FR2851602A1 - Enclosure protecting against the blast from an explosion or force from a high temperature flame - Google Patents

Abstract

The side walls (4) have a rigid metal envelope (42) containing metal beam(s) (43) which define a free volume at least 50% of the envelope volume. The free volume contains water or an aqueous solution which changes phase at less than 150 degrees C. The envelope has inlet(s) (63) for the water or solution, outlet(s) (42bis) for the steam and a water outlet in case the envelope leaks : A rigid enclosure with one or more side walls (4) and a roof (3) define an internal chamber. One or more bases (5) support of the side wall(s). The envelope has a thickness or size between 5 and 50cm, preferably between 10 and 50cm. The envelope is made of steel, preferably stainless, and has a free volume which can contain at least 0.5m3> of water or aqueous solution. The enclosure has several separate envelopes connected together by passages for the water or aqueous solution and by mechanical joints which can dilate when heated. The water inlet is connected to a level control maintaining the level of water in the envelope(s). The envelope(s) are also provided with an overflow (64) and are connected to means of avoiding the formation of gel. Each side wall is connected to at least one buttress (10) extending into the chamber (CI) and pressing on a base, to oppose an external load on the wall. The side walls have an insulating layer on the outside. The side walls define a circle or a polygonal shape with at least 5 sides, preferably at least 8. An independent claim is included for a gas or inflammable product treatment installation with at least part of the installation in an enclosure as described above.

Description

The subject of the invention is a breath protection enclosure

of an explosion

  or a thrust resulting from a flame at high temperature, as well as against the thermal effects of an ambient fire on a metal structure.

  Protection elements (flexible, light or substantially flexible) against fire exist, these elements enveloping a valve or a pipe of a chemical, petrochemical installation, etc. These elements, if they can resist the thermal effect of 10 fires or fires, are not able to resist the blast of an explosion.

  It has also been proposed (for example by document W002 / 07298 1) to use flexible bags or bags filled with water and placed one above the other to form protection against the blast of an explosion.

  The link connecting the bags or bags of water to each other is not sufficient to withstand the hot breath of an explosion in a gas processing installation. In addition, as soon as a temperature above about 1001C is reached in the bags or pockets, there is a risk of explosion of the bags or pockets, this then causing the wall to collapse.

  A wall of bags or pockets of water is only capable of providing protection for a short period of time. Finally, the use of bags requires daily inspections and the frequent replacement of defective bags. This makes the use of bags or bags filled with water unsuitable for use in industrial installations.

  Reinforced concrete protective buildings are also known capable of withstanding the blast of an explosion. However, such buildings are not capable of withstanding the prolonged thermal effects of a fire or a fire, for example because of expansion. of the concrete reinforcement. Indeed, the temperature gradually rises in the materials used and decreases their mechanical properties and strength accordingly. In addition, excessive temperatures can appear inside the enclosure after a certain time of exposure to fire - Such buildings are heavier and cannot be quickly removed if necessary.

  The present invention relates to a protective enclosure capable of withstanding the breath of an explosion or thrust resulting from a flame at high temperature, as well as the thermal effects of an ambient fire, for example for more than 30 minutes, in particular for more than 60 minutes or even much longer. The enclosure will define a protected chamber of volume greater than lm3, in particular of volume between 2 and 50mS3, 10 for example between 2 and 30mW, such as a volume of 3, 5, 8, 10, 15m3, 20rn3, etc. . The enclosure will preferably be easy to assemble and disassemble without requiring heavy equipment.

  The enclosure according to the invention comprises: - an enclosure comprising one or more side walls and a roof defining an interior chamber, - one or more bases serving to support at least a part of the side wall (s).

  The enclosure according to the invention is characterized: in that at least the side wall (s) have a rigid metallic structure forming an envelope comprising one or more metal beams located inside the envelope, said envelope having a thickness between 10 and 50cm (advantageously between 20 and 50cm) and defining a free volume to contain a medium capable of changing phase (preferably at a temperature below 1501C, more particularly at a temperature below 1 10'C, for example at a temperature between 50 and about 1000C), in particular water or an aqueous solution, said free volume corresponding to at least 50% of the total volume of the envelope, in that the envelope has at least one opening for the evacuation of steam and an opening for bringing water or an aqueous solution into the envelope, and in that the enclosure has at least one means for allowing the evacuation of water from the interior chamber in the event of an envelope leak.

  Advantageously, the envelope or each envelope is made of steel, advantageously stainless, and has a free volume capable of containing water or an aqueous solution of at least 0.5 m 3, for example at least 1 m 3 , l, 5m3, 2m3, 3m3, 10 Sm3, or even more. The envelope or envelopes once filled or partially filled with water ensure a sufficient weight of the enclosure so as to oppose a displacement of the enclosure following a blast.

  Preferably, the enclosure comprises several separate envelopes linked together by one or more conduits adapted to allow the passage of water or aqueous solution from one envelope to another envelope by the principle of communicating vessels.

  According to one embodiment, the enclosure is associated with a water supply and with a control device for adjusting the level of water or aqueous solution in the envelope or envelopes.

  According to an advantageous detail, the envelope or envelopes are associated with a means for preventing the formation of gel. One such means may be an electrical or heating resistance capable of maintaining a temperature above 0 ° C. of the water present in the envelope or envelopes.

  According to a detail of an embodiment, each side wall is associated with at least one buttress extending in the chamber and bearing on a base, said buttress being adapted to oppose an external thrust on the wall.

  For example, the side wall or walls have an insulating layer turned towards the outside of the enclosure with respect to an envelope adjacent to said insulating layer. According to an advantageous detail of an embodiment, the wall or walls include an envelope comprising a metal frame or structure to which one or more buttresses are attached.

  Advantageously, the enclosure comprises one or more lateral walls defining an exterior shape that is substantially circular or polygonal with at least 5 sides, advantageously with at least 6 sides, preferably with at least S sides, According to an advantageous shape, substantially all of the lower edge of the wall (s) 15 extends in a groove or groove in a base or in grooves in adjacent bases.

  Preferably, the groove or groove is associated with a channel for discharging water out of the enclosure.

  According to a particular embodiment, the wall or walls comprise at least 20 from the outside towards the inside of the chamber: - a protective plate, advantageously made of steel, in particular stainless steel, - a layer of thermal insulation , advantageously made of hard or semi-hard insulating material, said layer having a thickness of at least 20 mm, advantageously between 30mm and 200mm, preferably between 40mm and IO0nmm, 1 - an envelope comprising a connected metal structure or reinforcement at one or more buttresses, this envelope containing water or an aqueous solution and having a thickness of between 10 and 50 cm.

  Preferably, the envelope has a metal wall facing the insulation layer and a metal wall facing the interior of the chamber, said metal walls being connected together by metal I-beams. Advantageously, the metal walls have a thickness of at least 4mm, advantageously between 5 and 30, in particular between 8 and 20mm.

  Advantageously, the enclosure according to the invention comprises a channel for supplying fresh air into the chamber and a channel for discharging air from the chamber. Preferably, the inlet channel and the outlet channel pass under the lower level of a wall.

  The enclosure can be provided with means for controlling the quantity of water present in the envelope and / or for maintaining at least a minimum level of water in the envelope.

  The object of the invention is also to protect, by means of an enclosure according to the invention, at least one member of an installation which could be accidentally subjected to a large blast and fire. The installations concerned can be fuel and / or explosive gas treatment units, in particular liquefaction, gasification, expansion and / or compression units for gas, such as natural gas (methane), propane, hydrogen, etc. The invention also relates to chemical or petrochemical installations of which at least one organ is placed in an enclosure according to the invention.

  Special features and details of the invention will emerge from the following detailed description in which reference is made to the accompanying drawings. In these drawings, FIG. 1 is a view in vertical section of a substantially cylindrical enclosure according to the invention; Figure 2 is a partial view in horizontal section (line II-II) of the enclosure of Figure 1, - Figure 3 is a sectional view of a wall, - Figure 4 is a sectional view of a detail of the enclosure of Figure 1, - Figure 5 is a partial view in horizontal section of a variant of an enclosure according to the invention, and - Figure 6 is a view of a detail of wall.

  The enclosure of FIG. I is a substantially cylindrical closed enclosure i, in which an appropriate door 2 (for example of the type shown in FIG. 4) can be fitted to access the interior and a removable roof 3 to allow 10 big works.

  The protective enclosure 1 has a vertical wall 4 in one piece or a series of walls connected together allowing the mounting and dismounting of the enclosure. For example, in the form shown, the circular wall 4 comprises a series of wall parts 4A, 4B connected to each other by a junction piece J. A bottom or anchoring base S serves as a base or foundation for the wall 4. An access door 6 with rapid opening is provided in the vertical wall 4 (see FIG. 4). A vent system 7 makes it possible to evacuate undesirable substances which would accumulate in the enclosure and / or the gases or vapors formed during the phase change of a product present in the wall.

  Optionally, another vent suitable for removing the material which has undergone its phase change can be provided.

  The walls 4 of the enclosure 1 consist of at least one outer wall or sheet 40 of stainless steel or refractory having for example a thickness of 0.5 to 10 mm 25 (for example from 1 to 2 mm), an insulating layer 41 resistant to high temperatures, an envelope 42 intended to receive a substance or material M capable of changing phase below a limit temperature, for example at a temperature between 50 and about 1000C. A low temperature insulation layer can be added if necessary. along the inside of the envelope. According to embodiments, the bottom and the roof 3 can be constructed in the same way as the wall 4.

  The envelope 42 is formed by a structure comprising beams 43 advantageously in I (vertical and horizontal beams with possibly one or more braces), an internal metal wall of steel (for example stainless) 44 facing the internal chamber in which is located finds the material to be protected, a steel (for example stainless) wall 45 facing the insulating layer 41. The envelope 42 is filled with water or an aqueous solution. The change of phase of the water makes it possible to maintain a substantially constant temperature of the envelope and the parts in contact with the envelope, thanks to the use of the calories passing through the wall for evaporation until the water is used up. present in the envelope. The envelopes 42 containing water and the mechanical rigidity beams will therefore remain at a substantially constant temperature, around 000C during the evaporation phase. Consequently, it will be possible to maintain the mechanical (or even electrical) properties compatible with the needs envisaged. The elongation coefficients, the creep limits, the tensile, compressive, flexural, torsional and shear strengths as well as all the resulting properties are kept within the limits provided and acceptable for the application. .

  Such an accumulation device is advantageously combined with an evacuation 7 and 20 evacuating the heat instead of letting it propagate towards the interior of the enclosure so as to maintain an acceptable and preset temperature there.

  The envelope 42 has for example a thickness or width E of between 10 and 50 cm, in particular between 20 and 50 cm. The weight of the water present in the envelopes 25 thus participates in keeping the enclosure in place, despite the breath.

  The envelopes thus serve as absorbers and evacuators of calories. Such envelopes make it possible to build surrounding walls that are thinner and therefore more easy to handle, less costly, removable, etc. and light when they are not filled with water The envelopes also allow to keep a constant and precalculated stability to mechanical stresses and also allow to regulate the temperature inside the enclosure to the desired level. In addition, once the envelope is filled with water, it provides sufficient weight or seating for the enclosure.

  Enclosure 1 is designed to withstand high external pressures.

  To do this, the lower edge LA of the walls 4 is placed in a groove SA of the concrete base 5. In addition, buttresses 10 are attached to the envelope of the walls, the buttresses 10 being supported on the base 5. The buttresses are located on the inner side of the enclosure 1, so that they are protected from the thermal effect by the envelopes 42. Thus the mechanical properties of the buttresses 10 can be ensured even if the enclosure is subjected to a continuous fire.

  The envelope 42 is kept cold by the phase change of the material therein, and thus constitutes a force envelope resistant to significant external pressures. Indeed, the envelope itself, its inking in the ground or base 5, and the oblique uprights or buttresses 10 attached to the wall 44 of the envelope 42 (buttresses opposing external forces) are maintained at a temperature maximum determined thanks to the phase change of the material, and this during the entire phase change period. The mechanical resistance of these parts, in particular of the buttresses 10, can be calculated and designed at these temperatures (for example at a corresponding temperature without risk of deteriorating during the heating time as would occur in a conventional insulation system thermal). The anchoring and embedding of the wall (s) to the base 5 are obtained by inserting the lower part of the enclosure wall 4 into the groove or groove SA. Thus, the outer wall 40, the insulating layer 41 and the envelope 42 containing the material capable of changing phase (water) are, at their base, embedded in the concrete base S implanted in the ground or on a stable base and perfectly rigid, that a solid piping. The lower reinforcements (beams 43) and buttresses 10 of the casing 42 are fixed to said base 5. The upper part of the wall 4 is stiffened by the roof 3 which is embedded and fixed to the interior walls 44 (by bolts and nuts) while being removable.

  The system for attaching the roof to the wall 4 is thus located in the chamber CI and is therefore protected from fire.

  In the embodiment of Figure 1, the walls of the enclosure 1 form a cylindrical wall.

  The walls of the envelope are advantageously shaped in such a way that it is as continuous as possible along its perimeter, so as to ensure the smallest possible external surface and / or the most aerodynamic possible. We can therefore also use a polygonal profile (Figure 5) instead of a circular profile 1 5 (Figure 2). This way of designing ensures good resistance to significant external pressures (for example of dynamic origin), but also makes it possible to avoid marked junctions and therefore sealing problems between the different parts forming the wall of the pregnant. It also makes it possible to stiffen the assembly better and to ensure better mechanical resistance to external pressures. The different wall sections will be assembled by bolting and jointing and / or by welding.

  The enclosure is advantageously provided with an access door 11. (FIG. 4) In substantially monohull enclosures, it is advantageous to provide an access door for people, for checking, maintenance, etc. The door 11 is advantageously designed to reduce or avoid thermal bridges and leaks between the hot part (the exterior) and the cold part (the internal chamber CI). For this purpose, one can for example use a door 11 with direct translation (X) and perpendicular to the plane of the load-bearing wall 4, the door being mounted on a mobile carriage or being able to be mounted on a carriage 12.

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

  The substances used will preferably be chosen according to their temperature of change of state and their power to accumulate calories thereon on this occasion. Ease of use and cost will also be taken into account. The substances (M) will advantageously be substantially non-flammable, as will their transformation products.

  Water is the substance that best meets these criteria. At its boiling temperature of 1000C, most materials also retain interesting mechanical properties. In addition, anti-freeze and anti-corrosion additives can easily be added thereto.

  In the walls of the enclosure, a layer of insulation is used, intended to reduce the quantity of heat or calories which must be accumulated by the material with change of state.

  Preferably use a hard or semi-hard insulation which does not deform under the effect of external pressures. It will be fixed to the walls of the enclosure (outwards), taking care to minimize the effect of thermal bridges. The insulator will preferably be chosen to withstand high temperatures and to have a thermal conductivity in relation to the potential for evacuating heat which is contained in the envelope. The enclosure is advantageously ventilated. For example, a set of deux.conduits 13,14 ending respectively with an exhaust or chimney 7 and a suction mouth 6 of fresh air will allow natural or forced ventilation (thanks to a fan or blower 15) of the interior volume in order to '' remove harmful or explosive substances which may accumulate there. These conduits 13,14 extend at least partially into the ground to pass through the base 5 in D below the walls 4, which will avoid the need to form passage openings in the walls, such openings then inducing a deformation mechanics of these and sealing problems for them.

  In the embodiment shown, the evacuation of vapors or other products 10 due to the phase change can be done via the chamber CI. In this case, the envelope 42 has at its upper part one or more openings 42bis.

  In fact, in the case of water, the vapor formed will spread inside the chamber CI of the enclosure and will serve to dilute the existing atmosphere before being evacuated by the aeration duct (s). 13. The transformation products could also have been evacuated directly to the outside or via an additional heating circuit located in the hot part of the enclosure wall, which also extracted more calories.

  The evacuation of the vapors is done through the conduit 13 which has an end 13A 20 adapted to collect hot vapors in the vicinity of the roof or of the upper part of the enclosure, and a check or non-return valve 13B.

  The volume of the interior chamber is for example between 1 and 50m3, such as for example 5, 10, 15, 20, 30m.

  The enclosure is advantageously provided with means for collecting and discharging condensation water and with means for protecting the devices placed in the chamber against the effects of water condensation. Such means. are for example pipes 60,61 passing through the base. Line 60 is adapted to evacuate any water present in the SA gorge.

  When the enclosure comprises several adjacent or substantially adjacent envelopes, it is advantageous to provide one or more conduits or passages 62 to form a communication between the envelopes so as to allow the passage of water from one envelope to another envelope by the effect of communicating vases.

  The envelope 42 is advantageously connected to a water supply 63 to fill the envelope as required. The envelope 42 is also advantageously provided with a control device, ensuring for example a water level between a minimum level and a maximum level (the control device controlling the arrival of water in the envelope. Preferably, the casing 42 is associated with an overflow 64 to prevent the water level of the casing from exceeding a maximum level, depending on the location of the enclosure, it may be useful to provide adding an antifreeze product 15 to the envelope and / or providing a heating system (for example electrical resistance 65 located at the bottom of the envelope 42. The electrical resistance is for example controlled to ensure an average temperature of the water present in the envelope of at least 20C, for example between 2 and 51C, and / or to avoid the operation of the resistor, if the latter is not in contact with water.

  We could also have provided a circulation pump (for example placed inside the envelope) to ensure movement of the water or liquid present in the envelope.

Claims (11)

claims   1. Enclosure (I) for protection against the blast of an explosion or a thrust resulting from a flame at high temperature, as well as against the thermal effects of an ambient fire on a metal structure, said enclosure comprising: - a rigid enclosure (1) comprising one or more side walls (4) and a roof (3) defining an interior chamber (CI), - one or more bases: (5) serving to support at least part of the or side walls (4), characterized in that at least the side wall (s) (4) have a rigid metallic structure forming an envelope (42) comprising one or more metal beams (43) located inside the envelope, said envelope having a thickness or width (E) of between 10 and 50 cm and defining a free volume to contain a medium capable of changing phase, in particular at less than 150 ° C., advantageously water or a solution aqueous, said corresponding free volume at least 50% of the total volume of the envelope, in that the envelope (42) has at least one opening (42bis) for the evacuation of steam and an opening (63) for supplying water or an aqueous solution in the envelope, and in that the enclosure has at least one means (61) for allowing the evacuation of water from the interior chamber in the event of the envelope (42) leaking.   2. Enclosure according to claim 1, characterized in that the envelope (42) or each envelope is made of steel, advantageously stainless, and has a free volume capable of containing water or an aqueous solution of at least 0 , 5m3.   3. Enclosure according to claim 1 or 2, characterized in that it comprises several separate envelopes (42) connected together by one or more conduits or passages (62) adapted to allow the passage of water or aqueous solution of an envelope towards another envelope by the principle of communicating vases.   4. Enclosure according to any one of claims I to 3, characterized in that the enclosure is associated with a water supply (63) and with a control device for adjusting the level of water or of aqueous solution in the envelope or envelopes, the envelope or envelopes being advantageously provided with an overflow (64).   5. Enclosure according to any one of the preceding claims, characterized in that the envelope or the envelopes are associated with means (65) for preventing the formation of gel6- Enclosure according to any one of the preceding claims, characterized in 15 this each side wall (4) is associated with at least one buttress (10) extending in the chamber (CI) and bearing on a base (5), said buttress (10) being adapted to oppose a thrust outer (P) on the wall (4), 7. Enclosure according to any one of the preceding claims, characterized in that the side wall (s) (4) have an insulating layer (41) facing outwards from the enclosure relative to an envelope adjacent to said insulating layer.   8. Enclosure according to any one of the preceding claims, characterized in that the wall or walls (4) comprise an envelope comprising a metal frame or structure (43, 42) to which one or more buttresses (10) are attached, 9. Enclosure according to one of the preceding claims, characterized in that the enclosure comprises one or more lateral walls (4) defining an outer substantially circular or polygonal shape with at least 5 sides, advantageously with at least 6 sides, preferably at least 8 sides.   l 0. Enclosure according to any one of the preceding claims, characterized in that substantially the entire lower edge (4A) of the wall (s) (4) extends in a groove or groove (SA) of a base (5 ) or in adjacent base grooves.   1 1. Enclosure according to claim 10, characterized in that the groove or groove is associated with a channel for discharging water out of the enclosure.   12. Enclosure according to any one of the preceding claims, characterized in that the wall (s) (4) comprise at least from the outside towards the inside of the chamber (CI): - a protective plate (40), advantageously steel, in particular stainless steel, a thermal insulation layer (41), advantageously made of hard or semi-hard insulating material, said layer having a thickness of at least 20 mm, advantageously between 30mm and 200mm, preferably between 40 nm and 10 mm, - an envelope (42) comprising a metal structure or reinforcement connected to one or 20 buttresses, this envelope containing water or an aqueous solution and having a thickness of between 10 and 50 cm.   13. Enclosure according to the preceding claim, characterized in that the envelope (42) comprises a metal wall (45) facing the insulation layer (41) and a metal wall (44) facing the inside of the chamber (CI), said metal walls being interconnected by metal beams made of IL 14. Enclosure according to the preceding claim, characterized in that the metal walls (44,45) have a thickness of at least 4mm, advantageously between 5 and 30, in particular between 8 and 20mm.   15. Enclosure according to any one of the preceding claims, characterized in that it comprises a channel for supplying (14) fresh air into the chamber and a channel S for discharging (13) air from the chamber. .   - 16. Enclosure according to the preceding claim characterized in that the supply channel and the discharge channel passes under the lower level of a wall (4).   17. Enclosure according to any one of the preceding claims, characterized in that the material (M) capable of changing phase is a medium capable of changing phase at less than 1100C.   18. Gas transformation installation comprising a liquefaction or gasification or expansion or compression unit, in which at least one member of the installation is located in an enclosure according to any one of the preceding claims.