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DEVICE DS ABSORPTION JE HU? IEJ? D FOR AN ELECTRIC POWDER OF DIELECTRIC JELLY DESCRIPTION OF THE INVENTION The invention relates to electrical appliances of dielectric gas of those of the shielded type with sheath or metallic or porcelain cover, and specifically to a moisture absorption device with molecular sieve for said apparatuses. In a shielded electrical appliance with a metal casing or cover, for example, as a switch, it is used as a molecular sieve to absorb moisture and decomposition products formed during the incisions, an aluninosilicate in the form of small crystals or sticks. This molecular rate, eager for water, is placed in a tubular metal box which is secured in the neck of a hole provided in the metal casing of the apparatus, d. At the time of delivery, or during storage prior to putting the appliance into service, a sealing plate is placed between the tube containing the molecular sieve and the envelope or cover to prevent contact between the molecular sieve placed in the container. the tube and the air contained in the envelope or cover. When the electrical apparatus is put into service, the sealing plate is removed to make it communicate the inner volume of the tube containing the molecular sieve and the inner volume of the envelope or cover to be treated, then the vacuum is made in the envelope or cover of the apparatus before filling it with dielectric. The removal of this REF: 27833
Although it has not yet been put into service, both can, at the time of commissioning the appliance, therefore need a flange disassembly operation and after an assembly operation. of the flange that holds the tube on the envelope or cover. The object of the invention is to propose a moisture absorption device with a molecular sieve designed in such a way as to avoid these disassembly and assembly operations before putting into service said electrical device. To achieve this, the invention has for its object a device for absorbing moisture with a molecular sieve for electrical apparatus of dielectric gas comprising a box in which the molecular sieve is placed, and this box is characterized in that it is serrated by a plate provided with a valve by means of which the vacuum is created inside the box, and this plate is kept placed on a rim of the box by the play of a pressure difference between the inside and the outside of the box. box after having created the vacuum inside, and also characterized in that at least a first joint is placed between the plate and the flange to achieve the tightness of the interior volume of the box. This arrangement allows the moisture absorption device to be stored independently of the apparatus to be treated and when the moisture absorption product is not in contact with the air inside the box. When this device is mounted on an electrical apparatus that has not yet been put into service, both can also be stored without risk of the absorption product * -3- of moisture degrading. The contact of this product with the inner volume of the cover or cover of the cover is made without disassembly at the moment in which the vacuum is created in the envelope, separating the plate from the box by the set of the resultant Pressure forces exerted on this plate. Moreover, when separated from the box, the noise produced by the fall of the plate in the box allows to easily control the contacting of the product with the inner volume of the envelope or cover to be treated. Other features and advantages will be further appreciated upon reading the description that follows the embodiments of the invention illustrated with the drawings. Figure 1 shows in a very schematic way, in an aXial cut, a first example for realization of a moisture absorption device according to the invention. Figure 2 shows very schematically in axial section a second embodiment of a moisture absorption device according to the invention. Figure 3 shows very schematically in cross section a third example of embodiment of a moisture absorption device according to the invention. The molecular sieve moisture absorption device according to the invention is intended for all electrical apparatus. that works with a dielectric gas under pressure in a tight envelope or cover (armored connection), disconnector, switches, busbars, etc.). The figures partially show a hermetically sealed shell or cover 4 of said electrical apparatus. It has a hole 2 with a neck 3 on which the moisture absorption device according to the invention is secured. In the exemplary embodiment of FIGS. 1 and 2, the ab sorption device is fixed to the outside of the casing or cover of an electrical device of the shielded type "The moisture absorption device of FIG. 3 is mounted inside the a metallic cover or shell that defines a switch chamber for example, as shown in FIG. 1, the humidity absorption device comprises a box, here a metal tube 4, whose opening is anchored on the neck of the hole in the envelope or cover. The molecular sieve is placed in the bottom of the tube 4. The rebar 6 that extends radially inside the tube 4 serves as support for a plate 7 that comes to close the volume V in which the molecular sieve is placed. The tube 7 is provided with a valve 8 which serves to create the vacuum inside this volume in order to preserve the molecular sieve thus conditioned intact. The tightness of this volume is ensured by a gasket 9 placed between the plate and the flange. When the vacuum is created inside this volume, the plate is held in place by the play of the pressure difference between this outer volume of the box. At the moment when the vacuum is created inside the envelope or cover that is communicated through its hole 2 with the plate 7 * the latter is no longer maintained by the set of pressures and is separated from the case for example by gravity . Its fall in the box produces a noise that allows control of the communication of the volume V in which the molecular sieve and the inSbrior volume of the envelope or cover is placed and consequently the contacting of this product with the volume a try the device. This noise can also be caused by shaking the device. To ensure an even more effective separation of the plate and flange (especially if the gasket 9 is glued between the plate and the flange), a second gasket 10 can be provided which is arranged around the first gasket between the plate and the flange. To create the vacuum of the envelope or cover, the resultant pressure forces acting on the two together causes the plate to detach from the flange. This separation can be improved with the presence of a spring 11 which is compressed to act between the box and the plate as shown in figures 2 and 3. In this way the plate is ejected from the box when the vacuum is created in the wrap or cover to be treated whatever its position with respect to the vertical. A protective grid 12 disposed at the level of the hole 2 of the casing or cover prevents the plate from penetrating said casing when it is separated from the casing. In FIGS. 1 and 2, it is seen that the box is mounted on the cover c to be treated in such a way that the plate with the valve is placed on the side of the wrapper or cover for reasons of protection. In figure 3 »the box 4 is mounted in the interior volume of the envelope. In this case, an opening 13 is provided in the wall of the box so that the volume of the envelope or cover is communicated with the plate and to reach the valve in order to realize the vacuum in the box. In this configuration, the grid is not necessary and is replaced by a joining flange 14 which is secured on the neck of the hole of the casing or cover. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, the content in the following is claimed as property: