U.S. patent application number 11/912519 was filed with the patent office on 2008-08-28 for two-step-process for filling gas containers for airbag systems and gas filling device for a two-step-filling process.
Invention is credited to Thorsten Frank, Hans Hiller, Ulrich Klebe, Friedel Michel, Friedel Theissen, Lutz Thiedecke.
Application Number | 20080202629 11/912519 |
Document ID | / |
Family ID | 36146911 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080202629 |
Kind Code |
A1 |
Michel; Friedel ; et
al. |
August 28, 2008 |
Two-Step-Process for Filling Gas Containers for Airbag Systems and
Gas Filling Device for a Two-Step-Filling Process
Abstract
The invention concerns a process respectively a device for
filling a high pressure gas container (1), comprising the following
steps: Supplying a liquefied or solidified first gas (2) into a gas
container (1) while the gas container (1) is being cooled; stopping
the cooling of the gas container (1) after the supplying step of
the first gas; then introducing a gaseous second gas (3) into the
gas container (1) and closing the gas container (1). The invention
allows for a efficient, reproducible, reliable and economical
filling of high pressure gas containers (1), in particular for
airbag systems or for fuel cells, and allows to use conventional
devices for introducing gases respectively closing gas containers
that are not particularly adapted for low temperature respectively
high pressure applications.
Inventors: |
Michel; Friedel; (Erkrath,
DE) ; Thiedecke; Lutz; (Tonisvorst, DE) ;
Klebe; Ulrich; (Kerken, DE) ; Hiller; Hans;
(Duisburg, DE) ; Frank; Thorsten; (Duisburg,
DE) ; Theissen; Friedel; (Erkelenz, DE) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
ALEXANDRIA
VA
22314
US
|
Family ID: |
36146911 |
Appl. No.: |
11/912519 |
Filed: |
January 27, 2006 |
PCT Filed: |
January 27, 2006 |
PCT NO: |
PCT/EP2006/000713 |
371 Date: |
May 7, 2008 |
Current U.S.
Class: |
141/5 ;
141/82 |
Current CPC
Class: |
F17C 2265/02 20130101;
F17C 2250/043 20130101; F17C 2227/0311 20130101; F17C 2201/058
20130101; F17C 2270/059 20130101; F17C 2223/0138 20130101; F17C
2227/0383 20130101; F17C 2270/0181 20130101; F17C 2221/016
20130101; F17C 2225/036 20130101; F17C 2223/033 20130101; F17C
2223/0161 20130101; F17C 2227/0302 20130101; F17C 2221/017
20130101; F17C 2201/0104 20130101; F17C 2221/03 20130101; F17C
2265/025 20130101; F17C 2223/013 20130101; F17C 2225/0123 20130101;
F17C 2203/0617 20130101; F17C 5/06 20130101; F17C 2223/0123
20130101; F17C 2209/221 20130101; F17C 2205/0311 20130101; F17C
2201/0138 20130101; F17C 5/04 20130101 |
Class at
Publication: |
141/5 ;
141/82 |
International
Class: |
B65B 3/00 20060101
B65B003/00; B65B 31/02 20060101 B65B031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2005 |
DE |
10 2005 019 413.3 |
Aug 11, 2005 |
FR |
0552500 |
Claims
1. Process for filling a high pressure gas container (1),
comprising the following steps: supplying a liquefied or solidified
first gas (2) into a gas container (1) while the gas container (1)
is being cooled; stopping the cooling of the gas container (1)
after the supplying step of the first gas; then introducing a
gaseous second gas (3) into the gas container (1); closing the gas
container (1).
2. Process according to claim 1, characterized in that the cooling
of the gas container (1) is performed in a cooling bath (4), in
particular a cooling bath (4) of liquid nitrogen, and the cooling
is stopped by disconnecting the gas container (1) from the cooling
bath (4).
3. Process according to claim 1, characterized in that the first
gas (2) and/or the second gas (3) is a mixture of plural gases.
4. Process according to claim 1, characterized in that the first
gas (2) and/or the second gas (3) is an inert gas, in particular a
noble gas.
5. Process according to claim 1, characterized in that after the
supplying step of the first gas (2) and before the introducing step
of the second gas (3) the gas container (1) is temporarily
closed.
6. Process according to claim 5, characterized in that the gas
container (1) is temporarily closed using an auxiliary valve
(5).
7. Process according to claim 1, characterized in that the closing
of the gas container (1) is performed by welding.
8. Process according to claim 1, characterized in that the gas
containers (1) are for air bag systems.
9. Process according to claim 1, characterized in that gas
containers (1) are for fuel cells.
10. Process according to claim 1, characterized in that the
supplying of the first gas (2) is performed at a pressure in the
range from 0.2 bar to 15 bar, in particular in the range from 0.5
bar to 4 bar.
11. Process according to claim 1, characterized in that the
supplying of the second gas (3) is performed at a pressure in the
range from 2 bar to 100 bar, in particular, in the range from 5 bar
to 50 bar, for example in the range from 10 bar to 20 bar.
12. Process according to claim 1, characterized in that the first
gas (2) is supplied in a liquid state into the gas container (1)
and solidifies in the gas container (1).
13. Process according to claim 1, characterized in that the first
gas (2) is supplied at a temperature lower than its boiling
temperature, in particular at least 1.degree. K, preferably at
least 2.degree. K, lower than its boiling temperature, and at a
temperature higher than its freezing temperature, in particular at
least 1.degree. K.sub.5 preferably at least 2.degree. K, higher
than its freezing temperature.
14. Process according to claim 1, characterized in that after the
supplying step of the first gas (2) and before the introducing step
of the second gas (3), the gas container (1) is connected to a
sealing device (11), in particular a welding apparatus (12), and
after the introducing step of the second gas (3) the gas container
(1) is sealed by the sealing device (11), in particular by
welding.
15. Process according to claim 1, characterized in that the cooling
is performed using a liquefied third gas (6), in particular liquid
nitrogen, wherein in particular the temperature of the third gas
(6) is controlled by controlling the pressure in the third gas
(6).
16. Process according to claim 1, characterized in that the gas
container (1) is cooled before the supplying step of the first gas
(2).
17. Device for filling high pressure gas containers (1), comprising
a supplying unit (7) for supplying a liquefied or solidified first
gas (2) into a gas container (1) while the gas container (1) is
being cooled; a stopping unit (8) for stopping the cooling of the
gas container (1); an introducing unit (9) for introducing a
gaseous second gas (3) into the gas container (1) after the
supplying step of the first gas; a unit (10) for closing the gas
container (1).
18. Device according to claim 17, further comprising a cooling bath
(4) for cooling the gas container (1).
19. Device according to claim 18, further comprising a transport
mechanism (12) for transporting the gas containers (1) through the
cooling bath (4).
20. Device according to claim 17, characterized in that the unit
(10) for closing the gas container (1) is a welding apparatus
(12).
21. Device according to claim 17, characterized in that the de-vice
is for filling high pressure gas containers (1) for air bag systems
or for fuel cells.
22. Device according to claim 17, further comprising a gas supply
station (13) and at least one thermally insulated filling tube (14)
with a tube head (15) that is in fluid connection with the gas
supply station (13), wherein the filling tube (14) is for supplying
the first gas (2) to the gas containers (1).
23. Device according to claim 22, further comprising a positioning
device (16) for positioning the tube head (15) at the gas
containers (1).
Description
[0001] The invention concerns a process for filling a high pressure
gas container and a device for filling a high pressure gas
container, in particular a gas container for airbag systems.
[0002] For cold filling pressure containers, according to DE 101 07
895 a gas is cooled before its introduction into a pressure
container, wherein on completion of the filling process the
pressure container is sealed in a pressure-tight manner. As the gas
warms up the pressure in the pressure container rises rapidly.
[0003] According to DE 198 17 324 a fuel gas is filled into a light
weight tank made with a liner of chrome nickel steel inside of a
fibre reinforced shell, wherein the fuel is introduced in deep
cooled liquid form and is stored at a pressure above 300 bar.
[0004] According to WO 2005/043033 a pressure vessel, for example
of an airbag system, is filled with a gas or a gas mixture at a
temperature which is higher than the boiling point thereof, closing
the cold vessel and a pressure is produced in the filled and closed
vessel by heating it to ambient temperatures.
[0005] According to WO 2005/059431 a pressure container is filled
with a gas mixture, wherein a gas mixture is introduced in its
gaseous state or in its liquefied state or at least one gas
component of a gas mixture is introduced in its gaseous state or in
its liquefied state in a cooled pressure gas container.
[0006] U.S. Pat. No. 1,414,359 discloses a process for filling
compressed gas containers, wherein a given quantity of liquefied
gas is placed in a vessel of low specific heat capacity that is
suspended within the container, the container is closed, and the
walls of the container are maintained at a temperature above
0.degree. C. until the enclosed substance has been converted into
gaseous form.
[0007] DE 101 19 115 discloses a pressure container particularly
suited for filling with low boiling permanent gases or gas mixtures
at low temperatures which is provided on its inner surface with a
material having a low heat conducting coefficient.
[0008] EP 0 033 3 86 discloses a process for transporting and
storing permanent gases, in particular hydrogen, under pressure in
pressure containers, wherein the gases are cooled to low
temperatures above their boiling point and are transported and
stored in isolated pressure containers.
[0009] It is known, that airbags in vehicles are increasingly using
new types of gas generators, which in the event of an accident
inflate the airbag within a few milliseconds. High pressure gas
storage systems are used as gas generators.
[0010] Three different types of gas generators are currently in
use: [0011] Chemical generators which generate gas by reaction of a
chemical solid with ambient air; [0012] Hybrid generators which use
both a fuel solid and gas that is stored in a pressurized high
pressure gas container; [0013] Cold gas generators that store gas
in pressurized gas containers at high pressures up to 700 bar at
15.degree. C.
[0014] The gas generators, which are filled with various gases at
ambient temperatures, provide for considerable technical problems,
both in terms of their production and their filling with pressures
of up to 700 bar or above. The heat of compression in particular
during a rapid filling leads to undefined temperature conditions
which usually considerably affect the metering precision with which
the amount of gas is introduced into the gas containers. To meet a
high metering standard is important with respect to the subsequent
inflation characteristics of the airbag. Very expensive and complex
piston or diaphragm compressors are required to generate the very
high pressures. This entails high investment and high maintenance
costs. In addition, a correspondingly complex and expensive
downstream gas supply is required for these pressures.
[0015] The known cold filling techniques avoid the problem
originating from the filling of high pressures, however, these
techniques usually work at extremely low temperatures which makes
multiple adaptations of conventional process steps, such as the
sealing of the gas container, to the low temperature conditions
necessary, which is not desirable with respect investment and
maintenance costs.
[0016] An object of the present invention is to provide for a
process respectively a device for filling a high pressure gas
container with pressures up to 1000 bar or above which is
efficient, reliable and reproducible yet economical and quick and
allows for a precise metering of the amount of gas that is
introduced into the container.
[0017] This and other problems are solved according to the
invention by the process respectively device for filling a high
pressure gas container as defined in the claims below. Further
advantageous embodiments and developments which can be employed
individually or in any suitable combination are also provided.
[0018] According to the invention a process for filling a high
pressure gas container comprises the following steps: [0019]
Supplying a liquefied or solidified first gas into a gas container
while the gas container is being cooled; [0020] Stopping the
cooling in the gas container after the supplying step of the first
gas; then [0021] Introducing a second gas into the gas container;
[0022] Closing the gas container.
[0023] The first gas may be liquefied cryogenically or may be
solidified cryogenically meaning that the phase transition from the
gaseous state to the liquefied respectively solidified state is
performed through cooling of the first gas.
[0024] The determination and the control of the amount of gas that
is filled into the gas container may be performed manometrically,
volumetrically gravimetrically, and/or by opening time of a
valve.
[0025] The high pressure gas container is in particular for airbag
systems.
[0026] The first gas and/or the second gas may be an inert gas, in
particular a noble gas. Gases used in connection with airbag
systems may be argon, oxygen, nitrogen, hydrogen, helium,
dinitrogen monoxide (N.sub.2O) as pure gases or mixtures thereof.
Advantageously, the first gas may be argon, the second gas may be
helium.
[0027] The high pressure gas container may also be used in
connection with fuel cells for storing fuel gases such as
hydrogen.
[0028] The boiling temperature of the first gas is in particular
lower than the boiling temperature of the second gas.
[0029] The ratio of the gas particles density of the first gas to
the gas particles density of the second gas in the filled gas
container may range from 1:1 to 100:1, in particular from 5:1 to
10:1.
[0030] The first gas may be a pure gas or a mixture of gases. The
second gas may be a pure gas or a mixture of gases.
[0031] The first gas is supplied into the gas container at low
temperatures, in particular below 200.degree. K, in particular
below 100.degree. K. As the first gas is liquefied or solidified,
only small amounts of compression heat is generated during the
introducing step of the first gas into the gas container such that
the degree of efficiency of the filling process is increased. As
much less compression heat is generated, the temperature conditions
of the filling process are much better defined. Consequently, the
amount of the gases supplied respectively introduced into the gas
container may be metered much more precisely.
[0032] The liquefied first gas may be introduced into the gas
container by completely immersing the gas container into a bath of
liquefied first gas such that the first gas enters the gas
container. For this purpose, prior to immersing the gas container,
the gas container may be precooled in a separate cooling bath, such
as a cooling bath of liquid nitrogen.
[0033] Due to the cooling of the gas container the temperature of
the gas container as well as the temperature of the gas content
inside of the gas container is well-defined. A tight control of the
temperature allows for precise controlling the amount of gas
supplied into the gas container.
[0034] After supplying the first gas into the gas container and
before introducing the second gas into the gas container, the
cooling of the gas container may be stopped or at least
interrupted. Between the supplying step and the introducing step
the gas container may be transported from a supplying unit for
supplying the first gas to an introducing unit for introducing the
second gas. The heat capacity of the gas container as well as of
the first gas supplied into the gas containers helps to stabilize
the temperature of and in the gas container and the second gas may
be introduced at comparatively low pressures, in particular below
200 bars, advantageously below 100 bars, eventhough it may be
introduced at a ambient temperatures. A precise metering of the
amount of gases filled into the gas container is facilitated.
[0035] By this provision it is possible to use conventional
introducing units that are designed for comparatively low pressures
in particular below 200 bar, advantageously below 100 bars, without
them being adapted to operate at extremely low temperatures such as
below 100.degree. K.
[0036] In a specific embodiment the second gas may be precooled
before being introduced into the gas container. The temperature of
the second gas may be about the temperature of the first gas, in
particular may be below 200.degree. K, in particular below
100.degree. K.
[0037] After the introducing step of the second gas into the gas
container, the gas container is closed. The closing may be
performed using a membrane valve and/or may be performed by
welding.
[0038] After closing the gas container, it may be warmed up to
ambient temperature, such that a high pressure builds up within the
gas container. The pressure within the gas container at 15.degree.
C. may be in the range from 250 bar to 1300 bar, in particular in
the range from 500 bar to 800 bar.
[0039] The cooling of the gas container may be performed in a
cooling bath, in particular a cooling bath of liquid nitrogen, and
a cooling may be stopped by disconnecting the gas container from
the cooling bath. The gas container may be completely immersed in a
cooling bath containing the first gas. The gas container may also
be precooled prior to the supplying step of the first gas. With
help of the cooling bath the temperature of the gas container is
tightly controlled.
[0040] The process allows for tight metering control also in cases
of batching the filling processes for a multitude of gas
containers. This is important as the final pressure strongly
influences the operating characteristics of the filled gas
container in its use.
[0041] The cooling bath may be kept under a pressure other than
ambient pressure, in particular above ambient pressure, such as in
the range from 1.4 bar to 50 bar, in particular from 2 bar to 10
bar, in order to provide for a desired temperature in the cooling
bath. For this purpose a third gas which is liquefied may be used
as cooling medium in the cooling bath.
[0042] After the supplying step of the first gas and before the
introducing step of the second gas the gas container may be
temporarily closed. A temporal closing of the gas container may
facilitate the transport of the gas container from the supplying
unit, which supplies the first gas into the gas container, to the
introducing unit, which introduces the second gas into the gas
container. The temporal closing of the gas container helps to avoid
or at least reduce evaporation losses and helps to increase the
metering precision.
[0043] The gas container may be temporarily closed using an
auxiliary valve. The auxiliary valve may be a ball cock, a ball
valve, a bibcock, a butterfly valve, a gate valve, a globe valve,
check valve, a rotary valve, a piston valve or any other valve that
is able to temporarily close the gas container suitably.
[0044] The final respectively permanent closing of the gas
container may be performed by welding.
[0045] The first gas and/or the second gas may be a mixture of pure
gases. The gas containers may be adapted and destined for use in
airbag systems. The gas container may also be adapted and destined
for use in fuel cells.
[0046] The supplying of the first gas may be performed at a
pressure in the range from 0.2 bar to 15 bar, in particular in the
range from 0.5 bar to 4 bar.
[0047] The supplying of the second gas is performed at a pressure
in the range from 2 bar to 100 bar, in particular in the range from
5 bar to 50 bar for example in the range from 10 bar to 20 bar.
[0048] The pressure values are meant to be absolute and not with
respect to ambient pressure.
[0049] In a special embodiment of the invention the first gas may
be supplied in a liquid state into the gas container and solidifies
in the gas container. For this purpose the gas container
respectively the first gas needs to be colder than the freezing
temperature of the second gas.
[0050] The first gas may be supplied at a temperature lower than
its boiling temperature, in particular at least 1.degree. K,
preferably at least 2.degree. K, lower than its boiling
temperature, and at a temperature higher than its freezing
temperature, in particular at least 1.degree. K, preferably at
least 2.degree. K, higher than its freezing temperature.
[0051] After the supplying step of the first gas and before the
introducing step of the second gas, the gas container may be
connected to a sealing device, in particular a welding apparatus,
and after the introducing step of the second gas the gas container
is sealed by the sealing device, in particular by welding.
[0052] The described two-step process provides for more freedom
with respect to organizing the individual process steps. In
particular comparatively simple devices, in particular conventional
sealing devices or introducing units for introducing the second
gas, that are not adapted to high pressure or low temperature
appliances, may be used. In consequence complexity of the filling
process as well as investments and development cost are
considerably reduced. Due to the two-step structure the cold
filling technique may still be combined with the conventional
sealing technology known from high temperature filling without the
need of complex adaptation of the conventional devices to the cold
temperature environment. On the other hand the advantages of the
cold filling process with respect to its metering precision and its
high thermodynamic efficiency may still be enjoyed as eventhough
the sealing device may operate at ambient temperature, the gas
containers may remain at low temperatures. The pressures involved
in the gas container during the filling process may thus be kept
well below 250 bar, in particular well below 100 bar.
[0053] The cooling of the gas container may be performed using a
liquefied third gas in particular liquid nitrogen, wherein in
particular the temperature of the third gas is controlled by
controlling the pressure in the third gas. The gas container may be
cooled before the supplying step of the first gas. In particular
the gas container may be precooled in the cooling bath prior to the
supplying step of the first gas.
[0054] According to the invention, the device for filling high
pressure gas containers comprises: [0055] A supplying unit for
supplying liquefied or solidified first gas into a gas container
while the gas container is being cooled; [0056] A stopping unit for
stopping the cooling of the gas container; [0057] An introducing
unit for introducing a gaseous second gas into the gas container
after the supplying step of the first gas; [0058] A unit for
closing the gas container.
[0059] The device is in particular adapted for carrying out the
process according to the invention. The device is in particular
destined for carrying out the process according to the invention.
The introducing unit may be at a separate location of the supplying
unit and may be displaced therefrom. In particular the stopping
unit transports the gas container from the supplying unit to the
introducing unit. The stopping unit may disconnect the gas
container from a cooling unit for cooling the gas container. The
cooling unit may be a cooling bath in which the gas container is at
least partially immersed. The unit for closing the gas container
may comprise a welding apparatus.
[0060] The device may further comprise a transport mechanism for
transporting the gas containers through the cooling bath.
Advantageously the transport mechanism at least partially immerses
the gas container before the gas containers are connected to the
supplying unit, transports the gas container to the supplying unit
where the gas container are filled with the first gas and
transports the gas containers from the supplying unit to the
introducing unit, where the gas container are connected with the
introducing unit and are filled with the second gas. Advantageously
the transport mechanism transports the gas containers from the
introducing unit to the unit for closing the gas container. The
unit for closing the gas container may be a welding apparatus. The
stopping unit may be provided as being part of the transport
mechanism.
[0061] The device may be for filling high pressure gas containers
for airbag systems or for fuel cells.
[0062] The device may further comprise a gas supply station and at
least one thermally isolated filling tube with a tube head that is
in fluid connection with the gas supply station, wherein the
filling tube is for supplying the first gas to the gas containers.
The tube head is moveable and may be positioned by a positioning
device. The filling tube is flexible and helps to establish the
connection between the gas container and the gas supply station.
The flexible filling tube is particularly advantageous when a
multiplicity of gas containers need to be filled and a fast
connecting of the gas container with the gas supply station is
desired.
[0063] Further details and favourable aspects, which may be applied
alone or may be combined in any suitable manner, will be explained
with respect to the following drawings, which shall not restrict
the scope of the present invention but shall schematically and
exemplarily illustrate the invention.
[0064] FIG. 1 shows the two-step process according to the
invention;
[0065] FIG. 2 shows a high pressure gas container to be used
according to the invention shown in cross section;
[0066] FIG. 3 shows further high pressure gas container to be used
according to the invention shown in cross section;
[0067] FIG. 4 shows a detailed view of a supplying unit of a
filling device according to the invention; and
[0068] FIG. 5 shows a supplying unit of a further embodiment of the
filling device according to the invention.
[0069] FIG. 1 shows schematically the two-step process for filling
a high pressure gas container 1 with argon as a first gas 2 and
helium as a second gas 3 using a supplying unit 7 for supplying the
first gas 2 into the gas container 1 and an introducing unit 9 for
introducing the second gas 3 into the gas container 1. The gas
container 1 comprises a container body 26 for receiving the first
gas 2 and the second gas 3 and is connected to an auxiliary valve
5. The gas container 1 is connected to a cooling bath 4 which
comprises a third gas 6 which is liquefied in order to precool the
gas container 1 down to 86.degree. K which is a temperature a
little bit below the boiling temperature of argon. The third gas 6
is liquid nitrogen (boiling temperature of which is 77.degree. K at
normal pressure) which is kept under a slight pressure in the
cooling bath 4 in order to provide for 86.degree. K in the cooling
bath 4. This precooling is performed using a precooling unit 24
which at least partially immerses the gas container 1 in the
cooling bath 4. The gas container 1 is then transported with a
transport mechanism 12 to a supplying unit 7 for supplying liquid
argon as first gas 2 into the gas container 1. Then the auxiliary
valve 5 is closed in order to diminish evaporation losses of the
first gas 2. Subsequently the cooling of the gas container 1 is
stopped by disconnecting the gas container 1 from the cooling bath
2 by a stopping unit 8 and is transported to an introducing unit
for introducing the second gas 3 in its gaseous state. The second
gas 3 such as helium is taken from a second container 22 and is
evaporated by an evaporator 25 and is introduced through the
auxiliary valve 5. After completion of the introducing the
auxiliary valve 5 is temporarily closed until the gas container 1
is permanently closed using a unit 10 for closing the gas container
1. The unit 10 for closing comprises a sealing device 11 which
seals the gas container 1 by welding. Both the introducing unit 9
and the unit 10 for closing may be of a conventional type meaning
that they do not need to be adapted for cryogenical temperatures
and do not need to be capable of coping with high pressures above
300 bar. The second gas 3 is introduced at ambient temperature into
the gas container 1. After closing the gas container 1 the gas
container 1 are allowed to warm up to ambient temperatures such
that the pressure inside of the container body 26 rises to a
well-defined pressure around 600 bar. The first gas 2 may be
supplied at a pressure ranging from 0.5 bar to 3 bar and the second
gas 3 may be introduced at 15 bar. The amount of gas supplied
respectively introduced into the gas container 1 may be controlled
volumetrically, gravimetrically or by an opening time of a metering
valve. The second gas may be metered according to the partial
pressure that is eventually desired at room temperature. This
metering may be performed outside of the cooling bath 4 for
instance in the sealing device 11.
[0070] FIG. 2 shows a gas container 1 in cross section to be used
according to the invention. The gas container 1 comprises the
auxiliary valve 5 in a first connection line 28 to the container
body 26 and a first valve 27 in a second connection line 29 to the
container body 26. The first valve 27 is provided at the container
body 26 before the beginning of the filling process. The first
valve 27 is a membrane valve and is adapted to be opened at the
instance of operation of the gas container 1 for example during the
operation of the airbag system (not shown). The first valve 27
operates non-reversibly, i.e. opens only once. The first valve 27
may be welded to the container body 26 respectively to the second
connection line 29. The auxiliary valve 5 is for facilitating the
supplying of the first gas 2 respectively the introducing of the
second gas 3 into the container body 26. The auxiliary valve 5 is
for temporarily closing the container body 26 such that evaporation
losses are reduced. After the supplying step of the first gas 2
respectively after the introducing step of the second gas 3, the
auxiliary valve 5 is closed. The auxiliary valve 5 may also be
closed in between the supplying and the introducing step. Once the
container body 26 is completely filled with a gas 2, 3 or with a
mixture of gases 2, 3 the first connection line 28 is closed using
a sealing portion 31 by welding. The closing portion 31 makes sure
that after the closing of the gas container 1, gas may not escape
from the container body 26 through the first connection line 28.
The sealing portion 31 allows for using inexpensive auxiliary
valves 5 without limiting the advantages of temporarily closing the
container body 26.
[0071] FIG. 3 shows a further gas container 1 in cross section to
be used according to the invention, wherein the first valve 27 and
the auxiliary valve 5 are in a fluid series connection 30. In this
case the permanent closing of the container body 26 is realized by
the first valve 27 which is closed after the filling of the
container body 26 with a gas 2, 3 or a mixture of gases 2, 3. The
auxiliary valve 5 is used for facilitating the supplying of the
first gas and/or the introducing of the second gas 3.
[0072] FIG. 4 shows schematically the supplying unit 7 comprising a
gas supply station 13 with a flexible filling tube 14 which is to
be connected to the container 1. For connecting the filling tube 14
with the gas container 1, a tube head 15 is provided which
comprises a metering valve 17. The tube head 15 is positioned at
the gas container 1 with a positioning device 16. Due to the
flexibility of the filling tube 14 a gas tight connection between
the gas supply station 13, respectively the supplying unit 7, and
the gas container 1 is established in a short time. The filling
tube 14 is thermally isolated and comprises a gas channel 18 for
supplying the first gas 2 into the gas container 1. The gas channel
18 is isolated by means of an insulation vacuum. For this purpose
the filling tube 14 is doubled walled. For further reducing a heat
transfer through radiation within the insulation vacuum a heat
shield 19 is introduced, which is at least partially actively
cooled. The moveable tube head 15 allows for a fast connection
which is important if a multiplicity of gas containers 1 need to be
filled.
[0073] FIG. 5 shows a further embodiment of a supplying unit 7 of
the device for filling gas containers 1. Liquid argon is stored as
first gas 2 in a large supply tank 33 and is supplied through a
supply tube 32 into a first container 21 which also serves as phase
separator 20. The liquid argon from the phase separator 20 is
precooled in a second precooling unit 35 for precooling the second
gas 2. The liquid argon is cooled to 2.degree. K below its boiling
point in order to avoid any formation of gas bubbles within the
liquid phase, which might affect the metering precision of the
amount of gas supplied into the gas container 1. The second
precooling unit 35 uses liquid nitrogen as third gas 6 from a third
container 23 which is connected to the second precooling unit 35
with conduits 34. The precooled liquid argon is then supplied with
the filling tube 14 to the gas container 1. For this purpose the
filling tube 14 comprises a moveable tube head 15 which may be
positioned precisely at the gas container 1. The gas container 1 is
transported through the cooling bath by a transport mechanism 12.
The cooling bath 4 is closed with a cover 36 in order to establish
a pressure in the cooling bath 4 with which the temperature in the
cooling bath is precisely controlled.
[0074] In the following, further aspects, which are related to the
present invention, are described. These individual aspects may be
employed individually and separately or in any suitable combination
with each other respectively one another:
[0075] An advantageous process for filling high pressure gas
containers 1 comprises the steps: Supplying a liquefied or
solidified first gas 2 from a gas supply station 13 through a
thermally insulated filling tube 14 with a movable tube head 15 to
the high pressure gas container 1. During the supplying step of the
first gas 2, the gas container 1 may be cooled, in particular by a
cooling bath 4. The filling tube 14 is in particular cooled at
least partially along its length, in particular by the cooling bath
4. The filling tube 14 may be filled using a two step filling
process, in which after the supplying step of the first gas 2, a
gaseous second gas 3, in particular Helium, is introduced into the
gas container 1, wherein in particular during the supplying step of
the first gas 2, the gas container 1 is cooled, in particular by a
cooling bath 4, and before or during the introducing step of the
second gas 3 the cooling of the gas container 1 is stopped, in
particular the gas container 1 is taken out of the cooling bath 4.
Advantageously high pressure gas containers 1 for air bag systems
or for fuel cells are filled. The first gas 2 and/or the second gas
3 may be a mixture of gases.
[0076] An advantageous process of batch filling of high pressure
gas containers 1 with gas, comprises the step cooling multiple gas
containers 1 in parallel, which are filled sequentially using the
process according to the invention.
[0077] An advantageous arrangement for filling high pressure gas
containers 1 with gas comprises a gas supply station 13 and
multiple high pressure gas containers 1, wherein the gas supply
station 13 comprises at least one thermally insulated filling tube
14 with a movable tube head 15 for gas filling of the gas
containers 1, wherein the arrangement may comprise a positioning
device 16 for moving the tube head 15 to the individual gas
containers 1. Advantageously, a metering valve 17 for controlling a
gas flow through the filling tube 14 may be provided in the tube
head 15. The gas supply station 13 may comprise a cooling bath 4
for cooling the gas containers 1, wherein the filling tube 14 may
be at least partially immersed in the cooling bath 4 and wherein
the arrangement may further comprise a transport mechanism 12 for
transporting the gas containers 1 through the cooling bath 4. In a
useful embodiment, the filling tube 14 may be at least doubled
walled and may comprise an insulation vacuum for thermal
insulation. The filling tube 14 may be actively cooled by a cooling
medium, in particular a liquefied third gas 6 and/or may comprise a
gas channel 18 and a tubular heat shield 19 at least partially
around the gas channel 18, wherein the heat shield 19 is cooled by
the cooling medium. Tube head 15 may comprise an auxiliary valve 5
for temporarily closing the gas container 1. The gas filling tube
14 is in particular for filling a liquefied first gas 2 into the
gas containers 1. The gas supply station 13 may comprise a first
container 21 for a liquefied first gas 2. The gas supply station 13
may advantageously comprise an introducing unit 9 for introducing a
gaseous second gas 3 into the gas container 1. The gas supply
station 13 may comprise a second container 22 for a liquefied
second gas 3, wherein the gas supply station 13 may comprise an
evaporator 25 for converting the liquefied second gas 3 into its
gaseous state. The gas supply station 13 may comprise a third
container 23 for a liquefied third gas 6 as cooling medium.
[0078] An advantageous gas supply station 13 for filling high
pressure gas containers 1 with gas is adapted and in particular
destined for use in the arrangement according to the invention.
[0079] An advantageous high pressure gas container 1 with a
container body 26 for storing gas and at least one first valve 27
for discharging the stored gas, is characterized by further
comprising an auxiliary valve 5 for introducing the gas into the
container body 26 and for temporarily closing the container body 26
until the container body 26 is sealed permanently, wherein the
first valve 27 and the auxiliary valve 5 are in fluid connection
with the container body 26, wherein in particular the first valve
27 and the auxiliary valve 5 may be connected to the container body
26 with separate fluid connection lines 28, 29, or, wherein in
particular the first valve 27 and the auxiliary valve 5 may be
connected to the container body 26 in a fluid series connection 30.
The first valve 27 may be non-reversibly openable. Alternatively,
the auxiliary valve 5 may be reversibly openable and closable. A
sealing portion 31 may be provided at the auxiliary valve 5 for
permanently closing the auxiliary valve 5, wherein in particular
the sealing portion 31 may be provided in the fluid connection
between the auxiliary valve 5 and the container body 26, or,
wherein in particular the auxiliary valve 5 may be provided in the
fluid interconnection between the sealing portion 31 and the
container body 26. The auxiliary valve 5 may be one of the
following valves: a ball cock, a ball valve, a bibcock, a butterfly
valve, a gate valve, a globe valve, a check valve, a rotary valve,
or a piston valve. The first valve 27 may in particular be a
membrane valve. Advantageously, the high pressure gas container 1
may be adapted and/or destined for an air bag system, or, the high
pressure gas container 1 may be adapted and/or destined for a fuel
cell.
[0080] An advantageous process for filling a high pressure gas
container 1 having a container body 26 for storing gas, at least
one first valve 27 for discharging the stored gas and an auxiliary
valve 5, wherein the first valve 27 and the auxiliary valve 5 are
in fluid connection with the container body 26, comprises the
following steps: The gas is introduced into the container body 26
through the auxiliary valve 5; the auxiliary valve 5 is at least
temporarily closed; the auxiliary valve 5 is sealed permanently,
wherein in particular the auxiliary valve 5 may be sealed by
welding. The auxiliary valve 5 may also or instead be sealed by the
first valve 27. Prior to filling the container body 26 with gas,
the first valve 27 may be provided and may be configured at the gas
container 1.
[0081] The invention concerns a process respectively a device for
filling a high pressure gas container 1, comprising the following
steps: Supplying a liquefied or solidified first gas 2 into a gas
container 1 while the gas container 1 is being cooled; stopping the
cooling of the gas container 1 after the supplying step of the
first gas; then introducing a gaseous second gas 3 into the gas
container 1 and closing the gas container 1. The invention allows
for a efficient, reproducible, reliable and economical filling of
high pressure gas containers 1, in particular for airbag systems or
for fuel cells, and allows to use conventional devices for
introducing gases respectively closing gas containers that are not
particularly adapted for low temperature respectively high pressure
applications.
Reference Numerals
[0082] 1 gas container [0083] 2 first gas [0084] 3 second gas
[0085] 4 cooling bath [0086] 5 auxiliary valve [0087] 6 third gas
[0088] 7 supplying unit [0089] 8 stopping unit [0090] 9 introducing
unit [0091] 10 unit for closing [0092] 11 sealing device [0093] 12
transport mechanism [0094] 13 gas supply station [0095] 14 filling
tube [0096] 15 tube head [0097] 16 positioning device [0098] 17
metering valve [0099] 18 gas channel [0100] 19 heat shield [0101]
20 phase separator [0102] 21 first container [0103] 22 second
container [0104] 23 third container [0105] 24 precooling unit
[0106] 25 evaporator [0107] 26 container body [0108] 27 first valve
[0109] 28 first connection line [0110] 29 second connection line
[0111] 30 fluid series connection [0112] 31 sealing portion [0113]
32 supply tube [0114] 33 supply tank [0115] 34 conduits [0116] 35
second precooling unit [0117] 36 cover
* * * * *