EP0494921B1 - Method and device for maintaining a clean atmosphere at controlled temperature at a workstation - Google Patents

Method and device for maintaining a clean atmosphere at controlled temperature at a workstation Download PDF

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Publication number
EP0494921B1
EP0494921B1 EP90914739A EP90914739A EP0494921B1 EP 0494921 B1 EP0494921 B1 EP 0494921B1 EP 90914739 A EP90914739 A EP 90914739A EP 90914739 A EP90914739 A EP 90914739A EP 0494921 B1 EP0494921 B1 EP 0494921B1
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EP
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Prior art keywords
opening
jet
stream
gas
enclosure
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EP90914739A
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German (de)
French (fr)
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EP0494921A1 (en
Inventor
François Meline
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Societe Generale pour les Techniques Nouvelles SA SGN
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Societe Generale pour les Techniques Nouvelles SA SGN
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
    • F24F3/16—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by purification, e.g. by filtering; by sterilisation; by ozonisation
    • F24F3/163—Clean air work stations, i.e. selected areas within a space which filtered air is passed
    • 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

Definitions

  • the invention relates to a method and a device for maintaining a clean atmosphere at a controlled temperature on a work station, accessible from a contaminated room.
  • the applicant sought to isolate the workstations from the air in the room in which the operators are; the air in this room no longer has to undergo the "clean room” treatment.
  • slow jet the first jet
  • fast jet the second jet
  • sting the potential flow area
  • width the dimension (of the opening or jets) parallel to the direction of flow of the curtain
  • length the dimension (of the opening or the jets) perpendicular to the direction of flow of the curtain.
  • This technique makes it possible to isolate a clean room from the pollution contained in a contaminated room and avoids heat transfers but must be adapted to allow access by the operator to a clean work station located in a contaminated room (inversion).
  • the present invention provides a method and a device improving the subject of patent FR-A-1 257 262 for maintaining a clean atmosphere on a workstation (indoor), although the air curtain is crossed by an obstacle (the operator for example, located outside).
  • the invention is not limited to the atmospheres of air in which men work; it can be applied to any gaseous atmosphere, the work can be carried out by robot, remote manipulator, etc.
  • the workstation is generally isolated from the contaminated area by one or more walls and a gas curtain at each opening on said contaminated area.
  • the volume thus delimited in which the workstation is located constitutes the volume to be kept clean.
  • an enclosure provided with walls is generally arranged; it communicates with the outside, to allow the operator to access the workstation, through at least one opening.
  • the gases can be injected to form the curtain from either side of the opening. Preferably they are injected from the top to the bottom.
  • the jets are emitted so that at least the external face of the fast jet (that which is not in contact with the slow jet) arrives at the limit of the plane of the opening.
  • Said external face can advantageously arrive just at the limit of said opening.
  • the gas curtain encounters no obstacle and perfectly obstructs said opening.
  • Said external face can arrive inside the volume - enclosure - to keep clean.
  • the fast jet, and possibly the slow jet meets (nt), opposite their injection zone, a surface.
  • the work station can constitute said surface. It can also be the floor of the enclosure. It is then advisable to provide, at the level of said surface, a suction so that said jets are not disturbed.
  • the two walls of the opening which are perpendicular to the flow of the jets are extended beyond the plane of the opening on a distance at least equal to the thickness of the curtain at its effective range (that is to say at its end).
  • the gas curtain has a continuous shape, for example a circular shape, it obviously does not need to be delimited.
  • the speed of the slow jet is chosen so as to limit turbulence in the presence of an obstacle. It is generally of the order of 0.4 to 0.6 m / s, and more generally ⁇ 0.6 m / s.
  • the flow rate of the clean gas stream is at least equal to the flow rate induced by the external face of the rapid jet.
  • the stream of clean gas is directed perpendicular to the plane of the opening; therefore, in the case where the work station is inside an enclosure, from the wall of the enclosure opposite the opening protected by the gas curtain. Said current is also directed from the area to be kept clean to the contaminated area (exterior).
  • a laminar flow is then created in the volume to be protected which promotes the non-diffusion of the contaminants.
  • the stream of clean gas is emitted in the same direction as the gas curtain and substantially parallel thereto.
  • the temperature of the clean gas stream is chosen by the manufacturer according to his needs.
  • the clean gas stream participates in combination with the gas curtain in the insulation of the volume to be protected (from the enclosure) against thermal changes and against pollution.
  • the dart of the slow jet constitutes a barrier against contaminants because the velocity vectors are parallel and equal.
  • there is a slight backscatter of polluted gas due to the disturbance of the jet by the walls which limit its length.
  • the obstacle then constitutes a local source of back-diffusion of the contaminants.
  • the invention also relates to a device for implementing the above method.
  • the work station constitutes the floor of said enclosure.
  • said enclosure is parallelepiped. It has at least two side walls to limit the length of the gas curtain and avoid the turbulence of the jets. Said side walls, perpendicular to the flow of said jets, are extended beyond the opening by a distance at least equal to the thickness of the jets at their effective range.
  • the means for injecting the stream of clean gas is advantageously constituted by said wall, perforated (thus playing the role of diffusing wall) and supplied with said clean gas (by example, by a box, which covers the entire surface of the wall, into which the said gas arrives slightly).
  • the stream of clean gas arrives approximately in a direction perpendicular to the jets, coming from the nozzles.
  • the means for injecting the stream of clean gas consists of the wall on which the nozzles are fixed, said wall being perforated and supplied with gas to act as a diffusing wall.
  • the stream of clean gas is practically parallel to the jets from the nozzles.
  • said enclosure does not have a side wall but an opening around its entire periphery.
  • said enclosure has a bell shape.
  • the means for injecting the stream of clean gas here advantageously consists of several nozzles located at the top of the ceiling (of the bell) and oriented so as to distribute the gas along the walls of the ceiling and in the enclosure.
  • the nozzles are obviously associated with distribution boxes provided with any device allowing equal distribution of the flow over the entire section of the nozzles.
  • the nozzles are oriented so that the external face of the rapid jet arrives just at the limit of the opening.
  • the gases are oriented outside the enclosure and it is not necessary to provide therein a suction device.
  • the work station 1 is a horizontal work plan, around which a rectangular enclosure has been built having a ceiling 2 and three side walls (only two are shown, marked 3 and 4), the wall 4 being opposite at opening 5, the wall 3 being extended beyond the nozzles 7 and 8 by a distance at least equal to the thickness of the gas curtain at the work station.
  • This wall is transparent in FIG. 1.
  • This enclosure rests on the ground via the support 6.
  • nozzles 7 and 8 for injecting gas (here air) supplied by pipes (not shown).
  • the nozzle 7 diffuses the slow jet, the nozzle 8, the fast jet.
  • the flow rates and speeds are adjusted so as to obtain a so-called slow jet on the outside side and a so-called fast jet on the enclosure side.
  • the nozzles 7 and 8 can be inclined if necessary so that the jets arrive advantageously at the limit of the work plane 1, without being in contact with this plane and without being too far from it (to prevent contamination from the outside from reaching the enclosure from below the worktop).
  • the wall 4 opposite the opening 5 is provided over its entire surface with perforations, preferably uniformly distributed. Behind this wall is a means allowing a uniform distribution of the gas on the surface of the wall, such as for example a box 9 covering the entire surface of the wall, and into which the gas is brought which then crosses the wall through the perforations and diffuses in the enclosure.
  • a gas suction mouth 10 is arranged at the bottom of the support 6 (in the contaminated area) to create a controlled circulation of air.
  • Such an enclosure provided with the means of the invention is particularly suitable for the treatment of products to be packaged which are brought by the operator or circulate at slow speed on a conveyor.
  • Figures 2A and 2B show a work station 11 consisting of a horizontal plane which is, in this particular case, a turntable around a central shaft. This type of station is found in bottling workshops where the bottles are brought automatically to the tray, are filled at a station and are directed out of the tray to other stations.
  • an enclosure 12 in the form of a bell is placed, supported on the ground by uprights 13.
  • this enclosure can be raised or lowered at will.
  • two adjacent nozzles 14 and 15 are mounted to create the gas curtain (here air).
  • the speeds and flow rates being adjusted to form said curtain, the so-called slow jet being emitted by the nozzle 14, the so-called fast jet by the nozzle 15.
  • a suction mouth 19 is placed on the ground below the nozzles 14, 15.
  • Figure 3 shows a conveyor line 20 protected from the outside, line on which circulate bottles to keep clean.
  • the enclosure is formed by a floor 20 - the conveyor (work station) - and a ceiling 21 formed here by the boxes supplied with gas and containing the injection nozzles.
  • the side walls of the enclosure are transferred to the ends of the conveyor and not shown.
  • symmetrical quick jets are emitted over at least the entire length of the conveyor line and over at least its entire opening width, the distance between the boxes and the conveyor constituting the opening of the pregnant.
  • the external face of the rapid jets arrives at the limit of the conveyor line 20 constituting the work station and arrives as close as possible to the bottles.
  • slow jets are emitted over at least the entire length of the conveying line and over at least its entire width, the sting of each of the jets being adjusted so that its range is equal to the width of the 'opening.
  • the stream of clean gas at slow speed is emitted from the central box 24. It covers the entire volume of the enclosure and is emitted parallel to the two gas curtains.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ventilation (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Cleaning In General (AREA)
  • Cleaning Or Drying Semiconductors (AREA)
  • Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
  • Air Conditioning Control Device (AREA)
  • Control Of Heat Treatment Processes (AREA)

Abstract

PCT No. PCT/FR90/00700 Sec. 371 Date Mar. 30, 1992 Sec. 102(e) Date Mar. 30, 1992 PCT Filed Oct. 1, 1990 PCT Pub. No. WO91/05210 PCT Pub. Date Apr. 18, 1991.A method and device for maintaining a clean atmosphere at controlled temperature, at a workstation accessible from a contaminated room. A curtain of gas-in the form of a slow jet and of a fast jet-is generated at the level of the openings between the workstation and the contaminated zone. The fast jet is situated at the level of the opening on the workstation side; the jets are directed approximately in parallel to the opening so that at least the external face of the fast jet reaches up to the opening. Moreover, a stream of clean gas is generated, and sent in such a way as to create a uniform sweeping, inside the volume to be protected.

Description

L'invention concerne un procédé et un dispositif pour maintenir une atmosphère propre à température régulée sur un poste de travail, accessible à partir d'une salle contaminée.The invention relates to a method and a device for maintaining a clean atmosphere at a controlled temperature on a work station, accessible from a contaminated room.

Le problème de maintien d'une atmosphère propre sur un poste de travail se pose, par exemple, dans L'industrie agroalimentaire.The problem of maintaining a clean atmosphere on a workstation arises, for example, in the food industry.

Pour le conditionnement de produits (par exemple : embouteillage, mise sous vinyl de plats cuisinés...), il est indispensable d'opérer en atmosphère très propre : on ne doit pas dépasser des concentrations maximales admissibles en contaminants particulaires et microbiologiques, fixées par des réglementations.For the packaging of products (for example: bottling, placing cooked meals under vinyl, etc.), it is essential to operate in a very clean atmosphere: the maximum admissible concentrations of particulate and microbiological contaminants, fixed by regulations.

De plus, pour éviter la prolifération des microorganismes, on opère généralement en ambiance froide.In addition, to avoid the proliferation of microorganisms, one generally operates in a cold environment.

Il faut donc isoler les postes de travail :

  • de la pollution particulaire, microbiologique, gazeuse,
  • des transferts thermiques,

tout en permettant l'accès à des opérateurs.It is therefore necessary to isolate the workstations:
  • particulate, microbiological, gaseous pollution,
  • thermal transfers,

while allowing access to operators.

Jusqu'à présent, les opérateurs travaillent dans des salles dites "blanches". Tout l'air de ces salles est traité pour amener les concentrations en contaminants en-dessous des seuils admissibles. L'air desdites salles est également régulé en température. Le système de ventilation nécessaire est important et surtout coûteux. Les conditions de travail sont également désagréables pour le personnel, notamment les conditions de température.Until now, operators have worked in so-called "white" rooms. All the air in these rooms is treated to bring the contaminant concentrations below the permissible thresholds. The air in these rooms is also temperature controlled. The necessary ventilation system is important and above all expensive. The working conditions are also unpleasant for the staff, especially the temperature conditions.

Pour éviter ces inconvénients, la demanderesse a recherché à isoler les postes de travail de l'air de la salle dans laquelle sont les opérateurs ; l'air de cette salle n'ayant plus à subir le traitement "salle blanche".To avoid these drawbacks, the applicant sought to isolate the workstations from the air in the room in which the operators are; the air in this room no longer has to undergo the "clean room" treatment.

On a décrit, dans le brevet FR-A-1 257 562, un procédé et un dispositif pour maintenir une atmosphère, ayant des caractéristiques déterminées, dans une chambre ouverte d'un côté. Ledit procédé fait intervenir:

  • un rideau d'atmosphère, comportant un seul jet, au niveau de ladite ouverture,
  • le recyclage d'au moins une partie des gaz constituant ledit rideau;
  • une circulation d'arrière en avant, dans ladite chambre, de gaz recyclé. Le problème de la stabilité du rideau d'atmosphère n'est pas abordé dans ce document.
Patent FR-A-1 257 562 describes a method and a device for maintaining an atmosphere, having determined characteristics, in a chamber open on one side. Said process involves:
  • an atmospheric curtain, comprising a single jet, at the level of said opening,
  • recycling at least part of the gases constituting said curtain;
  • a circulation from back to front, in said chamber, of recycled gas. The problem of the stability of the air curtain is not addressed in this document.

On connait par ailleurs, en milieu nucléaire, le confinement de la pollution d'un local par rideau d'air (demande de brevet FR-A-2 530 163).We also know, in a nuclear environment, the confinement of the pollution of a room by air curtain (patent application FR-A-2,530,163).

Selon cette technique, on isole un local contaminé de l'extérieur (zone propre) en disposant sur l'ouverture du local deux buses d'injection d'air pour créer deux jets d'air :

  • un premier jet situé du côté du local contaminé ; ce jet comporte une zone à écoulement potentiel (dard) dont la portée est au moins égale à l'une des dimensions de l'ouverture ; le jet s'étendant également sur toute l'autre dimension pour couvrir L'ouverture ; ceci imposant une grande largeur de la buse d'injection ; (ce premier jet constitue la barrière de confinement) ;
  • un second jet situé du côté de la zone propre (extérieur), parallèle et de même sens que le premier jet, et tel que le débit d'air induit par sa face interne au contact du premier jet soit égal au débit dudit premier jet (ce second jet stabilise le premier).
According to this technique, a contaminated room is isolated from the outside (clean area) by placing two air injection nozzles on the opening of the room to create two air jets:
  • a first jet located on the side of the contaminated room; this jet comprises a potential flow zone (dart) whose range is at least equal to one of the dimensions of the opening; the jet also extending over the entire other dimension to cover the opening; this imposes a large width of the injection nozzle; (this first jet constitutes the confinement barrier);
  • a second jet located on the side of the clean area (outside), parallel and in the same direction as the first jet, and such that the air flow induced by its internal face in contact with the first jet is equal to the flow of said first jet ( this second jet stabilizes the first).

On appellera dans la suite de la présente description :
   jet lent : le premier jet ;
   jet rapide : le second jet ;
   dard : la zone à écoulement potentiel ;
   largeur : la dimension (de l'ouverture ou des jets) parallèle au sens de L'écoulement du rideau ;
   longueur : la dimension (de l'ouverture ou des jets) perpendiculaire au sens de l'écoulement du rideau.In the following description, we will call:
slow jet: the first jet;
fast jet: the second jet;
sting: the potential flow area;
width: the dimension (of the opening or jets) parallel to the direction of flow of the curtain;
length: the dimension (of the opening or the jets) perpendicular to the direction of flow of the curtain.

Cette technique permet d'isoler un local propre de la pollution renfermée dans un local contaminé et évite les transferts thermiques mais doit être adaptée pour permettre l'accés par l'opérateur à un poste de travail propre situé dans un local contaminé (inversion).This technique makes it possible to isolate a clean room from the pollution contained in a contaminated room and avoids heat transfers but must be adapted to allow access by the operator to a clean work station located in a contaminated room (inversion).

Dans ce but, la présente invention propose un procédé et un dispositif perfectionnant l'objet du brevet FR-A-1 257 262 pour maintenir une atmosphère propre sur un poste de travail (intérieur), bien que le rideau d'air soit traversé par un obstacle (I'opérateur par exemple, situé à l'extérieur).For this purpose, the present invention provides a method and a device improving the subject of patent FR-A-1 257 262 for maintaining a clean atmosphere on a workstation (indoor), although the air curtain is crossed by an obstacle (the operator for example, located outside).

L'invention n'est pas limitée aux atmosphères d'air dans lesquelles travaillent des hommes ; elle peut être appliquée à toute atmosphère gazeuse, le travail pouvant être effectué par robot, télémanipulateur, etc.The invention is not limited to the atmospheres of air in which men work; it can be applied to any gaseous atmosphere, the work can be carried out by robot, remote manipulator, etc.

Plus précisément, l'invention a pour objet un procédé pour maintenir une atmosphère propre à température régulée sur un poste de travail, ledit poste de travail étant accessible à partir d'une zone contaminée par au moins une ouverture, procédé dans lequel on génère d'une part, au niveau de ladite ouverture, un rideau de gaz couvrant toute la longueur de ladite ouverture et, d'autre part, sur ledit poste de travail , un courant de gaz propre à température contrôlée, dirigé de façon à s'opposer à l'entrée des contaminants et à balayer uniformément ledit poste de travail, caractérisé en ce que :

  • ledit rideau de gaz consiste en un jet lent et un jet rapide; ledit jet lent comportant un dard de portée égale à la largeur de ladite ouverture, ledit jet rapide ayant un débit induit par sa face interne au contact du jet lent égal au débit d'injection dudit jet lent; ledit jet rapide étant situé au niveau de ladite ouverture côté poste de travail; lesdits jets lent et rapide étant orientés sensiblement parallèlement à ladite ouverture de façon qu'au moins la face externe dudit jet rapide arrive en limite de ladite ouverture;
  • le débit dudit courant de gaz propre est au moins égal au débit d'alimentation de la face externe dudit jet rapide;
  • si nécessaire, on aspire au niveau de ladite ouverture et en vis-à vis de la zone d'injection des jets le gaz insufflé sous forme de jets et de courant.
More specifically, the subject of the invention is a method for maintaining a clean atmosphere at a regulated temperature at a work station, said work station being accessible from an area contaminated by at least one opening, process in which d on the one hand, at said opening, a gas curtain covering the entire length of said opening and, on the other hand, on said work station, a stream of clean gas at controlled temperature, directed so as to oppose at the entry of contaminants and uniformly sweeping said work station, characterized in that:
  • said gas curtain consists of a slow jet and a fast jet; said slow jet comprising a dart of range equal to the width of said opening, said rapid jet having a flow induced by its internal face in contact with the slow jet equal to the injection flow of said slow jet; said rapid jet being located at said opening on the workstation side; said slow and fast jets being oriented substantially parallel to said opening so that at least the external face of said fast jet arrives at the limit of said opening;
  • the flow rate of said stream of clean gas is at least equal to the supply flow rate of the external face of said rapid jet;
  • if necessary, the gas blown in the form of jets and current is sucked at the level of said opening and opposite the injection zone of the jets.

Le poste de travail est généralement isolé de la zone contaminée par une ou plusieurs parois et un rideau de gaz au niveau de chaque ouverture sur ladite zone contaminée. Le volume ainsi délimité dans lequel se trouve le poste de travail constitue le volume à maintenir propre.The workstation is generally isolated from the contaminated area by one or more walls and a gas curtain at each opening on said contaminated area. The volume thus delimited in which the workstation is located constitutes the volume to be kept clean.

Dans la pratique, autour du poste de travail, une enceinte munie de parois est généralement disposée; celle-ci communique avec l'extérieur, pour permettre à l'opérateur d'accéder au poste de travail, par au moins une ouverture.In practice, around the work station, an enclosure provided with walls is generally arranged; it communicates with the outside, to allow the operator to access the workstation, through at least one opening.

L'enceinte peut être de forme variée, comme cela sera illustré ci-après sur les figures (parallélépipède, cloche...). Le volume à maintenir propre (l'atmosphère de l'enceinte) est isolé de l'extérieur (zone contaminée), est maintenu propre et à température régulée au moyen

  • d'un rideau de gaz selon la demande de brevet FR-A-2 530 163 : le jet rapide est toutefois, selon l'invention, situé au niveau de l'ouverture côté zone propre, le jet lent lui est côté zone contaminée,
  • d'un courant de gaz propre circulant dans le volume à protéger et émis de façon à balayer uniformément tout ce volume.
The enclosure can be of various shapes, as will be illustrated below in the figures (parallelepiped, bell, etc.). The volume to be kept clean (the atmosphere of the enclosure) is isolated from the outside (contaminated area), is kept clean and at a temperature controlled by means
  • a gas curtain according to patent application FR-A-2,530,163: the rapid jet is however, according to the invention, located at the opening on the clean zone side, the slow jet is on the contaminated zone side,
  • a stream of clean gas circulating in the volume to be protected and emitted so as to uniformly sweep this entire volume.

Les gaz peuvent être injectés pour former le rideau à partir de n'importe quel côté de l'ouverture. De préférence ils sont injectés du haut vers le bas.The gases can be injected to form the curtain from either side of the opening. Preferably they are injected from the top to the bottom.

Les jets sont émis de façon qu'au moins la face externe du jet rapide (celle qui n'est pas en contact du jet lent) arrive en limite du plan de l'ouverture.The jets are emitted so that at least the external face of the fast jet (that which is not in contact with the slow jet) arrives at the limit of the plane of the opening.

Il ne faut pas en effet que la face externe du jet rapide soit trop éloignée de l'ouverture, car on libérerait alors un espace non protégé entre le poste de travail et ledit jet, par Lequel la contamination pourrait s'introduire.In fact, the external face of the rapid jet must not be too far from the opening, since an unprotected space would then be freed between the work station and said jet, through which contamination could be introduced.

Ladite face externe peut avantageusement arriver juste en limite de ladite ouverture. Dans cette hypothèse, le rideau de gaz ne rencontre aucun obstacle et obstrue parfaitement ladite ouverture.Said external face can advantageously arrive just at the limit of said opening. In this case, the gas curtain encounters no obstacle and perfectly obstructs said opening.

Ladite face externe peut arriver à L'intérieur du volume -enceinte- à maintenir propre. Dans cette hypothèse, le jet rapide, et éventuellement le jet lent, rencontre(nt), en vis-à-vis de leur zone d'injection, une surface. Le poste de travail peut constituer ladite surface. Il peut s'agir également du plancher de l'enceinte. Il convient alors de prévoir, au niveau de ladite surface, une aspiration de sorte que lesdits jets ne soient pas perturbés.Said external face can arrive inside the volume - enclosure - to keep clean. In this hypothesis, the fast jet, and possibly the slow jet, meets (nt), opposite their injection zone, a surface. The work station can constitute said surface. It can also be the floor of the enclosure. It is then advisable to provide, at the level of said surface, a suction so that said jets are not disturbed.

Lorsque le rideau de gaz est délimité en longueur, les deux parois de l'ouverture qui sont perpendiculaires à l'écoulement des jets sont prolongées au-delà du plan de l'ouverture sur une distance au moins égale à l'épaisseur du rideau au niveau de sa portée effective (c'est-à-dire au niveau de son extrémité).When the gas curtain is delimited in length, the two walls of the opening which are perpendicular to the flow of the jets are extended beyond the plane of the opening on a distance at least equal to the thickness of the curtain at its effective range (that is to say at its end).

Lorsque le rideau de gaz a une forme continue, par exemple une forme circulaire, il n'a évidemment pas besoin d'être délimité.When the gas curtain has a continuous shape, for example a circular shape, it obviously does not need to be delimited.

La vitesse du jet lent est choisie de façon à limiter les turbulences en présence d'un obstacle. Elle est généralement de l'ordre de 0,4 à 0,6 m/s, et plus largement < 0,6 m/s.The speed of the slow jet is chosen so as to limit turbulence in the presence of an obstacle. It is generally of the order of 0.4 to 0.6 m / s, and more generally <0.6 m / s.

Le débit du courant de gaz propre est au moins égal au débit induit par la face externe du jet rapide.The flow rate of the clean gas stream is at least equal to the flow rate induced by the external face of the rapid jet.

Sa direction à l'émission est telle ou' il s'oppose à l'entrée et la diffusion des contaminants dans le volume à protéger et qu'il assure le balayage du poste de travail.Its direction on emission is such that it opposes the entry and diffusion of contaminants in the volume to be protected and that it ensures the scanning of the workstation.

Selon une réalisation préférée de l'invention, le courant de gaz propre est dirigé perpendiculairement au plan de l'ouverture ; donc, dans le cas où le poste de travail se trouve à l'intérieur d'une enceinte, à partir de la paroi de l'enceinte opposée à l'ouverture protégée par le rideau de gaz. Ledit courant est aussi dirigé de la zone à maintenir propre vers la zone contaminée (extérieur).According to a preferred embodiment of the invention, the stream of clean gas is directed perpendicular to the plane of the opening; therefore, in the case where the work station is inside an enclosure, from the wall of the enclosure opposite the opening protected by the gas curtain. Said current is also directed from the area to be kept clean to the contaminated area (exterior).

On crée alors un flux laminaire dans le volume à protéger qui favorise la non-diffusion des contaminants.A laminar flow is then created in the volume to be protected which promotes the non-diffusion of the contaminants.

Dans un autre mode de réalisation, le courant de gaz propre est émis dans le même sens que le rideau de gaz et sensiblement parallèle à celui-ci.In another embodiment, the stream of clean gas is emitted in the same direction as the gas curtain and substantially parallel thereto.

La température du courant de gaz propre est choisie par l'industriel en fonction de ses besoins.The temperature of the clean gas stream is chosen by the manufacturer according to his needs.

Le courant de gaz propre participe en combinaison avec le rideau de gaz à L'isolation du volume à protéger (de l'enceinte) contre les modifications thermiques et contre la pollution.The clean gas stream participates in combination with the gas curtain in the insulation of the volume to be protected (from the enclosure) against thermal changes and against pollution.

Il assure la régulation thermique du volume à protéger et la propreté du poste de travail.It provides thermal regulation of the volume to be protected and the cleanliness of the workstation.

En l'absence d'obstacle traversant le rideau de gaz, le dard du jet lent constitue une barrière contre les contaminants parce que les vecteurs vitesses sont parallèles et égaux. Il se produit toutefois une légère rétrodiffusion de gaz pollué due à la perturbation du jet par les parois qui limitent sa longueur.In the absence of an obstacle crossing the gas curtain, the dart of the slow jet constitutes a barrier against contaminants because the velocity vectors are parallel and equal. However, there is a slight backscatter of polluted gas due to the disturbance of the jet by the walls which limit its length.

En présence d'un obstacle propre (par exemple le bras ganté d'un opérateur) traversant le rideau de gaz, le dard qui assure la fonction de barrière est perturbé.In the presence of a clean obstacle (for example the gloved arm of an operator) crossing the gas curtain, the sting which ensures the barrier function is disturbed.

L'obstacle constitue alors une source locale de rétro-diffusion des contaminants.The obstacle then constitutes a local source of back-diffusion of the contaminants.

Cette diffusion est reprise en majeure partie par :

  • le jet rapide qui évacue immédiatement une grande partie des contaminants ;
  • le courant de gaz propre qui balaye les contaminants qui ont pu par diffusion turbulente s'échapper de la face externe du jet rapide et gagner l'enceinte. Les directions choisies indiquées précédemment pour l'émission dudit courant permettent d'arriver à ce résultat.
This distribution is mainly taken up by:
  • the rapid jet which immediately removes a large part of the contaminants;
  • the stream of clean gas which sweeps away the contaminants which may have escaped from the external face of the rapid jet by turbulent diffusion and reach the enclosure. The chosen directions indicated above for the emission of said current make it possible to arrive at this result.

L'existence du courant gazeux (dans l'enceinte ou le volume à protéger), régulé pour atteindre la température voulue qui s'oppose au gradient de concentration, s'oppose également au gradient thermique.The existence of the gas current (in the enclosure or the volume to be protected), regulated to reach the desired temperature which opposes the concentration gradient, also opposes the thermal gradient.

On prévoit de préférence, notamment lorsque la face externe du jet rapide arrive en limite du poste ce travail, une aspiration du gaz des jets au-delà de l'ouverture, de façon à contrôler la ventilation de la zone contaminée.It is preferably provided, in particular when the external face of the rapid jet arrives at the limit of the work station, a suction of the gas from the jets beyond the opening, so as to control the ventilation of the contaminated area.

L'invention a également pour objet un dispositif pour mettre en oeuvre le procédé ci-dessus.The invention also relates to a device for implementing the above method.

Ledit dispositif comprend :

  • une enceinte dans laquelle on trouve le poste de travail ; ledit poste de travail étant accessible de l'extérieur par au moins une ouverture de ladite enceinte ;
  • deux buses disposées côte à côte, sur un côté de ladite ouverture pour l'injection du gaz sous forme de jets ; la longueur des buses étant égale à celle de l'ouverture, la dimension de la fente de chaque buse étant déterminée en fonction de la vitesse et de la portée du jet à obtenir, et l'orientation des buses étant déterminée de façon qu'au moins la face externe du jet rapide arrive en limite de ladite ouverture ;
  • au moins un moyen pour l'injection du courant de gaz propre ; ledit moyen étant choisi et disposé de façon que le gaz soit uniformément réparti dans le volume de l'enceinte (à protéger) et de façon que le courant de gaz propre arrive approximativement dans une direction perpendiculaire ou parallèle au plan de ladite ouverture ;
  • des tuyauteries et moyens pour l'alimentation en gaz desdites buses et dudit moyen pour l'injection du courant de gaz propre.
  • éventuellement, un dispositif d'aspiration des gaz insufflés sous forme de jets et de courant à l'intérieur de ladite enceinte.
Said device comprises:
  • an enclosure in which we find the workstation; said work station being accessible from the outside by at least one opening of said enclosure;
  • two nozzles arranged side by side, on one side of said opening for injecting gas in the form of jets; the length of the nozzles being equal to that of the opening, the dimension of the slot of each nozzle being determined as a function of the speed and of the range of the jet to be obtained, and the orientation of the nozzles being determined so that at least the external face of the rapid jet reaches the limit of said opening;
  • at least one means for injecting the stream of clean gas; said means being selected and arranged so that the gas is uniformly distributed in the volume of the enclosure (to be protected) and so that the stream of clean gas arrives approximately in a direction perpendicular or parallel to the plane of said opening;
  • pipes and means for supplying gas to said nozzles and said means for injecting the stream of clean gas.
  • optionally, a device for sucking in the blown gases in the form of jets and of current inside said enclosure.

Généralement, le poste de travail constitue le plancher de ladite enceinte.Generally, the work station constitutes the floor of said enclosure.

Selon une première variante, ladite enceinte est parallèlépipédique. Elle comporte au moins deux parois latérales pour limiter la longueur du rideau de gaz et éviter la turpulence des jets. Lesdites parois latérales, perpendiculàires à l'écoulement desdits jets, sont prolongées au-delà de l'ouverture d'une distance au moins égale à l'épaisseur des jets au niveau de leur portée effective.According to a first variant, said enclosure is parallelepiped. It has at least two side walls to limit the length of the gas curtain and avoid the turbulence of the jets. Said side walls, perpendicular to the flow of said jets, are extended beyond the opening by a distance at least equal to the thickness of the jets at their effective range.

Si ladite enceinte parallèlépipédique comporte une paroi latérale opposée à l'ouverture, le moyen pour l'injection du courant de gaz propre est avantageusement constitué par ladite paroi, perforée (jouant ainsi le rôle de paroi diffusante) et alimentée en ledit gaz propre (par exemple, par un caisson, qui couvre toute la surface de la paroi, dans lequel arrive ledit gaz en légère suppression). Dans ce cas, le courant de gaz propre arrive approximativement dans une direction perpendiculaire aux jets, issus des buses.If said parallelepiped enclosure has a side wall opposite the opening, the means for injecting the stream of clean gas is advantageously constituted by said wall, perforated (thus playing the role of diffusing wall) and supplied with said clean gas (by example, by a box, which covers the entire surface of the wall, into which the said gas arrives slightly). In this case, the stream of clean gas arrives approximately in a direction perpendicular to the jets, coming from the nozzles.

Ce mode de réalisation de l'invention est illustré sur la Figure 1 ci-après.This embodiment of the invention is illustrated in Figure 1 below.

Selon un autre mode de réalisation, notamment lorsque ladite enceinte ne comporte pas de paroi latérale opposée à l'ouverture -en fait, lorsque ladite enceinte comporte deux parois latérales en vis-à-vis et deux ouvertures en vis-à-vis-, le moyen pour l'injection du courant de gaz propre est constitué par la paroi sur laquelle sont fixées les buses, ladite paroi étant perforée et alimentée en gaz pour jouer le rôle de paroi diffusante. Dans ce cas, le courant de gaz propre est pratiquement parallèle aux jets issus des buses. Ce mode de réalisation est illustré sur la Figure 3 ci-après.According to another embodiment, in particular when said enclosure does not have a side wall opposite the opening - in fact, when said enclosure has two side walls facing each other and two openings facing each other, the means for injecting the stream of clean gas consists of the wall on which the nozzles are fixed, said wall being perforated and supplied with gas to act as a diffusing wall. In this case, the stream of clean gas is practically parallel to the jets from the nozzles. This embodiment is illustrated in Figure 3 below.

Selon une autre variante du dispositif de l'invention, ladite enceinte ne comporte pas de paroi latérale mais une ouverture sur tout son pourtour. Elle a par exemple une forme de cloche.According to another variant of the device of the invention, said enclosure does not have a side wall but an opening around its entire periphery. For example, it has a bell shape.

Le moyen pour l'injection du courant de gaz propre est ici avantageusement constitué par plusieurs buses situées au sommet du plafond (de la cloche) et orientées de façon à distribuer le gaz le long des parois du plafond et dans l'enceinte.The means for injecting the stream of clean gas here advantageously consists of several nozzles located at the top of the ceiling (of the bell) and oriented so as to distribute the gas along the walls of the ceiling and in the enclosure.

Dans ce cas, il existe un courant de gaz propre sensiblement parallèle aux jets issus des buses (ce courant circulant le long des parois de la cloche) et un courant de gaz propre arrivant pratiquement perpendiculairement aux jets des buses (c'est le courant issu de l'injection dans l'enceinte).In this case, there is a stream of clean gas substantially parallel to the jets from the nozzles (this stream flowing along the walls of the bell) and a stream of clean gas arriving almost perpendicular to the jets of the nozzles (this is the stream from injection into the enclosure).

Cette variante du dispositif de l'invention est illustrée sur les figures 2A - 2B ci-après.This variant of the device of the invention is illustrated in Figures 2A - 2B below.

Il est bien entendu que les termes "parallèle" et "perpendiculaire" employés pour les directions des jets et courants de gaz sont très approximatifs.It is understood that the terms "parallel" and "perpendicular" used for the directions of the jets and gas streams are very approximate.

Les buses sont évidemment associées à des caissons de répartition munis de tout dispositif permettant L'équirépartition du débit sur toute la section des buses.The nozzles are obviously associated with distribution boxes provided with any device allowing equal distribution of the flow over the entire section of the nozzles.

Avantageusement, les buses sont orientées de façon que la face externe du jet rapide arrive juste en limite de l'ouverture.Advantageously, the nozzles are oriented so that the external face of the rapid jet arrives just at the limit of the opening.

Dans cette hypothèse les gaz sont orientés à l'extérieur de l'enceinte et il n'est pas nécessaire de prévoir dans celle-ci un dispositif d'aspiration. Dans cette hypothèse, on peut toutefois avantageusement prévoir une bouche d'aspiration desdits gaz, à l'extérieur de l'enceinte, dans la zone contaminée, afin de contrôler la ventilation dans ladite zone.In this case, the gases are oriented outside the enclosure and it is not necessary to provide therein a suction device. In this hypothesis, it is however advantageously possible to provide a suction mouth for said gases, outside the enclosure, in the contaminated zone, in order to control the ventilation in said zone.

Lorsque la face externe du jet rapide arrive à l'intérieur de l'enceinte, il est alors nécessaire de prévoir un dispositif d'aspiration des gaz insufflés sous forme de jet(s) et de courant, à l'intérieur de ladite enceinte.When the external face of the rapid jet arrives inside the enclosure, it is then necessary to provide a device for sucking in the blown gases in the form of jet (s) and current, inside said enclosure.

L'invention sera illustrée par les figures ci-après :The invention will be illustrated by the figures below:

Les figure 1 à 3 représentent trois modes de réalisation de l'invention :

  • figure 1 : poste de travail pour le conditionnement de produits peu mobiles ;
  • figures 2A et 2B : poste de travail pour la mise en bouteilles de liquides alimentaires, les bouteilles étant mobiles ;
  • figure 3 : ligne de convoyage pour bouteilles propres.
Figures 1 to 3 represent three embodiments of the invention:
  • Figure 1: workstation for packaging products that are not very mobile;
  • FIGS. 2A and 2B: work station for bottling edible liquids, the bottles being mobile;
  • figure 3: conveyor line for clean bottles.

Selon la figure 1, le poste de travail 1 est un plan de travail horizontal, autour duquel on a bâti une enceinte parallélépipédique ayant un plafond 2 et trois parois latérales (seules deux sont représentées, repérées 3 et 4), la paroi 4 étant opposée à l'ouverture 5, la paroi 3 étant prolongée au-delà des buses 7 et 8 d'une distance au moins égale à l'épaisseur du rideau de gaz au niveau du poste de travail. Cette paroi est transparente sur la figure 1.According to FIG. 1, the work station 1 is a horizontal work plan, around which a rectangular enclosure has been built having a ceiling 2 and three side walls (only two are shown, marked 3 and 4), the wall 4 being opposite at opening 5, the wall 3 being extended beyond the nozzles 7 and 8 by a distance at least equal to the thickness of the gas curtain at the work station. This wall is transparent in FIG. 1.

Cette enceinte repose sur le sol par l'intermédiaire du support 6.This enclosure rests on the ground via the support 6.

Sur le côté plafond de l'ouverture, on a disposé deux buses 7 et 8 pour l'injection de gaz (ici d'air) amené par des tuyauteries (non représentées). La buse 7 diffuse le jet lent, la buse 8, le jet rapide.On the ceiling side of the opening, there are two nozzles 7 and 8 for injecting gas (here air) supplied by pipes (not shown). The nozzle 7 diffuses the slow jet, the nozzle 8, the fast jet.

Les débits et les vitesses (dimension des fentes) sont réglés de façon à obtenir un jet dit lent du côté de l'extérieur et un jet dit rapide côté enceinte.The flow rates and speeds (dimension of the slits) are adjusted so as to obtain a so-called slow jet on the outside side and a so-called fast jet on the enclosure side.

Les buses 7 et 8 peuvent être inclinées si besoin pour que les jets arrivent avantageusement en limite du plan de travail 1, sans être au contact de ce plan et sans en être trop éloigné (pour éviter que la contamination de l'extérieur n'atteigne l'enceinte à partir du dessous du plan de travail).The nozzles 7 and 8 can be inclined if necessary so that the jets arrive advantageously at the limit of the work plane 1, without being in contact with this plane and without being too far from it (to prevent contamination from the outside from reaching the enclosure from below the worktop).

Pour créer le courant de gaz propre à l'aide d'une paroi diffusante, la paroi 4 opposée à l'ouverture 5 est munie sur toute sa surface de perforations, de préférence uniformément réparties. Derrière cette paroi se trouve un moyen permettant une répartition uniforme du gaz sur la surface de la paroi, tel que par exemple un caisson 9 couvrant toute la surface de la paroi, et dans lequel est amené le gaz qui traverse ensuite la paroi par les perforations et diffuse dans l'enceinte.To create the stream of clean gas using a diffusing wall, the wall 4 opposite the opening 5 is provided over its entire surface with perforations, preferably uniformly distributed. Behind this wall is a means allowing a uniform distribution of the gas on the surface of the wall, such as for example a box 9 covering the entire surface of the wall, and into which the gas is brought which then crosses the wall through the perforations and diffuses in the enclosure.

Une bouche d'aspiration des gaz 10 est disposée en bas du support 6 (dans la zone contaminée) pour créer une circulation contrôlée de l'air.A gas suction mouth 10 is arranged at the bottom of the support 6 (in the contaminated area) to create a controlled circulation of air.

Une telle enceinte munie des moyens de l'invention est particulièrement adaptée au traitement des produits à conditionner qui sont amenés par l'opérateur ou circulent à vitesse lente sur un convoyeur.Such an enclosure provided with the means of the invention is particularly suitable for the treatment of products to be packaged which are brought by the operator or circulate at slow speed on a conveyor.

Les figures 2A et 2B montrent un poste de travail 11 constitué par un plan horizontal qui est, dans ce cas particulier, un plateau tournant autour d'un arbre central. Ce type de poste se rencontre dans les ateliers d'embouteillage où les bouteilles sont amenées automatiquement sur le plateau, sont remplies à un poste et sont dirigées hors du plateau vers d'autres postes.Figures 2A and 2B show a work station 11 consisting of a horizontal plane which is, in this particular case, a turntable around a central shaft. This type of station is found in bottling workshops where the bottles are brought automatically to the tray, are filled at a station and are directed out of the tray to other stations.

Au-dessus du plateau 11, on a disposé une enceinte 12 en forme de cloche, supportée au sol par des montants 13. Avantageusement cette enceinte peut être montée ou descendue à volonté.Above the plate 11, an enclosure 12 in the form of a bell is placed, supported on the ground by uprights 13. Advantageously, this enclosure can be raised or lowered at will.

Au niveau du plan d'ouverture de l'enceinte et sur toute sa périphérie, deux buses adjacentes 14 et 15 sont montées pour créer le rideau de gaz (ici d'air). Les vitesses et débits étant réglés pour former ledit rideau, le jet dit lent étant émis par la buse 14, le jet dit rapide par la buse 15.At the level of the enclosure opening plane and over its entire periphery, two adjacent nozzles 14 and 15 are mounted to create the gas curtain (here air). The speeds and flow rates being adjusted to form said curtain, the so-called slow jet being emitted by the nozzle 14, the so-called fast jet by the nozzle 15.

Au sommet du plafond (ou de la cloche 12), plusieurs buses 16 ont été placées pour créer un courant de gaz propre 17 qui suit les parois de la cloche et un courant gazeux de balayage 18 qui est émis en direction du centre du plateau tournant, qui se répartit dans l'enceinte et qui est réaspiré par le jet rapide. Il a ainsi une courbure telle qu'il arrive sensiblement perpendiculairement au rideau de gaz.At the top of the ceiling (or of the bell 12), several nozzles 16 have been placed to create a stream of clean gas 17 which follows the walls of the bell and a gaseous sweep stream 18 which is emitted towards the center of the turntable , which is distributed in the enclosure and which is sucked back by the fast jet. It thus has a curvature such that it arrives substantially perpendicular to the gas curtain.

Une bouche d'aspiration 19 est placée au sol en dessous des buses 14, 15.A suction mouth 19 is placed on the ground below the nozzles 14, 15.

La figure 3 montre une ligne de convoyage 20 protégée de l'extérieur, ligne sur laquelle circulent des bouteilles à maintenir propres.Figure 3 shows a conveyor line 20 protected from the outside, line on which circulate bottles to keep clean.

L'enceinte est formée d'un plancher 20 -le convoyeur (poste de travail)- et d'un plafond 21 constitué ici par les caissons alimentés en gaz et contenant les buses d'injection. Les parois latérales de l'enceinte sont reportées en bouts du convoyeur et non représentées.The enclosure is formed by a floor 20 - the conveyor (work station) - and a ceiling 21 formed here by the boxes supplied with gas and containing the injection nozzles. The side walls of the enclosure are transferred to the ends of the conveyor and not shown.

A partir des caissons 22 symétriques, des jets rapides symétriques sont émis sur au moins toute la longueur de la ligne de convoyage et sur au moins toute sa largeur d'ouverture, la distance entre les caissons et le convoyeur constituant l'ouverture de l'enceinte.From symmetrical boxes 22, symmetrical quick jets are emitted over at least the entire length of the conveyor line and over at least its entire opening width, the distance between the boxes and the conveyor constituting the opening of the pregnant.

La face externe des jets rapides (côté bouteille) arrive en limite de la ligne de convoyage 20 constituant le poste de travail et arrive le plus près possible des bouteilles.The external face of the rapid jets (bottle side) arrives at the limit of the conveyor line 20 constituting the work station and arrives as close as possible to the bottles.

A partir des caissons 23 symétriques, des jets lents sont émis sur au moins toute la longueur de la ligne de convoyage et sur au moins toute sa largeur, le dard de chacun des jets étant réglé pour que sa portée soit égale à la largeur de l'ouverture.From symmetrical boxes 23, slow jets are emitted over at least the entire length of the conveying line and over at least its entire width, the sting of each of the jets being adjusted so that its range is equal to the width of the 'opening.

Le courant de gaz propre à vitesse lente est émis à partir du caisson central 24. Il couvre tout le volume de l'enceinte et est émis parallèlement aux deux rideaux de gaz.The stream of clean gas at slow speed is emitted from the central box 24. It covers the entire volume of the enclosure and is emitted parallel to the two gas curtains.

Les figures ci-dessus décrites n'apportent pas de limitation à l'invention, dont le domaine d'application n'est pas limité à l'industrie agroalimentaire.The figures described above do not provide any limitation to the invention, the scope of which is not limited to the food industry.

A titre d'exemple, on a isolé un poste de travail situé dans une enceinte telle que celle de la figure 1, avec
   longueur de l'ouverture = 1,20 m
   largeur de l'ouverture = 0,80 m
   profondeur de l'enceinte = 0,70 mFor example, we isolated a workstation located in an enclosure like that of Figure 1, with
opening length = 1.20 m
opening width = 0.80 m
enclosure depth = 0.70 m

On a dimensionné
   fente de jet rapide = 6 mm inclinées de 12° par rapport
   fente de jet lent = 200 mm à la verticale, et vers l'extérieur
   débit jet rapide = 100 m³/h
   débit jet lent = 440 m³/h
   vitesse du dard du jet lent = 0,4 m/s
   vitesse jet rapide = 4 m/s
   débit courant de gaz propre = 470 m³/h
   vitesse courant de gaz propre = 0,15 m/s
température de l'enceinte = + 3°CWe have dimensioned
fast jet slot = 6 mm inclined 12 ° from
slow jet slot = 200 mm vertically, and outwards
fast jet flow = 100 m³ / h
slow jet flow = 440 m³ / h
speed of the slow jet sting = 0.4 m / s
fast jet speed = 4 m / s
current flow of clean gas = 470 m³ / h
current speed of clean gas = 0.15 m / s
enclosure temperature = + 3 ° C

Claims (11)

  1. Method for maintaining a clean atmosphere at controlled temperature at a workstation (1), said workstation (1) being accessible from a contaminated zone through at least one opening (5), method comprising generating on the one hand, at the level of said opening (5), a curtain of gas which covers the whole length of said opening (5) and, on the other hand, on said workstation (1) a stream of clean gas of controlled temperature which is directed so as to prevent contaminants from entering and to sweep evenly said workstation (1), characterized in that:
    - said gas curtain consists in a slow jet and in a fast jet; said slow jet comprising an inner cone of range equal to the width of said opening (5), said fast jet having a flowrate induced by its innner face in contact with the slow jet, which is equal to the injection flowrate of said slow jet; said fast jet being situated at the level of said opening (5) on the workstation side (1); said slow and fast jets being directed substantially in parallel to said opening (5) such that at least the outer face of said fast jet reaches to the limit of said opening (5);
    - the flowrate of said stream of clean gas is at least equal to the flowrate supplying the external face of said fast jet,
    - if necessary, the gas blown-in in the form of jets and stream, is sucked in at the level of said opening (5) and in facing relationship to the injection zone of the jets.
  2. Method according to claim 1, characterized in that the speed of the slow jet is comprised between 0.4 and 0.6 m/sec.
  3. Method according to one of claims 1 or 2, characterized in that the stream of clean gas is sent in a direction perpendicular to the plane of the opening (5), and, from the volume to be kept clean towards the contaminated zone.
  4. Methods according to one of claims 1 or 2, characterized in that the stream of clean gas is sent in a direction substantially parallel to the plane of the opening (5) and in the same direction as the jets.
  5. Device for carrying out the method according to any one of claims 1 to 4, comprising:
    - an enclosure in which is situated the workstation (1), said workstation (1) being accessible from the outside through at least one opening (5) of said enclosure,
    characterized in that it further comprises:
    - two nozzles (7, 8) placed side by side, on one side of said opening (5) for injecting gas in the form of jets; the length of the nozzles (7, 8) being equal to that of the opening (5), the size of the slot in each nozzle (7, 8) being determined as a function of the speed and of the range of the jet, said nozzles (7, 8) being so oriented that at least the external face of the fast jet reaches to the limit of said opening (5);
    - at least one means (9) for injecting the stream of clean gas, said means (9) being selected and disposed so that the gas is uniformly distributed in said enclosure and in such a way that the stream of clean gas arrives approximately in a direction perpendicular or parallel to the plane of the opening (5),
    - pipe systems and means for supplying gas to said nozzles (7, 8) and to said means (9) for injecting the stream of clean gas;
    - optionally, a suction device for sucking in the gases blown-in in the form of jets and stream inside said enclosure.
  6. Device according to claim 5, characterized in that the workstation (1) constitutes the floor of said enclosure.
  7. Device according to any one of claims 5 or 6, characterized in that said enclosure comprises at least two lateral walls, perpendicular to the flowing path of the jets and extended beyond said opening (5) over a distance at least equal to the thickness of said jets at the level of their effective range.
  8. Device according to claim 7, characterized in that said enclosure comprises a back wall (4) facing said opening (5) and in that said perforated back wall (4) is a diffusing wall for the stream of clean gas.
  9. Device according to claim 7, characterized in that the wall (21) on which are fixed the nozzles is a perforated diffusing wall for the stream of clean gas.
  10. Device according to one of claims 5 or 6, characterized in that said bell-shaped enclosure (12) comprises at its top part nozzles (16) for injecting clean gas along the walls of said bell and through its volume.
  11. Device according to any one of claims 5 to 10, characterized in that the external face of the fast jet reaches up to the opening (5) and in that it comprises a suction opening (10, 19) for sucking in the gases, which suction opening is situated in the contaminated zone.
EP90914739A 1989-10-02 1990-10-01 Method and device for maintaining a clean atmosphere at controlled temperature at a workstation Expired - Lifetime EP0494921B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR8912861A FR2652520B1 (en) 1989-10-02 1989-10-02 METHOD AND DEVICE FOR MAINTAINING A CLEAN ATMOSPHERE WITH REGULATED TEMPERATURE ON A WORKSTATION.
FR8912861 1989-10-02
PCT/FR1990/000700 WO1991005210A1 (en) 1989-10-02 1990-10-01 Method and device for maintaining a clean atmosphere at controlled temperature at a workstation

Publications (2)

Publication Number Publication Date
EP0494921A1 EP0494921A1 (en) 1992-07-22
EP0494921B1 true EP0494921B1 (en) 1995-02-08

Family

ID=9386010

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90914739A Expired - Lifetime EP0494921B1 (en) 1989-10-02 1990-10-01 Method and device for maintaining a clean atmosphere at controlled temperature at a workstation

Country Status (9)

Country Link
US (1) US5312294A (en)
EP (1) EP0494921B1 (en)
JP (1) JPH0833223B2 (en)
AT (1) ATE118268T1 (en)
DE (1) DE69016793T2 (en)
DK (1) DK0494921T3 (en)
ES (1) ES2071116T3 (en)
FR (1) FR2652520B1 (en)
WO (1) WO1991005210A1 (en)

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FI88541C (en) * 1991-04-23 1993-05-25 Ilmateollisuus Oy Method and apparatus for providing an air exchange for a treatment room
JPH04327736A (en) * 1991-04-30 1992-11-17 Mitsubishi Heavy Ind Ltd Fluid suction nozzle and fluid treatment device
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
FR2740205B1 (en) * 1995-10-23 1998-01-09 Unir Ultra Propre Nutrition In PROTECTION AGAINST AEROCONTAMINATION
FR2750199B1 (en) * 1996-06-21 1998-09-11 Cemagref Centre National Du Ma METHOD AND DEVICE FOR THE CLOSE PROTECTION OF A WORKTOP USING A CLEAN AIR FLOW
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
KR100709495B1 (en) * 1998-09-15 2007-04-20 지멘스 악시파 게엠베하 운트 콤파니 카게 Method and device for protecting persons and/or products from air-borne particles
US6626971B1 (en) 1998-09-15 2003-09-30 Siemens Axiva Gmbh & Co. Kg Method and device for protecting persons and/or products from air-borne particles
DE10046200C1 (en) * 2000-09-19 2002-05-23 Alfred Schneider Channel for pure air conditions
FR2824626B1 (en) 2001-05-14 2004-04-16 Pierre Bridenne METHOD AND DEVICE FOR BROADCASTING A PROTECTIVE FLOW WITH REGARD TO AN ENVIRONMENT
US8796589B2 (en) * 2001-07-15 2014-08-05 Applied Materials, Inc. Processing system with the dual end-effector handling
DE10226710B4 (en) * 2002-06-14 2004-05-13 Pöpplau, Jens H., Dr.-Ing. Device for removing foreign air from a clean room
ITBO20030375A1 (en) * 2003-06-19 2004-12-20 Ima Spa STRUCTURE FOR ROOFING AND INSULATION FROM THE ENVIRONMENT
AU2004203649B2 (en) 2003-08-12 2006-01-12 F. Hoffmann-La Roche Ag Thermostable Taq polymerase fragment
US20080311837A1 (en) * 2007-06-12 2008-12-18 United Microelectronics Corp. Preventive maintenance hood
CN103959048B (en) * 2011-10-04 2018-04-06 株式会社尼康 The manufacture method of X-ray apparatus, x-ray irradiation method and structure
FR3032391B1 (en) * 2015-02-06 2018-09-21 Alstom Transport Technologies DEVICE FOR GENERATING AN AIR CURTAIN, ESPECIALLY FOR EQUIPPING A RAILWAY VEHICLE
WO2020050228A1 (en) * 2018-09-06 2020-03-12 日本スピンドル製造株式会社 Booth and spouting device
FR3093454B1 (en) * 2019-03-07 2022-01-28 Hydro Fill HANDLING ELEMENT INCLUDING A GLOVE

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FR1257562A (en) * 1960-05-25 1961-03-31 Carrier Soc Method and device for maintaining an atmosphere having determined characteristics in a chamber open on one side
US3771323A (en) * 1972-05-17 1973-11-13 Dualjet Corp Refrigerated reach-in display compartment
FR2461205A1 (en) * 1979-07-09 1981-01-30 Sofrair Work post for materials giving off hazardous fumes - has double air curtain comprising two air streams with different velocities and with individual flow regulation
FR2530163B1 (en) * 1982-07-15 1986-08-29 Commissariat Energie Atomique METHOD FOR CONTAINING THE POLLUTION OF A PREMISES USING A GAS VEIN
FR2659782B1 (en) * 1990-03-14 1992-06-12 Sgn Soc Gen Tech Nouvelle METHOD AND DEVICE FOR DYNAMIC SEPARATION OF TWO ZONES.

Also Published As

Publication number Publication date
US5312294A (en) 1994-05-17
FR2652520B1 (en) 1992-02-07
JPH0833223B2 (en) 1996-03-29
DE69016793D1 (en) 1995-03-23
FR2652520A1 (en) 1991-04-05
WO1991005210A1 (en) 1991-04-18
ATE118268T1 (en) 1995-02-15
ES2071116T3 (en) 1995-06-16
JPH05500849A (en) 1993-02-18
EP0494921A1 (en) 1992-07-22
DE69016793T2 (en) 1995-06-22
DK0494921T3 (en) 1995-04-10

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