Valve and sealed container for submicron particles, and method for using same

A container with improved sealing, for improved security in the event of loading, transporting and/or unloading submicron particles, in particular nanopowder/nanoparticles, includes a connector for injecting liquid and/or gas. Such a container can also contain at least one inflatable seal (40) valve (3; 4). The container is provided with elements for changing the physical state of the material by heating, mixing or ultrasound bombardment. A method for using the container and an inflatable seal valve are also described.

TECHNICAL FIELD

The present invention relates to a container. It also relates to a valve associated with such a container. It further relates to a process for using such a container.

The field of the invention is more particularly that of submicron particles. In particular, but non-limitatively, the field of the invention is preferably that of nanometric powders or nanopowders or even nanoparticles. The container, the valve and the process according to the invention make it possible to ensure increased safety for a user by limiting as far as possible all contact of this user with the particles contained in the container according to the invention or isolated by a valve according to the invention.

STATE OF THE PRIOR ART

Double-valve devices are known (for example of the “Buck®” type, such as described for example in documents U.S. Pat. Nos. 5,690,152, 5,718,270 and 5,540,266), providing good hermeticity and good safety for transporting macroscopic objects such as pharmaceutical granules.

Moreover, a process is known for filling a container or recipient by means of such a double-valve device, as described for example in document EP 2 085 312 B1. The container contains one of the two valves of the double-valve device.

Many problems are posed by such a process of filling or by such a container according to the prior art:safety is not optimum, in particular when the container comprises submicron particles or nanopowders, the container then no longer being perfectly hermetic, in particular when pressure differences greater than 400 mbar occur between the container and the external environment or the process to which it is connected;the use of such a container is not very convenient, and may require many steps of handling the container and/or of the particles before or during filling the container, or during or after emptying from the container.
The purpose of the invention is to solve at least one of the following technical problems:improve the hermeticity of the container or more generally of the valve of the container, and/orreduce the number of steps of handling the container and/or of the particles before or during filling the container, or during or after emptying from the container.

DISCLOSURE OF THE INVENTION

This purpose is achieved with a container, characterized in that it comprises:an internal storage space,a filling valve having an open state allowing objects (typically particles, preferably submicron particles) to pass through the filling valve between the internal space and the exterior of the container and a closed state preventing the objects (typically particles, preferably submicron particles) to enter or leave the internal space through the filling valve, said filling valve preferably being equipped with locking means arranged for locking the filling valve in its closed state and for preventing opening thereof when this filling valve is not connected to a filling pipe,an emptying valve (combined with or separate from the filling valve) having an open state allowing the objects (typically particles, preferably submicron particles) to pass through the emptying valve between the internal space and the exterior of the container and a closed state preventing the objects (typically particles, preferably submicron particles) to enter or leave the internal space through the emptying valve, said emptying valve preferably being equipped with locking means arranged for locking the emptying valve in its closed state and for preventing opening thereof when this emptying valve is not connected to an emptying pipe.

According to a first aspect of the invention, the container can further comprise a connector arranged to be open to allow passage of fluid through this connector between the exterior of the container and the internal space when it is connected to a complementary connector of a source or discharge of fluid and to be closed to prevent passage of fluid through this connector between the internal space and the exterior of the container when it is not connected to the complementary connector of the source or discharge of fluid.

The filling and emptying valves are then preferably separate and the connector is preferably located closer to the filling valve than to the emptying valve (typically on the filling valve side and not the emptying valve side with respect to the internal space).

The connector can be a quick connector (preferably from Staubli) consisting of a male part or of a female part arranged for connecting to an associated female or male part respectively, the particular feature of this type of connector being that the male and female parts are closed when they are disconnected and open when they are connected, thus allowing a fluid (gas, vapour, liquid) to pass in total safety and under optimum conditions of hermeticity. This fluid can go towards the exterior of the container (pumping) or towards the interior of the container. This quick connector can be connected (preferably for the part in contact with the nanopowder) to a filter, preferably of the HEPA type of type H14.

The connector can be connected (preferably during transport of the container) to a safety valve (as complementary connector) so as to form a system arranged to open when there is a pressure difference between the internal space and the exterior of the container above a threshold (typically comprised between 100 and 500 mbar, preferably roughly equal to 300 mbar).

According to another aspect of the invention, at least one (preferably both) of the filling valve and emptying valve can comprise a swivel plate, which:when the filling valve or emptying valve respectively is closed, is in a so-called “horizontal” state (with respect to the sealing plane of the valve) and seals the filling valve or the emptying valve respectively, preferably so that the axis of the plate coincides with the axis of the valve (axis of passage of the materials) andwhen the filling valve or emptying valve respectively is open, is in a swiveled state with respect to its horizontal state so that it no longer seals the filling valve or the emptying valve respectively and allows the objects (typically particles, preferably submicron particles) to pass through.

This filling or emptying valve respectively can optionally further comprise:a seal arranged to be in contact with at least one part of the perimeter of the swivel plate when the plate is in its horizontal state so as to ensure hermeticity of the filling valve or the emptying valve respectively when this valve is closed, andmeans for inflating the seal against the swivel plate in its closed state.

For each seal between that of the filling valve and/or of the emptying valve, the means for inflating this seal can be:arranged to inflate the interior of the seal, the seal being hollow, and/orarranged to inflate the seal against the swivel plate by inflating an intermediate space comprised between the seal and a part of the valve on which the seal is held.

According to another aspect of the invention, the container according to the invention can further comprise means for fixing a cover (also called “casing”) on the filling valve and/or on the emptying valve, and/or a cover fixed on the filling valve and/or on the emptying valve.

At least one of (preferably each of) the filling valve and the emptying valve is equipped with clamping means (i.e. for fixing by clamping) allowing clamping (i.e. fixing by clamping) hermetically by means of a seal, a cover (also called “casing”) on its swivel plate in its closed state.

The container according to the invention can comprise, for one or both of the filling valve and the emptying valve, means for creating a vacuum (pumping to lower the pressure) in the space located between the cover and the plate of this valve and/or monitoring means for displaying, from the exterior of the container, the pressure in the space located between the cover and the plate of this valve.

Each valve equipped with clamping means is preferably further equipped with means for creating a vacuum between its swivel plate and the cover (or casing) for example by means of a quick connector connected to a pump.

Each valve equipped with clamping means can optionally comprise monitoring means making it possible to check the hermeticity between the cover (casing) and its closed swivel plate. These monitoring means can be a small pressure gauge or a chip comprising a powder whose colour changes as a function of the pressure, said chip being visible from the exterior by means of a small inspection window and in contact with the space located between the casing and the swivel plate. Thus, once the clamp is closed and the space between the casing and the swivel plate is pumped out, the colour of the chip assumes a hue A. This hue remains stable for as long as the vacuum is maintained and changes colour if the vacuum between the casing and the swivel plate is broken for example following an impact during the transport phase. Preferably the powder produces a reversible effect as a function of the pressure: when the colour becomes B following ingress of air, it becomes A again when the pressure decreases again, for example after the space is pumped out again. The indicator can also be constituted by a membrane that is visible from outside the container and that is broken if air enters the space in question.

According to another aspect of the invention, the container according to the invention can further comprise means for changing in situ, in the internal space, the physical state of the objects (typically particles, preferably submicron particles) contained in the internal space.

The means for changing in situ, in the container, the state of the objects (typically particles, preferably submicron particles) contained in the internal space can comprise means for emitting ultrasound within the internal space.

The means for changing in situ, in the container, the state of the objects (typically particles, preferably submicron particles) contained in the internal space can comprise means for mixing the objects (typically particles, preferably submicron particles) contained in the internal space.

The mixing means are preferably located closer to the emptying valve than to the filling valve (typically on the emptying valve side and not on the filling valve side with respect to the internal space).

The means for changing in situ, in the container, the state of the objects (typically particles, preferably submicron particles) contained in the internal space can comprise means for heating or drying the objects (typically particles, preferably submicron particles) within the internal space.

According to another aspect of the invention, the container according to the invention can further comprise means for measuring at least one physical parameter of the objects (typically particles, preferably submicron particles) within the internal space.

According to another aspect of the invention, the container according to the invention can contain submicron particles in its internal space. The container according to the invention can contain submicron particles in its internal space occupying a volume of at least 70% of the volume of its internal space.

According to another aspect of the invention, the emptying valve and the filling valve are preferably located on two opposite sides of the container with respect to the internal space.

Moreover, a process for using a container according to the invention is proposed, characterized in that:the container is filled with objects (typically particles, preferably submicron or nanometric particles), via its filling valve, at a filling site, thenthe container is transported to an emptying site remote from the filling site, thenthe objects (typically particles, preferably submicron or nanometric particles) are emptied from the container via its emptying valve, at the emptying site.

In the case when the container according to the invention comprises a connector as stated above:before filling the container with particles, the internal space can be emptied via the connector, then the internal space can be flushed with gas (preferably neutral) via the connector, and/orthe container can be filled with dry particles, and the process according to the invention can further comprise an injection of liquid into the internal space via the connector prior to the emptying step, preferably until the particles are dissolved in the internal space, and/orgas can be injected into the internal space via the connector while the container is being emptied.

The physical state of the objects (typically particles, preferably submicron particles) in the internal space can be changed after filling, preferably by the means for changing the physical state of the objects as mentioned above, in situ in the internal space.

These means are preferably contained in the internal space. These means preferably form part of the container. The state of the objects (typically particles, preferably submicron particles) is preferably changed while the filling and emptying valves are closed.

It is possible to use a container according to the invention the filling valve of which is equipped with an inflatable seal, and this seal can be inflated after filling but before transporting the container.

It is possible to use a container according to the invention the filling valve of which is equipped with an inflatable seal and the emptying valve of which is equipped with an inflatable seal, and both these seals are preferably inflated during transport.

It is possible to use a container according to the invention the emptying valve of which is equipped with an inflatable seal, and this seal can be deflated after transporting the container but prior to the emptying step.

It is also possible to use a container according to the invention the filling valve and/or emptying valve of which are equipped with clamping means as described above, and optionally additionally with means as described above for creating a vacuum in the space between its swivel plate and the cover (or casing) and/or with means as described above for monitoring the pressure in the space between the casing and the swivel plate, a vacuum preferably having been created in said space prior to the transport step via a quick connector.

Prior to transport, preferably a cover (or casing) is fixed on the filling valve and/or on the emptying valve, in such a way that this cover remains fixed throughout transport.

Prior to transport, preferably a vacuum is created (pumping to lower the pressure) in the space located between the cover of the filling valve and/or of the emptying valve respectively and the swivel plate of the filling valve and/or of the emptying valve respectively.

Moreover, a filling valve or emptying valve is proposed, having an open state allowing objects (typically particles, preferably submicron particles) to pass through it and a closed state preventing the objects from passing through it, said valve preferably being equipped with locking means arranged for locking the valve in its closed state and for preventing opening thereof when this valve is not connected to a filling pipe or emptying pipe, characterized in that it further comprises a swivel plate, which:when the valve is closed, is in a horizontal state and seals the valve,when the valve is open, is in a swiveled state with respect to its horizontal state so that it no longer seals the valve, and allows the objects to pass through,
this valve further comprising:a seal arranged to be in contact with at least one part of the perimeter of the swivel plate when the plate is in its horizontal state so as to ensure hermeticity of the valve when this valve is closed, andmeans for inflating the seal against the swivel plate in its closed state.

This valve can further comprise:clamping means as described above,optionally with means for creating a vacuum between its swivel plate and the casing as described above,and/or optionally with monitoring means as described above for monitoring, from outside the container, the pressure in the space located between its swivel plate and the casing.

These embodiments and variants shown are in no way limitative, and it will in particular be possible to imagine variants of the invention that only comprise a selection of the features (means or steps) described below, isolated from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention with respect to the prior art. This selection preferably comprises at least one feature that is preferably functional (preferably without structural details), and/or only a part of the structural details if this part on its own is sufficient to confer a technical advantage or to differentiate the invention with respect to the prior art.

We shall first describe, with reference toFIGS. 1 to 11Aand B, a preferred embodiment of container and of NanoAirLock® “passive” valve according to the invention.

The container1is preferably a container for submicron particles.

More preferably, the submicron particles preferably consist of a nanopowder, preferably a nanopowder of silicon carbide (SiC).

By “submicron particles” is meant particles whose largest dimension (i.e. for each particle, the greatest distance joining two points of this particle) is less than a micrometre.

By “nanopowder” is meant a powder consisting of particles whose largest dimension is of some nanometres or some tens of nanometres at most, and typically less than 100 nanometres.

The container1according to the invention comprises:an internal space2for storing the submicron particles, with a typical capacity of 500 litres,a filing valve3for filling with the submicron particles, having an open state connecting the internal space2to the exterior of the container and allowing the submicron particles to pass through the filing valve between the internal space2and the exterior of the container, and a closed state preventing the submicron particles from entering or leaving the internal space2through the filing valve, said filling valve3being equipped with locking means arranged for locking the filling valve3in its closed state and for preventing opening thereof when this filling valve3is not connected to a filling pipe45, and for unlocking the opening of the filling valve3when this filling valve3is connected to the filling pipe,a emptying valve4for emptying the submicron particles, having an open state allowing the submicron particles to pass through the emptying valve between the internal space2and the exterior of the container and connecting the internal space2to the exterior of the container and a closed state preventing the submicron particles from entering or leaving the internal space2through the emptying valve, said emptying valve4being equipped with locking means arranged for locking the emptying valve4in its closed state and for preventing opening thereof when this emptying valve4is not connected to an emptying pipe46, and for unlocking the opening of the emptying valve4when this emptying valve4is connected to the emptying pipe.

The internal space2is delimited by:an upper part5of a wall, preferably of concave shape on the side of the internal space2and preferably of stainless steel,a lower part6of a wall, preferably of stainless steel and preferably of conical shape to allow easy emptying of the contents of the container by gravity via the emptying valve4; its inside surface is preferably treated by electrolytic polishing, andbetween the upper part5and the lower part6, a main part7of a wall, also called main body, which is preferably of stainless steel; its inside wall preferably has a finish obtained by electrolytic polishing on its inside surface so as to limit the deposition of particles on its wall.

The upper5and lower6parts are welded to the main part7.

These parts5,6,7are fixed on a stackable chassis8.

The container1is a movable container. It is not inseparable from an industrial system such as a system for the production of submicron particles or for using submicron particles. The valves3and4are “free”, i.e. they are not necessarily fixed to something else. The container1can be moved on its own, without these valves3and4being fixed to something external to the container such as a filling or emptying pipe.

Each of the filling3and emptying4valves is a passive valve of the “Buck®” type (for example such as marketed by the company GEA Process Engineering Division) but modified with an inflatable seal as explained below.

The filling valve3is fitted on the upper part5.

The emptying valve4is fitted on the lower part6diametrically opposite the upper part5.

Thus, the emptying valve4and the filling valve3are separate. This makes it possible to reduce the number of steps of handling the container, as this avoids having to invert the heavy container between its filling and its emptying. Moreover, this makes it possible to optimize in different ways (respectively for filling and for emptying) the two valves3and4and the shape (concave or conical respectively) of the parts5and6respectively carrying these valves.

The emptying valve4and the filling valve3are located on two opposite sides6and5respectively of container1with respect to the internal space2.

The valves for filling3and for emptying4are positioned and aligned on the vertical axis9of the container respectively on its upper part5for providing filling and its lower part6for providing emptying. These “passive” valves3,4preferably have the same diameter, for example 250 mm, and are closed by default, thus ensuring perfect hermeticity of the container1and can only be opened once they are connected to an “active” valve10of a filling pipe45present on the production pipe of the supplier of powder for filling the container and to an “active” valve10of an emptying pipe46present at the customer for emptying the container.

The container1comprises means for clamping a cover11on the filling valve and/or on the emptying valve.

The clamping means comprise holes51provided with screw threads and arranged in the periphery24.

Of course, the cover11has to be removed from the valve3or4for the latter to be used. More precisely, each valve3,4is protected by a casing11to preserve its operational state and to guarantee hermeticity in all circumstances (for example in the case of impact during transport of the container1). The valves respectively for filling or emptying the container1are each equipped with means for hermetic clamping of each casing by means of a seal on the swivel plates of the valves for filling or emptying respectively.

The container1comprises means12for connecting to a source of fluid arranged for injecting this fluid (preferably a liquid) into the internal space2. These means12are located on the same side as the filling valve3. The means12are therefore located closer to the filling valve3than to the emptying valve4. The means12are arranged so that the fluid injected by the means12flows into the container in one and the same average direction as the direction of flow of the particles through the filling valve3. The means12comprise at least one male or female connector12arranged to be open to allow passage of fluid through this connector between the internal space and the exterior of the container when it is connected to a complementary connector, female or male respectively, of a source or discharge of fluid and to be closed to prevent passage of fluid through this connector between the internal space and the exterior of the container when it is not connected to the complementary connector of the source or discharge of fluid. Each connector12is separate from the filling valve3and the emptying valve4.

Each male or female connector12is fitted on the upper part5. Each connector12disconnected from a complementary connector is in the closed position and each connector12connected to a complementary connector is in the open position. Each connector is a “quick” connector with high hermeticity to vacuum and low leakage rate, and preferably has a diameter between 4 and 20 mm. Each connector12can allow gases or liquids to pass through. A possible supplier for each connector is the company Stäubli, in particular from its “quick” connector range. Each connector12allows gas or liquids to be introduced into the container. Each connector12also allows fluid to be pumped from the internal space2.

As shown inFIG. 23, each male or female connector12can be connected (preferably during transport of the container1) to a safety valve50equipped with a complementary connector, female or male respectively, so as to form a system arranged to open when there is a pressure difference between the internal space and the exterior of the container above a threshold (typically between 100 and 500 mbar, preferably roughly equal to 300 mbar).

Each connector12is separate from the filling valve3and the emptying valve4.

The means12for connection to a source of fluid are located closer to the filling valve3than to the emptying valve4. In the case of liquid, at least one connector12is equipped with a nozzle13placed in the internal space2for providing spraying of liquid on particles contained in the internal space2, for example for putting them in suspension. Thus, the fluid can be sprayed correctly, which would not be case if the nozzle were located on the side with the emptying valve and if the particles were packed against the nozzle.

The valves3and4and each connector12are fitted in such a way as to comply with the ADR standard for the transport of hazardous materials.

The container1generally comprises means for changing, in situ in the internal space, the physical state of the submicron particles contained in the internal space2.

The means for changing the state of the submicron particles in situ in the container comprise:means14for emitting ultrasound within the internal space; these emitting means can for example comprise one or more submersible ultrasound transducer/emitter rods of identical or different frequencies and with power suitable for the internal space2, for the nature of the particles contained in the volume2, and for the concentration of the suspension of particles to be treated. Emitters of the “PushPull” type may be suitable (possible supplier: Martin Walter). In one variant, these rods are integral parts of the container; in another variant these rods are only introduced into the container after liquid has been injected via a connector12. These ultrasound emitting means are preferably introduced via the top flange on which the “passive” filling valve3is fitted. The rods are distributed so as to ensure the most uniform possible treatment of the suspension, this treatment having the aim of ensuring optimum dispersion of the particles with respect to one another; and/or.means for mechanically mixing the submicron particles in the internal space2; the mixing means are located closer to the emptying valve4than to the filling valve3, and are typically located in the internal space2at the level of the aperture of the emptying valve4; these mixing means typically comprise an helix15for providing mechanical mixing of the suspension of particles contained in the internal space2; these mixing means15, coupled to the means14for emitting ultrasound, make it possible to homogenize the treatment of the suspension and/or to mix the particles to facilitate emptying thereof via the valve4; and/ormeans16for heating or drying the submicron particles within the internal space2; these means16typically comprise heating resistances for the in-situ drying of the suspension contained in the internal space2with the purpose of forming very compacted dry matter if necessary with additives precipitated chemically on the surface of the grains during the step of placing in suspension.

The fact that the emptying valve4and the filling valve3are separate means it is possible to equip the emptying valve4with the helix15to facilitate emptying of the particles, but without obstructing valve3for filling with particles.

The container1further comprises means17for measuring at least one physical parameter (pH and/or zeta potential, and/or temperature and/or pressure etc.) of the submicron particles within the internal space. These measuring means typically comprise a sensor for measuring:preferably the pH and/or the zeta potential of the aqueous suspension formed in space2after spraying a liquid; and/orthe temperature of the contents of space2; and/orthe pressure within space2.

Preferably the sensor17is introduced via a flange18located on the upper part5of the container, permanently (or in one variant, only once the liquid has been injected into the container).

The fact of being able to change the state of the particles or being able to measure a parameter while the container is closed makes it possible to isolate the particles from the exterior of the container and avoids a step of transferring the particles outside of the container for changing their state or for measuring a parameter thereof; this therefore makes it possible both to improve the hermeticity and safety of the process implemented with the container according to the invention and moreover makes it possible to reduce the number of steps of handling the particles.

The container1is arranged for being filled and for being emptied via a double-valve device comprising valve3(and valve10) for filling and valve4(and valve10) for emptying.

Each valve3and4according to the invention of the container1will now be described in more detail. As these valves3,4are identical in respect of their general principle, the following description thereof will be made without distinction (the expression “valve3;4” signifying “valve3or valve4respectively”).

The “passive” valve3;4is arranged to be coupled to a filling or emptying pipe comprising an “active” pipe valve10equipped with a swivel plate37so as to form a double butterfly valve device, the locking means being arranged so as to unlock the opening of the valve3;4when the swivel plate37of the pipe valve10is coupled to the swivel plate26of the valve3;4.

As explained above, the double-valve device comprises an “active” valve10not forming part of the container1and a “passive” valve3;4forming part of the container1.

Valve10is called “active” as it comprises means19(typically a handle) for operating the opening of valves10and3;4once these valves are coupled. This valve10is preferably different for filling and for emptying.

Valve3;4is called “passive” as it does not comprise such opening actuation means.

Valves10and3;4close independently of one another and hermetically.

However, these valves10and3;4can only be opened when they are coupled to one another: opening of the double-valve device (i.e. the combined and simultaneous opening of valves10and3;4) can only take place when the two valves10and3;4are coupled to one another, i.e. when the valves10and3;4are combined so as to unlock the locking means of the valve3;4. In the absence of coupling, the command for opening is blocked.

In this way, the inside faces20,21of valves3;4and10, which are in contact with the particles, are never in contact with the outside atmosphere breathed by the user.

Conversely, the outside faces22,23of valves3;4and10are in contact with the outside atmosphere breathed by the user when the valves3;4and10are uncoupled but are joined together when valves3;4and10are coupled, which prevents the particles soiling these outside faces.

The structure and the locking/unlocking of valve3;4will now be described in more detail.

Valve3;4comprises a periphery24typically of stainless steel. The periphery delimits an opening hole25of valve3;4; the particles can pass through this hole when valve3;4is open.

When valve3;4is closed, this swivel plate26is in a horizontal state27and seals the opening hole of valve3;4.

When valve3;4is open, this swivel plate26is in a swiveled state28with respect to its horizontal state so that it no longer seals the opening hole25of valve3;4and allows the submicron particles to pass through this hole.

The periphery24supports the swivel plate26. More precisely, the periphery24supports two rotation half-shafts29(roughly in the form of a half-cylinder) integral with the swivel plate26. The half-shafts are diametrically opposite with respect to the swivel plate26and are arranged so that they can swivel within the periphery24about a common axis of rotation30. For each half-shaft29, rotation about the axis30takes place by rotation of a groove31in a circular arc (hollowed-out in the half-shaft) on a rail32in a circular arc integral with the periphery24.

Each half-shaft29is in addition provided with a hole33.

At the level of each half-shaft29, the periphery24is provided with a housing34comprising a spring35that pushes a pin36(not shown inFIG. 4so as to be able to make out the housing34) integral with spring35, out of the housing.

For each pair of associated hole33and housing34, when valve3;4is closed and is not coupled to the active valve10(as shown inFIG. 6), the pin36comes out of its housing34and passes through hole33of half-shaft29so as to immobilize half-shaft29and prevent it rotating.

Thus, the locking means comprise at least one pin36blocking the rotation of the swivel plate26when valve3;4is closed and is not coupled to the active valve10.

The active valve10is structured similarly with a swivel plate37integral with half-shafts38diametrically opposite. Each half-shaft38carries a projection39complementary in shape to each hole33.

As shown inFIG. 7, when the valves10and3;4are coupled, the outside faces22,23of valves3;4and10are joined together.

As shown inFIG. 7, the whole is arranged so that, when the valves3;4and10are coupled, each projection39goes into a hole33so as to push a pin36back into its housing34and thus release the rotation of the half-shafts29(and38) and therefore of the swivel plates26(and37).

Thus, coupling of the two valves10and3;4makes it possible to release the locking, and the plates26,37(also called flaps or butterflies) can swivel under the action of the handle19.

Valve3;4further comprises an inflatable seal40preferably of rubber.

The seal is carried by the periphery24.

The seal40is arranged so that it is in contact with at least one part of the perimeter of the swivel plate26when plate26is in its horizontal state so as to ensure hermeticity of valve3;4when valve3;4is closed.

Valve3;4further comprises means41for inflating and deflating seal40, typically for inflating seal40against the swivel plate26in its closed state.

The means41are arranged for inflating seal40(FIG. 11A) against swivel plate26when valve3;4is closed (FIGS. 8 and 10). This improves the hermeticity of valve3;4when it is closed. The mechanical durability of valve3;4in the closed position and its hermeticity are improved, and it is made usable for higher pressure differences with the exterior of the container and it can withstand higher temperatures. Valve3;4and therefore the container according to the invention have better hermeticity than according to the prior art, in particular for pressure differences between the internal space2and the exterior of the container for example up to at least 1000 mbar, or even at least 1500 mbar.

The means41are arranged for deflating seal40(FIG. 11B) from against the swivel plate26before opening valve3;4. Thus, the swivel plate26is released from the pressure of seal40, in order to allow its rotation and the opening of valve3;4(FIG. 9).

The inflating and deflating means41comprise:a male or female connector42, anda pipe43connecting the connector42to the seal40.
The male or female connector42is arranged:to be open when it is connected to a complementary connector, female or male respectively, of a source or discharge of fluid to allow passage of this fluid between pipe43and this complementary connector so as to inflate seal40by the source of fluid or to deflate it in the discharge of fluid, andto be closed when it is not connected to this complementary connector, female or male respectively, to prevent this passage of this fluid between pipe43and this complementary connector so that the state of inflation of the seal remains unchanged.

The fluid for inflating the seal is a gas, preferably air or nitrogen.

InFIGS. 8, 9 and 10, the seal is shown on the left and on the right of these figures as it has approximately symmetry of revolution about axis9.

In a first variant (shown inFIGS. 8 and 9), the seal40is a hollow seal. The pipe43is connected to the hollow interior of the seal so as to permit inflation of the profile of the seal.

In a second variant (shown inFIGS. 10, 11A and 11B), pipe43opens onto the seal40forming a channel44which surrounds the seal40, preferably over the whole perimeter between the seal40and the periphery24. In this way, pipe43is arranged in order to allow inflation of seal40(FIG. 11A) towards the interior of valve3;4, i.e. against the swivel plate26when valve3;4is closed (typically towards the central axis9of valve3;4).

Thus, the means41are arranged for inflating the seal40by inflating an intermediate space (channel44) between the seal40and a part of valve3;4(periphery24) on which the seal40is held.

Preferably, the container1contains submicron particles in its internal space, preferably nanopowders preferably of silicon carbide (SiC). More preferably, the container contains submicron particles (preferably nanopowders preferably of silicon carbide (SiC)) in its internal space occupying a volume of at least 70% of the volume of its internal space2.

With reference toFIG. 24, valve3;4is equipped with clamping means51for hermetically clamping, by means of a seal (not shown), a casing11on its swivel plate in its closed state.

The clamping means comprise holes51provided with screw threads and arranged in the periphery24.

The casing11is fixed by tightening several screws, each screw passing through the casing11and screwed into one of the holes51.

Of course, this casing11is unclamped and removed so as to allow coupling of the valve3;4to the valve10.

In contrast, this casing11is clamped onto the valve3;4during transport of the container.

Valve3;4is provided with means52(connector52, identical to connector42but opening into a pipe53and not43) in order to create a vacuum between its swivel plate26and the casing11(when the latter is clamped) for example by means of a quick connector52connected to a pump.

Valve3;4comprises monitoring means55for monitoring the hermeticity between casing11(when the latter is clamped) and its closed swivel plate26. These monitoring means can be a small pressure gauge55or a chip55comprising a powder the colour of which changes as a function of the pressure, the chip or gauge being visible from the exterior through a small inspection window54and in contact with the space56located between the casing and the swivel plate. Thus, once the clamp is closed and the space between the casing and the swivel plate has been pumped out, the colour of the chip assumes a hue A. This hue remains stable for as long as the vacuum is maintained and changes colour if the vacuum between the casing and the swivel plate is broken, for example following an impact during the transport phase. Preferably the powder produces a reversible effect as a function of the pressure: when the colour becomes B following ingress of air, it becomes A again when the pressure decreases again, for example after the space is pumped out again. The indicator can also be constituted by a membrane visible from outside the container, which bursts if air enters the space in question.

An embodiment of a process according to the invention for using a container1according to the invention will now be described, with reference toFIGS. 12 to 22.

In this process, with reference toFIGS. 12 to 17, the container1is filled with nanometric particles, via its filling valve3. The container is preferably filled with dry particles, i.e. not in solution.

Filling is typically carried out at a filling site.

Filling typically proceeds in the following manner.

As shown inFIG. 12, a hopper45(i.e. the filling pipe) closed at its bottom end by the active valve10,10aof the “buck®” type will be positioned so as to connect it to the passive filling valve3located on the upper part5of the container1. Valve3and valve10,10aare brought into contact, their axes being perfectly aligned. Valves3and10,10aare connected hermetically.

Thus, valves10,10aand3are connected hermetically, while they are closed. The swivel plates26and37are closed, i.e. each in its horizontal position. This is the configuration shown inFIG. 13.

The complementary parts, male or female respectively, will be connected to the quick connectors12, female or male respectively, allowing pumping of the interior of the container (and of space2) then injection of a gas49into the container (into space2), either before (as shown inFIG. 12) or after (as shown inFIG. 13) connecting the valves10,10aand3. This gas49is a neutral gas.

It is important that valves3and4withstand large pressure differences between the internal space2and the exterior of the container, in particular during these steps of pumping and of injection of gas49, for which pressure differences of up to 900 mbar are typically reached.

The container is pumped via connector12, and is then flushed with the neutral gas49such as nitrogen before it is filled with nanopowders. It is a question of evacuating the air to the maximum possible extent.

Then, as shown inFIG. 14, the submicron particles47(shown in black), after production, are injected into the hopper45by various means that are possible for a person skilled in the art.

The seal40of valve3is deflated via its connector42.

Then, as shown inFIG. 15, the swivel plates26and37of valves3and10,10arespectively are swiveled together. While they swivel, these plates26and37are in contact with one another and swivel about an axis perpendicular to axis9of the container. While they swivel, plates26and37carry out a movement of rotation through an angle of 90° causing the opening of the lower part of the hopper45and of the upper part5of the container1. This results in filling the container by gravity, the contents of the hopper pouring out from within it.

Then, as shown inFIG. 16, the plates26and37swivel in the opposite sense through 90° so as to isolate the hopper45from the container. The lower part of the hopper45is therefore closed again and so is the upper part5of the container.

Then, the seal40of the valve3is inflated via its connector42as described above.

Next, the two valves3and10,10aare decoupled as shown inFIG. 17, the active valve10,10aremaining integral with the hopper45.

After filling the container, with reference toFIGS. 18 to 19, optionally the physical state of the particles47contained in the internal space2of the container1is changed, preferably while valves3and4are closed. The fact of being able to change the state of the particles while the container is closed makes it possible to isolate the particles from the exterior of the process or avoids a step of transferring the particles outside of the container in order to change their state; this therefore makes it possible to improve both the hermeticity and the safety of the process implemented with the container according to the invention and moreover makes it possible to reduce the number of steps of handling the particles.

Typically, the physical state of the particles is changed from a solid or dry state to a liquid state or a state in solution.

As shown inFIG. 18, the complementary parts, male or female respectively, will be connected to the quick connector12, female or male respectively, allowing a liquid48, for example water, to be injected into the container1. The liquid is sprayed into the container via the nozzle13so as to wet the particles47and then transform them into a state in solution.

It is possible to add additives in the liquid48so as to promote dispersion of the particles47with respect to one another in the liquid, the additives used depending on the liquid used and the nature of the particles and in particular their surface chemistry. Dispersants can in particular be used for ensuring dispersion of the particles by a steric or electrostatic effect, or even by both effects. It is also possible by this means to graft new molecules and/or chemically precipitate new phases on the surface of the particles that are useful for the application envisaged.

Then, as shown inFIG. 19, an active valve10,10b(preferably an active valve10other than the valve10,10ashown above for emptying particles) will be connected to valve3, this active valve10,10bbeing connected to a device of detachable ultrasound rods14. Once the two valves3and10,10bare connected (i.e. coupled), opening by swiveling is carried out again, after deflating seal40of valve3via its connector42, and the ultrasound rods14are introduced into the liquid48containing the particles47.

Then, still as shown inFIG. 19, the rods14are supplied with electric power and helix15is connected to an external motor that will drive it. Then the mechanical mixing is operated so that it alternates with the ultrasound for optimum dispersion of the particles47with respect to one another and thus homogeneously. The mixing makes it possible to circulate the liquid near the rods and provide optimum treatment in situ in container1.

It should be noted that in the variant or variants:in which the rods14are not introduced into the space2via a valve10bbut form an integral part of the container, ultrasound can be emitted while valve3is closed, and/orin which the helix15is equipped with a motor forming part of container1, this motor can be supplied electrically by simple electrical connection of container1to an external power source.

The acidity of the liquid suspension, especially in the case of an aqueous suspension, can be monitored by the submerged pH sensor17, which will in particular make it possible to adjust the injection of dispersants.

It is also possible to connect a viscosity measuring device17making it possible to take samples of the suspension for continuous analysis of its viscosity.

Then, the casing11is clamped on the valve3prior to transport of the container. In fact, throughout all the preceding steps, the casing11was not clamped on the valve3.

Throughout the preceding steps, the other casing11remained clamped on the valve4.

Then, the container is transported to an emptying site remote from the filling site, whereas its valves3and4are not connected or coupled to complementary valves10but are inflated.

During transport, at least one of the connectors12is connected to safety valve50, for safety reasons, in particular in case of increase of temperature and therefore of pressure in the container1.

During transport, the pressure within the container is of the order of 1000 mbar, and so is very close to atmospheric pressure.

Throughout the next steps, the casing11remains clamped on the valve3.

However, the other casing11is removed (declamped) from the valve4.

Finally, with reference toFIGS. 20 to 22, the submicron particles are emptied from container1via its emptying valve4.

Emptying typically takes place at the emptying site.

The container is preferably emptied with particles in solution.

As shown inFIG. 20, an active valve10,10c, integral with emptying pipe46into which it is wished to inject the suspension of particles, will be positioned on the emptying valve4located on the lower part6of the container. Thus the valves4and10care connected (i.e. coupled).

Then, as shown inFIG. 21, the complementary parts, male or female respectively, will be connected to the quick connector12, female or male respectively, for injecting a gas49into the container. This gas49can be, for example, air or a neutral gas. This makes it possible to balance the pressures between the interior of the container and the process or the pipeline46into which the powders are injected.

Still as shown inFIG. 21, the double-valve device4,10cis opened as before by swiveling the plates26,37into contact. The two plates26,37are in contact and are swiveled together, which causes the opening of the container on the pipe46allowing the particles (in suspension) to be injected into the pipe46. These particles47then flow into the system.

Then, as shown inFIG. 22, plates26,37are swiveled in the opposite sense so as to close the container and the pipe46again, simultaneously. Then, the seal40of valve4is inflated via its connector42and the two valves4,10care decoupled, and the container1is free for reuse.

In variants of the process according to the invention that have just been described, the change of state of the particles can take place at any moment, for example before and/or after transport of the container.

In variants of the process according to the invention that have just been described, the change of state of the particles can comprise heating (typically via means16) of the solution of particles47(preferably while valves3and4are closed). Said heating can be carried out so as to evaporate the liquid48so that the particles47contained in space2are dry. Thus, the particles47can be made more compact relative to a dry state prior to dissolution of them. After said heating/drying, filling container1can be completed by the same principle as described with reference toFIGS. 15 and 16.

Thus, in a clever way, it is possible for example to:dry the particles in the container at the filling site for compacting them, and then complete the filling,then optionally cause the particles in the container to pass from a dry state to a state in solution only once at the emptying site, so as to facilitate flow of the particles during emptying thereof while limiting the weight of the container without liquid for transport.

Of course, the invention is not limited to the examples that have just been described, and numerous adjustments can be made to these examples without exceeding the scope of the invention.

For example, the order of the steps of the process according to the invention can be changed. For example, for filling, the seal40can be inflated after or before decoupling valves3and10a.

The state of the particles (FIGS. 18 and 19) can also be changed after transporting the container.

Of course, the various features, forms and embodiment variants of the invention can be combined with one another in various combinations, provided that they are not incompatible or exclusive of one another.