FR3108579A1 - Method and device for releasing a ballast in an underwater environment. - Google Patents

Abstract

Method and device for releasing a ballast in an underwater environment According to the method of the invention, the ballast (5) is connected to at least one float (6) via a support (4) and a release device (7) of the ballast (5) is mounted on the support (4) interposed between said at least one float (6) and the ballast (5). A means for releasing the ballast (5) is implemented for its release by melting water (F1) in the form of ice contained in the release device (7), in contact with the underwater environment (2) in which the device release (7) is submerged. Abstract figure: Fig. 9

Description

Method and device for dropping a ballast in an underwater environment.

Technical field of the invention

The invention relates to the field of activities in an underwater environment, and relates more particularly to such activities for which a submerged object which is installed on a support connected to a float, is to be recovered from the surface of the water. More specifically, the invention relates to the surface recovery of water from a submerged object which is mounted on a support interposed between a float and a ballast release device, the ballast now submerged at least l object and/or the float against a counter-thrust exerted by the float.

The invention relates to a so-called ballast release device and a method for releasing said ballast. The invention relates more specifically to such a release device and such a method implementing a means for releasing the ballast in response to the immersion of the release device in the underwater environment.

Prior art

Among the activities in the underwater environment, it may be necessary to recover a submerged object from the surface of the water. By way of non-restrictive indication, such is for example the case in the field of oceanography for the surface recovery of various submerged oceanographic instruments, in the field of fishing for the recovery of fishing equipment such as for example a submerged trap, in the field of industrial activities in an aquatic environment such as maritime or river works for example, or even in fields relating to military activities and/or in the field of study of underwater bottoms or coastal zones.

By way of illustration in the field of oceanography, various instruments collecting information by measurement and/or by detection, and/or instruments for transmitting information remotely, are used to study the aquatic environment and/or its environment such as coastal areas or the seabed.

According to a technique used to immerse the instruments, these are installed on a support interposed between a float and a ballast. The support consists for example of a mooring cable or a rod, and the float is for example a surface float or a submerged float. The weighting of the support makes it possible to immerse the instruments to a desired depth against the counter-thrust towards the surface which is exerted by the float.

The problem therefore arises concerning the recovery of the instruments installed on the support. In fact, at least the instruments and/or also the float being in the immersion station as a result of the ballasting of the support, the ballast then obstructs easy recovery of the instruments on the surface.

This is why the ballast is then mounted on the support via a ballast release device which is interposed on the support between the ballast and the assembly comprising the instruments and the float. The instruments and/or the float, where applicable, being in the immersion station, the dropping of the ballast - which is then lost - makes it possible to recover the instruments installed on the support which are freed from the diving force exerted by the ballast on the support. In the case where the float is submerged, the free buoyancy of the float freed from the ballast then allows the float to rise to the surface to allow an operator to recover the instruments installed on the support.

Structurally, the release devices generally comprise a body provided with members for fixing to the support interposed between the float and the ballast. The fasteners are commonly arranged in an eyelet or hook and the release device is also equipped with a means of releasing the ballast.

In this context, a problem specifically posed resides in the organization of said release means between the release device and the ballast. For this purpose, various methods of arranging such release means are known.

It is for example known to provide the release device with a control member for opening a said hook connecting the release device to the ballast. The opening of the hook is then caused by the control member which is for example preprogrammed to cause the opening of the hook at the end of a predefined period, or for example still by reception by the control member of a command signal emitted remotely to cause the hook to be opened, in particular an acoustic signal emitted from a ship.

For example again, it has been proposed to provide the release device with a timed means for disintegrating or destroying a junction member via which the release device is fixed to the mooring cable, such as in particular by corrosion.

For example again, it has been proposed to provide the release device with a means reacting to the immersion conditions of the release device to cause the release of the ballast. It is for example known to cause the dropping of the ballast, to disintegrate a junction member between the dropping device and the ballast by natural galvanic corrosion in contact with saline water or by forced galvanic corrosion.

It is also known from document US 10/232914 B1 (SPAWAR SYSTEMS CENTER PACIFIC; US NAVY), to release the ballast via a hydrostatic means reacting to the pressure of the aquatic environment in which the release device is immersed. It is also known from document US 2008/311805 A1 (SPEARS REDRICK; OLSON MANFRED BRADLEY), to release the ballast by progressive disintegration of an effervescent body reacting in contact with the immersion water.

Presentation of the invention

The arrangement of the release devices essentially depends on the duration and/or the desired depth of immersion of the object to be recovered.

This is why the various release devices mentioned above have diversified structures and methods of implementation depending on the use dedicated to them. However, it appears that the release devices relating to the prior art deserve to be simplified.

In this context, the subject of the invention is a device for dropping a ballast in an underwater environment, the ballast being mounted, via the dropping device, on a support connected to a float. The invention also relates to a method for releasing said ballast.

The object of the invention is to propose a dropping device of simple structure and easy handling by an operator for its implementation - including by an operator who does not have specific training - in particular as regards the adaptation according to the requirements of the immersion time of the release device prior to the release of the ballast.

Such a release device is also sought to provide satisfactory implementation reliability and control of a release of the ballast at the end of a substantially predefined period of immersion of the release device.

The aim is also to find such a method and such a dropping device which are competitive on the market for devices for dropping a ballast in an underwater environment, in particular on a market segment meeting the needs of a short-term immersion and/or for the release of a ballast of potentially substantial mass. By way of non-restrictive indication, a market segment is targeted with an immersion time of the order of between a few minutes and a few hours, preferably between one hour and two hours and a weight of the ballast which can be 1. order of several tens of kilograms.

The aims targeted by the present invention are achieved individually or in combination by applying the following provisions.

A method in accordance with the invention is a method for dropping a ballast in an underwater environment, according to which the ballast is connected to at least one float via a support, such as for example a mooring cable or a rod. The float is likely to be used as a surface float, also called a buoy, or as a submerged float. A ballast release device is mounted on the support interposed between said at least one float and the ballast.

In accordance with the invention, the method implements a means of releasing the ballast for its release, by melting water in the form of ice contained in the release device, in contact with the underwater environment in which the release device is immersed .

The release of the ballast is caused by the phase change of the water in the solid state in the form of ice, following its freezing prior to the immersion of the release device in the underwater environment. The ballast is retained by the release device via a release device provided with a ballast attachment and an anchoring device held inside the release device by water previously frozen in the solid phase. The melting of the water under the effect of the temperature of the ambient medium of the water in which the release device is immersed causes the release of the release device and consequently the release of the ballast by gravity, or by other words under the effect of gravity.

In other words, the melting of the water contained in the dropping device in the form of ice causes the dropping of the ballast under the effect of a heat transfer between the dropping device and the immersion water in which the device release is submerged. The release of the ballast is caused by the phase change of the water in the form of ice previously frozen inside the release device, following the immersion of the release device in the underwater environment.

More specifically, since the water is in the solid phase as a result of its freezing prior to the immersion of the release device in the underwater environment, the ballast is retained by the release device via a release member provided with an attachment to the ballast and an anchor member which is held inside the release device by the water in the form of ice therein. The melting of the water under the effect of the temperature of the ambient medium of the immersion water causes a release of the release device and consequently the release of the ballast by gravity, or in other words under the effect of gravity.

In other words, the release member is mounted on the release device while being held by water in the form of ice prior to its immersion in the underwater environment. When the release device carrying the ballast via the release member is immersed in the underwater environment, a heat exchange occurs between the water and the immersion medium, essentially via the release member immersed in the water. 'immersion.

This has the effect of causing the melting of the ice, essentially via the heat exchange zones between the release device and on the one hand the immersion water and on the other hand the water in the solid phase via the anchor member with which the release member is provided. As a result of its melting, the water in the liquid state is then unable to retain the release member on the release device, which causes the release of the release member carrying the ballast, and causes the release of the ballast.

The release device and the ballast it carries are then lost. A water-filling container for the jettisoning device and, where appropriate, one or more objects, such as for example an instrumentation mounted on the support, can then be recovered from the surface. In the event of immersion of the float, its buoyancy is then exploited to cause the container, inside which the water is previously frozen, to rise to the surface, as well as objects mounted on the support. The float being a surface buoy, the release of the ballast facilitates the surface recovery of the container and the objects by traction operated on the support freed from the ballast.

The invention makes it possible to make the release device more reliable and to simplify it, which remains intrinsically static, with the exception of the free and unconstrained escape under the effect of the gravity of the release device as a result of the fusion of the water causing the ballast to drop. The structure of the release device can be reduced to a container, such as advantageously arranged as a necked bottle, for joint reception of the water and partially of the release member also emerging out of the container. The size and mass of the release device are at best limited, and the release device can be produced and operated at lower cost.

The release member can be essentially reduced to a rod provided at its periphery with reliefs constituting the anchoring member. Such a rod is of low cost and can be lost following the release of the ballast, without significant impact on the costs of obtaining and/or operating the release device. In addition, prior to the solidification of the water introduced inside the container in the liquid phase, the release member can be spontaneously maintained by gravity inside the container placed in a refrigeration chamber, until freezing of the water.

In the case where the container is filled on land, the water can advantageously be delivered by a hydraulic network. The freezing of the water inside the container can take place on land or on board a boat equipped with freezing means.

According to a preferred embodiment, the melting temperature of water can be adjusted from -5 to +10°C, by the addition of at least one additive making it possible to vary the melting temperature of water beforehand frozen. These additives can in particular be chosen from alcohols (EtOH and glycerol in particular), salts (NaCl) or a vegetable oil.

The elimination of water during the release of the ballast has no significant impact on the operating costs of the release device. The energy needed to operate the jettison device is reduced to that needed to freeze the water, which can be achieved using a standard commercial freezer. The freezer can be provided with simple arrangements for the appropriate reception of one or more release devices necessary for a companion study of an underwater environment.

Preferably, the freezer is equipped with a base suitable for receiving a plurality of release devices assembled in batches on the base. The base is then preferably removably installed inside the freezer. In the case of water freezing on land, at least one batch of jettisoning devices containing water in the solid phase can thus be easily transferred inside a thermally insulated and/or refrigerated container, via which container a batch of delivery devices can be transported to a site of use.

A delay in the release of the ballast from the immersion of the release device in the underwater environment can be structurally simple and easy to implement, for example from an initial adjustment of the position of the release member on the release device. Such an adjustment may be limited to an adjustment of the heat exchange surfaces of the release device respectively with the water in the solid phase in which the release device is maintained and with the external environment, in particular underwater.

Such a method of dropping and/or such a dropping device used for its implementation, are suitable for immersion times of the dropping device which can be significantly variable. The volume of the container and/or the heat exchange surfaces of the release device respectively with the water in the solid phase and with the underwater environment can be adapted without any particular difficulty depending on a desired immersion duration.

According to a specific embodiment, the dropping of the ballast is delayed from the immersion of the dropping device carrying the ballast in the underwater environment, in particular by taking into account any one at least of the following delay parameters: - ) on the one hand the temperature of the water considered in the solid phase and its enthalpy of fusion, and on the other hand the temperature of the underwater environment in which the release device is intended to be immersed, -) the volume of solid phase water inside which the release device is held, -) the thermal conductance of the release device, taking at least into account the heat exchange surfaces of the release device respectively with the water in the form of ice and with the underwater environment. He specified that the thermal conductance of the jettisoning device also takes into account its heat transfer coefficient and its thermal resistance, and/or -) the thermal resistance of a container for receiving water contained in the jettisoning device .

The thermal resistance of the container is preferably high to promote the melting of the ice essentially via the release member directly subjected to the temperature of the immersion water. The thermal resistance of the container can be obtained by its formation from a material with high thermal resistance and/or from thermal insulation of the container, integrated into the container at its periphery or attached around the container, preferably being removable to allow its removal during the freezing phase of the water.

Preferably and advantageously, the ballast release delay is adjustable by an operator on the basis of a known value of at least one of said delay parameters. Said at least one known value is then processed by the operator to identify the time delay for dropping the ballast from a previously established modeling of the behavior of the dropping device according to various values of at least one of said time delay parameters.

Such modeling can typically take the form of a correspondence table and/or an abacus, or even a digital calculation tool, making it possible to identify from said modeling the values of said at least one parameter to be applied. for a given use of the release device in a previously identified underwater environment.

The invention also relates to a device for dropping a ballast in an underwater environment. The release device comprises a container provided with a proximal attachment dedicated to attaching the container to said support and a distal attachment dedicated to attaching the container to said ballast. The container provides at least one water receiving tank.

It is understood here that the distal and proximal concepts are relative concepts considered with regard to the positioning of the release device in the station of use on the support, interposed between the float and the ballast. The proximal concept is applied with regard to the position of the release device with respect to the float and the distal concept is applied with regard to the position of the release device with respect to the ballast.

In this context and for example, the release device of the invention is recognizable in that the container is provided with a closable mouth for filling the reservoir via which water is introduced in the liquid phase inside the reservoir. . The container is also provided with a duct open towards the outside of the container, through which the release member provided with said distal attachment and said anchoring member is at least partly introduced inside the reservoir.

This exemplary embodiment is advantageous in the case of the use of water introduced in the liquid phase inside the container prior to its freezing. It will be noted that the structure of the release device is essentially reduced to two components respectively constituting the container and the release member, with an absence of fastening means between the release member and the container. The container can be arranged in a simple necked bottle, and the release member can be arranged in a simple rod provided with anchoring reliefs and introduced inside the bottle via its neck.

More particularly according to one embodiment, the container provides a shoulder at a proximal outlet of the duct open towards the inside of the reservoir. Said shoulder provides a proximal abutment for retaining water in the form of ice inside the tank. Such a shoulder against which bears the water in the solid phase and the influence of the release member inside the water in the solid phase via a predetermined heat exchange surface, in particular allows ballasting of the support by a ballast of potentially substantial mass for a desired period of ballasting of the support.

The anchoring member is provided with a distal abutment for pressing against the container at a distal outlet of the duct open towards the outside of the container. Said distal stop advantageously forms at least one obturator of the duct at its distal outlet.

Preferably, the distal abutment advantageously participates in the adjustment of said time delay, in particular by being movably mounted on the release member and by being immobilizable on the release member in a position previously selected by the operator.

The operator can thus adjust the extensions of the release device respectively on the one hand inside the container - and therefore inside the ice when the water is then frozen - and on the other hand with the underwater environment in which the release device is intended to be immersed. Said adjustment thus makes it possible to adjust the heat exchange surfaces of the release member respectively with the ice and with the immersion water of the underwater environment in which the release device is immersed.

Thus, according to one embodiment, relative mobility is provided between the distal stop and the anchoring member. Said distal abutment and the anchoring member are immobilizable to each other in a position of adjustment of the anchoring member on the container determining the heat exchange surfaces of the release member respectively with the ice and with the underwater environment.

According to one embodiment, the container is advantageously arranged as a necked bottle, the interior recess of which forms said reservoir. Such a configuration of the container makes it possible to exploit the neck of the bottle in order to spare both said duct and said filling mouth of the tank.

According to one embodiment, the release member is formed of a rod provided at least partially at its periphery with projecting reliefs constituting said anchoring member. The rod, typically of axial extension, has a radial dimension at most equal to the radial dimension of the duct, in particular to allow the introduction of the rod inside the container via the neck prior to the freezing of the water, taking into account the size of the anchoring member with which the rod is provided.

By way of non-restrictive examples: -) the anchoring member is for example formed of a thread provided on the periphery of the rod. In this case, said distal stop may advantageously be formed of at least one nut, or even alternatively also of a lock nut, cooperating with said threading to allow the operator to adjust said heat exchange surfaces of the member release respectively with the water considered in the solid phase and the underwater immersion medium of the release device. In this case, the adjustment of said time delay can be obtained more or less precisely depending on the pitch of the thread, and/or said time delay can be reserved for a more or less short time delay. -) According to other examples rather reserved for a time delay of more or less long duration by increasing, preferably adjustable, said heat exchange surfaces of the rod, the anchoring member is for example formed of a plurality of pins made on the periphery of the rod projecting transversely, crenellation made on the periphery of the rod, or for example even threaded washers distributed in a more or less substantial number at adjustable distances from each other along the rod. In these exemplary cases, the distal stop is for example configured as a washer extended by a shaft, which can be broached by the operator on the rod via transverse openings distributed along the rod receiving a broaching member, such as a pin for example.

According to one embodiment, the reservoir houses an elastically deformable member impermeable to the passage of water through it, preferably installed removable at the bottom of the reservoir. Said elastically deformable member forms a member for damping the thrust forces exerted by the water against said shoulder under the effect of the increase in its volume induced by its passage from its liquid phase to its solid phase, being understood as a result of its freezing.

Said elastically deformable member can for example be arranged as a gas or spring jack(s). Another solution is preferred which has the advantage of being structurally simpler and less expensive, according to which said elastically deformable member is formed of a compressible mass derived from a waterproof material, such as, for example, derived from an elastomer such as silicone or rubber for example, or any other intrinsically flexible and waterproof resin.

The invention also relates to a method for implementing a device for dropping a ballast in accordance with the invention in application - or in other words for the implementation - of a method relating to the invention. The method of the invention is recognizable in that it comprises at least the following operations carried out by an operator.

Essentially, said operations comprise at least a preparatory phase of the release device, followed by a preliminary phase of use of the release device which is then followed by a phase of use of the release device. During the preparatory phase of the release device, the following steps are carried out by the operator: -) fill said tank with water in the liquid state via said filling mouth. The tank is preferably calibrated to be completely filled with water in the liquid state. Then: -) introduce at least partially the release member provided with the anchoring member inside the tank via said conduit, leaving to emerge from the container at least the distal attachment including the release member is provided, then -) place the container in a refrigerated enclosure until the water freezes.

At the end of this preparatory phase, the release device is awaiting use.

The release member is preferably prepared prior to filling the reservoir with water. During such a step of preparing the release member, the axial position of the abutment on the release member is in particular adjusted, according to a predetermined position identifying the heat exchange surfaces of the release device respectively with the ice and with the underwater environment.

In other words, according to a specific implementation of the method, in the preparatory phase of the release device and prior to the introduction of the release member inside the tank, a ballast release delay is set from the immersion of the release device, at least by adjusting the heat exchange surfaces of the release member respectively placed inside the tank and outside the container.

During the preliminary phase of use of the release device, the release device is removed from the refrigerated enclosure. The release device is then attached to the support via the proximal attachment and the weight is attached to the release device via the distal attachment.

At the end of this preliminary phase, the release device is ready to be submerged in an underwater environment.

During the phase of use of the release device, submerge the release device in the underwater environment. The release device is kept submerged in the underwater environment until the melting of the water contained inside the tank, as a result of the heat transfer between the underwater environment and at least the release device. The passage of the water in the liquid phase has the effect of releasing by gravity, or in other words under the effect of gravity, the dropping device from the tank and consequently releasing the dropping device from the ballast.

The preparatory phase of the release device being for example carried out on land, being understood at a distance from an aquatic site for use of the release device, the preliminary phase of use of the release device comprises, where appropriate, a subsidiary step of transfer at least one release member removed from the refrigerated enclosure, the water being in the solid phase, and transfer of said at least one release member into a refrigerated transport box to the aquatic site for the use of release devices in suitable numbers during a study campaign of said aquatic site.

In other words, according to particular modalities of a method relating to the invention and at the end of the preparatory phase for using said at least one release device, said at least one release device is removed from the refrigerated enclosure, the water being of course maintained in the solid phase, and is transferred in a refrigerated box for transport to an aquatic site for use of said at least one drop device in a number suitable for a study campaign in an underwater environment of said aquatic site, via a instrumentation installed on the support.

To this end, use is therefore preferably made of a said removable base equipping the refrigerated enclosure, on which base one or more release devices are potentially installed for freezing the water contained inside the container that each comprise the release device(s) installed on the base. At the end of the preparatory phase of the release device, the removable base carrying the release device(s) is removed from the refrigerated enclosure and is transferred inside the refrigerated transport box to the aquatic site of use. the release device(s).

Presentation of figures

The invention will be better understood on reading the following detailed description of exemplary embodiments of the invention, in relation to the following figures of the appended plates:

FIG. 1 is a schematic illustration of a context of application of the invention to a study in an underwater environment of an aquatic site, according to which a ballast release device is mounted on a support interposed between a float placed immersed in the underwater environment and said ballast which is to be dropped.

FIG. 2 is an illustration of a ballast release device according to the invention according to a first example embodiment.

FIG. 3 is an illustration of a ballast release device according to the invention according to a second example embodiment.

FIG. 4 is an illustration of a ballast release device according to the invention according to a third example embodiment.

FIG. 5 is an illustration of a ballast release device according to the invention according to a fourth example embodiment.

FIG. 6 is an illustration of a ballast release device according to the invention according to a fifth example embodiment.

FIG. 7 is an illustration of methods for preparing the release device represented in FIG. 2, prior to its use in an underwater environment. The methods of preparation of the release device represented for example in FIG. 7, are illustrated by drawings showing successively stages of preparation of the release device prior to its immersion in an underwater environment.

FIG. 8 is an illustration of the ballast release device shown in FIG. 2 and previously prepared as shown in FIG. 7. In FIG. 8, the release device is shown submerged in an underwater environment, in an inactive station of use. In the inactive station of the dropping device, the ballast is retained by the dropping device by keeping it submerged in the underwater environment.

Figure 9 is an illustration of the device for dropping a ballast shown in Figure 2 and previously prepared as shown in Figure 7, which is submerged in an underwater environment as shown in Figure 8. In Figure 10, the release device is shown as an active ballast release station.

Detailed description of the invention

The figures and their non-limiting detailed descriptions set out the invention according to specific terms which are not restrictive as to the scope of the invention as defined by the claims. The figures and their detailed descriptions of exemplary embodiments of the invention can be used to better define it, if necessary in relation to the general description which has just been given. Furthermore, to avoid overloading the figures and thus facilitate their reading, the reference numbers assigned to the terms and/or concepts used to describe the invention and indicated in any of the figures are potentially included in the description of any other figure without implying their presence on all the figures.

In FIG. 1, an apparatus 1 for studying an underwater environment 2 and/or the seabed comprises various instruments 3 mounted on a support 4, such as a mooring cable in the example illustrated. The instruments 3 are participants in an instrumentation for studying the underwater environment 2 and/or the seabed. Such instruments 3 comprise for example one or more sensors of the physicochemical and/or biological characteristics of the underwater environment to be studied and/or of its dynamics, one or more instruments for detecting solid bodies surrounding the device 1 and/or various capture and/or remote transmission of information.

The support 4 is provided with a ballast 5 mounted at the distal one of the ends of the support 4, to drive said instruments 3 deep into the underwater environment 2. The problem therefore arises of recovering said instruments 3 at the end study of the underwater environment 2.

For this purpose, the support 4 is provided with a float 6 at the other proximal end of its ends and with a device 7 for releasing the ballast 5 which is mounted on the support 4 interposed between the float 6 and the ballast 5 It is understood that the interposition of the release device 7 between the float 6 and the ballast 5 is potentially a direct interposition, in particular in the case where the instrumentation is installed on the float 6, or an indirect interposition in the presence of said instruments 3 interposed between float 6 and release device 7 via support 4.

Following a release of the ballast 5, the instruments 3 mounted on the support 4, or even possibly also on the float 6, can rise to the surface of the underwater environment 2 under the effect of the counter-thrust generated by the buoyancy of the float 6. It will be noted that the apparatus 1 may comprise one or more floats 6 mounted on the support 4. Such a float 6 may be formed of a buoy floating on the surface of the underwater environment 2, the dropping of the ballast 5 then facilitating the ascent instruments 3 immersed by traction exerted on the surface on the support 4. According to a particularly useful application of the invention and as illustrated, the float 6 is provided to be immersed as a result of the ballasting of the support 4.

The problem therefore arises of the implementation of the release of the ballast 5, as well as the arrangement of the release device 7 and its operating methods. For the dropping of the ballast 5 via the dropping device 7, it is proposed by the invention to use the temperature of the immersion water of the dropping device 7 to melt a block from previously frozen water F1, via which the ballast 5 is retained by the release device 7.

The water F1 in the liquid phase is frozen prior to the use of the dropping device 7. Following the immersion of the dropping device 7, the melting of the block of ice under the effect of the temperature of the water of immersion in which the device is immersed, causes the release of the ballast 5 by the release device 7 as illustrated in Figure 9. Of course it is understood that the temperature of the immersion water is higher than that of the water F1 in solid phase.

In FIGS. 2 to 6, various exemplary embodiments of a release device 7 relating to the invention are represented respectively in these figures. Each of the release devices 7 is equipped with a release member 8 which is provided with a distal attachment 8b to the ballast 5 and with an anchoring member 9 inside the water F1 in solid phase.

Following its maintenance inside water F1 in the solid phase in the form of ice, the release member 8 and consequently the ballast 5 are retained on the release device 7, as illustrated in FIG. FIG. 9, the melting of the water F1 releases the release member 8 from its retention by the water F1, which causes the release of the release device 7 under the effect of gravity and consequently the release of the ballast 5 mounted on the release device 8.

The release devices 7 each comprise a container 10, as advantageously arranged as a necked bottle according to the various embodiments illustrated. The container 10 is provided with a proximal attachment 8a for its remote junction with the float 6 via the support 4. The container 10 provides a reservoir 11 for receiving water F1 provided with a mouth 12 for filling the reservoir 11 in water F1 in the liquid phase which is provided by the outlet of a neck 13 of the container 10 open towards the tank 11.

The neck 13 also conventionally provides a conduit 14, via which the release member 8 is able to be introduced inside the reservoir 11. The release member 8 is arranged in a rod 15 of axial extension A1 which passes through partially the reservoir 11 along its axis A1 of extension, via the proximal end of the rod 15 opposite to its distal end provided with the distal attachment 8b. The neck 13 of the container 10 still conventionally provides a shoulder 16 at a proximal outlet of the duct 14 open towards the inside of the reservoir 11 by delimiting said mouth 12. Such a shoulder 16 is used to provide an obstacle to the escape of the water F1 in the solid phase out of the container 10. In other words, the shoulder 16 forms a proximal stop 19, via which the water F1 in the solid phase is retained inside the reservoir 11.

Furthermore, said mouth 12 can be closed by a distal abutment 17 fitted to the stem 15. An elastomer washer 18 is preferably interfaced between the distal abutment 17 and the wall of the container 10 against which the washer 18 bears. Such a washer 18 strengthens the tightness of the reservoir 11 vis-à-vis the immersion water surrounding the container 10 and provides an elastic axial bearing of the distal stop 17 against the container 10. As a result of the introduction of the rod 15 inside the reservoir 11, the distal stop 17 limits the extension of the proximal part of the rod 15 introduced inside the reservoir 11 and bears axially against the container 10 to close said mouth 12 and thus isolate the tank 11 from the outside of the container 10.

The rod 15, or in other words the release member 8, forms a heat exchange member between the water F1 in the solid phase contained inside the tank 11 and the immersion water surrounding the container 10. The proximal part of the rod 15 which extends inside the tank 11, provides a first heat exchange surface with the water F1 in solid phase contained inside the tank 11. The distal part of the rod 15 which extends outside the container 10 provides a second heat exchange surface with the immersion water of the underwater environment 2 in which the release device 7 is immersed.

Furthermore, the distal stop 17 forms a member for adjusting the respective extensions of the proximal part of the rod 15 extending inside the reservoir 11 and of the distal part of the rod 15 extending outside the container 10. The distal stop 17 is movably mounted along the rod 15 while being immobilized on the rod 15 in a desired position. From an adjustment of the position of the distal stop 17 and its immobilization on the rod 15, the respective extensions of the proximal part of the rod 15 in the reservoir 11 and of the distal part of the rod 15 outside the container 10 can be jointly set. Such an adjustment makes it possible to adjust the first heat exchange surface of the rod 15 inside the water F1 in the solid phase and the second heat exchange surface of the rod 15 with the immersion water of the release device 7. This finally makes it possible to adjust a time delay for the release of the ballast 5 from the immersion of the release device 7 in the underwater environment 2.

The anchoring member 9 provides not only an anchoring of the dropping member 8 inside the water F1 in solid phase, but also participates in the formation of the first heat exchange surface of the member release 8 with the water F1 contained in the tank 11. The anchoring member 9 is in particular formed of projecting reliefs provided on the periphery and/or along the rod 15.

To allow the introduction of the rod 15 inside the reservoir 11, the radial dimension of the rod 15, being included with the presence of said anchoring reliefs, is at most equal to the radial dimension of the conduit 14 of introduction of the stem 15 in the reservoir 11 prior to the freezing of the water F1, and evacuation of the stem 15 from the reservoir 11 following the passage of the water F1 from its solid phase to its liquid phase in the station of use of the release device 7 immersed in the underwater environment 2.

Various arrangements of the shoulder 16 formed by the neck 13 inside the reservoir 11 and/or various configurations of the anchoring member 9 with which the stem 15 is provided, as well as various configurations of the distal stop 17, are illustrated. on the exemplary embodiments respectively shown in Figures 2 to 6. It is understood here that the various specific arrangements of the release devices 7 shown in Figures 2 to 6, are transposable subject to compatibility between them to any other release device 7, at least from those shown as examples in Figures 2 to 6.

In FIG. 2 and FIG. 6, the shoulder 16 has a flat bottom, oriented radially with respect to the axial extension A1 of the rod 15. The bottom of the shoulder 16 is oriented towards the duct 14 for introducing the rod 15 inside the tank 11. In Figures 3 to 5, the shoulder 16 has a generally conical arrangement. According to the exemplary embodiments respectively illustrated in FIG. 3 and in FIG. 5, the conical conformation of the shoulders 16 is defined along a rectilinear generatrix. According to the embodiment shown in Figure 4, the conical conformation of the shoulder 16 is defined along a curved generatrix giving it a curved conformation.

In Figures 2 to 4 and in Figure 6, the rod 15 is arranged as a threaded rod and the distal stop 17 is arranged as a nut. The threading of the rod 15 is then advantageously constitutive of the anchoring member 9. In FIG. 5, the rod 15 comprises at its periphery a castellation whose slots jointly form the anchoring member 9. The distal stop 17 is formed of a body slidably mounted on the rod 15 while being immobilized by broaching in a desired position on the rod 15, in particular via a pin 20. The pin 20 is inserted through one of the openings 21 selectively chosen by an operator among a plurality of openings 21 distributed along the rod 15 being arranged between said slots.

According to the embodiment illustrated in FIG. 6, the release device 7 is provided with an accessory formed from an elastomer body 22 which is placed inside the tank 11 at its bottom 23 axially A1 opposite the conduit 14 for introducing the rod 15 inside the container 10. Said elastomeric body 22 is arranged in an elastically deformable member 24 impermeable to a passage of water F1 through it. Such an elastically deformable member 24 makes it possible to dampen the potentially substantial thrust forces which are exerted by the water F1 in the solid phase against the shoulder 16 that the container 10 comprises as illustrated, under the effect of the increase in volume. water F1 as a result of its passage from its liquid phase to its solid phase.

In FIG. 7, the release device 7 is prepared prior to its use in an underwater environment 2, according to a preparatory phase E1 to E5 and a preliminary phase E6, E7. In the preparatory phase E1 to E5, a first step E1 is a calibration step E1 of the release device 8 according to a predefined duration of immersion of the release device 7, by adjusting the extensions of the release device 8 respectively to inside and outside the container 8. A second step E2 is a step of filling the container 10 with water F1 via the neck 13 that it comprises. It is understood here that the first step E1 and the second step E2 can be inverted, it being considered that these steps E1, E2 are carried out indifferently one before the other but prior to the introduction of the release member 8 to inside the container 10.

Then a third step E3 is a step of introducing the previously calibrated release member inside the container 10 previously filled with water F1 in the liquid state, via the neck 13 that it comprises. Then a fourth step E4 is a step of introducing at least one release device 7 inside a refrigerated enclosure 25 to cause the phase change of the water F1 filling the container 10 from its liquid phase to its solid phase. Several release devices 7 are preferably simultaneously refrigerated during a freezing step E5 of the water F1 contained in the containers 10.

To maintain the release devices 7 in the appropriate position inside the refrigerated enclosure 25, the latter is equipped with a base 26 provided with a plurality of cells 26a for receiving the release devices 7 in a vertical station. , the neck of the containers 10 of each of the release devices 7 being oriented upwards with respect to gravity to prevent an escape from the containers 10 of the water F1 prior to its passage into the solid phase.

The refrigeration of the dropping devices 7 inside the enclosure 25 is potentially carried out on land or on board a ship. It is considered the case where the refrigeration of the dropping devices 7 inside the enclosure 25 is carried out on land, at a distance from an aquatic site of use of the dropping devices 7. In this case, a preliminary phase E6, E7 of using the release devices 7 comprises a step E6 of removing the release devices 7 from the refrigerated enclosure 25 and installing the release devices 7 inside a refrigerated transport box 27 . To facilitate the execution by an operator of steps E6, E7 of said preliminary phase, the base 26a is advantageously removably mounted in the refrigerated enclosure 25. The base 26a is then used by an operator to manipulate the release devices 7 in batches. which are removed from the refrigerated enclosure 25 and stored in the refrigerated box 27 for their transport to the aquatic site of use of the release devices 7.

In FIGS. 8 and 9, the release device 7 is represented in the phase of use by being immersed in an underwater environment 2. On the aquatic site of use of the release device 7 and prior to its immersion, the container 10 is fixed to the support 4 via the proximal attachment 8a with which it is provided and the ballast 5 is fixed to the release member 8 via the distal attachment 8b with which it is provided.

In FIG. 8 the release device 7, the instruments 3 and the float 6, depending on the application of the release device 7 illustrated, are immersed in the underwater environment 2, in particular for a study of the underwater environment 2 and/or its environment. The release device 7 is in an inactive station in which the ballast 5 is retained by the release device 7 via the release device 8 anchored inside the block of ice formed by the water in the solid phase.

In FIG. 9, the water F1 initially in the solid phase changes to liquid form under the effect of a heat exchange between the water F1 and the immersion water, mainly via the submerged part in the underwater environment 2 of the release member 8, and more particularly the rod 15 that the release member 8 comprises. release device 8, the water F1 then being unable to retain the release device 8 inside the container 10. The release device 8 subjected to the weight of the ballast 5 then falls by gravity out of the container 10, which causes the release of the ballast 5.

The water F1 in the liquid phase flows out of the tank 11 through said mouth 12, and is evacuated from the container 10 via the neck 13 by mixing with the immersion water. Under the effect of a counter-thrust exerted by the float 6, the container 10 and the instruments 3 installed on the support 4 rise to the surface with the float 6 where they can then be recovered. The container 10 constituting the release device is also recovered, being reusable to subsequently cooperate with a new anchor member 8, and thus recompose a new release device 7.

Claims (13)

Method for releasing a ballast (5) in an underwater environment (2), the ballast (5) being connected to at least one float (6) via a support (4) and a device (7) for releasing the ballast (5 ) being mounted on the support (4) interposed between said at least one float (6) and the ballast (5), according to which method a means of releasing the ballast (5) is implemented for its release, by fusion of water (F1) in the form of ice contained in the release device (7), in contact with the underwater environment (2) in which the release device (7) is immersed. Method according to Claim 1, characterized in that the water (F1) being in the solid phase following its freezing prior to the immersion of the release device (7) in the underwater environment (2), the ballast (5) is retained by the release device (7) via a release device (8) provided with a ballast attachment (5) and an anchoring device (9) which is held inside the release device (7) by the water (F1) in the form of ice which it contains, the melting of the water (F1) under the effect of the temperature of the ambient medium of the immersion water causing a release of the release member (8) and consequently the release of the ballast (5) by gravity. Method according to either of Claims 1 and 2, characterized in that the release of the ballast (5) is delayed from the immersion of the release device (7) carrying the ballast (5) in the underwater environment (2 ), by taking into account any one at least of the following timing parameters: -) on the one hand the temperature of the water (F1) considered in the solid phase and its enthalpy of fusion, and on the other hand the temperature of the underwater environment (2) in which the release device (7) is intended to be immersed, -) the volume of water (F1) in solid phase inside which the release device (8 ), -) the thermal conductance of the release device (8), taking at least into account the heat exchange surfaces of the release device (8) respectively with the water (F1) in the form of ice and with the underwater environment (2), and/or -) the thermal resistance of a container (10) for receiving the water (F1) that the release device (7) comprises. Method according to Claim 3, characterized in that the delay of the release of the ballast (5) is adjustable by an operator on the basis of a known value of at least one of the said delay parameters, the said at least one known value being processed by the operator to identify the delay of the release of the ballast (5) from a previously established modeling of the behavior of the release device (7) according to various values of at least one of said delay parameters. Device (7) for dropping a ballast (5) in an underwater environment (2) arranged for the implementation of a method according to any one of claims 1 to 4, the dropping device (7) comprising a container (10) provided with a proximal attachment (8a) dedicated to fixing the container (10) to a said support (4) and a distal attachment (8b) dedicated to fixing the container (10) to said ballast (5 ), the container (10) providing at least one reservoir (11) for receiving water (2), characterized in that the container (10) is provided with a mouth (12) that can be closed for filling the reservoir (11) in water (F1) in the liquid phase, and a conduit (14) open to the outside of the container (10), through which the release member (8) provided with said distal attachment (8b) ) and an anchoring member (9) is at least partly introduced inside the tank (11). Dropping device (7) according to Claim 5, characterized in that the container (10) forms a shoulder (16) at a proximal outlet of the duct (14) open towards the inside of the reservoir (11), the said shoulder (16 ) providing a proximal abutment (19) for retaining water (F1) in the form of ice inside the tank (11), and in that the anchoring member (9) is provided with an abutment distal (17) for bearing against the container (10) at a distal outlet of the duct (14) open towards the outside of the container (10), said distal abutment (17) forming at least one obturator of the duct (14 ) at its distal outlet. Release device (7) according to Claim 6, arranged for the implementation of a method according to any one of Claims 3 and 4, characterized in that a relative mobility is provided between the distal stop (17) and the anchoring member (9), said distal stop (17) and the anchoring member (9) being immobilizable to each other in a position for adjusting the anchoring member (9) on the container (10) determining the heat exchange surfaces of the release member (8) respectively with the ice and with the underwater environment (2). Dropping device (7) according to any one of Claims 5 to 7, characterized in that the container (10) is arranged as a bottle with a neck, the interior recess of which accommodates the said reservoir (11), the neck (13) said pipe (14) and said mouth (12) for filling the tank (11). Release device (7) according to any one of claims 5 to 8, characterized in that the release member (8) is formed of a rod (15) provided at least partially at its periphery with projecting reliefs constituting said anchoring member (9), the rod (15) of axial extension (A1) having a radial dimension at most equal to the radial dimension of the duct (14). Dropping device (7) according to claim 6, characterized in that the reservoir (11) houses an elastically deformable member (24) impermeable to the passage of water (F1) through it, said elastically deformable member (24) forming a member for damping the thrust forces exerted by the water (F1) against said shoulder (16), under the effect of the increase in its volume induced by its passage from its liquid phase to its solid phase. Method of implementing a device (7) for dropping a ballast (5) according to any one of Claims 5 to 10, applying a method according to any one of Claims 1 to 4, characterized in that the method comprises at least the following operations carried out by an operator: -) in a preparatory phase of the jettisoning device (7), filling (E2) said tank (11) with water (F1) in the liquid state via said filling mouth (12), then introducing (E3) at least partially the release member (8) provided with the anchoring member (9) inside the tank (11) via said conduit ( 14), allowing at least the distal attachment (8b) with which the release member (8) is provided to emerge from the container (10), then placing (E4) the container (10) in a refrigerated enclosure (25) until the water has frozen (F1), then -) in a preliminary phase of using the release device (7), remove the release device (7) from the refrigerated enclosure (25), and fix the release device (7) to the support (4) via the proximal attachment (8a) and attach the ballast (5) to the release device (8) via the distal attachment (8b), then -) in one phase of use of the dropping device (7), immersing the dropping device (7) in the underwater environment (2) until the melting of the water contained inside the tank (11) as a result of the heat transfer between the underwater environment (2) and at least the release device (8), having the effect of releasing the release device (8) by gravity from the reservoir (11) and consequently releasing the release device ( 7) ballast (5). Method according to claim 11, for implementing a device (7) for dropping a ballast (5) according to any one of claims 5 to 10 by application of a method according to any one of claims 3 and 4, characterized in that in the preparatory phase of the release device (7) and prior to the introduction of the release device (8) inside the tank (11), set a delay for releasing the ballast (5) from the immersion of the release device (7) at least by adjusting the heat exchange surfaces of the release device (8) respectively placed inside the tank (11) and at the exterior of the container (10). Method according to either of Claims 11 and 12, characterized in that at the end of the preparatory phase for using said at least one release device (7), said at least one release device (7) is removed from the refrigerated enclosure (25) and is transferred into a refrigerated box (27) for transport to an aquatic site of use of said at least one release device (7) in a number suitable for a study campaign in an underwater environment (2 ) of said aquatic site, via an instrumentation (3) installed on the support (4).