EP0099818B1 - Method of confining the pollution of an area by making use of an air curtain - Google Patents

Method of confining the pollution of an area by making use of an air curtain Download PDF

Info

Publication number
EP0099818B1
EP0099818B1 EP83401438A EP83401438A EP0099818B1 EP 0099818 B1 EP0099818 B1 EP 0099818B1 EP 83401438 A EP83401438 A EP 83401438A EP 83401438 A EP83401438 A EP 83401438A EP 0099818 B1 EP0099818 B1 EP 0099818B1
Authority
EP
European Patent Office
Prior art keywords
air
zone
curtain
gas
room
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
Application number
EP83401438A
Other languages
German (de)
French (fr)
Other versions
EP0099818A1 (en
Inventor
François Meline
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.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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 Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP0099818A1 publication Critical patent/EP0099818A1/en
Application granted granted Critical
Publication of EP0099818B1 publication Critical patent/EP0099818B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F9/00—Use of air currents for screening, e.g. air curtains
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F9/00—Use of air currents for screening, e.g. air curtains
    • F24F2009/007—Use of air currents for screening, e.g. air curtains using more than one jet or band in the air curtain
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S55/00—Gas separation
    • Y10S55/29—Air curtains

Definitions

  • the present invention relates to methods of confining a polluted room using a gas stream and more specifically relates to such a process which allows to have a very high ratio between the level of pollution of the room and the pollution level outside of it.
  • FIG. 1 An example of application of this method is illustrated in FIG. 1 in which we see, inside a cell 1, a vertical partition 2 defining a room 4 inside which is installed a machine 6 used for cutting of nuclear fuel elements.
  • the room 4 containing the machine 6 communicates with the rest of the cell through an opening 8.
  • the air from the vein 12 is taken up by a suction mouth 14 and sent in a circuit comprising a cyclone 16 and a fan 18.
  • a suction mouth 14 The air from the vein 12 is taken up by a suction mouth 14 and sent in a circuit comprising a cyclone 16 and a fan 18.
  • the air leaving the cyclone 16 is generally rejected outside the enclosure 1: as it still contains a certain amount of radioactive dust, it is necessary to filter it using an absolute filter 19 before it release into the atmosphere.
  • these filters constitute very expensive materials, their replacement is a long and delicate operation because of all the protections which are necessary due to the high activity of the dusts.
  • they constitute active waste which must be conditioned before their disposal. This is why it is in our interest to reduce the frequency of replacement. For this, only part of the air leaving the cyclone 16 is discharged to the outside, the other part being recycled into the nozzle 10.
  • An opening 22, formed in the wall 23 of the cell 1, allows the ventilation air entering the cell in order to replace the air extracted through the filter 19 by the fan 20.
  • the gas stream 12 is composed of two parts: a first part, called the "transition zone", extends over a length 1 from the slot 7 and includes a 'potential core' or 'dart' 13, consisting solely of air injected through the nozzle 10, and which has, seen, in section, the shape of a triangle of length 1, the latter being equal to approximately 6 times the width e of the injection slot.
  • the gas speed is the same at all points of the sting 13 and it is equal to the injection speed.
  • the second part of the gas stream 12 is a so-called 'full zone development of the jet "15 in which the air injected by the nozzle 10 mixes, by suction, with the air present in the cell 4 and in the clean zone 5 of the enclosure 1.
  • the zone of full development of the jet s 'extends beyond the point of the dart, from this point to the return mouth 14.
  • the zone 15 having a very turbulent regime, it sucks a large pa rtie of dust contained in cell 4 (arrows 9).
  • the concentration of the pollution in the zone 5 may be of the order of half of what it is in zone 4 whereas, in the nuclear industry in particular, a concentration ratio is desired that is as low as possible and generally less than 1/100.
  • the dust activates the fixed installations located in zone 5 of cell 1 and the cumulative contamination thus produced can be very significant after a certain time.
  • Document DE-A-3 004 073 describes a process for ventilating premises consisting in blowing a secondary air jet through an ejector disposed in the immediate vicinity of the primary air outlet: this has the effect of increasing the range of the primary jet which would otherwise be too low because the injection speed is relatively reduced.
  • This process can also be used to create an air curtain in front of a door or an opening, but, in the case of a polluted room, the dust may still escape outside for the reasons indicated more high.
  • the purpose of the present invention is to remedy these drawbacks by means of a method of confining the pollution of a room communicating with the outside by means of at least one opening of the type in which a first gas stream is circulated at the level of the opening, the dimensions of this first gas stream being such that it covers the entire surface of the opening, as well as a second gas stream adjacent to the first and located on the side opposite the room relative to the latter, there first gas stream consisting of a transition zone and a zone of full development of the jet, the transition zone comprising a dart.
  • it is given a length equal to the range of the first vein and the flow rates of the two gas streams are adjusted so that the air flow induced by the face of the second vein which is in contact with the first being substantially equal to the injection rate of the first vein.
  • the dart covering the entire surface of the opening 8 there is no longer any risk of seeing the dust pass outside the premises through the turbulent mixing zone.
  • the second gas stream its role is to stabilize the first. Indeed, for the dart to have a sufficient length, it is necessary that the width of the injection slot is equal to approximately 1 / 6th of the distance between the nozzle 10 and the suction mouth 14: this requires a low speed injection (because otherwise the flow would be prohibitive) which risks making the jet unstable.
  • the second gas stream creates a suction effect which presses the first vein against the second and stabilizes it.
  • the injection rate of the first vein is equal to the air flow which would have been drawn into the room if the second vein had been left alone: this prevents the first vein from being deformed by bending towards the wall lower part of room 4.
  • the second vein therefore sucks, in room 4, the injection air of the first vein mixed by turbulent diffusion with a small fraction of the polluted air of room 4. It also sucks the clean air being in the zone 5 of the cell 1: therefore, the air evacuated by the suction mouth 14 is very little polluted compared to the atmosphere of the room 4.
  • the air from the two gas streams is partially recycled after having taken it up through a suction mouth and passed over a purification device which can, for example, be a cyclone or a trickle tower.
  • a purification device which can, for example, be a cyclone or a trickle tower.
  • the energy necessary for the circulation of air is supplied by a circulation device which can be a fan, a compressor, an air ejector, etc.
  • the invention also relates to an application of this process to the confinement of a room containing radioactive dust created by the cutting of nuclear fuel elements.
  • the first gas stream 12 itself comprises a turbulent mixing zone 15 which sucks the air from the room 4 and therefore certain dusts contained in it (arrows 11). Part of this dust is therefore extracted through the mouth 14 while the other part is recycled into the room 4 by the induced current.
  • the air sucked in through the mouth 14 is much less polluted than with the methods of the prior art. It then suffices to pass the air sucked in through this mouth 14 over a cyclone to reduce its concentration and obtain in the part 5 of the cell a concentration of polluting dust significantly lower than that of the room 4.
  • FIG. 3 illustrates the application of the method according to the invention to the cell of FIG. 1.
  • cell 1 fitted with the partition 2 defining room 4 containing the machine 6.
  • This room is separated from the upper part 5 of the cell by a double curtain of air consisting of the first gas stream 12 leaving the nozzle 10 and the second stream 24 leaving the nozzle 25.
  • the air sucked in by the return outlet 14 is first sent to cyclone 16 which decreases its concentration of pollutants.
  • part of the air leaving cyclone 16 is evacuated to 1, outside of cell 1 by means of the fan 20 after passing over an absolute filter 19.
  • Another part is recycled thanks to the fan 18.
  • Part of this recycled air is sent to the nozzle 10 via a valve 32 and another part to the nozzle 25 via a valve 30.
  • the external fan 20 and the fan 18 provide a total flow of 44,350 m 3 / h in the return outlet 14 and the cyclone 16. This flow comes on the one hand from the two gas streams 12 and 24 for 25,350 m 3 / h and on the other hand fresh air entering through opening 22 for 19,000 m 3 / h.
  • the ratio of the concentrations of radioactive dust between room 4 and zone 5 of the cell is approximately 100, that is to say a value considerably higher than that which could be obtained with the processes. prior art.
  • the method according to the invention has particularly advantageous advantages since it makes it possible to considerably reduce the cumulative contamination outside the room 4.
  • the dust concentration of the air passing through the cyclone 16 and the absolute filter 19 is lowered, which reduces the operating cost of the installation by increasing the life of the filters 19.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cyclones (AREA)

Description

La présente invention se rapporte aux procédés de confinement d'un local pollué à l'aide d'une veine gazeuse et a plus spécialement pour objet un tel procédé qui permette d'avoir un rapport très élevé entre le niveau de pollution du local et le niveau de pollution à l'extérieur de celui-ci.The present invention relates to methods of confining a polluted room using a gas stream and more specifically relates to such a process which allows to have a very high ratio between the level of pollution of the room and the pollution level outside of it.

Il est connu, notamment dans les installations nucléaires, d'isoler un local contenant une machine dégageant des poussieres radioactives en grande quantité à l'aide d'un rideau d'air afin de pouvoir intervenir facilement sur ladite machine à travers ce rideau d'air. Un exemple de mise en application de ce procédé est illustré à la figure 1 sur laquelle on voit, à l'intérieur d'une cellule 1, une cloison verticale 2 définissant un local 4 à l'intérieur duquel est installée une machine 6 servant au découpage d'éléments combustibles nucléaires. Le local 4 contenant la machine 6 communique avec le reste de la cellule par une ouverture 8. Une veine gazeuse divergente 12, sortant par une buse 10, recouvre toute la surface de l'ouverture 8 empêchant ainsi l'air pollué du local 4 de pénétrer dans la zone propre 5 de la cellule 1. L'air de la veine 12 est repris par une bouche d'aspiration 14 et envoyé dans un circuit comprenant un cyclone 16 et un ventilateur 18. Dans la suite du présent texte, on appellera 'portée du jet", ou de la veine 12, la distance parcourue par celle-ci depuis la fente d'injection 7 jusqu'à la bouche de reprise ou d'aspiration 14, et qui correspond à la largeur de l'ouverture 8.It is known, in particular in nuclear installations, to isolate a room containing a machine releasing radioactive dust in large quantities using an air curtain in order to be able to easily intervene on said machine through this curtain. air. An example of application of this method is illustrated in FIG. 1 in which we see, inside a cell 1, a vertical partition 2 defining a room 4 inside which is installed a machine 6 used for cutting of nuclear fuel elements. The room 4 containing the machine 6 communicates with the rest of the cell through an opening 8. A divergent gas stream 12, exiting through a nozzle 10, covers the entire surface of the opening 8 thus preventing the polluted air in room 4 from enter the clean zone 5 of the cell 1. The air from the vein 12 is taken up by a suction mouth 14 and sent in a circuit comprising a cyclone 16 and a fan 18. In the remainder of this text, we will call 'range of the jet ", or of the vein 12, the distance traveled by the latter from the injection slot 7 to the return or suction mouth 14, and which corresponds to the width of the opening 8 .

L'air sortant du cyclone 16 est généralement rejeté à l'extérieur de l'enceinte 1: comme il contient encore une certaine quantité de poussieres radioactives, il est nécessaire de le filtrer à l'aide d'un filtre absolu 19 avant de le rejeter dans l'atmosphère. Cependant, outre le fait que ces filtres constituent des matériels très coûteux, leur remplacement est une opération longue et délicate à cause de toutes les protections qui sont nécessaires en raison de la forte activité des poussieres. De plus, ils constituent des déchets actifs qu'il faut conditionner avant leur évacuation. C'est pourquoi on a tout intéret à en diminuer la fréquence de remplacement. Pour cela, on ne rejette à l'extérieur qu'une partie de l'air sortant du cyclone 16, l'autre partie étant recyclée dans la buse 10. Une ouverture 22, pratiquée dans la paroi 23 de la cellule 1, permet à l'air de ventilation de pénétrer dans la cellule afin de remplacer l'air extrait à travers le filtre 19 par le ventilateur 20.The air leaving the cyclone 16 is generally rejected outside the enclosure 1: as it still contains a certain amount of radioactive dust, it is necessary to filter it using an absolute filter 19 before it release into the atmosphere. However, in addition to the fact that these filters constitute very expensive materials, their replacement is a long and delicate operation because of all the protections which are necessary due to the high activity of the dusts. In addition, they constitute active waste which must be conditioned before their disposal. This is why it is in our interest to reduce the frequency of replacement. For this, only part of the air leaving the cyclone 16 is discharged to the outside, the other part being recycled into the nozzle 10. An opening 22, formed in the wall 23 of the cell 1, allows the ventilation air entering the cell in order to replace the air extracted through the filter 19 by the fan 20.

Un tel procédé présente des inconvénients importants. En effet, comme on peut le voir sur la figure 1, la veine gazeuse 12 se composé de deux parties: une première partie, dite 'zone de transition", s'étend sur une longueur 1 à partir de la fente 7 et comprend un 'noyau potentiel" ou 'dard" 13, constitué uniquement par de l'air injecté à travers la buse 10, et qui a sensiblement, vu en coupe, la forme d'un triangle de longueur 1, cette derniere étant égale à environ 6 fois la largeur e de la fente d'injection. La vitesse du gaz est la même en tout point du dard 13 et elle est égale à la vitesse d'injection. La deuxieme partie de la veine gazeuse 12 est une zone dite 'de plein développement du jet" 15 dans laquelle l'air injecté par la buse 10 se mélange, par aspiration, à l'air présent dans la cellule 4 et dans la zone propre 5 de l'enceinte 1. La zone de plein développement du jet s'étend au-delà de la pointe du dard, depuis cette pointe jusqu'à la bouche de reprise 14. La zone 15 ayant un régime très turbulent, elle aspire une grande partie des poussieres contenues dans la cellule 4 (fleches 9). Au-delà d'une certaine concentration dans la veine 12, ces poussieres risquent d'être rejetées dans la partie propre 5 de - l'enceinte par diffusion turbulente: dans le cas le plus défavorable, la concentration de la pollution dans la zone 5 peut être de l'ordre de la moitié de ce qu'elle est dans la zone 4 alors que, dans l'industrie nucléaire notamment, on souhaite un rapport de concentrations aussi faible que possible et généralement inférieur à 1/100. De plus, les poussieres activent les installations fixes se trouvant dans la zone 5 de la cellule 1 et la contamination cumulative ainsi produite peut être très importante au bout d'un certain temps.Such a method has significant drawbacks. In fact, as can be seen in FIG. 1, the gas stream 12 is composed of two parts: a first part, called the "transition zone", extends over a length 1 from the slot 7 and includes a 'potential core' or 'dart' 13, consisting solely of air injected through the nozzle 10, and which has, seen, in section, the shape of a triangle of length 1, the latter being equal to approximately 6 times the width e of the injection slot. The gas speed is the same at all points of the sting 13 and it is equal to the injection speed. The second part of the gas stream 12 is a so-called 'full zone development of the jet "15 in which the air injected by the nozzle 10 mixes, by suction, with the air present in the cell 4 and in the clean zone 5 of the enclosure 1. The zone of full development of the jet s 'extends beyond the point of the dart, from this point to the return mouth 14. The zone 15 having a very turbulent regime, it sucks a large pa rtie of dust contained in cell 4 (arrows 9). Beyond a certain concentration in the vein 12, this dust risks being discharged into the clean part 5 of the enclosure by turbulent diffusion: in the most unfavorable case, the concentration of the pollution in the zone 5 may be of the order of half of what it is in zone 4 whereas, in the nuclear industry in particular, a concentration ratio is desired that is as low as possible and generally less than 1/100. In addition, the dust activates the fixed installations located in zone 5 of cell 1 and the cumulative contamination thus produced can be very significant after a certain time.

Afin de remédier à ce défaut, on a essaye d'augmenter la vitesse de l'air insufflé, mais cette méthode n'améliore rien et ne fait qu'augmenter les coûts d'exploitation.In order to remedy this defect, an attempt has been made to increase the speed of the supply air, but this method does not improve anything and only increases operating costs.

Une autre méthode consiste à faire circuler deux veines gazeuses au niveau de l'ouverture séparant le local de l'extérieur. Le document DE-A-3 004 073 décrit un procédé pour la ventilation de locaux consistant à insuffler un jet d'air secondaire à travers un éjecteur disposé à proximité immédiate de la sortie d'air primaire: ceci a pour effet d'augmenter la portée du jet primaire qui, sinon, serait trop faible car la vitesse d'injection est relativement réduite. Ce procédé peut aussi être utilisé pour créer un rideau d'air devant une porte ou une ouverture mais, s'il s'agit d'un local pollilé, les poussières risquent encore de s'echapper à l'extérieur pour les raisons indiquées plus haut.Another method is to circulate two gas streams at the opening separating the room from the outside. Document DE-A-3 004 073 describes a process for ventilating premises consisting in blowing a secondary air jet through an ejector disposed in the immediate vicinity of the primary air outlet: this has the effect of increasing the range of the primary jet which would otherwise be too low because the injection speed is relatively reduced. This process can also be used to create an air curtain in front of a door or an opening, but, in the case of a polluted room, the dust may still escape outside for the reasons indicated more high.

La présente invention a justement pour but de remédier à ces inconvénients grâce à un procédé de confinement de la pollution d'un local communiquant avec l'extérieur grâce à au moins une ouverture du type dans lequel on fait circuler une première veine gazeuse au niveau de l'ouverture, les dimensions de cette première veine gazeuse étant telles que celleci couvre toute la surface de l'ouverture, ainsi qu' une deuxième veine gazeuse adjacente à la première et située du côté opposé au local par rapport à celle-ci-, là première veine gazeuse se composant d'une zone de transition et d'une zone de plein développement du jet, la zone de transition comportant un dard. Selon l'invention, on donne à celui-ci une longueur égale à la portée de la première veine et on règle les débits des deux veines gazeuses de sorte que le débit d'air induit par la face de la deuxieme veine qui est en contact avec la première soit sensiblement egal au débit d'injection de la première veine.The purpose of the present invention is to remedy these drawbacks by means of a method of confining the pollution of a room communicating with the outside by means of at least one opening of the type in which a first gas stream is circulated at the level of the opening, the dimensions of this first gas stream being such that it covers the entire surface of the opening, as well as a second gas stream adjacent to the first and located on the side opposite the room relative to the latter, there first gas stream consisting of a transition zone and a zone of full development of the jet, the transition zone comprising a dart. According to the invention, it is given a length equal to the range of the first vein and the flow rates of the two gas streams are adjusted so that the air flow induced by the face of the second vein which is in contact with the first being substantially equal to the injection rate of the first vein.

Ainsi, le dard couvrant toute la surface de l'ouverture 8 on ne risque plus de voir les poussieres passer à l'extérieur du local à travers la zone de mélange turbulent. Quant à la deuxieme veine gazeuse, elle a pour rôle de stabiliser la première. En effet, pour que le dard ait une longueur suffisante, il faut que la largeur de la fente d'injection soit égale à 1/6e environ de la distance entre la buse 10 et la bouche d'aspiration 14: ceci impose une faible vitesse d'injection (car sinon le débit serait prohibitif) qui risque de rendre le jet instable. La deuxième veine gazeuse crée un effet d'aspiration qui plaque la première veine contre la deuxième et la stabilise.Thus, the dart covering the entire surface of the opening 8 there is no longer any risk of seeing the dust pass outside the premises through the turbulent mixing zone. As for the second gas stream, its role is to stabilize the first. Indeed, for the dart to have a sufficient length, it is necessary that the width of the injection slot is equal to approximately 1 / 6th of the distance between the nozzle 10 and the suction mouth 14: this requires a low speed injection (because otherwise the flow would be prohibitive) which risks making the jet unstable. The second gas stream creates a suction effect which presses the first vein against the second and stabilizes it.

D'autre part, le debit d injection de la première veine est égal au débit d'air qui aurait été aspiré dans le local si on avait laissé la deuxième veine seule: on évite ainsi que la première veine se déforme par infléchissement vers la paroi inférieure du local 4. La deuxième veine aspire donc, dans le local 4, l'air d'injection de la première veine mélangé par diffusion turbulente à une faible fraction de l'air pollué du local 4. Elle aspire d'autre part de l'air propre se trouvant dans la zone 5 de la cellule 1: de ce fait, l'air évacué par la bouche d'aspiration 14 est très peu pollué par rapport à l'atmosphère du local 4.On the other hand, the injection rate of the first vein is equal to the air flow which would have been drawn into the room if the second vein had been left alone: this prevents the first vein from being deformed by bending towards the wall lower part of room 4. The second vein therefore sucks, in room 4, the injection air of the first vein mixed by turbulent diffusion with a small fraction of the polluted air of room 4. It also sucks the clean air being in the zone 5 of the cell 1: therefore, the air evacuated by the suction mouth 14 is very little polluted compared to the atmosphere of the room 4.

Selon une autre caractéristique du procédé objet de l'invention, on recycle partiellement l'air des deux veines gazeuses après l'avoir repris par une bouche d'aspiration et fait passer sur un appareil d'épuration qui peut être, par exemple, un cyclone ou une tour a ruissellement. L'énergie nécessaire à la mise en circulation de l'air est fournie par un appareil de circulation qui peut être un ventilateur, un compresseur, un éjecteur d'air, etc...According to another characteristic of the process which is the subject of the invention, the air from the two gas streams is partially recycled after having taken it up through a suction mouth and passed over a purification device which can, for example, be a cyclone or a trickle tower. The energy necessary for the circulation of air is supplied by a circulation device which can be a fan, a compressor, an air ejector, etc.

Enfin, l'invention a également pour objet une application de ce procédé au conf inement d'un local contenant des poussières radioactives créées par le découpage d'éléments combustibles nucléaires.Finally, the invention also relates to an application of this process to the confinement of a room containing radioactive dust created by the cutting of nuclear fuel elements.

L'invention apparaitra mieux à la lecture de la description qui va suivre, donnée à titre d'exemple purement illustratif et nullement limitatif, en réference aux dessins annexés, dans lesquels:

  • - la figure 1, déjà décrite, est une vue schématique en coupe illustrant um procédé de confinement d'un local selon l'art antérieur;
  • - la figure 2 est une vue schématique en coupe montrant les deux veines gazeuses utilisées dans le procédé objet de l'invention, et
  • - la figure 3 est une vue schématique en coupe semblable à la figure 1 montrant l'application du procédé selon l'invention au même local:
    • Sur la figure 2, on voit qu'on a transformé la buse 10 en donnant à la fente d'injection 7 une largeur suffisante pour que l'extrémité du dard 13 de la première veine se trouve au niveau de la bouche de reprise 14. Selon l'invention, on pilote cette premiere veine 12 à l'aide d'une deuxième veine gazeuse 24 qui arrive par une buse 25 placée au voisinage immédiat de la buse 10. Les débits sont calculés pour que la veine 24 aspire, du côte du local 4, un débit d'air égal au débit d'injection de la première veine: comme le dard 13 couvre toute la surface de l'ouverture 8, et empêche ainsi les poussières de passer à l'extérieur du local 4, c'est de l'air peu pollué qui est aspiré par la bouche 14.
The invention will appear better on reading the description which follows, given by way of purely illustrative and in no way limitative example, with reference to the appended drawings, in which:
  • - Figure 1, already described, is a schematic sectional view illustrating a method of confining a room according to the prior art;
  • FIG. 2 is a schematic sectional view showing the two gas streams used in the process which is the subject of the invention, and
  • FIG. 3 is a schematic sectional view similar to FIG. 1 showing the application of the method according to the invention to the same room:
    • In FIG. 2, it can be seen that the nozzle 10 has been transformed by giving the injection slot 7 a width sufficient for the end of the dart 13 of the first vein to be at the level of the return mouth 14. According to the invention, this first stream 12 is piloted using a second gas stream 24 which arrives by a nozzle 25 placed in the immediate vicinity of the nozzle 10. The flow rates are calculated so that the stream 24 sucks, from the side from room 4, an air flow equal to the injection flow from the first vein: as the sting 13 covers the entire surface of the opening 8, and thus prevents dust from passing outside of room 4, c is little polluted air which is sucked in through the mouth 14.

En réalité, une petite partie des poussières contenues dans le local 4 est évacuée par la bouche 14 pour la raison suivante: en effet, la première veine gazeuse 12 comporte elle-même une zone de mélange turbulent 15 qui aspire l'air du local 4 et donc certaines poussières contenues dans celle-ci (flèches 11 ). Une partie de ces poussières est donc extraite par la bouche 14 tandis que l'autre partie est recyclée dans le local 4 par le courant induit. Cependant, l'air aspiré par la bouche 14 est beaucoup moins pollué qu'avec les procédés de l'art antérieur. Il suffit alors de faire passer l'air aspiré par cette bouche 14 sur un cyclone pour diminuer sa concentration et obtenir dans la partie 5 de la cellule une concentration en poussieres polluantes notablement inférieure à celle du local 4.In reality, a small part of the dust contained in the room 4 is evacuated by the mouth 14 for the following reason: in fact, the first gas stream 12 itself comprises a turbulent mixing zone 15 which sucks the air from the room 4 and therefore certain dusts contained in it (arrows 11). Part of this dust is therefore extracted through the mouth 14 while the other part is recycled into the room 4 by the induced current. However, the air sucked in through the mouth 14 is much less polluted than with the methods of the prior art. It then suffices to pass the air sucked in through this mouth 14 over a cyclone to reduce its concentration and obtain in the part 5 of the cell a concentration of polluting dust significantly lower than that of the room 4.

La figure 3 illustre l'application du procédé selon l'invention à la cellule de la figure 1. Sur cette figure, on voit encore la cellule 1 équipée de la cloison 2 déf inissant le local 4 contenant la machine 6. Ce local est séparé de la partie supérieure 5 de la cellule par un double rideau d'air constitué de la première veine gazeuse 12 sortant de la buse 10 et de la deuxième veine 24 sortant de la buse 25. L'air aspiré par la bouche de reprise 14 est d'abord envoyé sur le cyclone 16 qui diminue sa concentration en polluants. Comme dans l'exemple de la figure 1, une partie de l'air sortant du cyclone 16 est évacuée à 1,ex-térieur de la cellule 1 grâce au ventilateur 20 après être passée sur un filtre absolu 19. Une autre partie est recyclée grâce au ventilateur 18. Une partie de cet air recyclé est envoyée dans la buse 10 par l'intermédiaire d'une vanne 32 et une autre partie dans la buse 25 par l'intermédiaire d'une vanne 30.FIG. 3 illustrates the application of the method according to the invention to the cell of FIG. 1. In this figure, we can still see cell 1 fitted with the partition 2 defining room 4 containing the machine 6. This room is separated from the upper part 5 of the cell by a double curtain of air consisting of the first gas stream 12 leaving the nozzle 10 and the second stream 24 leaving the nozzle 25. The air sucked in by the return outlet 14 is first sent to cyclone 16 which decreases its concentration of pollutants. As in the example in FIG. 1, part of the air leaving cyclone 16 is evacuated to 1, outside of cell 1 by means of the fan 20 after passing over an absolute filter 19. Another part is recycled thanks to the fan 18. Part of this recycled air is sent to the nozzle 10 via a valve 32 and another part to the nozzle 25 via a valve 30.

A titre d'exemple, on a appliqué le procédé objet de l'invention à une cellule telle que 1, contenant une machine 6 servant au découpage d'éléments combustibles nucléaires. L'ouverture 8 séparant le local 4 de la zone supérieure 5 de la cellule a une longueur de 9 m pour une largeur de 3 m. La distance entre la sortie de la buse 10 et l'entrée de la bouche d'aspiration 14 est de 2,4 m. Le débit total d'air entrant dans la cellule est de 44 350 m3/h dont 19 000 m3/h d'air frais entrant dans la cellule par l'ouverture 22 et 25 350 m3/h d'air recyclé. Celui-ci est partagé de la manière suivante:

  • - 6 350 m3/h passent à travers la buse 25 pour créer la deuxième veine rapide 24; et
  • -19 000 m3/h passent à travers la buse 10 pour créer la première veine lente 12.
By way of example, the process which is the subject of the invention has been applied to a cell such as 1, containing a machine 6 used for cutting nuclear fuel elements. The opening 8 separating the room 4 from the upper zone 5 of the cell has a length of 9 m for a width of 3 m. The distance between the outlet of the nozzle 10 and the inlet of the suction mouth 14 is 2.4 m. The total air flow entering the cell is 44,350 m 3 / h including 19,000 m 3 / h of fresh air entering the cell through the opening 22 and 25,350 m 3 / h of recycled air. This is shared as follows:
  • - 6,350 m 3 / h pass through the nozzle 25 to create the second rapid vein 24; and
  • -19,000 m 3 / h pass through the nozzle 10 to create the first slow vein 12.

Le ventilateur extérieur 20 et le ventilateur 18 assurent un débit total de 44 350 m3/h dans la bouche de reprise 14 et le cyclone 16. Ce débit provient d'une part des deux veines gazeuses 12 et 24 pour 25 350 m3/h et d'autre part de l'air frais entrant par l'ouverture 22 pour 19 000 m3/h. Avec les valeurs de débit indiquées ci-dessus, le rapport des concentrations en poussières radioactives entre le local 4 et la zone 5 de la cellule est d'environ 100, soit une valeur notablement supérieure à celles que l'on pouvait obtenir avec les procédés de l'art anterieur.The external fan 20 and the fan 18 provide a total flow of 44,350 m 3 / h in the return outlet 14 and the cyclone 16. This flow comes on the one hand from the two gas streams 12 and 24 for 25,350 m 3 / h and on the other hand fresh air entering through opening 22 for 19,000 m 3 / h. With the flow rate values indicated above, the ratio of the concentrations of radioactive dust between room 4 and zone 5 of the cell is approximately 100, that is to say a value considerably higher than that which could be obtained with the processes. prior art.

De plus, d'autres séries d'essais ont montré qu'il etait possible de faire passer un bras de télémanipulateur à travers un rideau d'air conforme à l'invention sans perturber de façon sensible l'efficacité du confinement.In addition, other series of tests have shown that it was possible to pass a manipulator arm through an air curtain according to the invention without appreciably disturbing the effectiveness of the confinement.

Le procédé selon l'invention présente des avantages particulièrement intéressants puisqu'il permet de diminuer considérablement la contamination cumulative à l'extérieur du local 4. De plus, la concentration en poussières de l'air passant à travers le cyclone 16 et le filtre absolu 19 est abaissée, ce qui diminue le coût d'exploitation de l'installation en augmentant la durée de vie des filtres 19.The method according to the invention has particularly advantageous advantages since it makes it possible to considerably reduce the cumulative contamination outside the room 4. In addition, the dust concentration of the air passing through the cyclone 16 and the absolute filter 19 is lowered, which reduces the operating cost of the installation by increasing the life of the filters 19.

Quant aux applications du procédé, elles sont nombreuses et variées et ne se limitent pas è l'industrie nucléaire. On peut, par exemple dans l'industrie chimique, isoler de la même manière un local où sont manipulés des produits particulièrement toxiques. Par exemple, dans le cas d'installations produisant du chlore, on peut utiliser une tour à ruissellement de solutions alcalines à la placé du cyclone et du filtre pour éliminer le chlore. Enfin, le procédé s'applique à toute installation produisant des poussières en grande quantité, que celles-ci soient radioactives ou non.As for the applications of the process, they are numerous and varied and are not limited to the nuclear industry. One can, for example in the chemical industry, isolate in the same way a room where are handled particularly toxic products. For example, in the case of installations producing chlorine, an alkaline solution trickle tower can be used in place of the cyclone and the filter to remove the chlorine. Finally, the process applies to any installation producing large quantities of dust, whether or not it is radioactive.

Claims (5)

1. Process for the confinement of pollution within a zone (4) communicating with the exterior through at least one opening (8), of the type in which a first gas curtain is circulated around the opening (8), the dimensions of said first gas curtain (12) being such that it covers the entire surface of the opening (8), with a second gas curtain (24), adjacent to the first and located on the opposite side of the zone (4) with respect to the latter, the first gas curtain (12) comprising a transition zone and a zone of full development of the jet (15), the transition zone comprising a zone of unmixed injected gas (sting) (13), characterized in that the sting has a length equal to the span of the first curtain (12) and in that the flow rates of the two gas curtains (12) and (24) are controlled such that the flow of air induced at the surface of the second curtain (24) which is in contact with the first curtain (12) are substantially equal to the injection rate of said first curtain (12).
2. Process according to claim 1, characterized in that the air of the two gas curtains is partially recycled after they have passed through an outlet vent (14) and a purification means (16), the air being circulated by a circulation apparatus (18).
3. Process according to claim 2, characterized in that a cyclone (16) is used as purification means.
4. Process according to claim 2, characterized in that a trickle tower is employed as purification means.
5. Application of the process according to any one of claims 1 to 4 for the protection of a zone containing radioactive particles produced by the breaking up of nuclear fuel elements.
EP83401438A 1982-07-15 1983-07-12 Method of confining the pollution of an area by making use of an air curtain Expired EP0099818B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8212382 1982-07-15
FR8212382A FR2530163B1 (en) 1982-07-15 1982-07-15 METHOD FOR CONTAINING THE POLLUTION OF A PREMISES USING A GAS VEIN

Publications (2)

Publication Number Publication Date
EP0099818A1 EP0099818A1 (en) 1984-02-01
EP0099818B1 true EP0099818B1 (en) 1986-02-26

Family

ID=9275993

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83401438A Expired EP0099818B1 (en) 1982-07-15 1983-07-12 Method of confining the pollution of an area by making use of an air curtain

Country Status (5)

Country Link
US (1) US4576613A (en)
EP (1) EP0099818B1 (en)
JP (1) JPS5924297A (en)
DE (1) DE3362295D1 (en)
FR (1) FR2530163B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4234250A1 (en) * 1992-10-10 1994-04-14 Hartwig Sylvius Univ Prof Dr Air curtain system for confining accidental gas discharge - having segmented nozzle pipe individually operating with air or inert gas

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2621887B1 (en) * 1987-10-20 1990-03-30 Sgn Soc Gen Tech Nouvelle DYNAMIC CONTAINMENT AND NON-CONTACT MOUNTING
GB2220255B (en) * 1988-05-13 1992-01-02 Heinz Hoelter A method of,and apparatus for cooling and keeping clean the roof of a coke oven
DE3836278A1 (en) * 1988-10-25 1990-04-26 Schlick Heinrich Gmbh Co Kg Device for blasting, or the like, the inner surfaces of channels with granular material
US4902313A (en) * 1989-04-17 1990-02-20 Penter Albert P Apparatus and method of reducing pollution for tire buffing equipment
FR2652520B1 (en) * 1989-10-02 1992-02-07 Sgn Soc Gen Tech Nouvelle METHOD AND DEVICE FOR MAINTAINING A CLEAN ATMOSPHERE WITH REGULATED TEMPERATURE ON A WORKSTATION.
FR2659782B1 (en) * 1990-03-14 1992-06-12 Sgn Soc Gen Tech Nouvelle METHOD AND DEVICE FOR DYNAMIC SEPARATION OF TWO ZONES.
FR2662296B1 (en) * 1990-05-15 1994-06-17 Cogema REMOTE SANITATION INSTALLATION, BY DEGRADATION, OF A SURFACE LOCATED IN HOSTILE ENVIRONMENT, WITH RECOVERY AND TREATMENT OF WASTE.
US5338248A (en) * 1993-01-25 1994-08-16 Midwest Air Products Co., Inc. Ventilation apparatus for removing vapors
US5457270A (en) * 1993-10-04 1995-10-10 Hildebrand; Philip B. Chemical control system for confining volatile liquids
FR2730297B1 (en) * 1995-02-02 1997-05-09 Soc Generale Pour Les Techniques Nouvelles Sgn CONTAINMENT METHOD AND DEVICE, ESPECIALLY OF A PARTICULAR ATMOSPHERE IN A CONTINUOUS PROCESSING SPACE OF THROUGHPUT PRODUCTS
US5711705A (en) * 1995-05-25 1998-01-27 Flanders Filters, Inc. Isolation work station
FR2740205B1 (en) * 1995-10-23 1998-01-09 Unir Ultra Propre Nutrition In PROTECTION AGAINST AEROCONTAMINATION
FR2756910B1 (en) 1996-12-10 1999-01-08 Commissariat Energie Atomique PROCESS FOR DYNAMIC SEPARATION OF TWO AREAS BY A CLEAN AIR CURTAIN
FR2757933B1 (en) 1996-12-27 1999-01-22 Commissariat Energie Atomique DEVICE FOR DYNAMICALLY SEPARATING TWO ZONES BY AT LEAST ONE BUFFER ZONE AND TWO CURTAINS OF CLEAN AIR
FR2760199B1 (en) 1997-03-03 1999-05-21 Unir Ultra Propre Nutrition In DEVICE FOR SEPARATING TWO ZONES WITH DIFFERENT ATMOSPHERES
FR2770330B1 (en) 1997-10-24 2000-01-14 Cogema METHOD AND DEVICE FOR CONTAINMENT BY THERMAL LAMINATION
US6503324B1 (en) 2000-07-27 2003-01-07 Howmet Research Corporation Stucco tower and method
NL1027520C2 (en) * 2004-11-16 2006-05-17 Haskoning Nederland B V Climate control system for painting on display, comprises flow of air parallel to wall and forming barrier between painting and surrounding atmosphere
FR2928718B1 (en) * 2008-03-11 2010-12-10 Bhd Ingenierie GAS EMISSION EVACUATION SYSTEM PROVIDED BY AT LEAST ONE EMISSIVE POSITION IN A LOCAL
FR2990143B1 (en) * 2012-05-07 2015-01-30 Paul Brunon MULTI-JET BLOWING NOZZLE
CN103264033B (en) * 2013-05-21 2015-09-30 山东泰北环保设备股份有限公司 A kind of workshop toxic and harmful treatment facility

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2593702A (en) * 1948-04-13 1952-04-22 Claude B Schneible Gaseous curtain for ventilating exhaust
GB1237694A (en) * 1968-08-19 1971-06-30 Progress Jets Ltd Improvements relating to air curtains
DE2002349C3 (en) * 1970-01-20 1975-11-27 Brueckner-Apparatebau Gmbh, 6122 Erbach Device for the sealing implementation of a web-shaped material through a slot
SE350114B (en) * 1970-07-01 1972-10-16 Svenska Flaektfabriken Ab
JPS50146961A (en) * 1974-05-16 1975-11-25
DE3004073A1 (en) * 1980-02-05 1981-08-13 TTL Tür + Torschleier lufttechnische Geräte GmbH, 7065 Winterbach Ventilation equipment for room - has high-pressure fan supplying room air to secondary air ejector nozzles

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4234250A1 (en) * 1992-10-10 1994-04-14 Hartwig Sylvius Univ Prof Dr Air curtain system for confining accidental gas discharge - having segmented nozzle pipe individually operating with air or inert gas

Also Published As

Publication number Publication date
FR2530163B1 (en) 1986-08-29
JPS5924297A (en) 1984-02-07
US4576613A (en) 1986-03-18
JPH0519119B2 (en) 1993-03-15
EP0099818A1 (en) 1984-02-01
FR2530163A1 (en) 1984-01-20
DE3362295D1 (en) 1986-04-03

Similar Documents

Publication Publication Date Title
EP0099818B1 (en) Method of confining the pollution of an area by making use of an air curtain
CA2275950C (en) Device for dynamic separation of two zones
FR2723404A1 (en) ASPIRE AIR FILTER
BE1006536A3 (en) Device inerting bath welding machine welding wave.
WO1997040325A1 (en) Fabric sheath for ventilation and laminar flow hood
EP0923972A1 (en) Selfwashable device for separating and filtering solid particles in a liquid flow and use in a fuel injection system provided with such a device
EP2829809B1 (en) Self-cleaning kitchen hood
FR2460701A1 (en) DEVICE FOR SEPARATING SOLID MATERIALS IN A LIQUID CURRENT
EP0195703B1 (en) Installation for dust-free work, especially for the production and checking of electronic components, and method for operating it
EP0199649B1 (en) Coating of float glass by pyrolysable powder compounds
FR3060717B1 (en) DEVICE FOR TREATING THE AIR
CA2747266C (en) Hood for sucking-up fine particles, and a device intended for the laser ablation of a surface layer of a wall and including such a hood
CA2747870C (en) Mouth of a hood for sucking up fine particles, and laser device for ablating a surface layer of a wall comprising such a hood
FR2793427A1 (en) Device for picking up metal particles suspended in fluid in closed circuit heating system comprises tank fitted with fluid inlet and outlet, glove finger and magnetic bar
FR2621887A1 (en) DYNAMIC CONFINEMENT AND CONTACT-FREE ACCOMMODATION
EP1738097B1 (en) Device for diverting a gas flow through a single-blade flag valve
FR2890574A1 (en) Rain water drop and air flow separating device, for e.g. cowl vent grille, has filter constituted of mesh network comprising crossed surface permitting separation and discharge of water drop in air flow crossing mesh network
EP0165145B1 (en) Fan silencer which can be regenerated in situ, for use in ventilation plants fed with dusty air, and process to regenerate this silencer in situ
FR3039100A1 (en) VEHICLE EQUIPPED WITH AN AIR TREATMENT FACILITY
FR2863949A1 (en) Air conditioner for use in vehicle`s passenger compartment, has cyclone filter, which can be self-cleaned, arranged in downstream of air pulser to filter air, and fine filter arranged in upstream of cyclone filter
BE1013310A5 (en) Cryogenic tunnel.
FR2904097A1 (en) Air treating method for temporarily confined volume/room, involves performing air extraction using suction inlets, which are connected to suction system and arranged in zone placed opposite to air introducing area with respect to work area
FR3137000A1 (en) ASBESTOS WASTE PRE-TREATMENT FACILITY AND DECONTAMINATION HALL INCLUDING IT
FR2477029A1 (en) Self:cleaning air or gas filter - where cleaning air is periodically and automatically blown through filter grid in countercurrent to normal direction of air or gas flow
FR2901151A1 (en) PARTICULATE SEPARATOR CONTAINED IN A GASEOUS CURRENT, IN PARTICULAR SOLID AND / OR LIQUID AND / OR PASSIZED PARTICLES.

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

AK Designated contracting states

Designated state(s): BE DE GB IT SE

17P Request for examination filed

Effective date: 19840707

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE DE GB IT SE

REF Corresponds to:

Ref document number: 3362295

Country of ref document: DE

Date of ref document: 19860403

ITF It: translation for a ep patent filed

Owner name: JACOBACCI & PERANI S.P.A.

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
ITTA It: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 83401438.3

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

Ref country code: SE

Payment date: 19990708

Year of fee payment: 17

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

Ref country code: GB

Payment date: 19990709

Year of fee payment: 17

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

Ref country code: BE

Payment date: 19990713

Year of fee payment: 17

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

Ref country code: DE

Payment date: 19990726

Year of fee payment: 17

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

Ref country code: GB

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

Effective date: 20000712

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 NON-PAYMENT OF DUE FEES

Effective date: 20000713

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: 20000731

BERE Be: lapsed

Owner name: COMMISSARIAT A L'ENERGIE ATOMIQUE ETABLISSEMENT D

Effective date: 20000731

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

Effective date: 20000712

EUG Se: european patent has lapsed

Ref document number: 83401438.3

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

Ref country code: DE

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

Effective date: 20010501