EP2597025B1 - Vessel provided with a transfer area of a potentially dangerous liquid product - Google Patents

Description

The present invention relates to a ship, for example operating on natural gas, which is equipped with a bridge of which at least part constitutes a transfer zone of a potentially dangerous liquid product, between at least one feed unit and means for storing and / or using this liquid.

Such a ship is known from the document EP 2 088 075 , considered the closest prior art.

Throughout the present application will be understood, by the term "ship", any floating structure, which includes including ships themselves and, not exclusively, barges.

At present, when it is a question of a ship transferring liquefied natural gas (LNG) from a power unit external to the ship to a storage unit or a device consuming that gas located on the ship, it is traditional to use a fixed network of piping. This methodology induces the use on the ship of fixed storage units powered by "bunkering" (in French "bunkering") or removable and therefore replaceable once empty, if the connecting pipes allow.

Everyone knows that LNG is a potentially dangerous liquid product, so we take enormous safety precautions during this transfer operation.

This applies not only to liquefied natural gas but also to other liquids or gases, especially chemical ones.

In practical terms, the connection of the transfer pipes is made either at the "bunker station" for a connection with an external power unit located on a quay or a barge, or at mobile power units arranged momentarily inside the ship.

In any case, when the piping connection is made inside the vessel, there is at least one transfer station that includes at least one transfer pipe and a valve, for supplying a tank or a network with liquid gas .

Of course, the presence of this transfer station, when it comes to connecting the mobile power units in said area, is particularly troublesome, because it contributes to increase the risk of incident, and it hinders people and vehicles during their displacement.

The present invention precisely has the function of overcoming these difficulties.

This is achieved, according to the invention, by a vessel, for example, operating on natural gas, which is equipped with a bridge of which at least a part constitutes a transfer zone of a potentially dangerous liquid product between at least a feed unit and a means for storing and / or using this liquid within said vessel, using a transfer station comprising at least one transfer line and a valve, characterized in that said zone comprises at least one receiving area of at least one mobile power supply unit and said bridge has, below its floor, at least one storage space of said transfer station, capable of being covered with minus a removable hatch extending in the plane of said ground.

With this set of features, there is no transfer station protruding from the bridge in the transfer area, so that the safety of the installation is particularly improved, as well as the movement of people and vehicles.

• ledit pont comporte sous son sol une structure alvéolée, chaque alvéole formant caisson et ledit espace de stockage est délimité par au moins un de ces caissons ;
• ledit caisson comporte une paroi de fond rapportée au dit pont ;
• ladite paroi est rapportée au dit pont par l'intermédiaire de raidisseurs, créant ainsi un caisson isolé hermétiquement du pont situé en dessous ;
• ledit espace comporte au moins un logement de stockage d'au moins un tuyau flexible ;
• ledit logement a une forme cylindrique
• au moins une partie de la tuyauterie située sous le pont ou à l'extérieur dudit espace est à double enveloppe étanche ;
• ledit produit est du gaz naturel liquéfié ;
• ledit produit est utilisé comme carburant pour un moteur de propulsion.

According to other features and advantages, but not limiting, of the invention:

• said bridge comprises under its ground a honeycomb structure, each cell forming box and said storage space is delimited by at least one of these boxes;
• said box has a bottom wall attached to said bridge;
• said wall is attached to said bridge by means of stiffeners, thereby creating a box isolated hermetically from the bridge below;
• said space comprises at least one storage housing of at least one flexible pipe;
• said housing has a cylindrical shape
• at least part of the piping below or outside the deck is double-jacketed;
• said product is liquefied natural gas;
• said product is used as a fuel for a propulsion engine.

• la figure 1 est, comme précisé plus haut, un schéma montrant la structure classique d'un navire utilisant ou stockant du gaz naturel liquide ;
• la figure 2 est une vue en perspective de la zone de transfert d'un navire transportant des unités d'alimentations mobiles;
• la figure 3 est une vue en perspective et de détail d'une partie de citerne et de la zone de sol du pont du navire qui reçoit une station de transfert.

Other characteristics and advantages of the invention will appear on reading the following description of a preferred embodiment of the invention. This description is made with reference to the appended drawings in which:

• the figure 1 is, as mentioned above, a diagram showing the classical structure of a ship using or storing liquid natural gas;
• the figure 2 is a perspective view of the transfer area of a vessel carrying mobile power units;
• the figure 3 is a perspective and detail view of a tank section and the deck ground area of the ship receiving a transfer station.

The ship according to the invention has substantially the same structure as that presented above and schematically illustrated in FIG. figure 1 .

However, according to an essential feature of the invention and as illustrated in FIG. figure 2 zone 2 comprises an area 20 for receiving at least one potentially dangerous liquid mobile supply unit, in this case liquid natural gas (LNG). This transfer zone is constituted by a portion of a bridge 4 constituting the structure of the ship.

Each mobile feed unit 3 is constituted here of a tank 30 resting on an axle structure, forming the trailer of a tanker truck but these units can take other forms.

In practical terms, the tankers parked on the dock near the ship are introduced in turn into the transfer area and each driver parks his tank 30 in the area 20 provided for this purpose.

There are shown twelve tanks, but it is of course possible to provide an area 20 capable of accommodating a different number of tanks, greater or less than 12.

The bridge 4 referred to above is structurally constituted by a metal floor 40, which rests on a set of primary stiffeners 41 and 42, respectively transverse (barrels) and longitudinal (coamings).

It is a perfectly known structure in itself, which gives rigidity and thickness to the entire bridge 4.

On the figure 2 the soil of this bridge 4 has been referenced 40.

Although this is not visible at the figure 2 but as shown in figure 3 , there exists between each pair of tanks 30, a transfer station 5.

According to an essential characteristic of the present invention, each transfer station is put in place in a storage space E which is situated under the plane of the ground 40, that is to say in the thickness of the structure itself. bridge 4.

In the present case, the bridge 4, with its floor 40 and its stiffeners 41 and 42, constitute a traditional honeycomb structure thus creating spaces forming "caissons" and said space E consists of at least one caisson C.

The term "honeycomb" means, throughout the present application, any structure having at least one cavity with a bottom and side walls, the contour of this cavity is hexagonal or non-hexagonal.

These boxes are closed, in their lower part by a bottom wall 43 attached to the bridge 4, and more precisely welded to the stiffeners 41 and 42.

The transfer station 5 consists of at least one transfer piping T and at least one tap R.

This station also comprises flexible hoses 50 and 51 which can be connected respectively to valves 310 and 311 integral with the associated tank 30 and able to respectively distribute the liquid and gaseous fractions of the stored material.

In the illustration of the figure 3 these flexible hoses are duplicated, so that another tank not shown can be connected.

Reference 52 of the figure 3 designates the sealed double-walled pipes which run under the ground 4 of the bridge, either towards the engine M of the ship, or towards a fixed storage chamber for the liquid gas. Thus, under the bridge is created a secure space vis-à-vis the dangerousness of the product transported, space that can be qualified as non-dangerous.

Under the casing 5 is present a drain 7 for the evacuation of the liquids which would accumulate on the surface of the wall 43.

Finally, four housings 6, here of cylindrical shape, are provided in the box and allow to store flexible hoses in the period of non-use.

Of course, the floor 40 of the deck 4 is provided with openings O vertically of each space E and it has as many removable hatches 53 as O openings. Each hatch 53 covers an opening O in the period of non-use of the transfer station. So just open them to access the station.

Each external pipe enters the space E by the same wall, thus allowing the concentration of all the fittings. This has the effect, in addition to being centralized, allow the use of access hatches easily manipulated manually.

Similarly, the hoses are also positioned side by side allowing, in the same way, to use traps of optimized dimensions for manual handling. These hatches, breakable, are repositionable once the hoses connected to allow traffic between the tanks again.

This allows a fast and secure connection.

An "incorporation" of the transfer stations into the structure of the bridge makes it possible to have a maximum of portable tanks on the receiving area and not to impede the movement of vehicles and / or pedestrians when the tanks are not in use. not in place.

The routing of the product transfer pipes in the structure, via sealed and secure double-jacketed pipes, allows a passage in areas that can now be qualified as "non-hazardous".

In addition, there is no additional congestion penalizing the traffic on the other side of the structure.

The integration of the transfer stations in the structure of the bridge itself is practically not overweight compared to a conventional structure.

In any case, it is incommensurate with a solution of transfer in gutters or on grating which would have allowed a path of the pipes in double bottom leaving also the free bridge of circulation.

In addition, piping is structurally better protected, and station maintenance is limited.

Of course, throughout the foregoing description, it is assumed that each tank carries its own pump.

Claims (9)

1. Ship (1), for example operating on natural gas, which is equipped with a deck (4) at least part (2) of which constitutes a zone for transferring a potentially dangerous liquid product between at least one supply unit (3) and another means (M) of storing and/or using this liquid within said ship, by means of a transfer station (5) comprising at least one transfer pipe (T) and a valve (R), characterised by the fact that said zone (2) comprises at least one area (20) for receiving at least one mobile supply unit (3) and in that said deck (4) has, below its floor (40), at least one space (E) for storing said transfer station (5), able to be covered with at least one removable trapdoor (53) lying in the plane of said floor (40).
2. Ship according to claim 1, characterised by the fact that said deck (4) comprises, under its floor (40), an alveolar structure, each cell or said alveolar structure forming a chamber (C), and in that said storage space (E) is delimited by at least one of these chambers (C).
3. Ship according to claim 2, characterised by the fact that said chamber (C) comprises a bottom wall (43) attached to said deck (4).
4. Ship according to claim 3, characterised by the fact that said wall (43) is attached to said deck by means of stiffeners (41, 42), thus creating a chamber hermetically isolated from the deck situated below.
5. Ship according to one of the preceding claims, characterised by the fact that said space (E) comprises at least one housing (6) for storing at least one flexible hose (50; 51).
6. Ship according to claim 5, characterised by the fact that said housing (6) has a cylindrical shape.
7. Ship according to one of the preceding claims, characterised by the fact that at least part of the pipe (T) situated under the deck (4) or outside said space (E) is of the gastight double-envelope type.
8. Ship according to one of the preceding claims, characterised by the fact that said product is liquefied natural gas.
9. Ship according to claim 8, characterised by the fact that said product is used as a fuel for a propulsion engine (M).

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