial space and/or wall interstitial
space of a storage tank, designed in particular for the storage of liquid flammable,
toxic and caustic materials, which has been damaged due to the sealing failure in
the bottom interstitial space and/or wall interstitial space.
[0053] The present invention may be applicable in particular in all cases of a damage consisting
in the sealing failure of the bottom interstitial space and/or wall interstitial space
of a storage tank, which results in the necessity of cleaning or sealing said space.
Considering the above, the present solution according to the invention is likely to
be widely applied in particular in the petrochemical sector where the highest safety
standards are required, especially in fuel depots and liquid fuel stations where storage
tanks with bottom interstitial spaces and/or wall interstitial spaces are installed.
[0054] The invention may also be applicable in the case of some long-distance transmission
pipelines equipped with interstitial spaces and used to transport oil and oil products.
1. A method of cleaning the bottom interstitial space (110) and/or wall interstitial
space (120) of a storage tank (100; 200) in the event of a sealing failure in the
bottom interstitial space (110) and/or wall interstitial space (120) of a storage
tank (100; 200), consisting in that the emptied storage space (195) of a storage tank
(100; 200) is supplied in a continuous manner with fresh air through at least one
inspection hatch (170) thus ventilating the storage space (195) of the storage tank
(100; 200) by means of ventilators (160), and consisting in the continuous monitoring
of the storage space (195) of the storage tank (100; 200) by means of sensors measuring
the level of an explosive atmosphere and determining the concentration of carbohydrates
as percentage with respect to the lower and upper explosive limit of gases and oxygen
content in the storage space (195) of the storage tank (100; 200), as well as the
minimum admissible concentration of toxic gases in the storage space (195) of the
storage tank (100; 200), wherein a fluid is sucked in, in the case of low-pressure
function of bottom interstitial space (110) and/or wall interstitial space (120),
or forced in, in the case of high-pressure function of bottom interstitial space (110)
and/or wall interstitial space (120), into the bottom interstitial space (110) and/or
wall interstitial space (120), and subsequently, after filling the bottom interstitial
space (110) and/or wall interstitial space (120) of a storage tank (100; 200) with
the fluid, the sucked-in or forced-in fluid, respectively, which has been mixed with
the product (150) remaining in the bottom interstitial space (110) and/or wall interstitial
space (120), which product (150) previously penetrated into the bottom interstitial
space (110) and/or wall interstitial space (120) of the storage tank (100; 200) due
to sealing failure, is respectively sucked off or drained from the bottom interstitial
space (110) and/or wall interstitial space (120), wherein in the course of, respectively,
sucking off or draining the fluid that was mixed with the product (150) remaining
in the bottom interstitial space (110) and/or wall interstitial space (120) a neutral
gas is forced into the bottom interstitial space (110) and/or wall interstitial space
(120) of the storage tank (100; 200), and the concentration of explosive gases in
the bottom interstitial space (110) and/or wall interstitial space (120) of the storage
tank (110; 200) is measured in a continuous manner, and in the case the measurement
is beyond the admissible range, the process of cleaning the bottom interstitial space
(110) and/or wall interstitial space (120) of the storage tank (110; 200) is repeated
until the concentration of explosive gases reaches the lower explosive limit.
2. The method according to claim 1, characterized in that the fluid being, respectively, sucked into or forced into the bottom interstitial
space (110) and/or wall interstitial space (120) of the storage tank (100; 200) is
water or water with washing agents in the form of surfactants that react with the
product (150), and corrosion inhibitors or reduced water vapour from a technological
installation or a steam generator.
3. The method according to claim 1 or 2, characterized in that the fluid is sucked, through at least one inspection stub pipe (130) of the system
monitoring leakages, into the bottom interstitial space (110) and/or wall interstitial
space (120)of the storage tank (100; 200) by means of a pump, in particular a low-pressure
pneumatic diaphragm pump or other Ex pump allowing suitable selection of low pressure
within the rage from 0 to -1 bar.
4. The method according to claim 1 or 2, characterized in that the liquid is forced, through at least one inspection stub pipe (130) of the system
monitoring leakages, into the bottom interstitial space (110) and/or wall interstitial
space (120) of the storage tank (100; 200) by means of a pressure installation with
a suitable pressure reducing valve allowing suitable selection of pressure within
the rage from 0 to 1 bar.
5. The method according to claim 1 or 2, characterized in that the fluid that has been mixed with the product (150) remaining in the bottom interstitial
space (110) and/or wall interstitial space (120) is sucked off through at least one
inspection stub pipe (130) of the system monitoring leakages from the bottom interstitial
space (110) and/or wall interstitial space (120) of the storage tank (100; 200) by
means of a pump, in particular a low-pressure pneumatic diaphragm pump or another
Ex pump allowing suitable selection of low pressure within the rage from 0 to -1 bar.
6. The method according to claim 1 or 2, characterized in that, the fluid that has been mixed with the product (150) remaining in the bottom interstitial
space (110) and/or wall interstitial space (120) is drained through at least one inspection
stub pipe (130) of the system monitoring leakages from the bottom interstitial space
(110) and/or wall interstitial space (120) of the storage tank (100; 200) by means
of a pressure installation with a suitable pressure reducing valve allowing suitable
selection of pressure within the rage from 0 to 1 bar.
7. The method according to claim 1, characterized in that, the neutral gas is forced into the bottom interstitial space (110) and/or wall interstitial
space (120) of the storage tank (100; 200) through at least one inspection stub pipe
(130) of the system monitoring leakages by means of gas regulators allowing suitable
selection of pressure within the range from 0 to 1 bar, from bottle bundles or a cryogenic
tank or a nitrogen generator or a technological installation.
8. The method according to claim 1 or 7, characterized in that, nitrogen is used as a neutral gas to eliminate the explosive atmosphere inside the
bottom interstitial space (110) and/or wall interstitial space (120) of the storage
tank (100; 200).
9. The method according to claim 1, characterized in that the process of cleaning the bottom interstitial space (110) and/or wall interstitial
space (120) of the storage tank (100; 200) is repeated until the concentration of
explosive gases reaches the lower explosive limit which is below 10% for all types
of carbohydrate mixtures, below 4% for gaseous hydrogen and oxygen content is below
5% for all types of gaseous mixtures.
10. The method according to claim 1 or 9, characterized in that in the case where the process of cleaning the bottom interstitial space (110) and/or
wall interstitial space (120) of the storage tank (100; 200) has been repeated at
least twice and the concentration of explosive gases in the bottom interstitial space
(110) and/or wall interstitial space (120) of the storage tank (100; 200) is outside
the admissible range, inspection holes (250) having 1 mm to 50 mm in diameter are
drilled in the upper surface delimiting the bottom interstitial space (110) and/or
in the inner surfaces of walls delimiting the wall interstitial space (120) in the
amount from several to several tens depending of the size of the area of the bottom
interstitial space (110) and/or wall interstitial space (120) of the storage tank
(100; 200) and/or the number of inspection stub pipes (130) of the system monitoring
leakages in the bottom interstitial space (110) and/or wall interstitial space (120)
and/or depending on the size of sections (280) into which the bottom interstitial
space (110) and/or the wall interstitial space (120) of the storage tank (100; 200)
has been divided.
11. The method according to claim 1 or 9, characterized in that the concentration of explosive gases in the bottom interstitial space (110) and/or
wall interstitial space (120)is measured by means of gas meters on at least one inspection
stub pipe (130) of the system monitoring leakages and/or in inspection holes (250)
in the upper surface delimiting the bottom interstitial space (110) or in inspection
holes (250) in the inner surfaces of walls delimiting the wall interstitial space
(120) made for proper cleaning of the bottom interstitial space (110) and/or wall
interstitial space (120) of the storage tank (100; 200).
12. The method according to claim 10, characterized in that the inspection holes (250) after cleaning the bottom interstitial space (110) and/or
wall interstitial space (120) of the storage tank (110; 200), are plugged with magnet
plugs with rubber gaskets providing additional sealing around the inspection holes
(250) in order to lock outflow of a neutral gas into the storage space (195) of the
storage tank (100; 200).
13. The method according to claim 12, characterized in that, neodymium magnet plugs are used as magnet plugs.
1. Verfahren zur Reinigung des Bodens eines interstitiellen Raums (110) und/oder der
Wand eines interstitiellen Raums (120) eines Lagertanks (100; 200), im Zusammenhang
mit der Dehermetisierung des Bodens eines interstitiellen Raums (110) und/oder der
Wand eines interstitiellen Raums (120) des Lagertanks (100; 200), das darauf beruht,
dass zu einem entleerten Lagerraum (195) des Lagertanks (100; 200) über mindestens
einen Kontrollschacht (170) Frischluft stetig zugeführt wird, indem der Lagerraum
(195) des Lagertanks (100; 200) mit Hilfe von Lüftern (160) belüftet wird, und das
darauf beruht, den Lagerraum (195) des Lagertanks (100; 200) mit Hilfe von den Pegel
der explosionsfähigen Atmosphäre messenden Sensoren zu stetig überwachen, die die
Konzentration von Kohlenwasserstoffen als Prozent bezüglich der unteren und der oberen
Explosionsgrenze von Gasen und des Sauerstoffgehalts im Lagerraum (195) des Lagertanks
(100; 200) sowie auch des unteren zulässigen Konzentrationswerts von toxischen Gasen
im Lagerraum (195) des Lagertanks (100; 200) bestimmen, wobei in den Boden eines interstitiellen
Raums (110) und/oder die Wand eines interstitiellen Raums (120) eine Flüssigkeit,
im Fall des mit Unterdruck arbeitenden Bodens eines interstitiellen Raums (110) und/oder
der mit Unterdruck arbeitenden Wand eines interstitiellen Raums (120), eingesaugt
oder im Fall des mit Überdruck arbeitenden Bodens eines interstitiellen Raums (110)
und/oder der mit Überdruck arbeitenden Wand eines interstitiellen Raums (120), eingepresst
wird, und anschließend nach der Befüllung des Bodens eines interstitiellen Raums (110)
und/oder der Wand eines interstitiellen Raums (120) des Lagertanks (100; 200) mit
der Flüssigkeit, entsprechend von dem Boden eines interstitiellen Raums (110) und/oder
der Wand eines interstitiellen Raums (120) die eingesaugte oder dorthin eingepresste
Flüssigkeit abgesaugt oder abgeführt wird, die mit einem in dem Boden eines interstitiellen
Raums (110) und/oder der Wand eines interstitiellen Raums (120) verbleibenden Produkt
(150) vermischt wurde, das vorher infolge der Dehermetisierung in den Boden eines
interstitiellen Raums (110) und/oder die Wand eines interstitiellen Raums (120) des
Lagertanks (100; 200) gelangt ist, wobei während, entsprechend, der Absaugung oder
der Abführung der Flüssigkeit, die mit dem in dem Boden eines interstitiellen Raums
(110) und/oder der Wand eines interstitiellen Raums (120) verbleibenden Produkt (150)
vermischt wurde, in den Boden eines interstitiellen Raums (110) und/oder die Wand
eines interstitiellen Raums (120) des Lagertanks (100; 200) Inertgas eingepresst wird
und die Konzentration von Explosionsgasen in dem Boden eines interstitiellen Raums
(110) und/oder der Wand eines interstitiellen Raums (120) des Lagertanks (100; 200)
stetig gemessen wird, und falls diese Messung außerhalb des zulässigen Bereichs liegt,
wird das Reinigungsverfahren des Bodens eines interstitiellen Raums (110) und/oder
der Wand eines interstitiellen Raums (120) des Lagertanks (100; 200) wiederholt, bis
die Konzentration von Explosionsgasen in der unteren Grenze der Explosionsfähigkeit
von Gasen erreicht wird.
2. Verfahren nach Anspruch 1, gekennzeichnet dadurch, dass als Flüssigkeit in den Boden eines interstitiellen Raums (110) und/oder die Wand
eines interstitiellen Raums (120) des Lagertanks (100; 200), Wasser oder Wasser mit
Reinigungsmitteln in Form von mit dem Produkt (150) reagierenden grenzflächenaktiven
Substanzen und Korrosionsinhibitoren oder ein reduzierter Wasserdampf aus einer Technologieanlage
oder einem Dampfentwickler entsprechend eingesaugt oder eingepresst werden.
3. Verfahren nach Anspruch 1 oder 2, gekennzeichnet dadurch, dass die Flüssigkeit über mindestens einen Kontrollstutzen (130) des Leckage-Überwachungssystems
in den Boden eines interstitiellen Raums (110) und/oder die Wand eines interstitiellen
Raums (120) des Lagertanks (100; 200) mit Hilfe von einer Pumpe, insbesondere einer
pneumatischen Unterdruckmembranpumpe oder einer anderen Ex-Pumpe, die eine entsprechende
Wahl des Unterdrucks im Bereich von 0 bis -1 bar erlaubt, eingesaugt wird.
4. Verfahren nach Anspruch 1 oder 2, gekennzeichnet dadurch, dass die Flüssigkeit über mindestens einen Kontrollstutzen (130) des Leckage-Überwachungssystems
in den Boden eines interstitiellen Raums (110) und/oder die Wand eines interstitiellen
Raums (120) des Lagertanks (100; 200) mit Hilfe von einer Druckanlage mit einem entsprechenden
Druckminderventil, das eine entsprechende Wahl des Drucks im Bereich von 0 bis 1 bar
erlaubt, eingepresst wird.
5. Verfahren nach Anspruch 1 oder 2, gekennzeichnet dadurch, dass die Flüssigkeit, die mit dem in dem Boden eines interstitiellen Raums (110) und/oder
der Wand eines interstitiellen Raums (120) verbleibenden Produkt (150) vermischt wurde,
über mindestens einen Kontrollstutzen (130) des Leckage-Überwachungssystems von dem
Boden eines interstitiellen Raums (110) und/oder der Wand eines interstitiellen Raums
(120) des Lagertanks (100; 200) mit Hilfe von einer Pumpe, insbesondere einer pneumatischen
Unterdruckmembranpumpe oder einer anderen Ex-Pumpe, die eine entsprechende Wahl des
Unterdrucks im Bereich von 0 bis -1 bar erlaubt, abgesaugt wird.
6. Verfahren nach Anspruch 1 oder 2, gekennzeichnet dadurch, dass die Flüssigkeit, die mit dem in dem Boden eines interstitiellen Raums (110) und/oder
der Wand eines interstitiellen Raums (120) verbleibenden Produkt (150) vermischt wurde,
über mindestens einen Kontrollstutzen (130) des Leckage-Überwachungssystems von dem
Boden eines interstitiellen Raums (110) und/oder der Wand eines interstitiellen Raums
(120) des Lagertanks (100; 200) mit Hilfe von einer Druckanlage mit einem entsprechenden
Druckminderventil, das eine entsprechende Wahl des Drucks im Bereich von 0 bis 1 bar
erlaubt, abgeführt wird.
7. Verfahren nach Anspruch 1, gekennzeichnet dadurch, dass Inertgas in den Boden eines interstitiellen Raums (110) und/oder die Wand eines interstitiellen
Raums (120) des Lagertanks (100; 200) über mindestens einen Kontrollstutzen (130)
des Leckage-Überwachungssystems mit Hilfe von Gasreduzierventilen, die eine entsprechende
Wahl des Drucks im Bereich von 0 bis 1 bar aus Gasflaschenbündeln oder einem Kryobehälter
oder einem Stickstofferzeuger oder einer Technologieanlage erlauben, eingepresst wird.
8. Verfahren nach Anspruch 1 oder 7, gekennzeichnet dadurch, dass als Inertgas Stickstoff für Beseitigung der explosionsfähigen Atmosphäre in dem Inneren
des Bodens eines interstitiellen Raums (110) und/oder der Wand eines interstitiellen
Raums (120) des Lagertanks (100; 200) eingesetzt wird.
9. Verfahren nach Anspruch 1, gekennzeichnet dadurch, dass das Reinigungsverfahren des Bodens eines interstitiellen Raums (110) und/oder der
Wand eines interstitiellen Raums (120) des Lagertanks (100; 200) wiederholt wird,
bis die Konzentration von Explosionsgasen in der unteren Grenze der Explosionsfähigkeit
unter 10% bezogen auf alle Arten von Kohlenwasserstoffmischungen, unter 4% für den
gasförmigen Wasserstoff und den Sauerstoffgehalt, unter 5% für alle Arten von Gasmischungen
erreicht wird.
10. Verfahren nach Anspruch 1 oder 9, gekennzeichnet dadurch, dass wenn das Reinigungsverfahren des Bodens eines interstitiellen Raums (110) und/oder
der Wand eines interstitiellen Raums (120) des Lagertanks (100; 200) mindestens zwei
Mal wiederholt wurde, und die Konzentration von Explosionsgasen in dem Boden eines
interstitiellen Raums (110) und/oder der Wand eines interstitiellen Raums (120) des
Lagertanks (100; 200) außerhalb des zulässigen Bereichs liegt, dann werden Kontrollöffnungen
(250) mit einem Durchmesser zwischen 1 mm und 50 mm in der oberen den Boden eines
interstitiellen Raums (110) begrenzenden Fläche und/oder in den inneren die Wand eines
interstitiellen Raums (120) begrenzenden Wandflächen in einer Anzahl von einigen bis
einigen zehn in Abhängigkeit von der Flächengröße des Bodens eines interstitiellen
Raums (110) und/oder der Wand eines interstitiellen Raums (120) des Lagertanks (100;
200) und/oder der Anzahl der Kontrollstutzen (130) des Leckage-Überwachungssystems
in dem Boden eines interstitiellen Raums (110) und/oder der Wand eines interstitiellen
Raums (120) und/oder in Abhängigkeit von der Größe der Sektionen (280), in die der
Boden eines interstitiellen Raums (110) und/oder die Wand eines interstitiellen Raums
(120) des Lagertanks (100; 200) aufgeteilt wurde, gebohrt.
11. Verfahren nach Anspruch 1 oder 9, gekennzeichnet dadurch, dass die Konzentration von Explosionsgasen in dem Boden eines interstitiellen Raums (110)
und/oder der Wand eines interstitiellen Raums (120) mit Hilfe von Gasmessern an mindestens
einem Kontrollstutzen (130) des Leckage-Überwachungssystems und/oder den Kontrollöffnungen
(250) in der oberen den Boden eines interstitiellen Raums (110) begrenzenden Fläche
oder den Kontrollöffnungen (250) in den inneren die Wand eines interstitiellen Raums
(120) begrenzenden Wandflächen, die zur korrekten Reinigung des Bodens eines interstitiellen
Raums (110) und/oder der Wand eines interstitiellen Raums (120) des Lagertanks (100;
200) hergestellt wurden, gemessen wird.
12. Verfahren nach Anspruch 10, gekennzeichnet dadurch, dass die Kontrollöffnungen (250) nach der Reinigung des Bodens eines interstitiellen Raums
(110) und/oder der Wand eines interstitiellen Raums (120) des Lagertanks (100; 200)
mit Verschlußpropfen aus mit den Bereich der Kontrollöffnungen (250) abdichtenden
Gummidichtungen ausgestatteten Magneten verschlossen werden, um die Ausströmung des
Inertgases in den Lagerraum (195) des Lagertanks (100; 200) zu sperren.
13. Verfahren nach Anspruch 12, gekennzeichnet dadurch, dass als Verschlußpropfen aus Magneten, Verschlußpropfen aus Neodym-Magneten eingesetzt
werden.
1. Procédé de nettoyage d'un espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) d'un réservoir de stockage (100; 200), en raison d'un défaut d'étanchéité
de l'espace de l'interstice du fond (110) et/ou de l'interstice de la paroi (120)
d'un réservoir de stockage (100; 200), qui consiste à amener en continu de l'air frais
dans l'espace de stockage (195) vidé du réservoir de stockage (100; 200), par au moins
un regard de visite (170) en ventilant l'espace de stockage (195) du réservoir de
stockage (100; 200) à l'aide des ventilateurs (160), et qui consiste à surveiller
en continu l'espace de stockage (195) du réservoir de stockage (100; 200) à l'aide
des capteurs mesurant le niveau de l'atmosphère explosive qui déterminent les concentrations
des hydrocarbures comme un pourcentage relatif aux limites inférieure et supérieure
de l'explosivité des gaz et la teneur en oxygène dans l'espace de stockage (195) du
réservoir de stockage (100; 200), ainsi que la teneur admissible en concentrations
des gaz toxiques dans l'espace de stockage (195) du réservoir de stockage (100; 200),
dans lequel on aspire, dans le cas de l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) fonctionnant en dépression ou on injecte, dans le cas de l'espace
de l'interstice du fond (110) et/ou de l'interstice de la paroi (120) fonctionnant
en surpression, un fluide dans l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120), et ensuite après avoir rempli avec le fluide l'espace de l'interstice
du fond (110) et/ou de l'interstice de la paroi (120) du réservoir de stockage (100;
200), respectivement, on aspire ou on évacue de l'espace de l'interstice du fond (110)
et/ou de l'interstice de la paroi (120) le fluide y aspiré ou injecté, qui c'est mélangé
dans l'espace de l'interstice du fond (110) et/ou de l'interstice de la paroi (120),
avec le produit (150) présent qui, à l'issu d'un défaut d'étanchéité, c'est introduit
auparavant dans l'espace de l'interstice du fond (110) et/ou de l'interstice de la
paroi (120) du réservoir de stockage (100; 200), ceci étant, pendant, respectivement,
l'aspiration ou l'évacuation du fluide, qui c'est mélangé dans l'espace de l'interstice
du fond (110) et/ou de l'interstice de la paroi (120), avec le produit (150) présent
on injecte un gaz inerte dans l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) du réservoir de stockage (100; 200) et on mesure en continu la concentration
des gaz explosifs dans l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) du réservoir de stockage (100; 200), et dans le cas lorsque ladite
mesure s'avère être hors de la plage admissible, le processus de nettoyage de l'espace
de l'interstice du fond (110) et/ou de l'interstice de la paroi (120) du réservoir
de stockage (100; 200) est réitéré, jusqu'à l'obtention d'une teneur en gaz explosifs
au niveau de la limite inférieure de l'explosivité des gaz.
2. Procédé selon la revendication 1, caractérisé en ce que comme fluide dans l'espace de l'interstice du fond (110) et/ou de l'interstice de
la paroi (120) du réservoir de stockage (100; 200), respectivement, on aspire ou on
injecte de l'eau ou de l'eau avec des agents de lavage sous forme de surfactants réagissant
avec le produit (150) et des inhibiteurs de corrosion ou de la vapeur d'eau réduite
d'une installation technologique ou d'un générateur de vapeur d'eau.
3. Procédé selon la revendication 1 ou 2, caractérisé en ce que le fluide est aspiré, par au moins un manchon de contrôle (130) du système de surveillance
des fuites, dans l'espace de l'interstice du fond (110) et/ou de l'interstice de la
paroi (120) du réservoir de stockage (100; 200) à l'aide d'une pompe, notamment d'une
pompe pneumatique à dépression à diaphragme ou d'une autre pompe en exécution Ex permettant
un choix approprié de dépression dans la plage de 0 à -1 bar.
4. Procédé selon la revendication 1 ou 2, caractérisé en ce que le fluide est injecté, par au moins un manchon de contrôle (130) du système de surveillance
des fuites, dans l'espace de l'interstice du fond (110) et/ou de l'interstice de la
paroi (120) du réservoir de stockage (100; 200) à l'aide d'une installation pressurisée
avec un détendeur approprié permettant un choix approprié de dépression dans la plage
de 0 à 1 bar.
5. Procédé selon la revendication 1 ou 2, caractérisé en ce que le fluide, qui c'est mélangé dans l'espace de l'interstice du fond (110) et/ou de
l'interstice de la paroi (120), avec le produit (150) présent est aspiré par au moins
un manchon de contrôle (130) du système de surveillance des fuites, dans l'espace
de l'interstice du fond (110) et/ou de l'interstice de la paroi (120) du réservoir
de stockage (100; 200) à l'aide d'une pompe, notamment d'une pompe pneumatique à dépression
à diaphragme ou d'une autre pompe en exécution Ex permettant un choix approprié de
dépression dans la plage de 0 à -1 bar.
6. Procédé selon la revendication 1 ou 2, caractérisé en ce que le fluide, qui c'est mélangé dans l'espace de l'interstice du fond (110) et/ou de
l'interstice de la paroi (120), avec le produit (150) présent est évacué par au moins
un manchon de contrôle (130) du système de surveillance des fuites, dans l'espace
de l'interstice du fond (110) et/ou de l'interstice de la paroi (120) du réservoir
de stockage (100; 200) à l'aide d'une installation pressurisée avec un détendeur approprié
permettant un choix approprié de dépression dans la plage de 0 à 1 bar.
7. Procédé selon la revendication 1, caractérisé en ce que le gaz inerte est injecte dans l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) du réservoir de stockage (100; 200) par au moins un manchon de contrôle
(130) du système de surveillance des fuites à l'aide des détendeurs permettant un
choix approprié de pression dans la plage de 0 à 1 bar en provenance des groupes de
bouteilles ou d'un réservoir cryogénique ou d'un générateur d'azote ou d'une installation
technologique.
8. Procédé selon la revendication 1 ou 7, caractérisé en ce que comme gaz inerte on utilise l'azote pour éliminer l'atmosphère explosive à l'intérieur
de l'espace de l'interstice du fond (110) et/ou de l'interstice de la paroi (120)
du réservoir de stockage (100; 200).
9. Procédé selon la revendication 1, caractérisé en ce que le processus de nettoyage de l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) du réservoir de stockage (100; 200) est réitéré jusqu'à l'obtention
d'une teneur en gaz explosifs au niveau de la limite inférieure de l'explosivité des
gaz en dessous de 10% pour tous les types de mélanges d'hydrocarbures, en dessous
de 4% pour l'hydrogène gazeux et une teneur en oxygène en dessous de 5% pour tous
les types de mélanges gazeux.
10. Procédé selon la revendication 1 ou 9, caractérisé en ce que dans le cas où le processus de nettoyage de l'espace de l'interstice du fond (110)
et/ou de l'interstice de la paroi (120) du réservoir de stockage (100; 200) a été
réitéré au moins deux fois, et la teneur des gaz explosifs dans l'espace de l'interstice
du fond (110) et/ou de l'interstice de la paroi (120) du réservoir de stockage (100;
200) se trouve hors de la plage admissible, on perce alors des ouvertures de contrôle
(250) de 1 mm à 50 mm de diamètre dans la surface supérieure délimitant l'espace de
l'interstice du fond (110) et/ou dans les surfaces intérieures des parois délimitant
l'espace de l'interstice de la paroi (120) au nombre allant de quelques à quelques
dizaines selon l'étendue de la surface de l'espace de l'interstice du fond (110) et/ou
de l'interstice de la paroi (120) du réservoir de stockage (100; 200) et/ou le nombre
des manchons de contrôle (130) du système de surveillance des fuites dans l'espace
de l'interstice du fond (110) et/ou de l'interstice de la paroi (120) et/ou selon
la grandeur des sections (280) en lesquelles a été divisée l'espace de l'interstice
du fond (110) et/ou de l'interstice de la paroi (120) du réservoir de stockage (100;
200).
11. Procédé selon la revendication 1 ou 9, caractérisé en ce que la teneur des gaz explosifs dans l'espace de l'interstice du fond (110) et/ou de
l'interstice de la paroi (120) est mesurée à l'aide des appareils de mesure de gaz
sur au moins un manchon de contrôle (130) du système de surveillance des fuites et/ou
les ouvertures de contrôle (250) dans la surface supérieure délimitant l'espace de
l'interstice du fond (110) ou les ouvertures de contrôle (250) dans les surfaces intérieures
des parois délimitant l'espace de l'interstice de la paroi (120) réalisés pour un
nettoyage correct de l'espace de l'interstice du fond (110) et/ou de l'interstice
de la paroi (120) du réservoir de stockage (100; 200).
12. Procédé selon la revendication 10, caractérisé en ce que les ouvertures de contrôle (250) après le nettoyage de l'espace de l'interstice du
fond (110) et/ou de l'interstice de la paroi (120) du réservoir de stockage (100;
200) sont obturées avec des obturateurs munis des joints d'étanchéité en caoutchouc
assurant l'étanchéité de la zone des ouvertures de contrôle (250) afin de bloquer
l'écoulement du gaz inerte dans l'espace de stockage (195) du réservoir de stockage
(100; 200).
13. Procédé selon la revendication 12, caractérisé en ce que comme obturateurs en aimants on utilise des obturateurs en aimants de néodyme.