DESCRIPTION OF PREFERRED EMBODIMENTS

[0052] The enclosure of FIG. 1 is a substantially cylindrical, closed enclosure 1 , in which a suitable door 2 (of the type illustrated in FIG. 4 , for example) can be disposed to provide access to the interior, and which comprises a removable roof 3 to enable major work to be carried out.

[0053] The protective enclosure 1 comprises a vertical, one-piece wall 4 or a series of walls which are joined to each other to permit the installation and dismantling of the enclosure. For example, in the embodiment illustrated, the circular wall 4 comprises a series of wall parts 4 A, 4 B joined to each other by a junction piece J. A bottom or anchoring base 5 serves as the basis or foundation for the wall 4 . A rapid-opening access door 6 is provided in the vertical wall 4 (see FIG. 4 ). A vent system 7 permits the removal of undesirable substances which would accumulate in the enclosure and/or of gases or vapours formed during the phase transition of a product present in the wall. Another vent suitable for removing material which has undergone its phase transition can be provided, if necessary.

[0054] The walls 4 of the enclosure 1 are formed by at least one wall or external metal sheet 40 made of stainless steel or refractory having a thickness of 0.5 to 10 mm, for example (e.g. of 1 to 2 mm), an insulating layer 41 which is resistant to high temperatures, an envelope 42 intended to receive a substance or material M capable of exhibiting a phase transition below a restricted temperature, for example at a temperature between 50 and about 100° C. A low-temperature insulating layer can be added, if necessary, along the internal side of the envelope. Depending on the embodiment, the bottom and the roof 3 can be constructed in the same manner as the wall 4 .

[0055] The envelope 42 is formed by a structure comprising beams 43 , which are advantageously I-beams (vertical and horizontal beams, possibly with one or more cross-bracing elements), an internal metal wall 44 made of steel (for example stainless steel) facing the internal chamber in which the material to be protected is situated, and a wall 45 made of steel (for example stainless steel) facing the insulating layer 41 . The envelope 42 is filled with water or an aqueous solution. The phase transition of water enables the envelope and parts in contact with the envelope to be maintained at a substantially constant temperature, by virtue of the use of calories passing through the wall for evaporation until the water present in the envelope is consumed. The envelopes 42 containing water and the mechanically rigid beams 43 therefore remain at a substantially constant temperature, of about 100° C., during the evaporation phase. It is therefore possible to maintain the mechanical (or even electrical) properties compatible with the envisaged requirements. The coefficients of expansion, the creep limits, and the tensile, compressive, flexural, torsion and shear strengths, as well as all the properties which result therefrom, are maintained within the specified limits which are acceptable for the application.

[0056] Instead of allowing heat to propagate towards the interior of the enclosure, a storage device such as this is advantageously combined with a venting system 7 for dissipating heat, in order to maintain an acceptable, predetermined temperature there.

[0057] The envelope 42 has a thickness or width E between 10 and 50 cm, for example, particularly between 20 and 50 cm. The weight of the water present in the envelopes thus participates in maintaining the enclosure in place despite the blast.

[0058] The envelopes thus serve to absorb and dissipate calories. Envelopes such as these enable enclosures to be constructed which are less thick, and which are therefore easier to handle, less costly, dismantleable and light, etc, when they are not filled with water. The envelopes also enable a constant, pre-calculated stability to mechanical stresses to be maintained, and also enable the temperature in the interior of the enclosure to be controlled at the desired level. Moreover, once the envelope is filled with water it provides a weight or foundation which is sufficient for the enclosure.

[0059] The enclosure 1 is designed to withstand high external pressures.

[0060] For this purpose, the bottom edge of the walls 4 is placed in a recess 5 A in the concrete base 5 . Moreover, buttresses 10 are attached to the envelope of the walls, and said buttresses 10 are supported on the base 5 . The buttresses are situated on the inside of the enclosure 1 , so that they are protected from thermal effects by the envelopes 42 . The mechanical properties of the buttresses 10 can thus be ensured even if the enclosure is subjected to a continuous fire.

[0061] The envelope 42 is kept cold by the phase transition of the material situated in it, and thus constitutes an envelope which is strongly resistant to high external pressures. In fact, the envelope itself, its anchorage in the ground or base 5 , and the sloping stanchions or buttresses 10 attached to the wall 44 of the envelope 42 (buttresses which withstand external forces) are maintained at a given maximum temperature by virtue of the phase transition of the material, during the entire duration of the phase transition. The mechanical strength of these parts, particularly of the buttresses 10 , can be calculated and designed for these temperatures (for example for a corresponding temperature without risk of deterioration during the time of heating such as that which would occur in a conventional thermal insulation system).

[0062] Anchorage and embedding of the wall or walls in the base 5 is achieved by inserting the bottom part of the enclosure 4 in the recess or channel 5 A. Thus, the outside wall 40 , the insulating layer 41 and the envelope 42 containing the material capable of exhibiting a phase transition (water) are embedded at the bottom in the concrete base 5 , which is installed in the ground or on a stable, perfectly rigid foundation, such as a solid pipeline. The lower reinforcements (beams 43 ) and buttresses 10 of the envelope 42 are fixed to said base 5 . The upper part of the wall 4 is stiffened by the roof 3 which is mounted on and fixed to the internal walls 44 (by bolts and nuts) whilst being removable. The system for attaching the roof to the wall 4 is thus situated in the chamber CI and is therefore protected from fire.

[0063] In the embodiment shown in FIG. 1 , the walls of the enclosure 1 form a cylindrical wall.

[0064] The walls of the envelope are advantageously shaped so that the latter is as continuous as possible along its perimeter, in order to ensure an external surface which is the smallest possible and/or the most aerodynamic possible. Therefore, a polygonal profile can also be used ( FIG. 5 ) instead of a circular profile ( FIG. 2 ). This mode of design enables a good resistance to high external pressures (of dynamic origin for example) to be ensured, and also enables pronounced joints to be avoided, and therefore enables problems of leak-tightness between the different parts forming the wall of the enclosure to be avoided. It also enables the assembly to be stiffened better, and results in an improved mechanical resistance to external pressures. The various wall sections are joined by means of screwed joints and/or by welding.

[0065] The enclosure is advantageously provided with an access door 11 ( FIG. 4 ).

[0066] In substantially one-piece enclosures, it is advantageous to provide an access door for persons, for inspection, maintenance, etc.

[0067] The door 11 is advantageously designed so as to reduce or prevent thermal bridges and losses of leak-tightness between the hot part (the outside) and the cold part (the internal chamber CD. For this purpose, for example, a door 11 can be used which moves by direct displacement (X) perpendicular to the plane of the supporting wall 4 , said door being mounted on a movable trolley or being capable of being mounted on a trolley 12 .

[0068] The envelopes 42 contain one or more materials capable of changing their state when they are subjected to a rise in temperature.

[0069] The substances used are preferably selected according to their change of state temperature and their capacity for storing calories when a change of state occurs. Their ease of use and their cost is also taken in consideration. The substances (M) are advantageously substantially flameproof, as are their transformation products.

[0070] Water is the substance which best fulfils these criteria. At its boiling temperature of 100° C., most materials retain the majority of their important mechanical properties. Moreover, antifreeze and anti-corrosion additives can easily be added to water.

[0071] In the walls of the enclosure, a layer of insulation is used which is intended to reduce the quantity of heat or calories which have to be stored by the material which changes its state.

[0072] A rigid or semi-rigid insulation which is not deformed under the effect of external pressures is preferably used. It is fixed to the walls of the envelope (towards the outside) whilst taking care to minimise the effect of thermal bridges. An insulation is preferably selected which withstands high temperatures and which has a thermal conductivity related to its potential for storing heat which can be dissipated and which is present in the envelope.

[0073] The enclosure is advantageously aerated. For example, an assembly of two ducts 13 , 14 ending respectively at a ventilation orifice or shaft 7 and a cool air aspiration orifice 6 permit natural or forced ventilation (by virtue of a fan or blower 15 ) of the interior volume in order to eliminate harmful or explosive substances which would otherwise accumulate therein. These conduits 13 , 14 extend at least partially in the ground so as to pass through the base 5 below the walls 4 , which avoids the necessity of forming passageway openings in the walls, such openings resulting in the mechanical weakening of the walls and in leak-tightness problems therefor.

[0074] In the embodiment illustrated, the removal of vapours or other products resulting from the phase transition can be effected via the chamber CI. In this case, the envelope 42 has one or more openings 42 bis at its top part.

[0075] In the case of water, the vapour formed in fact spreads inside the chamber CI of the enclosure and serves to dilute the existing atmosphere before being removed by the ventilation duct or ducts 13 . It is also possible to discharge the products of transformation directly to the outside or via an additional reheating circuit installed in the hot part of the enclosure wall, which extracts all the more calories.

[0076] The removal of vapours is effected by virtue of the duct 13 , which has an end 13 A suitable for collecting hot vapours in the vicinity of the roof or the top part of the enclosure, and a non-return or check valve 13 B.

[0077] The volume of the internal chamber ranges, for example, between 1 and 50 m3, such as 5, 10, 15, 20 or 30 m3, for example.

[0078] The enclosure is advantageously provided with means for collecting and removing water of condensation and with means for protecting devices placed in the chamber from the effects of water of condensation. Examples of such means include the pipelines 60 , 61 which pass through the base. The pipeline 60 is suitable for removing water which may be present in the channel 5 A.

[0079] When the enclosure comprises a plurality of adjacent or substantially adjacent envelopes, it is advantageous to provide one or more ducts or passages 62 to form a communication between the envelopes in order to permit the passage of water from one envelope to another envelope by the effect of communicating vessels.

[0080] The envelope 42 is advantageously provided with a passage 63 a fluidically connected to a water supply 63 in order to fill the envelope as needed. The envelope 42 is also advantageously provided with a control device 63 b , which, for example, ensures a water level between a minimum level and a maximum level (said control device controlling the inflow of water into the envelope). The envelope 42 is preferably associated with an overflow 64 to prevent the water level in the envelope from exceeding a maximum level. Depending on the installation of the enclosure, it may be useful to provide systems for the addition of an antifreeze product to the envelope and/or to provide a heating system (for example an electrical resistor 65 situated in the base of the envelope 42 ). The electrical resistor can be controlled, for example, in order to ensure a mean temperature of the water present in the envelope of at least 2° C., for example between 2 and 5° C., and/or to prevent the operation of the resistor if the latter is not in contact with water.

[0081] It is also possible to provide a circulating pump (placed in the interior of the envelope, for example) to effect movement of the water or liquid present in the envelope.

[0082] FIG. 7 is a schematic illustration (in horizontal cross-section) of part of an enclosure having sidewalls 4 and a door 6 in an open position (partial open position).

[0083] The sidewalls 4 form an aperture 100 defined between the two side edges 101 , 102 and between a bottom edge 1031 and a top edge 103 S. Buttresses 10 are provided in the vicinity of the side edges 101 , 102 and are each formed by three flat bars 104 , 105 , 106 which are attached to each other (by bolts, by weld points or lines, etc.) Bar 104 and bar 105 form an L-shaped angle which extends vertically, the vertex 107 of the elbow being adjacent to an internal vertical wall. Bar 106 itself extends in a vertical plane but has an axis 106 A which is inclined with respect to the vertical axis. A buttress 10 serves to bear hinges 108 ( 3 , 4 or more, for example) to which the door 6 is attached. The hinges 108 are situated in the internal chamber CI of the enclosure and have the same swivelling axis 109 . A series of curved arms 108 A extend between the hinges 108 and the door 106 . The opening of the door 6 can be operated against the action of one or more springs 108 B.

[0084] In cross-section, the bottom edge 1031 is in the shape of a stairway or flight of steps, while the upper edge 103 S forms with the cover 153 a stairway shape. The distance 111 separating the stairway shapes of the edges 1031 , 103 S from each other is lower on the side of the internal chamber CI than the distance 112 separating said stairway shapes of the edges 1031 , 103 S on the external side.

[0085] The side edges of the window themselves are suitable for enabling the door to be opened and closed simply by rotation.

[0086] On its external face, the door 6 can be provided with one or more extensions intended to cover the sidewalls 4 and/or bottom/upper edges when the door 6 is in its closed position.

[0087] The bottom part of the bottom edge 1031 is placed in the channel 130 of the base 5 , said channel 130 being connected to drain channels or a drain 131 by a pipeline 132 .

[0088] The sidewalls 4 and the door 6 comprise an envelope 140 , 141 (made of stainless steel plates welded together, with I-beams 200 therebetween, said beams having a perforated web for enabling the free flowing of water and/or water vapor from one side of the web towards the other side of the web, while the wings of the beams are attached at least partly to steel plates) suitable for containing water in liquid form, a layer of thermal insulation 142 (rigid, for example), and an external protective wall 143 .

[0089] The envelopes 140 , 141 are provided with a valve 144 which controls the release, in the chamber CI, of vapour which may possibly be formed in an envelope, and a bursting disc 145 , said disc being ruptured if the pressure in the envelope is too high. When the envelopes 140 are connected therebetween with pipes 170 , 171 for enabling passage of water and water vapor from one envelope towards another envelope, only one envelope 140 can be provided with a control valve 144 and a bursting disc 145 .

[0090] The enclosure also comprises a reservoir 150 situated in the internal chamber CI. This reservoir advantageously has a volume which corresponds to at least the sum of the free volumes of all the envelopes 140 , 141 which are capable of containing water.

[0091] This reservoir 150 comprises a submerged pump 151 which is capable of forcing water into the pipeline 152 , the top part of which extends in the vicinity of the roof 153 . Pipes 154 and hoses 155 connect the different envelopes 140 , 141 to the pipeline 152 . The hose 155 enables a connection to be maintained between the envelope 140 and the pipeline 152 during a swivelling movement of the door 6 .

[0092] The pipes 154 and hoses 155 are provided with controlled valves 157 to ensure the supply of water to an envelope or envelopes when the water level in said envelope or envelopes is lower than a defined level.

[0093] The bottom part of the envelope 141 of the door 6 is advantageously connected by a hose 158 to a controlled valve 159 , to enable the water in the envelope 141 to be at least partly emptied, by gravity or via a communicating vessel or by means a sucking pump (such as a pump 159 A), into the reservoir 150 .

[0094] An emergency or reserve supply of electrical energy 161 is advantageously provided in the internal chamber CI of the enclosure for the operation of the pumps 151 , 159 A and the control system 160 for the pump and valves.

[0095] The volume of the reservoir 150 is greater than 1 m3, such as 2, 4, 5 or 10 m3, or even greater.

[0096] The envelopes 140 of the three side walls 4 are connected by means of pipes 170 , whereby water from one envelope can flow towards another envelope by gravity of by the principle of communicating vessels. Pipes 171 are also provided so as to enable a free passage of water vapour from one envelope towards another envelope 140 . The pipes 171 are located near the cover 153 , while the pipes 170 are located near the base 5 .

[0097] The envelope 140 can be provided with an overflow 172 , returning water above a predetermined maximum authorised water level 173 , said overflow 172 returning water to the reservoir 150 .

[0098] The reservoir 150 is advantageously provided with a water supply 174 with a controlled valve 175 , as well as of an overflow 176 conducting excessive water of the reservoir into the drain 131 . The overflow 176 is also connected to an outlet pipe 198 with a controlled outlet valve 199 , for running off the water of the reservoir 150 .

[0099] The cover 153 is also provided on its inner face with an insulation layer 142 .

[0100] The enclosure of FIG. 7 is advantageously provided with aerating means 6 , 7 , 13 , 13 A, 14 such as the door, vent system and/or ducts disclosed for the embodiment of FIG. 1 .