[go: up one dir, main page]

EP1054721B1 - Method for preserving silver-plated objects and filtering device for carrying out said method - Google Patents

Method for preserving silver-plated objects and filtering device for carrying out said method Download PDF

Info

Publication number
EP1054721B1
EP1054721B1 EP99900931A EP99900931A EP1054721B1 EP 1054721 B1 EP1054721 B1 EP 1054721B1 EP 99900931 A EP99900931 A EP 99900931A EP 99900931 A EP99900931 A EP 99900931A EP 1054721 B1 EP1054721 B1 EP 1054721B1
Authority
EP
European Patent Office
Prior art keywords
silver
chamber
preserving
conserving
objects
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP99900931A
Other languages
German (de)
French (fr)
Other versions
EP1054721A1 (en
Inventor
No[L Lacoudre
Teyeb Beldjoudi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electricite de France SA
Original Assignee
Electricite de France SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Electricite de France SA filed Critical Electricite de France SA
Publication of EP1054721A1 publication Critical patent/EP1054721A1/en
Application granted granted Critical
Publication of EP1054721B1 publication Critical patent/EP1054721B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F15/00—Other methods of preventing corrosion or incrustation

Definitions

  • the invention relates to the field of protection and conservation of silver metallic objects.
  • the method according to the invention allows to purify gases intended to constitute the environment of these objects.
  • the method according to the invention is implemented, for example, for protect and conserve such objects while they are exposed to public.
  • Table 1 shows the main air polluting species responsible for tarnishing silver, as well as their respective concentrations. According to FRANEY (1985): "The corrosion of silver by atmospheric sulfurous gases", Corrosion Science, Vol 25, n ° 2. pollutants SCO SO 2 H 2 S CS 2 Average Concentration In ppb 0.5 0.1 0.03 0.03
  • Carbonyl sulfide, OCS is the main pollutant identified, it is also the most reactive, ahead of H 2 S, SO 2 then CS 2 .
  • the sulphurization of silver is moreover very sensitive to humidity of the air because the presence of a few monolayers of water on the surface of the metal is sufficient to hydrolyze OCS, to dissolve and dissociate H 2 S allowing the reaction: 4Ag + 2HS - TM 2Ag 2 S + H 2 + 2e -
  • This reaction is responsible for the darkening, tarnishing and corrosion of silver.
  • the object of the present invention is to provide a method of conservation of silver objects which does not have the disadvantages noted above, and which is nevertheless very effective.
  • the invention is a method of preserving and conservation of silver objects including the step of conditioning the objects in a desulfurized atmosphere characterized in that one desulfurizes the atmosphere in contact with cathodically activated metallic silver.
  • a material composed of silver metallic allows to trap sulfur compounds likely to be find in a gas intended to form the atmosphere of silver objects 1 to protect, before this gas comes into contact with these objects 1.
  • metallic silver is preferably put in a form having a large surface specific.
  • This surface is developed, the more the trapping surface sulfur compounds is important. This both promotes exchanges with the gas and increase the quantity of molecules that can be trapped before reaching the saturation of this surface with respect to sulfurization reactions.
  • the silver objects 1 to be protected are placed in an enclosure 300, in order to confine the atmosphere surrounding these silver objects 1 (figure 1). But we can also consider placing these objects 1 under a gas flow.
  • the silver objects 1 are placed in an enclosure 300, the atmosphere thereof is maintained at overpressure relative to outside the enclosure 300. In this way, it is possible to use enclosures 300 of limited sealing, and therefore less difficult to produce and less expensive than 300 waterproof enclosures. Overpressure at the interior of the enclosure 300 limits the penetration of gas which has not been removed by the interstices of it.
  • the gas is de-fumed before or at its entry into the enclosure.
  • a purification device 100 then convey the gas desulfured by the device treatment plant 100 to enclosure 300 by a suitable conduit 150 (see figure 2).
  • the metallic silver for trapping sulfur compounds is placed in a 200 cassette, at an opening inlet 310 of the gas into the enclosure 300, while a fan 50 is located in an outlet opening 320 for gas from the enclosure 300. From this way, the gas is sucked into the enclosure 300 and fumed at its entry while it is extracted from the enclosure 300 by the fan 50 (FIG. 3),
  • silver metallic trap for sulfur compounds is placed in a cassette 200 so as to be both swept by the gas entering the enclosure 300 and by part of the gas from the enclosure 300 (FIG. 4). In this way, the gas in enclosure 300 undergoes recycling.
  • the method according to the invention can also be implemented by having metallic silver activated cathodically, in several locations in enclosure 300.
  • activated metallic silver cathodically can be arranged in such a way as to desorb the incoming gas in enclosure 300, while another amount of activated metallic silver cathodically can be placed elsewhere in enclosure 300 to desulfurize the recycled gas from this enclosure 300.
  • the enclosure 300 is a showcase. As illustrated in Figure 1, in in this case, the enclosure 300 comprises a window 305, behind which are exposed silver objects 1, on a shelf 5.
  • a purification device 100 is placed in the display case 300, with an entry grid 12 communicating with the outside of this display case 300.
  • the gas to be purified enters the apparatus 100, passes through an extractable cassette 200 containing the silver cathodically activated metal and constitutes the environment for silver objects 1 to be protected (arrow in broken lines). Crossing the cassette 200, the sulfur compounds are retained on metallic silver cathodically activated. The environment of silver objects exhibited in the display case 300 is thus removed.
  • the purification device 100 for implementing the method according to the invention can be adjustable in terms of extraction power and air circulation. So these dimensions are variable, depending on whether you want to purify an enclosure with a volume of 1 to 10 m 3 or an enclosed storage room of several tens of cubic meters.
  • this one is a small module. It essentially comprises a cover 30 sealed, extractor fan 50 and extractable cassettes 200, 210, 220, 230 ( Figures 5 and 6).
  • the cover 30 is generally an elongated rectangular parallelepiped.
  • the inlet face 10 is provided with a grid inlet 12 for stale gas.
  • the outlet face 20 is provided with flaps 22.
  • One 14 of the faces perpendicular to the inlet face 10 and to the outlet face 20 is provided with a handle 40.
  • One 16 of the faces perpendicular to the face inlet 10 and outlet face 20, adjacent to face 14 provided with the handle 40, includes openings suitable for receiving the cassettes 200, 210, 220, 230.
  • an electrical power outlet 60 and a switch 70 are arranged on this same face 16.
  • the input face 10 and the face of outlet 20 have the approximate dimensions 130 mm x 160 mm.
  • the fan 50 is electrically powered and ensures the extraction and air circulation. As shown in FIG. 6, this fan 50 is located inside the cover 30, near the outlet face 20. This fan 50 puts all of the extractable cassettes 200 under vacuum, 210, 220, 230 placed upstream of it. Fan 50 diffuses gas purified to flaps 22.
  • a fan 50 whose approximate dimensions are 119 x 119 x 32 mm 3 . It will be powered by direct current at a voltage of 12 volts (delivered by a battery for a stand-alone device or by a transformer connected to 220 volts mains) for a power of 1.2 W (1,550 rpm). Its flow will then be around 95 m 3 / h. It will have a noise level of 30 dB.
  • the purification device 100 can include a flap device 22 oriented upwards to ensure the air circulation of the enclosure 300, when for example, the apparatus 100 is arranged on the bottom wall of the enclosure 300 (FIG. 7a).
  • the flaps 22 can be oriented downwards when the purification device 100 is placed at a height (FIG. 7b).
  • the purification device 100 it is portable.
  • the purification device 100 can include casters to facilitate transport.
  • the purification device 100 comprises at least one cassette 200 containing cathodically activated metallic silver which advantageously has a large surface specific.
  • This silver is in the form of wool, felt or foam silver. This money fixes the sulfur compounds. It can be delivered as of consumable in waterproof plastic bags.
  • the money is for example under form of compacted wool 150
  • This wool 150 is inserted into a retaining frame 160.
  • the assembly consisting of frame 160 and the wool 150 is introduced into the purification device 100 by means of rails sliding 170 fixed horizontally in the latter.
  • the cassette 200 loaded with wool, felt or cathodically activated silver foam is itself delivered under form of consumable, in waterproof plastic bags.
  • a such cassette can also be returned to the manufacturer who can judge the opportunity to cathodically reactivate its content (in the context of a maintenance contract, for example).
  • the cathodic activation of a cassette 200 is therefore carried out on 200 new cassettes or to recycle.
  • Wool, felt or silver foam consists of purified silver 99.9% or an alloy where the concentration of silver is higher or equal to 90%.
  • the specific surface of wool, felt or silver foam is approximately 100 cm 2 / g.
  • a cassette 200 for the purification device 100 preferably contains 10 g of silver, which represents a total surface area of deployed silver of approximately 1000 cm 2 .
  • Such a cassette 200 can fix 0.1 g of sulfide.
  • Electrochemical assembly for the implementation of the process cathodic activation of silver is shown in Figure 9.
  • This mounting preferably includes an electrolytic cell 400 containing an electrolytic bath, a stabilized power supply 410, a 420 voltmeter, a 430 stainless steel grid, an electrode reference 440.
  • the electrolytic bath is constantly mixed with agitators 450.
  • the positive terminal of the stabilized power supply 410 is connected to the grid 430, while its negative terminal is connected to silver wool via, for example, the conductive holding frame 160 of a cassette 200.
  • the potential is measured using the 420 voltmeter between the electrode reference 440 and the silver wool via the retaining frame 160.
  • the cassette 200 is fully immersed in the electrolytic bath.
  • the nature of the electrolysis bath can be a solution of carbonate (Na 2 CO 3 ), sodium or potassium sulphate (Na 2 SO4, K 2 SO4) of sodium chloride (NaCI), etc., with a concentration between 0.1 and 1 mol / l, in pH ranges between 6 and 8.
  • Electrolysis currents to cathodically activate a cassette 200 such as the one whose characteristics were specified above is lie in a range from 100 mA to 1A.
  • the amount of current (or the duration of electrolysis) is related to the quantity of product to be treated.
  • a wool sample is shown cathodically activated 162 and a sample of non-activated wool 164, after 4 min of sulfurization.
  • Cathodically activated wool 162 has been much darker during sulfurization than unactivated wool 164.
  • Cathodically activated wool 162 therefore fixed much more sulfur compounds as unactivated wool, which highlights the increased efficiency of cathodically activated silver wool 162 and the importance of the cathodic activation process.
  • Figure 11 also shows a wool sample cathodically activated 162 and a sample of non-activated wool 164, after 65 hours of sulfurization, the result is similar to the previous one, which shows that cathodic activation has a lasting effect.
  • these cassettes 200 can be fitted with saturation sensors.
  • These can be sensors optoelectronics, color-changing chemical sensors, electrochemical sensors, sensors sensitive to conductivity, pH or depression.
  • a saturation indicator 205 consisting of a transparent sight, is arranged on the face of the cassette 200, visible on the face 16 of the purification device 100. This look makes it possible to observe the content of metallic silver with a large specific surface, contained in the cassette 200 to check its saturation state. Such indicators of saturation 205 is not always necessary, as is the case, when procedures for systematic change of cassettes 200 are drawn up after preliminary study.
  • the fixing of sulfur compounds can be carried out by circulation gas from the enclosure 300 into the purification device 100 introduced therein.
  • This purification device 100 does not put air in the enclosure 300 (display case exposure for example) in depression and therefore does not cause perpetual introduction of pollutants.
  • cassettes 210 for filtering dust or cassettes 220, 230 containing various filters capable of specifically fixing other species pollutants or even humidity can contain other filter substances than activated metallic silver cathodically.
  • These substances are for example activated carbon, zeolites, carbonate pellets or alkali hydroxides (with retention for deliquescent products), zinc oxide, sieves molecular, etc.
  • the 200 cassettes are extracted from their packaging waterproof and slid into slide rack supports.
  • the device treatment plant 100 is then energized and an optional hour meter is triggered.
  • cassettes 200 After a certain operating time (for example after 6 months), an in-depth expertise can be carried out on the content of cassettes 200.
  • Additional control and measurement devices can also be installed for the establishment of this in-depth diagnosis, in order to optimize the operation of the purification device 100 according to the invention, as a means for fixing sulfur compounds and so to prevent tarnishing and corrosion of silver metallic objects.
  • a purification device 100 is particularly suitable for eliminate polluting gaseous molecules from the gases supplying the atmosphere of display cases.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Chemically Coating (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Catalysts (AREA)
  • Gas Separation By Absorption (AREA)

Abstract

The invention relates to a method for preserving and conserving silver-plated objects (1), according to which the objects (1) are placed in an atmosphere of desulfurized gas. The invention is characterized in that the gas is desulfurized by contact with cathodically activated silver metal.

Description

L'invention concerne le domaine de la protection et de la conservation d'objets métalliques argentés. Le procédé selon l'invention permet d'épurer des gaz destinés à constituer l'environnement de ces objets. Le procédé selon l'invention est mis en oeuvre, par exemple, pour protéger et conserver de tels objets pendant que ceux-ci sont exposés au public.The invention relates to the field of protection and conservation of silver metallic objects. The method according to the invention allows to purify gases intended to constitute the environment of these objects. The method according to the invention is implemented, for example, for protect and conserve such objects while they are exposed to public.

Il est connu que les composés soufrés au contact de l'argent forment des sulfures d'argent responsables du ternissement et de la corrosion des objets argentés.It is known that sulfur compounds in contact with silver form silver sulfides responsible for tarnishing and corrosion of silver objects.

Dans le tableau 1, figurent les principales espèces polluantes dans l'atmosphère, responsables du ternissement de l'argent, ainsi que leur concentration respective. D'après FRANEY (1985): « The corrosion of silver by atmospheric sulfurous gases », Corrosion Science, Vol 25, n°2. Polluants OCS SO2 H2S CS2 Concentration Moyenne En ppb 0,5 0,1 0,03 0,03 Table 1 shows the main air polluting species responsible for tarnishing silver, as well as their respective concentrations. According to FRANEY (1985): "The corrosion of silver by atmospheric sulfurous gases", Corrosion Science, Vol 25, n ° 2. pollutants SCO SO 2 H 2 S CS 2 Average Concentration In ppb 0.5 0.1 0.03 0.03

Le sulfure de carbonyle, OCS, est le principal polluant identifié, c'est aussi le plus réactif, devant H2S, SO2 puis CS2. La sulfuration de l'argent est de plus très sensible à l'humidité de l'air car la présence de quelques mono-couches d'eau à la surface du métal suffit à hydrolyser OCS, à dissoudre et à dissocier H2S permettant la réaction : 4Ag + 2HS-™ 2Ag2S + H2 + 2e- Carbonyl sulfide, OCS, is the main pollutant identified, it is also the most reactive, ahead of H 2 S, SO 2 then CS 2 . The sulphurization of silver is moreover very sensitive to humidity of the air because the presence of a few monolayers of water on the surface of the metal is sufficient to hydrolyze OCS, to dissolve and dissociate H 2 S allowing the reaction: 4Ag + 2HS - ™ 2Ag 2 S + H 2 + 2e -

Cette réaction est responsable du noircissement, du ternissement et de la corrosion de l'argent.This reaction is responsible for the darkening, tarnishing and corrosion of silver.

Cette corrosion par les polluants soufrés altère les propriétés électriques des contacts en argent qui sont encore nombreux en connectique. De même, le noircissement d'objets en métal argenté tel que bijoux, instruments de musique, daguerréotype, les services de table, objets d'art et d'archéologie, etc., est un problème très gênant vis à vis de l'esthétique et de leur présentation au public, mais aussi, à terme, vis à vis de l'intégrité de ces objets ou de ces oeuvres eux-mêmes, surtout lorsque les épaisseurs d'argent métallique sont très faibles (daguerréotype, pellicule d'argent sur des cadres en bois de tableaux, argenture électrolytique d'instruments de musique, etc.).This corrosion by sulfur pollutants alters the properties silver contacts which are still numerous in connectivity. Similarly, the blackening of silver metal objects such as jewelry, musical instruments, daguerreotype, tableware, objects of art and archeology, etc., is a very embarrassing problem with regard to aesthetics and their presentation to the public, but also, ultimately, vis-à-vis the integrity of these objects or works themselves, especially when the metallic silver thicknesses are very low (daguerreotype, film silver on wooden picture frames, electroplating musical instruments, etc.).

Pour empêcher l'altération des surfaces argentées, deux grandes catégories de parades sont utilisées :

  • a - l'élimination totale des espèces chimiques polluantes dans l'environnement de l'objet métallique argenté ; dans cette catégorie entrent des procédés souvent lourds et très onéreux, tels que l'inertage, qui consiste à mettre l'enceinte qui contient l'objet sous gaz neutre (azote par exemple) après avoir purgé le volume ; dans cette catégorie entre une autre parade qui consiste à disposer dans les enceintes contenant les objets à protéger, des diffuseurs de produits inhibiteurs du ternissement de l'argent ; mais ces inhibiteurs sont volatiles et présentent quelques inconvénients, tels que l'absence de témoin d'épuisement et l'absence de données sur leur innocuité vis à vis de matériaux constitutifs des objets à protéger (bois, ivoire, nacre, liège, peinture, etc) ;
  • b - une barrière physique entre l'objet et son environnement ; dans cette deuxième catégorie entrent par exemple les vernis, l'encapsulage et l'ensachage ; la pose d'un vernis consomme à peu près 50% du temps de restauration des objets et provoque des corrosions différentielles très inesthétiques, lorsqu'il y a des défauts ou des lacunes dans le vernis ; l'encapsulage et l'ensachage ne peuvent pas constituer non plus une solution universelle; ils ne peuvent, par exemple, pas convenir pour l'exposition au public des objets ainsi protégés.
    • To prevent damage to silver surfaces, two main categories of displays are used:
  • a - the total elimination of polluting chemical species from the environment of the silver metallic object; in this category fall often heavy and very expensive processes, such as inerting, which consists in putting the enclosure which contains the object under neutral gas (nitrogen for example) after having purged the volume; in this category between another parade which consists in having in the enclosures containing the objects to be protected, diffusers of products inhibiting the tarnishing of silver; but these inhibitors are volatile and have some drawbacks, such as the absence of exhaustion control and the absence of data on their harmlessness with regard to materials constituting the objects to be protected (wood, ivory, mother-of-pearl, cork, paint, etc);
  • b - a physical barrier between the object and its environment; this second category includes, for example, varnishes, encapsulation and bagging; the installation of a varnish consumes approximately 50% of the time of restoration of the objects and causes very unsightly differential corrosions, when there are defects or gaps in the varnish; encapsulation and bagging cannot be a universal solution either; they cannot, for example, be suitable for the exhibition to the public of objects thus protected.

    • Le but de la présente invention est de fournir un procédé de conservation des objets argentés qui ne présente pas les inconvénients relevés ci-dessus, et qui est néanmoins d'une très grande efficacité.The object of the present invention is to provide a method of conservation of silver objects which does not have the disadvantages noted above, and which is nevertheless very effective.

    Plus précisément, l'invention est un procédé de préservation et conservation d'objets argentés comprenant l'étape de conditionner les objets sous atmosphère désoufrée caractérisé en ce que l'on désoufre l'atmosphère au contact d'argent métallique activé cathodiquement.More specifically, the invention is a method of preserving and conservation of silver objects including the step of conditioning the objects in a desulfurized atmosphere characterized in that one desulfurizes the atmosphere in contact with cathodically activated metallic silver.

    D'autres aspects, buts et avantages de l'invention apparaítront à la lecture de la description détaillée qui suit.Other aspects, objects and advantages of the invention will become apparent from reading of the detailed description which follows.

    On comprendra aussi mieux l'invention à l'aide des références aux dessins annexés, sur lesquels :

    • la figure 1 est une représentation, en perspective, avec arrachement partiel d'une paroi de côté et du dos, d'une vitrine d'exposition d'objets argentés, dont l'atmosphère est désoufrée par le procédé selon l'invention ;
    • la figure 2 représente schématiquement, en coupe longitudinale, un exemple d'enceinte compatible avec l'utilisation du procédé selon l'invention ;
    • la figure 3 représente schématiquement, en coupe longitudinale un autre exemple d'enceinte compatible avec l'utilisation du procédé selon l'invention ;
    • la figure 4 illustre schématiquement encore un autre exemple de mise en oeuvre du procédé selon l'invention ;
    • la figure 5 représente en perspective un exemple d'appareil d'épuration pour la mise en oeuvre du procédé selon l'invention ;
    • la figure 6 représente schématiquement, une coupe longitudinale de l'appareil d'épuration représenté à la figure 5 ;
    • la figure 7 représente schématiquement deux exemples de positions possibles pour placer un appareil d'épuration tel que celui représenté sur les figures 5 et 6 ; sur la figure 7a, des volets placés à la sortie de cet appareil sont orientés vers le haut ; sur la figure 7b, ces volets sont orientés vers le bas ;
    • la figure 8 représente schématiquement la structure et l'agencement d'une cassette pour la mise en oeuvre du procédé selon l'invention ;
    • la figure 9 représente schématiquement un dispositif pour activer cathodiquement l'argent métallique nécessaire à la mise en oeuvre du procédé selon l'invention ;
    • la figure 10 est une photographie de deux échantillons de laine d'argent soumis à sulfuration, pendant 4 mn ; l'un des échantillons a été préalablement activé cathodiquement et l'autre pas ; et
    • la figure 11 est une photographie de deux échantillons de laine d'argent soumis à sulfuration pendant 65 heures ; l'un des échantillons a été préalablement activé cathodiquement, l'autre pas,
    The invention will also be better understood using the references to the appended drawings, in which:
    • Figure 1 is a perspective representation, with partial cutaway of a side wall and back, a display case for silver objects, whose atmosphere is desulfurized by the method according to the invention;
    • FIG. 2 schematically represents, in longitudinal section, an example of an enclosure compatible with the use of the method according to the invention;
    • FIG. 3 schematically represents, in longitudinal section, another example of an enclosure compatible with the use of the method according to the invention;
    • FIG. 4 schematically illustrates yet another example of implementation of the method according to the invention;
    • FIG. 5 shows in perspective an example of a purification device for implementing the method according to the invention;
    • Figure 6 shows schematically a longitudinal section of the purification device shown in Figure 5;
    • FIG. 7 schematically represents two examples of possible positions for placing a purification device such as that shown in FIGS. 5 and 6; in FIG. 7a, flaps placed at the outlet of this device are oriented upwards; in FIG. 7b, these flaps are oriented downwards;
    • FIG. 8 schematically represents the structure and the arrangement of a cassette for implementing the method according to the invention;
    • FIG. 9 schematically represents a device for cathodically activating the metallic silver necessary for implementing the method according to the invention;
    • FIG. 10 is a photograph of two samples of silver wool subjected to sulfurization, for 4 min; one of the samples was previously activated cathodically and the other not; and
    • Figure 11 is a photograph of two silver wool samples subjected to sulfurization for 65 hours; one of the samples has been cathodically activated beforehand, the other not,

    Dans le procédé selon l'invention, une matière composée d'argent métallique permet de piéger des composés soufrés susceptibles de se trouver dans un gaz destiné à former l'atmosphère d'objets argentés 1 à protéger, avant que ce gaz n'arrive au contact de ces objets 1.In the process according to the invention, a material composed of silver metallic allows to trap sulfur compounds likely to be find in a gas intended to form the atmosphere of silver objects 1 to protect, before this gas comes into contact with these objects 1.

    Pour accroítre l'efficacité de ce procédé, l'argent métallique est préférentiellement mis sous une forme présentant une grande surface spécifique. Plus cette surface est développée, plus la surface de piégeage des composés soufrés est importante. Ceci permet à la fois de favoriser les échanges avec le gaz et d'augmenter la quantité de molécules pouvant être piégées avant d'atteindre la saturation de cette surface vis à vis des réactions de sulfuration.To increase the efficiency of this process, metallic silver is preferably put in a form having a large surface specific. The more this surface is developed, the more the trapping surface sulfur compounds is important. This both promotes exchanges with the gas and increase the quantity of molecules that can be trapped before reaching the saturation of this surface with respect to sulfurization reactions.

    Selon un mode de mise en oeuvre particulier du procédé selon l'invention, les objets argentés 1 à protéger sont placés dans une enceinte 300, afin de confiner l'atmosphère environnant ces objets argentés 1 (figure 1). Mais on peut aussi envisager de placer ces objets 1 sous un flux de gaz désoufré. Lorsque les objets argentés 1 sont placés dans une enceinte 300, l'atmosphère de celle-ci est maintenue en surpression par rapport à l'extérieur de l'enceinte 300. De cette manière, on peut utiliser des enceintes 300 d'étanchéité limitée, et donc moins difficiles à réaliser et moins coûteuses que des enceintes 300 étanches. La surpression à l'intérieur de l'enceinte 300 limite la pénétration de gaz non désoufré par les interstices de celle-ci.According to a particular embodiment of the method according to the invention, the silver objects 1 to be protected are placed in an enclosure 300, in order to confine the atmosphere surrounding these silver objects 1 (figure 1). But we can also consider placing these objects 1 under a gas flow désoufré. When the silver objects 1 are placed in an enclosure 300, the atmosphere thereof is maintained at overpressure relative to outside the enclosure 300. In this way, it is possible to use enclosures 300 of limited sealing, and therefore less difficult to produce and less expensive than 300 waterproof enclosures. Overpressure at the interior of the enclosure 300 limits the penetration of gas which has not been removed by the interstices of it.

    Préférentiellement, le gaz est désoufré avant ou à son entrée dans l'enceinte.Preferably, the gas is de-fumed before or at its entry into the enclosure.

    Selon une variante du procédé selon l'invention, on peut utiliser un appareil d'épuration 100 puis acheminer le gaz désoufré par l'appareil d'épuration 100 jusqu'à l'enceinte 300 par un conduit 150 approprié (voir figure 2).According to a variant of the method according to the invention, one can use a purification device 100 then convey the gas desulfured by the device treatment plant 100 to enclosure 300 by a suitable conduit 150 (see figure 2).

    Selon une autre variante, l'argent métallique de piégeage des composés soufrés est placé dans une cassette 200, à une ouverture d'entrée 310 du gaz dans l'enceinte 300, alors qu'un ventilateur 50 est situé dans une ouverture de sortie 320 du gaz de l'enceinte 300. De cette manière, le gaz est aspiré dans l'enceinte 300 et désoufré à son entrée alors qu'il est extrait de l'enceinte 300 par le ventilateur 50 (figure 3),According to another variant, the metallic silver for trapping sulfur compounds is placed in a 200 cassette, at an opening inlet 310 of the gas into the enclosure 300, while a fan 50 is located in an outlet opening 320 for gas from the enclosure 300. From this way, the gas is sucked into the enclosure 300 and fumed at its entry while it is extracted from the enclosure 300 by the fan 50 (FIG. 3),

    Selon encore une autre variante du procédé selon l'invention, l'argent métallique de piégeage des composés soufrés est placé dans une cassette 200 de manière à être à la fois balayées par le gaz entrant dans l'enceinte 300 et par une partie du gaz de l'enceinte 300 (figure 4). De cette manière, le gaz de l'enceinte 300 subit un recyclage.According to yet another variant of the method according to the invention, silver metallic trap for sulfur compounds is placed in a cassette 200 so as to be both swept by the gas entering the enclosure 300 and by part of the gas from the enclosure 300 (FIG. 4). In this way, the gas in enclosure 300 undergoes recycling.

    Le procédé selon l'invention peut aussi être mis en oeuvre en disposant de l'argent métallique activé cathodiquement, en plusieurs endroits de l'enceinte 300. Par exemple, de l'argent métallique activé cathodiquement peut être disposé de manière à désoufrer le gaz entrant dans l'enceinte 300, tandis qu'une autre quantité d'argent métallique activé cathodiquement peut être disposée ailleurs dans l'enceinte 300 pour désoufrer le gaz recyclé de cette enceinte 300.The method according to the invention can also be implemented by having metallic silver activated cathodically, in several locations in enclosure 300. For example, activated metallic silver cathodically can be arranged in such a way as to desorb the incoming gas in enclosure 300, while another amount of activated metallic silver cathodically can be placed elsewhere in enclosure 300 to desulfurize the recycled gas from this enclosure 300.

    Selon un mode de mise en oeuvre préférentiel du procédé selon l'invention, l'enceinte 300 est une vitrine. Comme l'illustre la figure 1, dans ce cas, l'enceinte 300 comprend une vitre 305, derrière laquelle sont exposés les objets argentés 1, sur une étagère 5. Un appareil d'épuration 100 est placé dans la vitrine 300, avec une grille d'entrée 12 communiquant avec l'extérieur de cette vitrine 300. Ainsi, le gaz à épurer pénètre dans l'appareil 100, traverse une cassette extractible 200 contenant l'argent métallique cathodiquement activé et vient constituer l'environnement des objets argentés 1 à protéger (flèche en traits discontinus). En traversant la cassette 200, les composés soufrés sont retenus sur l'argent métallique cathodiquement activé. L'environnement des objets argentés exposés dans la vitrine 300 est ainsi désoufré. According to a preferred embodiment of the method according to the invention, the enclosure 300 is a showcase. As illustrated in Figure 1, in in this case, the enclosure 300 comprises a window 305, behind which are exposed silver objects 1, on a shelf 5. A purification device 100 is placed in the display case 300, with an entry grid 12 communicating with the outside of this display case 300. Thus, the gas to be purified enters the apparatus 100, passes through an extractable cassette 200 containing the silver cathodically activated metal and constitutes the environment for silver objects 1 to be protected (arrow in broken lines). Crossing the cassette 200, the sulfur compounds are retained on metallic silver cathodically activated. The environment of silver objects exhibited in the display case 300 is thus removed.

    L'appareil d'épuration 100 pour la mise en oeuvre du procédé selon l'invention peut être modulable en puissance d'extraction et de circulation de l'air. Donc ces dimensions sont variables, selon que l'on veut épurer une enceinte d'un volume de 1 à 10 m3 ou un local de stockage clos de plusieurs dizaines de mètres cubes.The purification device 100 for implementing the method according to the invention can be adjustable in terms of extraction power and air circulation. So these dimensions are variable, depending on whether you want to purify an enclosure with a volume of 1 to 10 m 3 or an enclosed storage room of several tens of cubic meters.

    Selon un mode de réalisation préférentiel de l'appareil d'épuration 100, celui-ci est un petit module. Il comporte essentiellement un capot 30 étanche, un ventilateur 50 extracteur et des cassettes extractibles 200, 210, 220, 230 (figures 5 et 6).According to a preferred embodiment of the purification device 100, this one is a small module. It essentially comprises a cover 30 sealed, extractor fan 50 and extractable cassettes 200, 210, 220, 230 (Figures 5 and 6).

    Le capot 30 est globalement un parallèpipède rectangle allongé. Les deux faces de ce parallèlipède, perpendiculaires à son axe longitudinal, forment respectivement la face d'entrée 10 et la face de sortie 20 de l'appareil d'épuration 100. La face d'entrée 10 est munie d'une grille d'entrée 12 du gaz vicié. La face de sortie 20 est munie de volets 22. L'une 14 des faces perpendiculaires à la face d'entrée 10 et à la face de sortie 20 est munie d'une poignée 40. Une 16 des faces perpendiculaires à la face d'entrée 10 et la face de sortie 20, adjacente à la face 14 munie de la poignée 40, comprend des ouvertures aptes à recevoir les cassettes 200, 210, 220, 230. Eventuellement, une prise d'alimentation électrique 60 et un interrupteur 70 sont disposés sur cette même face 16. Selon un mode particulier, mais non limitatif de l'invention, la face d'entrée 10 et la face de sortie 20 ont pour dimensions approximatives 130 mm x 160 mm.The cover 30 is generally an elongated rectangular parallelepiped. The two faces of this parallelepiped, perpendicular to its longitudinal axis, respectively form the inlet face 10 and the outlet face 20 of the purification device 100. The inlet face 10 is provided with a grid inlet 12 for stale gas. The outlet face 20 is provided with flaps 22. One 14 of the faces perpendicular to the inlet face 10 and to the outlet face 20 is provided with a handle 40. One 16 of the faces perpendicular to the face inlet 10 and outlet face 20, adjacent to face 14 provided with the handle 40, includes openings suitable for receiving the cassettes 200, 210, 220, 230. Optionally, an electrical power outlet 60 and a switch 70 are arranged on this same face 16. According to a mode particular, but not limiting of the invention, the input face 10 and the face of outlet 20 have the approximate dimensions 130 mm x 160 mm.

    Le ventilateur 50 est alimenté électriquement et assure l'extraction et la circulation de l'air. Comme représenté sur la figure 6, ce ventilateur 50 est situé à l'intérieur du capot 30, à proximité de la face de sortie 20. Ce ventilateur 50 met en dépression l'ensemble des cassettes extractibles 200, 210, 220, 230 placées en amont de celui-ci. Le ventilateur 50 diffuse le gaz purifié vers les volets 22.The fan 50 is electrically powered and ensures the extraction and air circulation. As shown in FIG. 6, this fan 50 is located inside the cover 30, near the outlet face 20. This fan 50 puts all of the extractable cassettes 200 under vacuum, 210, 220, 230 placed upstream of it. Fan 50 diffuses gas purified to flaps 22.

    Préférentiellement, pour traiter une vitrine fermée de 25 m3, on disposera d'un ventilateur 50 dont les dimensions approximatives sont de 119 x 119 x 32 mm3. Il sera alimenté par un courant continu sous une tension de 12 volts (délivrée par une batterie pour un appareil autonome ou par un transformateur branché sur 220 volts secteur) pour une puissance de 1,2 W (1 550 tr/mn). Son débit sera alors de 95 m3/h environ. Il aura un niveau de bruit de 30 dB.Preferably, to treat a closed showcase of 25 m 3 , we will have a fan 50 whose approximate dimensions are 119 x 119 x 32 mm 3 . It will be powered by direct current at a voltage of 12 volts (delivered by a battery for a stand-alone device or by a transformer connected to 220 volts mains) for a power of 1.2 W (1,550 rpm). Its flow will then be around 95 m 3 / h. It will have a noise level of 30 dB.

    Selon une variante de l'appareil d'épuration 100, celui-ci peut comporter un dispositif à volets 22 orientés vers le haut pour assurer la mise en circulation de l'air de l'enceinte 300, lorsque par exemple, l'appareil 100 est disposé sur la paroi inférieure de l'enceinte 300 (figure 7a).According to a variant of the purification device 100, it can include a flap device 22 oriented upwards to ensure the air circulation of the enclosure 300, when for example, the apparatus 100 is arranged on the bottom wall of the enclosure 300 (FIG. 7a).

    Réciproquement, les volets 22 peuvent être orientés vers le bas lorsque l'appareil d'épuration 100 est posé en hauteur (figure 7b).Conversely, the flaps 22 can be oriented downwards when the purification device 100 is placed at a height (FIG. 7b).

    Avec une orientation adaptée des volets 22, le recyclage préférentiel de l'air à proximité de l'appareil d'épuration 100 est minimisé.With an adapted orientation of the flaps 22, the preferential recycling air near the purification device 100 is minimized.

    Pour améliorer la circulation de l'air purifié dans l'enceinte 300, il peut être avantageux d'équiper l'appareil d'épuration 100, de volets 22 oscillants grâce à un moteur.To improve the circulation of purified air in enclosure 300, it can be advantageous to equip the purification device 100 with oscillating flaps 22 thanks to a motor.

    Selon une autre variante de l'appareil d'épuration 100, celui-ci est portatif.According to another variant of the purification device 100, it is portable.

    Selon encore une autre variante, l'appareil d'épuration 100 peut comprendre des roulettes pour faciliter sont transport.According to yet another variant, the purification device 100 can include casters to facilitate transport.

    L'appareil d'épuration 100 comprend au moins une cassette 200 contenant de l'argent métallique activé cathodiquement qui, de manière avantageuse, a une grande surface spécifique. Cet argent est scus forme de laine, de feutre ou de mousse d'argent. Cet argent fixe les composés soufrés. Il peut-être livré sous forme de consommable en sachets étanches en matière plastique.The purification device 100 comprises at least one cassette 200 containing cathodically activated metallic silver which advantageously has a large surface specific. This silver is in the form of wool, felt or foam silver. This money fixes the sulfur compounds. It can be delivered as of consumable in waterproof plastic bags.

    Comme représenté sur la figure 8, l'argent est par exemple sous forme de laine compactée 150 Cette laine 150 est insérée dans une armature de maintien 160. L'ensemble constitué de l'armature 160 et de la laine 150 est introduit dans l'apparel d'épuration 100 grâce à des rails de coulissement 170 fixés horizontalement dans ce dernier.As shown in Figure 8, the money is for example under form of compacted wool 150 This wool 150 is inserted into a retaining frame 160. The assembly consisting of frame 160 and the wool 150 is introduced into the purification device 100 by means of rails sliding 170 fixed horizontally in the latter.

    Dans une autre variante, la cassette 200 chargée de laine, de feutre ou de mousse d'argent cathodiquement activé, est elle-même livrée sous forme de consommable, en sachets étanches en matière plastique. Une telle cassette peut d'ailleurs être renvoyée au fabricant qui peut juger de l'opportunité de réactiver cathodiquement son contenu (dans le cadre d'un contrat de maintenance, par exemple). In another variant, the cassette 200 loaded with wool, felt or cathodically activated silver foam, is itself delivered under form of consumable, in waterproof plastic bags. A such cassette can also be returned to the manufacturer who can judge the opportunity to cathodically reactivate its content (in the context of a maintenance contract, for example).

    L'activation cathodique d'une cassette 200 s'effectue donc sur des cassettes 200 neuves ou à recycler.The cathodic activation of a cassette 200 is therefore carried out on 200 new cassettes or to recycle.

    La laine, le feutre ou la mousse d'argent est constitué d'argent purifié à 99,9 % ou d'un alliage où la concentration de l'argent est supérieure ou égale à 90%.Wool, felt or silver foam consists of purified silver 99.9% or an alloy where the concentration of silver is higher or equal to 90%.

    La surface spécifique de la laine, du feutre ou de la mousse d'argent est approximativement de 100 cm2/g.The specific surface of wool, felt or silver foam is approximately 100 cm 2 / g.

    Une cassette 200 pour l'appareil d'épuration 100 contient préférentiellement 10g d'argent, ce qui représente une surface totale d'argent déployé d'environ 1000 cm2. Une telle cassette 200 peut fixer 0,1g de sulfure.A cassette 200 for the purification device 100 preferably contains 10 g of silver, which represents a total surface area of deployed silver of approximately 1000 cm 2 . Such a cassette 200 can fix 0.1 g of sulfide.

    La cinétique de formation d'Ag2S est rapide jusqu'à ce que l'on en ait formé environ 100 nm d'épaisseur, puis cette cinétique devient lente jusqu'à la saturation.The kinetics of formation of Ag 2 S is rapid until approximately 100 nm thick has been formed, then this kinetics becomes slow until saturation.

    Ainsi, si l'on veut maintenir une efficacité maximale des cassettes 200, il faut conserver une cinétique rapide et changer ou réactiver les cassettes 200 avant passage à une cinétique lente. Dans ce dernier cas, la longévité d'une cassette 200 ayant les caractéristiques décrites dans les quatre paragraphes précédents, est estimée à un an environ, dans une atmosphère ayant un taux d'H2S de l'ordre de 0,5 ppm.Thus, if one wishes to maintain maximum efficiency of the cassettes 200, it is necessary to maintain rapid kinetics and to change or reactivate cassettes 200 before switching to slow kinetics. In the latter case, the longevity of a cassette 200 having the characteristics described in the preceding four paragraphs, is estimated at approximately one year, in an atmosphere having a level of H 2 S of the order of 0.5 ppm.

    Le procédé d'activation cathodique, mis en oeuvre pour activer l'argent métallique destiné à un usage dans un appareil d'épuration 100 comprend les étapes consistant à :

    • dépoussiérer, la laine, le feutre ou la mousse d'argent brut de réception par soufflage puis trempage dans un bain aqueux de tensioactifs avec des ultrasons ;
    • dégraisser dans de l'acétone ;
    • rincer dans de l'éthanol et de l'eau ;
    • immerger dans une cellule électrolytique 400 à trois électrodes avec un électrolyte neutre, cet argent métallique ou une cassette 200 contenant cet argent métallique ;
    • procéder à un balayage cathodique en potentiel avec enregistrement de l'intensité en fonction du potentiel, de la solution électrolytique à température ambiante, depuis un potentiel d'immersion jusqu'au potentiel de réduction des polluants présents à la surface de l'argent ;
    • réduire totalement, à température ambiante, les espèces par maintien potentiostatique au potentiel de réduction ;
    • rincer, sécher rapidement, conditionner sous gaz neutre et encapsuler sous feuilles de matière plastique thermo-soudées étanches, l'argent métallique ou bien encore la cassette 200 contenant cet argent métallique.
    The cathodic activation process, implemented to activate metallic silver intended for use in a purification apparatus 100 comprises the steps consisting in:
    • dust, wool, felt or raw silver foam for reception by blowing then soaking in an aqueous bath of surfactants with ultrasound;
    • degrease in acetone;
    • rinse in ethanol and water;
    • immerse in a three-electrode electrolytic cell 400 with a neutral electrolyte, this metallic silver or a cassette 200 containing this metallic silver;
    • carry out a potential cathodic scan with recording of the intensity as a function of the potential, of the electrolytic solution at ambient temperature, from an immersion potential to the potential for reduction of the pollutants present on the surface of the silver;
    • completely reduce the species at room temperature by maintaining the potentiostatic potential for reduction;
    • rinse, dry quickly, condition under neutral gas and encapsulate under sheets of waterproof thermo-welded plastic, metallic silver or else the cassette 200 containing this metallic silver.

    Le montage électrochimique pour la mise en oeuvre du procédé d'activation cathodique de l'argent est représenté sur la figure 9. Ce montage comprend préférentiellement une cellule électrolytique 400 contenant un bain électrolytique, une alimentation stabilisée 410, un voltmètre 420, une grille en acier inoxydable 430, une électrode de référence 440. Le bain électrolytique est mélangé en permanence par des agitateurs 450.Electrochemical assembly for the implementation of the process cathodic activation of silver is shown in Figure 9. This mounting preferably includes an electrolytic cell 400 containing an electrolytic bath, a stabilized power supply 410, a 420 voltmeter, a 430 stainless steel grid, an electrode reference 440. The electrolytic bath is constantly mixed with agitators 450.

    La borne positive de l'alimentation stabilisée 410 est connectée à la grille 430, tandis que sa borne négative est connectée sur la laine d'argent via, par exemple, l'armature conductrice de maintien 160 d'une cassette 200. Le potentiel est mesuré grâce au voltmètre 420 entre l'électrode de référence 440 et la laine d'argent via l'armature de maintien 160.The positive terminal of the stabilized power supply 410 is connected to the grid 430, while its negative terminal is connected to silver wool via, for example, the conductive holding frame 160 of a cassette 200. The potential is measured using the 420 voltmeter between the electrode reference 440 and the silver wool via the retaining frame 160.

    Pendant les étapes d'activation électrochimique, la cassette 200 est immergée dans son intégralité dans le bain électrolytique. La nature du bain d'électrolyse peut être une solution de carbonate (Na2CO3), de sulfate de sodium ou potassium (Na2SO4, K2SO4) de chlorure de sodium (NaCI), etc., de concentration comprise entre 0,1 et 1 mol/l, dans des gammes de pH comprises entre 6 et 8.During the electrochemical activation steps, the cassette 200 is fully immersed in the electrolytic bath. The nature of the electrolysis bath can be a solution of carbonate (Na 2 CO 3 ), sodium or potassium sulphate (Na 2 SO4, K 2 SO4) of sodium chloride (NaCI), etc., with a concentration between 0.1 and 1 mol / l, in pH ranges between 6 and 8.

    Les courants d'électrolyse pour activer cathodiquement une cassette 200 telle que celle dont les caractéristiques ont été précisées plus haut se situent dans une gamme de 100 mA à 1A. La quantité de courant (ou la durée d'électrolyse) est en relation avec la quantité de produit à traiter.Electrolysis currents to cathodically activate a cassette 200 such as the one whose characteristics were specified above is lie in a range from 100 mA to 1A. The amount of current (or the duration of electrolysis) is related to the quantity of product to be treated.

    Pour mettre en évidence l'efficacité de l'activation cathodique pour la fixation préférentielle des sulfures d'argent, il a été effectué des essais accélérés de sulfuration de laines d'argent neuves. Ces essais ont été réalisés dans une enceinte close, étanche (cloche en verre), dans laquelle règne une atmosphère saturée en sulfure. Cette atmosphère est constituée d'un mélange de 20 cm3 d'eau et de 4 cm3 de sulfure d'ammonium (NH4)2 S à 20% en poids.To demonstrate the effectiveness of cathodic activation for the preferential fixation of silver sulfides, accelerated sulfurization tests of new silver wool were carried out. These tests were carried out in a closed, sealed enclosure (glass bell), in which an atmosphere saturated with sulphide prevails. This atmosphere consists of a mixture of 20 cm 3 of water and 4 cm 3 of ammonium sulfide (NH 4 ) 2 S at 20% by weight.

    Les résultats de ces essais sont représentés sur les figures 10 et 11,The results of these tests are shown in FIGS. 10 and 11,

    Sur la figure 10 sont représentés un échantillon de laine cathodiquement activée 162 et un échantillon de laine non activée 164, après 4 min de sulfuration. La laine cathodiquement activée 162 a été beaucoup plus noircie au cours de la sulfuration que la laine non activée 164. La laine cathodiquement activée 162 a donc fixé beaucoup plus de composés soufrés que la laine non activée, ce qui met en évidence l'efficacité accrue de la laine d'argent cathodiquement activée 162 et l'importance du procédé d'activation cathodique.In Figure 10 a wool sample is shown cathodically activated 162 and a sample of non-activated wool 164, after 4 min of sulfurization. Cathodically activated wool 162 has been much darker during sulfurization than unactivated wool 164. Cathodically activated wool 162 therefore fixed much more sulfur compounds as unactivated wool, which highlights the increased efficiency of cathodically activated silver wool 162 and the importance of the cathodic activation process.

    Sur la figure 11, sont aussi représentés un échantillon de laine cathodiquement activée 162 et un échantillon de laine non activée 164, après 65 heures de sulfuration, le résultat est similaire au précédent, ce qui montre que l'activation cathodique a un effet durable.Figure 11 also shows a wool sample cathodically activated 162 and a sample of non-activated wool 164, after 65 hours of sulfurization, the result is similar to the previous one, which shows that cathodic activation has a lasting effect.

    Selon une variante de ces cassettes 200, celles-ci peuvent être munies de capteurs de saturation. Il peut s'agir de capteurs optoélectroniques, de capteurs chimiques à changement de couleur, de capteurs électrochimiques, de capteurs sensibles à la conductivité, au pH ou à la dépression.According to a variant of these cassettes 200, these can be fitted with saturation sensors. These can be sensors optoelectronics, color-changing chemical sensors, electrochemical sensors, sensors sensitive to conductivity, pH or depression.

    Préférentiellement, un indicateur de saturation 205, constitué d'un regard transparent, est disposé sur la face de la cassette 200, visible sur la face 16 de l'appareil d'épuration 100. Ce regard permet d'observer le contenu de l'argent métallique à grande surface spécifique, contenu dans la cassette 200 pour vérifier son état de saturation. De tels indicateurs de saturation 205 ne sont cependant pas toujours nécessaires, comme c'est le cas, lorsque des procédures de changement systématique de cassettes 200 sont rédigées après étude préalable.Preferably, a saturation indicator 205, consisting of a transparent sight, is arranged on the face of the cassette 200, visible on the face 16 of the purification device 100. This look makes it possible to observe the content of metallic silver with a large specific surface, contained in the cassette 200 to check its saturation state. Such indicators of saturation 205 is not always necessary, as is the case, when procedures for systematic change of cassettes 200 are drawn up after preliminary study.

    La fixation des composés soufrés peut s'effectuer par la circulation du gaz de l'enceinte 300 dans l'appareil d'épuration 100 introduit dans celle-ci. Cet appareil d'épuration 100 ne met pas l'air de l'enceinte 300 (vitrine d'exposition par exemple) en dépression et ne provoque donc pas l'introduction perpétuelle de polluants.The fixing of sulfur compounds can be carried out by circulation gas from the enclosure 300 into the purification device 100 introduced therein. This purification device 100 does not put air in the enclosure 300 (display case exposure for example) in depression and therefore does not cause perpetual introduction of pollutants.

    Il est aussi concevable de disposer l'appareil d'épuration 100 à l'entrée d'une l'enceinte peu étanche, de façon à alimenter en gaz désoufré celle-ci, tout en provoquant une légère surpression empêchant l'entrée de la pollution.It is also conceivable to have the purification device 100 to the entrance to a poorly sealed enclosure, so as to supply desulfurized gas this, while causing a slight overpressure preventing entry of the pollution.

    L'appareil d'épuration 100 peut être conçu de façon modulaire :

    • en capacité volumique de traitement ; dans ce cas, les dimensions des cassettes 200 de traitement et du ventilateur 50 sont plus importantes ;
    • en capacité qualitative de traitement ; dans ce cas d'autres cassettes spécifiques sont installées grâce à un système de type « rack » dont peut disposer l'appareil d'épuration 100.
    The purification device 100 can be designed in a modular fashion:
    • in volume processing capacity; in this case, the dimensions of the treatment cassettes 200 and of the fan 50 are larger;
    • in qualitative processing capacity; in this case other specific cassettes are installed using a “rack” type system which the purification device 100 can have.

    On peut alors, outre les cassettes 200 d'argent métallique, disposer des cassettes 210 pour filtrer la poussière ou des cassettes 220, 230 contenant des filtres divers aptes à fixer spécifiquement d'autres espèces polluantes ou même l'humidité. Ces autres cassettes 210, 220, 230 peuvent contenir d'autres substances filtrantes que de l'argent métallique activé cathodiquement. Ces substances sont par exemple du charbon actif, des zéolithes, des pastilles de carbonate ou d'hydroxydes alcalins (avec bac de rétention pour les produits déliquescents), de l'oxyde de zinc, des tamis moléculaires, etc.We can then, in addition to the 200 metallic silver cassettes, have cassettes 210 for filtering dust or cassettes 220, 230 containing various filters capable of specifically fixing other species pollutants or even humidity. These other cassettes 210, 220, 230 can contain other filter substances than activated metallic silver cathodically. These substances are for example activated carbon, zeolites, carbonate pellets or alkali hydroxides (with retention for deliquescent products), zinc oxide, sieves molecular, etc.

    Pour être utilisées, les cassettes 200 sont extraites de leur emballage étanche et glissées dans des supports de rack à glissière. L'appareil d'épuration 100 est alors mis sous tension et un compteur horaire optionnel est déclenché.To be used, the 200 cassettes are extracted from their packaging waterproof and slid into slide rack supports. The device treatment plant 100 is then energized and an optional hour meter is triggered.

    Une surveillance régulière permet de s'assurer du bon fonctionnement de l'appareil d'épuration 100 et de repérer la saturation des cassettes pour les changer si nécessaire.Regular monitoring helps to ensure good operation of the purification device 100 and to identify the saturation of the cassettes to change them if necessary.

    Après un certain temps de fonctionnement (par exemple après 6 mois), une expertise approfondie peut être effectuée sur le contenu des cassettes 200. After a certain operating time (for example after 6 months), an in-depth expertise can be carried out on the content of cassettes 200.

    Cette expertise détermine la nature exacte des polluants, par exemple par microscopie électronique à balayage, couplée à la micro fluorescente X et à la diffraction de rayons X. Des solutions spécifiques, avec des cassettes 200, 210, 220, 230 spéciales, peuvent alors être proposées pour améliorer la purification de l'atmosphère de l'enceinte 300This expertise determines the exact nature of the pollutants, by example by scanning electron microscopy, coupled to the micro fluorescent X and X-ray diffraction. Specific solutions, with special cassettes 200, 210, 220, 230, can then be proposed to improve the purification of the atmosphere of enclosure 300

    Des dispositifs supplémentaires de contrôle et de mesure (télémesure de l'hygrométrie et de la température), peuvent aussi être installés pour l'établissement de ce diagnostic approfondi, ceci afin d'optimiser le fonctionnement de l'appareil d'épuration 100 selon l'invention, en tant que moyen pour fixer des composés soufrés et ainsi pour prévenir le ternissement et la corrosion d'objets métalliques argentés.Additional control and measurement devices (hygrometry and temperature telemetry), can also be installed for the establishment of this in-depth diagnosis, in order to optimize the operation of the purification device 100 according to the invention, as a means for fixing sulfur compounds and so to prevent tarnishing and corrosion of silver metallic objects.

    Un appareil d'épuration 100 est particulièrement approprié pour éliminer des molécules gazeuses polluantes des gaz alimentant l'atmosphère de vitrines d'exposition.A purification device 100 is particularly suitable for eliminate polluting gaseous molecules from the gases supplying the atmosphere of display cases.

    Claims (14)

    1. Method of preserving and conserving silver-plated objects (1) in which the objects (1) to be conserved are placed under an atmosphere comprising a desulphurized gas, characterized in that the gas is desulphurized on contact with cathodically activated metallic silver.
    2. Method according to Claim 1, characterized in that the metallic silver is in a form having a large specific surface area.
    3. Method according to either of the preceding claims, characterized in that the silver-plated objects (1) to be preserved and conserved are placed in a chamber (300).
    4. Method according to Claim 3, characterized in that the atmosphere of the chamber (300) is kept at an overpressure with respect to the outside of this chamber (300).
    5. Method according to either of Claims 3 and 4, characterized in that the gas of the chamber (300) is desulphurized before or on its entry into the chamber (300).
    6. Method according to any one of Claims 3 to 5, characterized in that the gas of the chamber (300) undergoes recycling.
    7. Method according to any one of Claims 3 to 6, characterized in that the chamber (300) is a display cabinet.
    8. Chamber for preserving and conserving silver-plated objects, characterized in that it comprises, placed inside, a purification apparatus making it possible to desulphurize the atmosphere of the chamber using cathodically activated metallic silver.
    9. Chamber for preserving and conserving silver-plated objects according to Claim 8, characterized in that its purification apparatus comprises at least one cassette (200) containing cathodically activated metallic silver.
    10. Chamber for preserving and conserving silver-plated objects according to either of Claims 8 and 9, characterized in that the cathodically activated metallic silver is in the form of wool (150).
    11. Chamber for preserving and conserving silver-plated objects according to either of Claims 9 and 10, characterized in that its purification apparatus (100) comprises cassettes (210, 220, 230) containing filtering substances other than cathodically activated metallic silver.
    12. Chamber for preserving and conserving silver-plated objects according to one of Claims 8 to 11, characterized in that its purification apparatus (100) is fitted with a saturation indicator (205) for the metallic silver.
    13. Chamber for preserving and conserving silver-plated objects according to Claim 12, characterized in that the saturation indicator (205) is a transparent peephole making it possible to observe the colour of the metallic silver.
    14. Chamber for preserving and conserving silver-plated objects according to one of Claims 8 to 13, characterized in that its purification apparatus (100) is portable.
    EP99900931A 1998-01-16 1999-01-15 Method for preserving silver-plated objects and filtering device for carrying out said method Expired - Lifetime EP1054721B1 (en)

    Applications Claiming Priority (3)

    Application Number Priority Date Filing Date Title
    FR9800420A FR2773821B1 (en) 1998-01-16 1998-01-16 PROCESS FOR THE PRESERVATION OF SILVER OBJECTS AND A PURIFICATION APPARATUS FOR IMPLEMENTING IT
    FR9800420 1998-01-16
    PCT/FR1999/000071 WO1999036161A1 (en) 1998-01-16 1999-01-15 Method for preserving silver-plated objects and filtering device for carrying out said method

    Publications (2)

    Publication Number Publication Date
    EP1054721A1 EP1054721A1 (en) 2000-11-29
    EP1054721B1 true EP1054721B1 (en) 2003-04-09

    Family

    ID=9521842

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP99900931A Expired - Lifetime EP1054721B1 (en) 1998-01-16 1999-01-15 Method for preserving silver-plated objects and filtering device for carrying out said method

    Country Status (6)

    Country Link
    EP (1) EP1054721B1 (en)
    AT (1) ATE236703T1 (en)
    DE (1) DE69906705T2 (en)
    ES (1) ES2191410T3 (en)
    FR (1) FR2773821B1 (en)
    WO (1) WO1999036161A1 (en)

    Families Citing this family (4)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    US6551552B1 (en) * 2000-09-27 2003-04-22 Cor/Sci Llc Systems and methods for preventing and/or reducing corrosion in various articles
    KR20040007265A (en) * 2002-07-12 2004-01-24 닛폰 에쿠스란 고교 가부시키가이샤 Discoloration inhibitor for metals
    NO20063247L (en) * 2006-07-12 2008-01-14 Norsk Hydro As Protection of process equipment having a significant vapor pressure by adding a vaporizing component to the gas in contact with said equipment
    FR2933879B1 (en) * 2008-07-15 2010-07-30 Saint Gobain Quartz Sas PARTICLE FILTER WITH MINERAL FILTER MEDIA

    Family Cites Families (2)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE2913329C2 (en) * 1979-04-03 1984-11-22 Dechema Deutsche Gesellschaft F. Chem. Apparatewesen E.V., 6000 Frankfurt Process for the separation of traces of gaseous pollutants based on sulfur from exhaust gases by chemical absorption
    US5451268A (en) * 1993-11-15 1995-09-19 Shepherd; Samuel L. Process for the removal of sulfur from silver

    Also Published As

    Publication number Publication date
    DE69906705D1 (en) 2003-05-15
    FR2773821A1 (en) 1999-07-23
    EP1054721A1 (en) 2000-11-29
    FR2773821B1 (en) 2000-04-07
    ES2191410T3 (en) 2003-09-01
    ATE236703T1 (en) 2003-04-15
    WO1999036161A1 (en) 1999-07-22
    DE69906705T2 (en) 2003-11-13

    Similar Documents

    Publication Publication Date Title
    US8925290B2 (en) Mask storage device for mask haze prevention and methods thereof
    Quevauviller et al. Occurrence of methylated tin and dimethyl mercury compounds in a mangrove core from Sepetiba Bay, Brazil
    Tétreault et al. Corrosion of copper and lead by formaldehyde, formic and acetic acid vapours
    EP2179236B1 (en) Method of treating a transport support for the atmospheric storage and conveyance of semiconductor substrates
    Chen et al. Influence of UV irradiation and ozone on atmospheric corrosion of bare silver
    Stoulil et al. Electrochemical properties of corrosion products formed on Zn‐Mg, Zn‐Al and Zn‐Al‐Mg coatings in model atmospheric conditions
    EP1054721B1 (en) Method for preserving silver-plated objects and filtering device for carrying out said method
    WO2007149513A4 (en) System for purging reticle storage
    WO2007135347A1 (en) Method and device for removing pollution from a confined environment
    Green et al. Determination of free and total copper and lead in wine by stripping potentiometry
    CN108352345B (en) Method and system for measuring contaminants of transport containers for atmospheric transport and storage of substrates
    FR2883412A1 (en) METHOD AND DEVICE FOR CONTROLLING THE CONTAMINATION OF SUBSTRATE PADS
    EP2588639A2 (en) Method for the surface treatment of a fluid product dispensing device
    JP2000294530A (en) Semiconductor substrate cleaning method and cleaning apparatus
    US7655473B2 (en) Method and device for determining the concentration of nitrite
    CN118067808A (en) A low-temperature hydrogen sulfide gas sensor for detecting the freshness of refrigerated meat and a preparation method thereof
    US11624740B2 (en) Protective enclosure for gas sensors
    FR2897941A1 (en) DEVICE AND METHOD FOR RAPID MICROBIOLOGICAL ANALYSIS.
    Wang et al. Silver doping of polycarbonate films for surface-enhanced Raman scattering
    EP3193157B1 (en) Device for measuring viscosity under inert atmosphere, analysis method and use
    FR2549229A1 (en) APPARATUS FOR MEASURING IMPURITIES IN ULTRAPURATED WATER
    Kanno et al. Passive ozone/oxidant sampler with coulometric determination using iodine/nylon-6 charge-transfer complex
    Rao et al. Synergetic effect of temperature and humidity on the leakage of KOH electrolyte and related reliability of zinc-air batteries
    Zeszut et al. Comparison of Atmospheric Corrosion of Silver Across Multiple Locations
    Sosnin et al. Excilamp application in the chemical sample pretreatment process

    Legal Events

    Date Code Title Description
    PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

    Free format text: ORIGINAL CODE: 0009012

    17P Request for examination filed

    Effective date: 20000731

    AK Designated contracting states

    Kind code of ref document: A1

    Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

    17Q First examination report despatched

    Effective date: 20020125

    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    GRAA (expected) grant

    Free format text: ORIGINAL CODE: 0009210

    AK Designated contracting states

    Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: FI

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030409

    Ref country code: CY

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030409

    REG Reference to a national code

    Ref country code: GB

    Ref legal event code: FG4D

    Free format text: NOT ENGLISH

    REG Reference to a national code

    Ref country code: CH

    Ref legal event code: EP

    GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

    Effective date: 20030409

    REG Reference to a national code

    Ref country code: IE

    Ref legal event code: FG4D

    Free format text: FRENCH

    REG Reference to a national code

    Ref country code: CH

    Ref legal event code: NV

    Representative=s name: MICHELI & CIE INGENIEURS-CONSEILS

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: SE

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030709

    Ref country code: PT

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030709

    Ref country code: DK

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030709

    REG Reference to a national code

    Ref country code: GR

    Ref legal event code: EP

    Ref document number: 20030402325

    Country of ref document: GR

    REG Reference to a national code

    Ref country code: ES

    Ref legal event code: FG2A

    Ref document number: 2191410

    Country of ref document: ES

    Kind code of ref document: T3

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: LU

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20040115

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: MC

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20040131

    PLBE No opposition filed within time limit

    Free format text: ORIGINAL CODE: 0009261

    STAA Information on the status of an ep patent application or granted ep patent

    Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

    26N No opposition filed

    Effective date: 20040112

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: IE

    Payment date: 20151218

    Year of fee payment: 18

    Ref country code: GR

    Payment date: 20151217

    Year of fee payment: 18

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: PLFP

    Year of fee payment: 18

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: NL

    Payment date: 20151214

    Year of fee payment: 18

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: ES

    Payment date: 20160126

    Year of fee payment: 18

    Ref country code: IT

    Payment date: 20160113

    Year of fee payment: 18

    Ref country code: CH

    Payment date: 20160106

    Year of fee payment: 18

    Ref country code: DE

    Payment date: 20160108

    Year of fee payment: 18

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: FR

    Payment date: 20160201

    Year of fee payment: 18

    Ref country code: BE

    Payment date: 20151224

    Year of fee payment: 18

    Ref country code: GB

    Payment date: 20160118

    Year of fee payment: 18

    Ref country code: AT

    Payment date: 20151222

    Year of fee payment: 18

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: BE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170131

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R119

    Ref document number: 69906705

    Country of ref document: DE

    REG Reference to a national code

    Ref country code: CH

    Ref legal event code: PL

    REG Reference to a national code

    Ref country code: NL

    Ref legal event code: MM

    Effective date: 20170201

    REG Reference to a national code

    Ref country code: AT

    Ref legal event code: MM01

    Ref document number: 236703

    Country of ref document: AT

    Kind code of ref document: T

    Effective date: 20170115

    GBPC Gb: european patent ceased through non-payment of renewal fee

    Effective date: 20170115

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: ST

    Effective date: 20170929

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: AT

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170115

    Ref country code: FR

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170131

    Ref country code: GR

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170811

    Ref country code: CH

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170131

    Ref country code: LI

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170131

    REG Reference to a national code

    Ref country code: IE

    Ref legal event code: MM4A

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: NL

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170201

    Ref country code: GB

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170115

    Ref country code: DE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170801

    REG Reference to a national code

    Ref country code: BE

    Ref legal event code: MM

    Effective date: 20170131

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: IT

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170115

    Ref country code: IE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170115

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: ES

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20170116

    REG Reference to a national code

    Ref country code: ES

    Ref legal event code: FD2A

    Effective date: 20180626