The present invention relates to a liferaft system comprising a container containing an inflatable liferaft and means for inflating the liferaft by means of an inflating gas, preferably carbon dioxide or a mixture of gases.
Inflatable liferafts enclosed in the self-opening containers are well known and are used as mandatory life-saving equipment throughout the world on almost any commercial ship and vessel.
The liferaft is inflated with an inflation gas preferably carbon dioxide from a gas cylinder. The gas cylinder is attached to the liferaft, and the gas is distributed from the cylinder into the inflatable chambers. Depending on the type and size of the liferaft there will be one or more gas cylinders connected to the liferaft. Furthermore, the gas from one cylinder can be distributed to one or more inflation inlets on the liferaft.
As the carbon dioxide is vented from the gas cylinder into the liferaft, expansive cooling occurs, which can result in the formation of carbon dioxide "snow", thus creating localised temperature below -40 DEG C. At this temperature, the inflatable chamber fabric freezes, loses its flexibility and the inflation time will depend on how fast this temperature can be raised. It is well known to try to solve the carbon dioxide snow formation by different types of gas inlet nozzles, adapted to trap or prevent carbon dioxide snow formation.
Furthermore, an apparatus has been provided to alleviate the problem caused when cold inflation gases impact inflation chamber surfaces. One such apparatus is an elongated, porous sleeve having a longitudinal passage and a side opening. The sleeve is positioned over the gas inlet valve with the outlet openings within the side opening of the sleeve. Gas emanating from the outlet openings passes axially through the longitudinal passage toward either end of the sleeve, and is dispersed through the sleeve material into the inflation chamber.
It is furthermore well-known to solve the problem associated with the fast evaporation of the carbon dioxide liquid from the cylinder and thereby carbon dioxide snow formation that for the desired evaporation, heat should be conveyed from the surroundings. It is well-known that if the entire amount of inflation gas is let in at only a single inlet there will be a high risk of insufficient heat supply to that place. The inlet may end up as one big ice lump, from which the gas will be only slowly generated. If, on the other hand, the gas liquid is supplied to several different areas, many times, more heat can then be attracted from the close surroundings to the total amount of the supplied gas, and it is then practically possible to get down the prescribed, relative brief inflation times, e.g. three minutes for a large size life raft, even with the use of a single gas cylinder.
All the above mentioned solutions on the carbon dioxide snow formation all more or less depend on the heat from the surroundings, and they all more or less try to solve the problem by increasing the gas contact area. All the above mentioned solutions depend on the ambient temperature, and this is a problem when the liferaft has to be inflated in surroundings with low temperature e.g. below -30 DEG C.
Liferaft systems placed on ships or vessels sailing in low temperature area have furthermore problems with icing up of the container. If the container is iced up, there will be a risk that the release system does not function. The crew tries to overcome this problem by covering the container with anti ice liquids and by scraping the container free of ice, with the risk that the container will be damaged. From
Thus, there is a need for providing a flexible solution to the above-mentioned disadvantages.
An object of the present invention is to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide a liferaft system with fast inflation and minimise the carbon dioxide snow formation.
It is also an object of the present invention to provide a liferaft system which will not be covered with ice.
The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention where the container furthermore contains means for heating the system. By a system with heating means it is possible to minimise or avoid carbon dioxide snow, and it will furthermore be possible to avoid that the container will be covered by ice.
The term "liferaft" has in this application the meaning inflatable, lifesaving equipment such as liferaft, platform and dinghy.
The system can be provided with heated gas. The heated gas can e.g. be blown into the container. Preferably, the gas is a dry heated gas e.g. air.
The system according to the invention as defined by claim 1 comprises electric heating cables. The heating cables can be placed inside the container in one or both container parts; the electric heating cables can furthermore be isolated from the liferaft. Another embodiment according to the invention is to cast or embed the electric cables into the container parts.
The system according to the invention as defined by claim 2 comprises one or more heating mats. The heating mat is heated with electricity. An electric heated mat can be provided with cables running forwards and backwards inside the mat.
The system according to the invention can furthermore be provided with electric heating cables uniformly distributed in channels on one side of the mat.
The electric cables according to the invention can furthermore be cast or embedded into one or more elastic mats.
The elastic material can be a plastic material or a rubber, e.g. a silicone rubber.
A system according to the invention can furthermore be provided with one or more mats which wholly or partly encircle the liferaft.
The system according to the invention has an openable container to allow deployment of the liferaft, said openable container consists of at least two container parts.
The system according to the invention can furthermore be provided with one or more heating mats placed in the container parts.
The mats can furthermore be attached to the inside of the container parts e.g. with two-sided tape.
The invention and its many advantages will be described in more details below with reference to the accompanying schematic drawing, which for the purpose of illustration shows one non-limiting embodiment.
The figure is highly schematic and not necessarily to scale, and it shows only parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.
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In a merely illustrative, non-limiting embodiment, the system may comprise a dehumidifier/heater. The dehumidifier/heater is adapted to dehumidify as well as heat a gas to a predetermined temperature, whereinafter said dehumidified and heated gas is led to the container and is being used for heating the system. Preferably, the gas is air.
Furthermore, the container may comprise an inlet for the dehumidified and heated gas as well as an outlet, for discharging excess air. Said inlet and outlet may comprise valve means.
Although the invention above has been described in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.