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.

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...

AI Technical Summary

Benefits of technology

[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.

[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.

Problems solved by technology

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.

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.

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.

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