U.S. patent application number 10/551077 was filed with the patent office on 2007-02-22 for system and method for supplying breathing gas to a diver.
This patent application is currently assigned to INTERSPIRO AB. Invention is credited to Imre Botos, Pierre Buhlmann.
Application Number | 20070039617 10/551077 |
Document ID | / |
Family ID | 20290846 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070039617 |
Kind Code |
A1 |
Buhlmann; Pierre ; et
al. |
February 22, 2007 |
System and method for supplying breathing gas to a diver
Abstract
The invention concerns a system and a method for supplying
breathing gas to a diver. The system is of the open circuit type
and comprises a gas source consisting of a pressurized container
(1), which is intended to be placed at a distance from the diver
and which delivers breathing gas under a high pressure, a breathing
apparatus (4) which is intended to be carried by the diver and a
flexible tube (3), which connects the gas source with the breathing
apparatus. The flexible tube is of the high-pressure type, the gas
is conducted through the flexible tube under a pressure, which is
essentially equal to the pressure delivered from the gas source,
and the gas source is arranged to be able to deliver breathing gas
at a pressure, which exceeds approx. 30 bars.
Inventors: |
Buhlmann; Pierre; (Lidingo,
SE) ; Botos; Imre; (Tystberga, SE) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN LLP
233 S. WACKER DRIVE, SUITE 6300
SEARS TOWER
CHICAGO
IL
60606
US
|
Assignee: |
INTERSPIRO AB
Lidingo
SE
S-181 10
|
Family ID: |
20290846 |
Appl. No.: |
10/551077 |
Filed: |
March 29, 2004 |
PCT Filed: |
March 29, 2004 |
PCT NO: |
PCT/SE04/00479 |
371 Date: |
July 17, 2006 |
Current U.S.
Class: |
128/201.28 ;
128/201.27 |
Current CPC
Class: |
A62B 7/02 20130101; B63C
11/202 20130101; B63C 11/18 20130101 |
Class at
Publication: |
128/201.28 ;
128/201.27 |
International
Class: |
B63C 11/02 20060101
B63C011/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 2003 |
SE |
0300898-4 |
Claims
1. A system for providing a diver/user with breathing gas, the
system being an open system and comprising an external gas source
in the form of a pressurized container which is intended to be
located at a distance from the diver and which delivers breathing
gas under high pressure, a breathing device which is intended to be
worn by the diver/user, and a hose which connects the gas source to
the breathing device, characterized in that the hose is of the
high-pressure type, and in that the breathing gas in conveyed
through the hose from the gas source to the breathing device or a
pressure-reducing means arranged in proximity to the device under
essentially the pressure which is delivered from the gas
source.
2. The system as claimed in claim 1, the container being
pressurized to between around 50 and around 700 bar.
3. The system as claimed in claim 1, the container being
pressurized to around 200 or around 300 or around 700 bar when it
is full.
4. The system as claimed in claim 1, the hose being designed to
transport the breathing gas under a pressure of up to around 700
bar.
5. The system as claimed in claim 1, the hose being made of, or
containing, carbon fibers, preferably Kevlar.
6. The system as claimed in claim 1, comprising a pressure-reducing
valve which is arranged at or in proximity to the breathing device
and reduces the pressure downstream of the-valve from the pressure
prevailing in the hose.
7. The system as claimed in claim 6, the pressure-reducing valve
reducing the pressure to around 10 bar.
8. The system as claimed in claim 1, the breathing device
comprising a breathing valve, a first pressure-reducing valve
arranged upstream of the breathing valve, and a reserve gas
container arranged upstream of the first pressure-reducing valve,
and the hose being connected to the breathing device between the
pressure-reducing valve and the reserve gas container.
9. The system as claimed in claim 1, the breathing device
comprising a breathing valve, a first pressure-reducing valve
arranged upstream of the breathing valve, and a reserve gas
container arranged upstream of the first pressure-reducing valve,
and the hose, via a second pressure-reducing valve, being connected
to the breathing device between the breathing valve and the first
pressure-reducing valve.
10. The system as claimed in claim 1, the breathing device
comprising a pressure-reducing valve and being designed to deliver
breathing gas to a helmet, mask or hood which is intended to be
worn by the diver.
11. The system as claimed in claim 1, the hose (3) comprising means
for being fastened to the diver, so that the hose can constitute a
lifeline.
12. The system as claimed in claim 1, the breathing gas consisting
of air or nitrox.
13. A method for providing a diver/user with breathing gas, the
breathing gas being conveyed through an open system from a gas
source in the form of a pressurized container which is located at a
distance from the diver/user through a hose to a breathing device
which is worn by the diver, characterized in that the gas is
conveyed from the gas source to the breathing device or a
pressure-reducing means arranged in proximity to the breathing
device through a hose of the high-pressure type under essentially
the pressure which is delivered by the gas source.
14. The method as claimed in claim 13, the breathing gas being
conveyed through the hose under a pressure of between around 50 and
around 700 bar.
15. The method as claimed in claim 13, the breathing gas being
conveyed through the hose under a maximum pressure of around 200
bar.
16. The method as claimed in claim 13, the breathing gas being
conveyed through the hose under a maximum pressure of around 300
bar.
17. The method as claimed in claim 13, the breathing gas being
conveyed through the hose under a maximum pressure of around 700
bar.
18. The method as claimed in claim 13, the pressurized container
being exchanged when the pressure in it falls to a limit value.
19. The method as claimed in claim 18, the limit value being around
50 bar.
20. The method as claimed in claim 13, the breathing gas consisting
of air or nitrox.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a system for providing a diver with
breathing gas, the system being an open system and comprising an
external gas source in the form of a pressurized container which is
intended to be located at a distance from the diver and which
delivers breathing gas under high pressure, a breathing device
which is intended to be worn by the diver, and a hose which
connects the external gas source to the breathing device. The
invention also relates to a method for providing a diver with
breathing gas.
[0002] The system can be used in, for example, what is known as
surface-supplied diving or deep diving, the diver, via a hose,
being provided with breathing gas from pressurized gas containers
located above the surface of the water or in a space which may be
located below the surface of the water. The system can also be used
in smoke-helmeted firefighting or other hose diving where the user
or diver is provided with breathing gas via a hose from a gas
source which is located outside the area where the user/diver is
active.
BACKGROUND OF THE INVENTION
[0003] Generally, such hose-diving systems can be divided into two
different types, namely open and closed systems. In the open
systems, the diver breathes in the breathing gas which is delivered
through the hose, after which the exhalation gas is conveyed out to
the environment surrounding the diver. In the more complicated
closed systems, or push-pull systems, on the other hand, the
exhalation gas is returned through a second hose to the gas source
for regeneration of breathing gas.
[0004] Hose-diving systems have considerable advantages compared
with other systems where the diver himself/herself carries the gas
source with him/her, usually in the form of a pressurized gas
container. For example, the diver does not have to come up to the
surface or leave the working area in order to replenish the gas
supply. In the case of hose-diving, such replenishment can take
place by assistants at the gas source coupling a new container to
the hose when the gas in the previously used container has been
used up. The diver can continue to work during this operation, and
the length of the working period is therefore not dependent on the
size of the gas supply the diver would otherwise carry with
him/her. Another advantage of hose-diving systems is that the diver
does not have to carry heavy, unwieldy gas containers. This
contributes to increased mobility and a reduced risk of hose-diver
fatigue.
[0005] Hose-diving is therefore often used for-protracted and
complicated work, such as underwater repairs and rescue work in
smoke-filled premises. Hose-diving systems are also often used in
rescue operations in other situations, for example in caves with
poisonous or otherwise dangerous atmosphere.
[0006] In order for it to be possible for a hose-diver/user to
perform good, effective work, it is therefore of vital importance
that the mobility of the diver/user is impaired to the minimum
possible extent. It is also important that the equipment the
diver/user carries weighs as little as possible and is easy to
handle. Another important aspect, especially in the case of rescue
operations, is that the entire system is simple to transport, even
over rough terrain. In this connection, it is furthermore of great
importance that the system can be set in operation quickly and that
the diver/user can transfer rapidly and unhindered from the
installation site where the gas source is located to the area where
the rescue operation is to be effected. Another important aspect is
that the system has great reliability and includes as few
components as possible, which may suffer breakdown or
malfunction.
[0007] In known open hose-diving systems, such as the system
described in U.S. Pat. No. 4,986,267, the gas source often consists
of a pressurized gas container. When filled completely with
breathing gas, the container is usually pressurized to a maximum of
around 300 bar. A first pressure regulator is arranged in direct
proximity to the container. A breathing device worn by the diver
comprises a breathing valve with a mouthpiece through which the
diver breathes. The first pressure regulator is arranged to reduce
the pressure from the container, so that the pressure in the hose
between the first pressure regulator and the breathing device is
around 10 bar plus around 1 bar above the ambient pressure applying
around the diver. The breathing device often also comprises a
second pressure regulator, for fine adjustment of the pressure
between this second pressure regulator and the breathing valve.
Finally, the breathing valve reduces the pressure to a breathing
pressure which is approximately the same as the ambient water or
atmospheric pressure.
[0008] As the breathing gas is conveyed from the first pressure
regulator via the hose to the breathing device under a reduced
pressure of around 10 bar plus around 1 bar above the ambient
pressure around the diver, a certain minimum inner cross-sectional
area of the hose is required in order to ensure a sufficiently
great flow of breathing gas through the hose. In particular in the
case of long hoses, this causes considerable problems as the hose
has to be designed with a relatively large inner cross-sectional
area. This results in the hose having to be made relatively thick,
which in turn leads to the hose being heavy and unwieldy to handle.
Moreover, such a thick hose constitutes considerable wind
resistance when it is used outdoors on land, which of course makes
it more difficult for the user to move unhindered. This problem is
even worse for a diver because a thick hose constitutes great water
resistance and because the action of the water on the hose results
in great forces which are difficult to deal with but have to be
overcome and resisted by the diver. It is especially
disadvantageous and even dangerous to use a thick hose in water
with underwater currents because such currents can pull the hose
along with such force that the diver cannot resist it but is
instead pulled away from the working area.
[0009] U.S. Pat. No. 4,037,594 and U.S. Pat. No. 3,370,585 describe
two closed hose-diving systems. These closed systems are
considerably more complicated than the open systems and comprise a
gas source in the form of a regeneration apparatus for regenerating
fresh breathing gas from used exhalation gas and a pump for
conveying the breathing gas through a first hose to the diver. The
breathing gas is conveyed through the hose under a pressure which
is slightly higher than the ambient pressure in order to feed the
gas to the diver. The exhalation gas is conveyed back to the gas
source through a second hose. In the closed systems, the problems
of the hose hindering the diver in his or her work are of course
even greater because the relatively low feed pressure requires a
large cross-sectional area of the feed hose and because the system
itself requires two hoses or alternatively a heavy coaxial
hose.
OBJECTS OF THE INVENTION
[0010] One object of the invention is therefore to produce a system
and a method of the kind indicated in the introduction, which
substantially increase the freedom of movement of the diver.
[0011] Another object is to produce such a system and method which
are reliable and where the number of components included is
minimized.
[0012] A further object is to produce such a system and method
which allow a relatively thin and light hose to be used in order to
minimize the negative effect of the hose on the freedom of movement
of the diver.
SUMMARY OF THE INVENTION
[0013] According to the invention, these and other objects are
achieved with a system of the kind indicated in the first paragraph
of this description, which is characterized in that the hose is of
the high-pressure type and in that the breathing gas is conveyed
through the hose from the gas source to the breathing device under
essentially the pressure which is delivered from the gas
source.
[0014] By virtue of the fact that the breathing gas is conveyed
through the hose under the high pressure which is delivered from
the gas source, a sufficiently great gas flow through the hose can
be ensured even if the hose is designed with a relatively small
inner cross-sectional area. With a suitable choice of hose
material, the outer circumference of the hose can then also be kept
small, the hose then constituting during use considerably smaller
wind or water resistance than was previously possible. The small
cross-sectional dimension of the hose also reduces the weight of
the hose, which makes both the work at the site of the diver and
transport, installation and setting in operation of the system
easier. A hose with a small cross-sectional dimension is moreover
more flexible and easier to handle, which also makes both the work
of the diver at the site and letting-out and hauling-in of the hose
easier.
[0015] Another advantage of the system according to the invention
is that the number of components included can be kept to a minimum
because no pressure regulator is necessary at the gas source. The
risk of malfunctioning of the system is thus reduced.
[0016] Other advantages of the invention emerge from the dependent
claims. For example, the hose can be made wholly or partly of
polyamide fibers, such as Kevlar. Such a high-strength material
ensures that the hose can withstand the high pressures of up to 700
bar or 300 bar which are delivered by the gas source. Moreover, if
it is made from such a material, the hose can, in addition to
serving as a gas line, also be designed so as itself to constitute
a lifeline with which the diver/user can, for example, be pulled up
to the surface or out of smoke-filled premises in the event of an
accident. In this way, an otherwise necessary separate lifeline is
eliminated.
[0017] The system also allows flexibility with regard to how the
breathing gas is coupled to the conventional breathing device which
is worn by the diver. According to one embodiment, for example, the
hose can be coupled to the breathing device so that the breathing
gas delivered from the gas source can be used in order to fill a
reserve gas container under high pressure which is carried by the
diver.
[0018] The invention also relates to a method for conveying
breathing gas to a diver. The method is defined in independent
patent claim 13, and further features and advantages of the method
emerge from subordinate patent claims 14 to 20.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] Different illustrative embodiments are described below with
reference to the accompanying figures, in which:
[0020] FIG. 1 shows a diagrammatic sketch of a first embodiment of
the invention, and
[0021] FIG. 2 shows a corresponding diagrammatic sketch of a second
embodiment.
[0022] FIG. 1 shows a first embodiment of a system according to the
invention. The system comprises a gas source in the form of a
pressurized container 1 which contains breathing gas, for example
air or nitrox. The container is of the standard type found on the
market. These standard containers have different maximum pressure
for different markets. The maximum pressure, which corresponds to
the pressure in the container when it is full, is 200 bar on some
markets, for example, while it is 300 bar on other markets.
Containers with a maximum pressure of 700 bar are also found. All
these different standard containers, but also other containers
which deliver breathing gas under high pressure, can be used in the
system according to the invention. The main point is that the
container can deliver exhalation gas under a pressure which is
considerably higher than the ambient pressure surrounding the
diver.
[0023] The container is connected, via a shut-off valve 2, to a
high-pressure hose 3. During normal use, the shut-off valve 2 is
open, so that the pressure prevailing in the container 1 also
prevails in the hose 3. The shut-off valve is closed, for example,
when the container 1 is exchanged, so as to maintain the high
pressure in the hose 3, and after work is completed, when the
system is demounted. The hose 3 is made from a high-strength
material and is designed to withstand the high container pressures.
In other words, the high-pressure hose 3 is constructed and
manufactured so as to be capable of with a good margin supporting
internal pressures of 300 bar and in some applications 700 bar
without risk of the high pressure damaging the hose. The hose 3
can, for example, comprise an inner gastight layer, an intermediate
pressure-absorbing layer and an outer durable layer. The
intermediate layer can, for example, consist of or contain carbon
fibers, such as Kevlar, or braided metal.
[0024] At its other end, via a non-return valve 3a, the hose 3 is
coupled to a breathing device 4 which is worn by the diver (not
shown). The breathing device 4 comprises a mouthpiece 5 through
which the diver breathes, a breathing valve 6, a pressure-reducing
valve 7, a shut-off valve 8 and a reserve gas container 9.
[0025] During use, the breathing gas is conveyed from the container
1 under unregulated container or bottle pressure via the hose 3 to
the breathing device 4. In other words, the pressure prevailing in
the container 1 at any time also prevails in the hose 3. The
shut-off valve 8 of the breathing device 4 is normally closed. The
unregulated bottle pressure also prevails in the line 10 between
this shut-off valve 8 and the pressure-reducing valve 7. The
pressure-reducing valve 7 is arranged so as, irrespective of the
pressure upstream of it, that is to say in the container 1, the
hose 3 and the line 10, to keep the pressure in the line 11 at
around 10 bar. This pressure is reduced further by the breathing
valve 6, so that the pressure prevailing in the mouthpiece is
approximately the same as or slightly higher than the ambient water
or atmospheric pressure.
[0026] During use of the system, the pressure in the container 1
falls gradually as the breathing gas is used up. When the container
pressure falls below a certain value, a sufficient flow through the
hose can no longer be guaranteed on account of the pressure drop
along the hose. Personnel at the container 1 then close the
shut-off valve 2, the pressure in the system downstream of this
valve 2 then being maintained in a controlled manner, so that the
container 1 can be exchanged. In order to ensure a good gas supply,
this is done when the pressure in the container and the hose
reaches a lower limit value. This limit value can be related to the
ambient pressure surrounding the diver, for example to the ambient
pressure around the diver plus around 30 bar. In practice, a fixed
limit value can be set at around 50 bar. During the time it takes
to exchange the container, the quantity of breathing gas present in
the hose is sufficient for supplying the diver. When the container
1 has been exchanged, the valve 2 is opened again, the hose 3 then
being repressurized to the unregulated bottle pressure.
[0027] In the event of, for example, the high-pressure hose 3
breaking, or if the supply of breathing gas from the container 1
should stop for any other reason, the non-return valve 3a
guarantees that the pressure in the breathing device does not fall
in an uncontrolled manner. The diver can then open the shut-off
valve of the breathing device 4, breathing gas from the reserve
container 9 then being received.
[0028] In the embodiment shown in FIG. 1, an opportunity is also
afforded for refilling the reserve container 9 in the course of
working. In this connection, the shut-off valve 8 of the breathing
device 4 is opened, the high unregulated container pressure in the
hose 3 and the line 10 overcoming the pressure in the reserve gas
container 9, so that breathing gas from the container 1 can fill
the reserve container 9.
[0029] FIG. 2 shows an alternative embodiment. The components which
have an equivalent in FIG. 1 have the same reference number in FIG.
2 as well. The embodiment shown in FIG. 2 differs from that in FIG.
1 in that the breathing gas from the container 1 is supplied to a
breathing device 4 downstream of the pressure-reducing valve 7 of
the breathing device 4. For this, a further pressure-reducing valve
12 is arranged at the end of the high-pressure hose 3 at or in
proximity to the breathing device 4. This pressure-reducing valve
12 is adapted so as, irrespective of the pressure in the container
1 and the hose 3, to keep the pressure in the line 11 at around 10
bar. A non-return valve 13 is arranged between this pressure
regulator 12 and the line 11 in order to prevent uncontrolled
pressure drop in the breathing device 4 in the event of, for
example, the hose 3 breaking. Alternatively, the pressure-reducing
valve 12 and the non-return valve 13 can consist of one and the
same component.
[0030] The embodiment shown in FIG. 2 has inter alia the advantage
that connection to the breathing device 4 is easier to carry out
because the connection takes place on the low-pressure side of the
breathing device.
[0031] According to an embodiment which is not shown, fastening
means are arranged in proximity to the downstream end of the hose.
These fastening means are designed to be fastened to, for example,
a harness which is worn by the diver or to the diving suit. The
fastening means also have load-relievers so that the gas-conveying
coupling between the hose and the breathing device is not loaded
even if great forces arise between the hose and the diver. With the
aid of the fastening means, the diver is therefore attached
securely to the hose, so that the hose can be used as a lifeline in
order, for example, to hoist a diver up through the water or to
pull a smoke-helmeted firefighter out of smoke-filled premises. In
this way, a separate lifeline, which should otherwise always form
part of a hose-diving system for safety reasons, is eliminated
completely. Fastening means with load-relievers can of course also
be arranged at the upstream end of the hose in order to secure the
hose/the lifeline against being pulled loose.
[0032] In the example shown, the maximum container pressure is
around 300 bar, and the total length of the hose is around 100 m.
In order to ensure a sufficient gas flow through the hose to the
diver, the high-pressure hose has an inner diameter of around 3 mm.
If, as in the example, the hose is made wholly from Kevlar, the
outer diameter of the hose can than be kept as small as 9 mm. This
is to be compared with conventional systems where the pressure in
the hose is reduced from 300 bar to around 10 bar plus around 1 bar
above the ambient pressure around the diver and where the inner
diameter of the hose, with the same hose length, is usually around
9 mm in order to provide a sufficient flow. This minimum permitted
inner diameter gives an outer hose diameter of around 22 mm. With
the system according to the invention, it is therefore possible
considerably to reduce the cross-sectional dimension of the hose,
which results in the advantages described above.
[0033] The embodiments described above are given as examples, and
it will be understood that the invention can be varied within the
scope of the following patent claims. For example, the reserve
containers 9 and the shut-off valves 8 shown in the figures can be
dispensed with if deemed appropriate.
[0034] The breathing device can be designed in many different ways,
as long as the system comprises pressure-reducing means which are
worn by the diver and which reduce the pressure in the hose to a
suitable breathing pressure. The breathing device can, for example,
comprise a pressure regulator or a nozzle which, on the upstream
side, is connected to the high-pressure hose and, on the downstream
side, is connected to a helmet, mask or hood which is worn by the
diver or to a diving bell in which the diver is located.
* * * * *