EP0830549B1 - Close contamination protection device - Google Patents

Abstract

PCT No. PCT/FR96/00563 Sec. 371 Date Jan. 16, 1998 Sec. 102(e) Date Jan. 16, 1998 PCT Filed Apr. 12, 1996 PCT Pub. No. WO96/32613 PCT Pub. Date Oct. 17, 1996A method for closely protecting materials (10) sensitive to contamination by airborne contaminating agents and placed on a work surface (P). At least one decontaminated gas stream (1, 2) is fed from either side towards the materials in a direction substantially parallel to the work surface, and each gas stream (3) leaves the work surface in an intermediate area between the edges of the work surface and in a direction substantially perpendicular thereto. Alternatively, at least one gas stream is fed towards the materials from above the work surface at an intermediate area between the edges thereof, and in a direction substantially perpendicular thereto, and each gas stream leaves the work surface in a direction substantially parallel thereto and on either side of the materials.

Description

The present invention relates generally to the protection close to a work station located in a contaminated atmosphere, and more particularly a process and a device for close protection of products sensitive to contamination by contaminating agents conveyed by the atmosphere, said products being positioned on a work surface.

The problem of protecting workstations against air contamination arises in particular in the food industry, the pharmaceutical industry or still in the hospital environment.

In general, to respond to this type of problem, workstations are located in so-called "white" rooms in which the air is filtered and treated so that the level of dust is below a threshold. admissible controlled and subject to strict regulations.
In addition, the air circulating in these clean rooms is often regulated at a low temperature.

The personnel having to work in such work stations must be covered with painful specialized outfit to put on and wear.

Close protection of each individual workstation is a solution to the aforementioned drawbacks.

Document FR-A-2 485 700 teaches a process (and associated device) for close protection of the workstation against contamination carried by the atmosphere, according to which we create a single vertical flow descending towards products, this flow on the one hand having dimensions equal to or greater than those the workstation to be protected so as to completely cover it with sterile air, and on the other hand evacuating the work plan on a single rear side thereof.

However, this close protection must take into account the fact that the personnel working at these workstations must intervene manually on the products sensitive to aerocontamination. This prohibits for such protection close use of any vertical sterile air flow whose dimensions are equal to or greater than that of the position to be protected so as to completely cover sterile air said station because such a flow would reduce contamination on the products from operators' hands and forearms.

Finally we know from document US-A-4 872 400 a device for protecting the external environment, releases of harmful film from reactions chemicals performed at a work station. According to the teachings of this document, there is a protective hood mounted on a laboratory bench, this hood being able to produce above a work surface a stream of fresh air which first presents an inclined path that deviates from the work plane, then a path horizontal substantially parallel to the work surface towards a discharge pipe which is located in the lower part.

However, such a device is not suitable for protecting against the external contamination of products sensitive to contaminants, disposed on a horizontal plane where it is planned to intervene manually, because with such a path air stream, all the contaminants would be automatically brought down on the products in question.

In this context, the invention proposes a new protection method close-up of products sensitive to air contamination by contaminating agents conveyed by the atmosphere, in accordance with the characteristics of claim 1.

The invention also provides a method according to claim 2.

Thus, the products positioned on the worktop are isolated from the environment contaminated by a flow of decontaminated gas which covers them, and which either flows vertically down towards the worktop and then transversely to the edges of said plane, ie from the edges of said work plane transversely to said products, then vertically upwards from said workplan.

Contamination brought by personnel working on products sensitive positioned on the work surface is then automatically driven by the flow of decontaminated gas along either path, towards the outside of said path work plan without this contamination reaching said products.

In addition, it should be noted that the dimensions of each flow stream are optimized.

One embodiment of the method conforms to the characteristics of the claim 3.

According to a particularly advantageous characteristic of the conforming process in the invention, each gas stream is sucked above said products or conversely, each gas stream is sucked on either side of said products.

So, sucking the veins of sterile gas carrying the particles contaminated, we avoid, if necessary, the fallout of contaminated particles heavier on the products.

According to an advantageous characteristic of this embodiment of the method according to the invention, the products being aligned on a conveyor belt which runs according to direction X, we direct from the longitudinal edges of said mat, two veins of decontaminated gas towards the middle of said conveyor belt and said veins are aspirated gas in the plane of symmetry of said mat, or vice versa we direct in the plane symmetry of the conveyor belt, a stream of decontaminated gas towards the belt and sucks towards the longitudinal edges of said conveyor belt the gas streams decontaminated.

The method according to the invention can be improved to adapt it to the work or conveyor belt which are not tightly connected to the frame. according to this variant, we direct a vein of decontaminated gas on the sides and under the plane of work or conveyor belt so that the work surface or conveyor belt conveying is enveloped by the protective veins.

In the case of a conveyor belt where only the belt traction chain creates a lack of tightness allowing the induction of contaminated air, the process according to the invention consists in blocking induction by deflecting part of each vein of decontaminated gas substantially parallel to the work plan, previously described, toward the edges of said mat.

The invention also provides a close protection device according to claim 8 and a device according to claim 9.

According to a characteristic of the device according to the invention, it is possible to provide means for suction of the blown decontaminated gas.

According to a first embodiment of the protection device according to the present invention, the insufflation means comprise at least one inlet for gas and at least two decontaminated gas outlets facing each other, each gas outlet in the form of a slot positioned on one side of the plane and extending longitudinally to the direction X of positioning of the products.

According to an advantageous characteristic of this first embodiment of the device according to the invention, suction means comprise a mouth suction placed above the work surface next to said products, in a middle region located between the two decontaminated gas outlets of the appliance insufflation.

According to a second embodiment of the conforming protection device in the present invention, the insufflation means comprise a gas inlet, and a decontaminated gas outlet positioned opposite the products above the plane of work in a middle region of said work plan.

According to this embodiment of the suction means comprise two suction ports arranged opposite one another, each suction port in the form of a slot positioned on one side of said work surface and extending longitudinally to said direction X.

The protection device can be improved to adapt it to unsealed work.

According to a first variant, the device comprises means additional insufflation including at least one gas inlet which can be that of the main insufflation means and at least two gas outlets decontaminated opposite each other, each gas outlet being under the form of a slot positioned at the edge and under the worktop and extending longitudinally to the product positioning direction X. The gas veins evacuating according to the plane of symmetry perpendicular to the work plane.

According to a second variant, the device comprises a lower duct allowing a vein of gas to circulate along the underside as well as the along the edges of the work surface or conveyor belt.

According to another variant adapted to a conveyor belt where only the chain traction of the carpet creates a lack of tightness allowing air induction contaminated, the insufflation means comprise at least one gas inlet and at minus two decontaminated gas outlets opposite each other, each outlet gas in the form of a slot positioned on one side of the worktop and extending longitudinally to the product positioning direction X and are provided with an aerodynamic means ensuring the deflection of part of the vein of decontaminated gas along the edges of said conveyor belt in a direction perpendicular to the plane thereof.

The following description with reference to the accompanying drawings, given as non-limiting examples, will make it clear what the invention consists of, and how it can be achieved.

• la figure 1 est une vue schématique en perspective d'un dispositif de protection rapprochée conforme à l'invention, monté sur un poste de travail,
• la figure 2 est une vue schématique en coupe verticale d'une partie d'un appareil d'insufflation faisant partie du dispositif de protection rapprochée conforme à l'invention,
• la figure 3 est une vue schématique de face d'une variante de réalisation du dispositif de protection rapprochée de la figure 1.
• la figure 4 est une vue schématique en coupe transversale d'une variante de réalisation du dispositif de protection pourvu de moyens d'insufflation auxiliaires.
• la figure 5 est une vue schématique en coupe transversale d'une autre variante de réalisation du dispositif de protection pourvu de moyens d'insufflation auxiliaires.
• la figure 6 est une vue schématique en coupe transversale d'une autre variante de réalisation du dispositif de protection pourvu d'un moyen aérodynamique de déviation de la veine de gaz horizontale.

In the accompanying drawings:

• FIG. 1 is a schematic perspective view of a close protection device according to the invention, mounted on a work station,
• FIG. 2 is a schematic view in vertical section of part of an insufflation apparatus forming part of the close protection device according to the invention,
• FIG. 3 is a schematic front view of an alternative embodiment of the close protection device of FIG. 1.
• Figure 4 is a schematic cross-sectional view of an alternative embodiment of the protection device provided with auxiliary insufflation means.
• Figure 5 is a schematic cross-sectional view of another alternative embodiment of the protection device provided with auxiliary insufflation means.
• Figure 6 is a schematic cross-sectional view of another alternative embodiment of the protection device provided with an aerodynamic means for deflecting the horizontal gas stream.

In Figure 1, there is shown a work station comprising a frame 30 supporting a work plan P on which are arranged in file in a direction horizontal X of products 10 sensitive to air contamination, for example foodstuffs. We can predict that the work plan P is formed by a mat conveyor capable of scrolling said products 10 in the direction X.

The personnel who must work on these sensitive products 10, position themselves on either side of the frame 30 and intervenes on the products 10 from above.

On the frame 30, is mounted a device for close protection of the products 10.

This device includes an insufflation apparatus 200 for a decontaminated gas comprising on each longitudinal side (only one of which is visible here) of said plane of work P, here two inputs 201 of a decontaminated gas, for example sterile air. Obviously, according to variants not shown, a number top of decontaminated gas inlets. These inputs 201 are positioned remotely from each other on each longitudinal side of said work plan P and open out in an enclosure provided with a sterile air outlet 202 in the form a slot extending longitudinally to said direction X over the entire length of the side of the worktop P. The two outlet slots 202 of the insufflation device are located at the level of the work plan P on which the products 10 and are arranged opposite each other.

In addition, the device shown in Figure 1, includes an apparatus suction 100 of the blown decontaminated gas, comprising a suction mouth 101 in the form of a slot, extending longitudinally at the product positioning direction X, and positioned above the plane of work P, opposite said products in a middle region of the work plan located between the two outlet slots 202 of the insufflation apparatus 200.

The suction device 100 here has two air outlets 102 located above from the suction mouth 101 so that they allow evacuation towards the high the gas flow 102 aspirated. These two gas outlets 102 are positioned at distance from each other near the end edges of said mouth suction 101. Of course, according to a variant not shown, one can provide more gas outlets.

The suction device 100 is mounted integral with the insufflation device 200 using support arms 110 so that it hangs above the plane of work P. Here there are four support arms 110 arranged in pairs, each pair support arm 110 is positioned on either side of the suction mouth 101 and is fixed on the one hand to the suction device 100 and on the other hand, to an enclosure insufflation device 200.

Such a device operates in the following manner.

A sterile air flow enters the blowing device 200 through the inlets 201 and is distributed on the products through the outlet slots 202 of said device insufflation so that the sterile air leaving said slots 202 follows a path A directed essentially parallel to said plane P, transversely to said direction X. The sterile air coming from these slots 202 then licks the products 10 located on the plane of work P. Simultaneously, the suction device 100 sucks in through its mouth suction 101 sterile air from the outlet slots 202 of the insufflation apparatus. The air from the outlet slots 202 of the suction device is therefore sucked into a middle region of the work plane P so that the path A of the sterile air flow is deflected upward perpendicular to said work plane P on which are positioned products 10. Two main veins of sterile air 1, 2 come out said outlet slots 202. These two veins 1, 2 are directed towards each other and meet in a middle region of the work plane to form a vein upwardly directed flow perpendicular to said work plane P in direction of the suction mouth 101.

Of course, according to a variant not shown of the device of FIG. 1, one can consider eliminating the suction device. In this case, the sterile air jets from the exit slots meet face to face, in the middle region of the plane of work, which has the effect of naturally creating a central vein which evacuates in a vertical direction perpendicular to said direction X upwards from said plan by entraining contaminated particles.

In Figure 3, there is shown another alternative embodiment of the device of figure 1.

According to this variant, the insufflation device 200 of decontaminated gas is mounted above the worktop P, and the suction device is positioned on the frame 30, along the longitudinal sides of said work plane P, longitudinally at the product positioning direction X 10.

The insufflation device 200 is mounted integral with the suction device 100 via the same support arm system 110 already described above.

The insufflation device 200 has a gas inlet 201 and a decontaminated gas outlet 202. This sterile gas outlet 202 is in the form a slit extending longitudinally in the direction X above the plane P in look of said products 10. The suction device 100 has two mouths suction 101 in the form of two slots 101 extending on the sides longitudinal of said work plan P. These suction outlets 101 are connected to air outlets 102.

Such a variant works in the following manner.

The insufflation device 200 produces, through its outlet 202, a gas stream decontaminated 3 towards products 10 located on plane P. This gas stream decontaminated 3 follows a path A directed perpendicular to said plane P. When this vein of decontaminated gas 3 comes into contact with said plane P, it separates in two flow veins 1, 2 which follow paths A essentially oriented parallel to said plane P and transversely to the positioning direction X of said products 10, in opposite directions so that the veins of sterile air flow lick the products 10 positioned on the plane P. These decontaminated gas flow streams 1, 2 are drawn in through the vents 101 of the suction device 100 so that the gas is evacuated on the sides of worktop P.

Here too, it is of course possible to envisage a variant not shown of the device of Figure 3, not including the suction device. In this case, the two flow veins parallel to the work plan drain naturally on the edges of plane P.

In Figure 2, there is shown in vertical section, a detailed view of inside an embodiment of part of an insufflation apparatus making part of an anti-microbial protection device according to the invention. This mode of embodiment of the insufflation device is a variant of that shown on the figure 1

With reference to this figure 2, the insufflation apparatus comprises on each side of work plan P a gas inlet 201 positioned on the sides of plan P below of said plane P so that the gas entering said apparatus is transported in a vertical upward path toward a slit exit 202 located at the level of said plane P. This insufflation apparatus 200 comprises in a housing which extends vertically on the side of the frame 30, between the inlet 201 and the outlet 202, a grease filter 211 which extends horizontally over the entire width of the box, relative to the vertical direction F of entry of the gas flow into said insufflation device, then successively a pre-filter 212 which also extends over the entire width of the housing, a fan 213 which allows the gas to be transported filtered towards the upper part of the insufflation device 200. This fan 213 is positioned in a baffle path 214 formed by deflectors 214a of the flow of gas so that at the end of this baffled path the flow of filtered gas flows according to the vertical direction F directed upwards from the blower 200. Above of the baffle path 214 is arranged in parallel a pair of absolute filters 215 of which the efficiency is advantageously equal to or greater than that of a very high filter efficiency (standardized filter). These filters 215 extend in said vertical direction F. Above the absolute filters 215 is positioned in a horizontal direction an anti-turbulence grid so as to reduce the turbulence rate of the flow sterile air which opens into an enclosure 217 having an angled path, and converge in order to further reduce the turbulence rate, bringing the flow of decontaminated gas to the slit-shaped outlet 202 directed in one direction substantially transverse to direction X.

It is indeed advantageous to reduce the turbulent diffusion speed (directed perpendicular to the direction of flow) of the particles contaminated entrained by the gas flow to prevent them from reaching the products.

This turbulent diffusion speed is strongly linked to the rate of turbulence, and the size of the vortices present in the flow, reducing the diffusion speed involves reducing the turbulence rate.

In FIG. 4, a workstation P is schematically represented on which are arranged in a file in a horizontal direction X of the products 10 susceptible to air contamination. The worktop is not tightly connected to the rest of frame 30. As a result, there may be an induction of air contaminated by the space left free between the worktop and the frame.

Two additional sterile air outlets 203 are provided, presenting in the form of a slot extending longitudinally to said direction X over any the length at the edges and under the worktop P. An air outlet 202 identical to that described in FIG. 1 and in FIG. 2 is also provided.

The gas stream 204 is distributed on either side of the work plan according to a path bypassing the edges of said plane then sweeping the underside of said plane to the longitudinal center line of said plane where the gas veins meet are directed in a direction perpendicular to said plane.

In FIG. 5 which includes the same work station P not connected to the frame 30 as in Figure 4, a U-profile 205 fixed under the frame forms a conduit bringing a slight overpressure sterile air stream under workstation P preventing any induction of contaminated air by the spaces left free due to the lack of sealing between the frame and the worktop.

In FIG. 6, the device comprises a conveyor belt P, the traction chain (not shown) creates a lack of tightness with the frame 30. The outlets 202 are provided in the lower zone with an elbow 206 creating a conduit 207 diverting part of the sterile air flow towards the edges of the conveyor belt thereby preventing any induction of contaminated air.

Claims (26)

1. A method of closely protecting products (10) that are sensitive to being contaminated by contaminating agents conveyed by the atmosphere, in which method said products (10) are placed on a work surface (P) and at least two streams (1, 2) of decontaminated gas are directed towards said products (10) from either side thereof, the method being characterized in that the streams are directed substantially parallel to said work surface (P) from respective ones of two opposite edges of the work surface, each gas stream (3) being evacuated upwards from the work surface (P) from a middle zone situated between the edges of the work surface (P), in a direction that is substantially perpendicular to said work surface (P).
2. A method of closely protecting products (10) that are sensitive to being contaminated by contaminating agents conveyed by the atmosphere, in which method said products (10) are placed on a work surface (P) and at least one gas stream (3) is directed towards said products (10) from above the work surface (P) in a middle zone of said work surface (P) situated between the edges of said work surface, in a direction that is substantially perpendicular to said work surface (P), the or each gas stream (1, 2) being evacuated from the work surface (P) in a direction that is substantially parallel to said work surface (P), the method being characterized in that the or each stream is directed so that it is evacuated on either side of said products (10) towards each of the edges of said work surface.
3. A method according to claim 1 or claim 2, characterized in that the products are disposed in a horizontal direction X, and two streams (1, 2) of decontaminated gas are directed towards said products (10) from either side of said direction X in a direction Y that is substantially transverse to said direction X, and said gas streams (3) are evacuated upwards in a vertical direction Z that is substantially perpendicular to said direction X, or conversely a stream (3) of decontaminated gas is directed towards said products (10) from above the work surface (P) in the vertical direction Z that is substantially perpendicular to said direction X, said gas stream (1, 2) being evacuated in the direction Y that is substantially transverse to said direction X, on either side of said direction X towards each of the edges of the work surface.
4. A method according to any one of claims 1 to 3, characterized in that each gas stream (3) is sucked-up from above said products (10), or conversely each gas stream (1, 2) is sucked-in on either side of said products (10).
5. A method according to claim 3 or claim 4, characterized in that the products (10) are aligned on a conveyor belt (P) which moves in the direction X, and two streams (1, 2) of decontaminated gas are directed from the longitudinal edges of said belt towards the middle of said conveyor belt (P) and a gas stream (3) is sucked into the plane of symmetry of said conveyor belt (P), or conversely a stream (3) of decontaminated gas is directed on the plane of symmetry of said conveyor belt (P) towards said conveyor belt (P), and the gas streams (1, 2) are sucked towards the longitudinal edges of said conveyor belt (P).
6. A method according to claim 5, characterized in that when the work surface (P) or conveyor belt is not connected in sealed manner to a frame (30) of the work surface, an additional stream (204) of decontaminated gas is directed over the sides and under the work surface in such a manner that the work surface is surrounded by the streams (1, 2) situated above the work surface and by the additional gas stream (204).
7. A method according to claim 6, characterized in that when a leak is created between the frame and the conveyor belt by the traction chain of said belt, the induction of contaminated air is blocked by deflecting a portion of each stream (1, 2) of decontaminated gas towards the edges of said belt.
8. A device for closely protecting products (10) that are sensitive to being contaminated by contaminating agents conveyed by the atmosphere, the products (10) being positioned on a work surface (P), the device including blower means (200) that are capable of producing at least two streams (1, 2) of decontaminated gas from either side of said products (10) and towards the products (10), the device being characterized in that each stream (1, 2) of decontaminated gas follows a path that is oriented firstly substantially parallel to said work surface (2) so that each stream (1, 2) of decontaminated gas flows over said products (10), and is then directed upwards from a middle zone of the work surface (P) situated between the edges of said work surface, substantially perpendicular to said work surface (P).
9. A device for closely protecting products (10) that are sensitive to being contaminated by contaminating agents conveyed by the atmosphere, the products (10) being positioned on a work surface (P), the device including blower means (200) that are capable of producing at least one stream (1, 2) of decontaminated gas from either side of said products (10) and towards the products (10), each stream (1, 2) of decontaminated gas following a path that is firstly directed towards said products (10) from above the work surface (P), and substantially perpendicular to said work surface (P), in a middle zone of said work surface (P) situated between the edges of said work surface, the device being characterized in that the path is then oriented substantially parallel to said work surface (P) on either side of said products (10) towards each of the edges of said work surface.
10. A protection device according to claim 8 or claim 9, characterized in that it includes suction means (100).
11. A protection device according to claim 10, characterized in that the blower means (200) are mounted by being fixed to the air suction means (100), or vice versa.
12. A protection device according to any one of claims 8 to 11, characterized in that for products (10) disposed in a direction X, the blower means (200) are capable of blowing two streams (1, 2) of decontaminated gas from either side of said product-positioning direction X, the two gas streams being directed towards each other in a direction Y that is transverse to said direction X.
13. A protection device according to claim 12, characterized in that the blower means (200) comprise at least one gas inlet (201), and at least two facing outlets (202) for decontaminated gas, each gas outlet (202) being in the form of a slit positioned on one side of the work surface (P) and extending longitudinally relative to the product-positioning direction X.
14. A protection device according to any one of claims 12 to 13, characterized in that it includes suction means (100) that are capable of sucking the two gas streams (1, 2) up above the product-positioning work surface so as to form a common stream directed in a direction Z that is perpendicular to said surface (P).
15. A protection device according to claim 14, characterized in that the suction means (100) include an intake opening (201) disposed above the surface (P) facing said products (10), in a middle zone between the two decontaminated-gas outlets (202) of the blower means (200).
16. A protection device according to any one of claims 8 to 11, characterized in that for products (10) disposed in a direction X, the blower means (200) are capable of blowing a stream (3) of decontaminated gas towards the products (10) from above the work surface (P) on which the products are positioned.
17. A protection device according to claim 16, characterized in that the blower means (200) comprise an inlet (201) for decontaminated gas, and a decontaminated-gas outlet (202) positioned above said work surface (P), in a middle zone of said work surface (P), and facing the products (10).
18. A protection device according to claim 16 or 17, characterized in that it includes suction means (100) that are capable of sucking-up, on either side of said product-positioning direction X, the gas stream (3) that is separated into two gas streams (1, 2) that are directed transversely to said direction X in opposite directions.
19. A protection device according to claim 18, characterized in that the suction means (100) include two intake openings (101) disposed facing each other, each intake opening (101) being in the form of a slit positioned on one side of the work surface (P) and extending longitudinally relative to said direction X.
20. A protection device according to claim 13 or claim 17, characterized in that the blower means (200) successively include between each inlet (201) for decontaminated gas and each outlet (202) for decontaminated gas, at least air filtering means (211, 212, 215) and transport means (213) for transporting the gas from the inlet (201) to the outlet (202).
21. A protection device according to claim 20, characterized in that the blower means (200) further include anti-turbulence means (216) placed in the vicinity of said outlet (202) for decontaminated gas.
22. A protection device according to claim 20 or claim 21, characterized in that the air filtering means comprise at least one filter (215) having efficiency that is not less than that of a very high efficiency filter, and in that the transport means comprise a fan (213).
23. A protection device according to claim 8 or claim 9, characterized in that the device includes additional blower means comprising at least one gas inlet which can be the same as that of the main blower means and at least two facing outlets (203) for decontaminated gas, each gas outlet being in the form of a slit positioned on the edge and under the work surface, and said outlet extending longitudinally relative to the product-positioning direction X, the gas streams being evacuated in the plane of symmetry perpendicular to the work surface.
24. A protection device according to claim 8 or claim 9, characterized in that the device includes a bottom duct (205) that enables a stream of gas to circulate along the bottom face and along the edges of the work surface.
25. A protection device according to claim 8 or claim 9, characterized in that when a leak is created by the chain of the conveyor belt, thereby enabling contaminated air to be induced, the blower means comprise at least one inlet (201) for decontaminated gas, and at least two facing outlets (202) for decontaminated gas, each gas outlet (202) being in the form of a slit positioned on one side of the work surface and extending longitudinally relative to the product-positioning direction X, and each gas outlet is provided with aerodynamic means (206) for deflecting a portion of the stream of decontaminated gas along the edges of said conveyor belt in a direction that is perpendicular to the plane of said conveyor belt.
26. A protection device according to claim 25, characterized in that the aerodynamic means is a bend (206) situated in the bottom zone of the gas outlets (202), said bend deflecting a portion of the sterile-air flow towards the edges of the conveyor belt.

Images