GB2042099A - Fluid seal for safety enclosures - Google Patents

Abstract

An enclosure for the secure containment and handling of noxious materials has one or more transfer ports 46, 47 each surrounded by a trough 49 containing decontaminating or neutralising medium 54 and each transfer port may be closed by a removable cover plate having downwardly projecting side walls which fit into the trough and extend below the level of the medium. Preferably the upper enclosure has, in its lower surface, a transfer port surrounded by a downwardly extending trough 50, 51 containing decontaminating or neutralising medium 55, 56. A cover plate 52, 53 to close the transfer port has a rim extending into the medium in the trough. The cover plates may be removed to allow communication between the upper and lower enclosures without breaking the fluid seal. The lower enclosure may be provided with means for sterilisation. <IMAGE>

Description

SPECIFICATION Fluid seal for safety enclosures The present invention relates to a means for reversibly connecting together safety cabinets, and to systems of safety enclosures incorporating such means and especially to fluid seals for modular safety chambers for total microbiological containment.

In chemical or biological research laboratories it is frequently necessary to handle materials or organisms which may be harmful to humans, or potentially dangerous if allowed to contaminate the atmostphere. Similarly, some materials are highly sensitive to certain components of the atmosphere and require to be maintained under conditions, where these components are rigorously excluded. In all these cases it is necessary to provide safe, air-tight enclosures in which the materials can be handled.

Conventionally such safety enclosures or cabinets are provided with elaborate air-lock systems to allow either access from the exterior or movement between cabinets without altering the conditions within said cabinets. In the case of biological use at least, the air-locks may have means provided for sterilising articles and materials passing through them. An alternative means of access from the exterior or movement between enclosures that maintains a steady state within the cabinets during biological use, comprises a tank of sterilising liquid extending through or under a wall of the chamber so that articles can be introduced or removed from the chamber by pushing them under the lower lip of the wall through the sterilising liquid.This is a rather inconvenient procedure when material is to be passed between cabinets, especially when there is no necessity to isolate the enclosures from each other and these precautions are only necessary because the materials must pass through the external atmosphere between the enclosures. It is, accordingly, an object of the present invention to provide a direct means of communication between respective cabinets, which is easily connected, disconnected or closed off as required.

According to the present invention there is provided an enclosure for the secure containment and handling of noxious materials having one or more transfer ports each surrounded by a trough to contain a liquid or semi-liquid decontaminating or neutralising medium. In use each trough may be filled with decontaminating or neutralising medium and the one or more transfer ports may be closed by removable cover plates each having side-walls to fit into said trough and to extend below the level of the decontaminating or neutralising medium in said trough to close said ports.

In one advantageous embodiment of this invention at least one of the troughs of the enclosure extends around a transfer port on a lower surface of said enclosure and is capable of receiving a cover plate inserted from within said enclosure. In use, said trough may itself be inserted into a similar, but wider, trough in the upper surface of a second, lower enclosure. If both troughs are filled with decontaminating or neutralising medium then, when the cover plate is removed, connection is made between the upper and lower enclosures without contacting the surrounding atmosphere or passing through a liquid-filled "dunk-tank".

In another aspect of the invention, there is provided a connecting enclosure having at least two transfer ports each surrounded by a trough to receive a decontaminating or neutralising medium.

The transfer ports may each be surrounded by a separate trough or may be surrounded by a common trough. In use neutralising medium is placed in the trough or troughs which may then receive downwardly projecting portions of the enclosures to be connected. Said downwardly projecting portions are preferably themselves troughs, filled with neutralising medium and capable of being closed by cover plates as described above.

The connecting enclosure will normally be substantially empty and provide an open channel between the enclosures to be connected. However, where it is necessary to isolate the said enclosures from each other, the connecting enclosure may itself be filled with a neutralising medium and will then function as a removablë dunk-tank, but communicating directly with the enclosures rather than via the surrounding atmosphere as would occur with conventional fixed dunk-tanks.

The aforementioned enclosures are preferably provided with sterilising means so that their interiors may be sterilised before and/or after use. In a particular aspect of this invention the aforementioned connecting enclosure may be sealed to the enclosures to be connected and then the interior of the connecting enclosure may be sterilised before the cover plates of the other enclosures are removed. After transfers between said other enclosures are complete, the cover plates may be replaced and the connecting enclosure again sterilised before removing it and exposing it to the atmosphere. Said sterilising means may, for example, comprise a source of ultra-violet light or means for introducing and subsequently removing a sterilising liquid.Alternatively or additionally the enclosure may be provided with means for otherwise controlling the atmosphere within it, for example desiccating means or means for flushing with a decontaminating gas.

The decontaminating or neutralising medium may be liquid or semi-liquid. The terms semi-liquid as used herein is intended to cover any medium which will allow the ready introduction into and removal of the wall portion from the trough. Semi-liquid media according to this definition will include gels, greases and soft fats. The decontaminating or neutralising medium may be a pure liquid, eg formaldehyde or other decontaminating medium, or a solution eg any of the well known disinfectant solutions. Where the noxious material it is sought to enclose is, on the other hand, a highly reactive chemical, the liquid medium may conveniently comprise any liquid which is inert to the chemical or which will neutralise the chemical.

The enclosures may be any approved type of safety cabinets, and may for example be manufac tured by either moulding or pressing materials such as metal or plastic into the correct shape. Alternatively they may be made by either welding or bolting parts, composed of said materials, together. Reinforced plastic enclosures manufactured, for exam ple, from a glass-reinforced plastic composition, may be particularly suitable when the materials being handled are not hostile to such a composition.

The enclosures may include windows of either glass or a transparent polymeric substance, such as polymethylmethacrylate, or in another embodiment, they may be prepared in toto from such materials.

The invention will now be further described with reference to the accompanying drawings in which a variety of enclosure systems are illustrated.

In Figure 1 of the drawings, two enclosures 1 and 2 are shown, with the enclosure 1 supported by the top of the enclosure 2 on blocks 3-and 4. Enclosure 1 has a downwardly depending cylindrical extension 5 surrounding a transfer port 6 in the bottom of the member, and the lower ports of the walls of the extension engage in a circular trough 7 provided around an opening 8 in the top of member 2. Trough 7 is filled with a sterilising liquid 9. Communication is thus provided between the interiors of enclosures 1 and 2 via openings 6 and 8.When member 1 is to be removed, or when for any other reason it is desired to close the intercommunication between the two vessels, then a cover plate 10 (shown in outline in the drawing) can be introduced from within member 1 until its downwardly projecting side wall 11 is below the level of the liquid in the trough 7, so that the member 1 can be withdrawn from its engagement (if desired) without the member 2 being exposed to the ambient atmosphere.

Figure 2 of the drawings shows a modification of the apparatus of Figure 1 wherein the upper enclosure has a downwardly depending trough 12 which engages within the trough 7 of the lower enclosure 2 and which itself provides a seating for the cover plate 10. Troughs 7 and 12 are filled with sterilising liquids 9 and 13 respectively, which may be the same or different. In this embodiment enclosure 1 remains sealed when the enclosures are separated.

In Figure 3 of the drawings the lower ends of two independently supported enclosures are shown at 41 and 42. Beneath them is a connecting enclosure 43. This connecting enclosure 43 has two upwardly extending tubes 44 and 45 which surround openings 46 and 47 in the top of enclosure 43 and together with an upward extension 48 of the wall of the enclosure form a trough 49 around said openings.

The upper enclosures 41 and 42 each have a downwardly depending trough 50 and 51 respective ly, which engage within the trough 49 and which themselves provide a seating for cover plates 52 and 53 respectively. Troughs 49, 50 and 51 are filled with sterilising liquids 54, 55 and 56 respectively, which may be the same or different liquids. The transfer enclosure 43 is provided with wheels 57, preferably having a raising and lowering mechanism (not shown) so that it may be inserted or removed from under fixed enclosures 41 and 42.It is further provided with an external pipe 58 communicating with its interior and equipped with a valve 59 so that the enclosure may be filled with sterilising liquid either before and/or after use or for use as a "dunk-tank. Cover plates 52 and 53 are provided with safety filters 60 and 61 respectively in order to allow pressure equilisation between enclosure 43 and each of enclosures 41 and 42, and with handles 62 and 63 respectively to facilitate their removal and replacement.

Figure 4 contains substantially all the elements 41 to 63 of Figure 3 and the two independently supported enclosures 41 and 42 are extended by means similar to those described in our copending patent application No.7901446, Serial No. 2042100.

The outwardly extending base units 71 and 72 of the upper enclosures 41 and 42 are joined perpendicularly to downwardly extending walls 73 and 74.

Said walls 73 and 74 fit into troughs 75 and 76 which are formed by U-shaped members 77 and 78 and which contain decontaminating or neutralising medium 79 and 80. To the bottom of the U-shaped members 77 and 78 are welded downwardly extending walls 81 and 82 which in turn fit into troughs 83 and 84 formed by U-shaped members 85 and 86 and containing decontaminating or neutralising medium 87 and 88. Again, to the bottom of the U-shaped members 85 and 86 are welded further downwardly extending walls 89 and 90 which in turn are welded perpendicularly to metal base units 91 and 92.

Claims (19)

1. An enclosure for the secure containment and handling of noxious materials having one or more transfer ports each surrounded by a trough to contain a liquid or semi-liquid decontaminating or neutralising medium.

2. An enclosure according to Claim 1 wherein at least one transfer port is provided with a removable cover plate having side walls to fit into the said trough and in use to extend below the level of the medium in said trough to close said port.

3. An enclosure according to either Claim 1 or Claim 2 wherein at least one of said troughs extends around a transfer port on a lower surface of said enclosure and is capable of receiving a cover plate inserted from within said enclosure.

4. An enclosure according to any preceding Claim provided with at least two such transfer ports each surrounded by such a trough to receive downwardly projecting portions of other enclosures to form a connecting enclosure between said other enclosures.

5. An enclosure according to Claim 4 wherein at least two transfer ports are surrounded by a single, common trough.

6. An enclosure according to Claim 4 or Claim 5 connected to at least one other enclosure by means of a downward projection of said other enclosure inserted in a medium-containing trough of said enclosure according to claim 4.

7. An enclosure according to Claim 6 wherein said downward projection is a trough containing a decontaminating or neutralising medium and capable of receiving a cover plate inserted from within said other enclosure.

8. An enclosure according to any preceding Claim wherein the enclosure is provided with sterilising means for sterilising the interior of said enclosure.

9. An enclosure according to Claim 8 wherein the sterilising means comprises a source of ultra-violet radiation.

10. An enclosure according to Claim 8 wherein the sterilising means comprises means for introducing and removing a sterilising liquid.

11. An enclosure according to any one of Claims 1 to 7 wherein the enclosure is provided with a means for controlling the atmosphere within said enclosure.

12. An enclosure according to Claim 11 wherein the means for controlling the atmosphere is a dessicating means.

13. An enclosure according to Claim 11 wherein the means for controlling the atmosphere is a means for flushing with decontaminating or neutralising gas

14. An enclosure according to any preceding Claim wherein the trough, contains a liquid or semi-liquid decontaminating or neutralising medium which comprises formaldehyde.

15. An enclosure according to any one of Claims 1 to 13 wherein the liquid or semi-liquid decontaminating or neutralising medium comprises a solution of a disinfectant in a solvent medium.

16. An enclosure according to any one of Claim 1 to 13 wherein the liquid or semi-liquid decontaminating or neutralising medium comprises a material which is inert to the material to be contained within the enclosure.

17. An enclosure according to any one of claims 1 to 13 wherein the liquid or semi-liquid decontaminating or neutralising medium comprises a material which neutralises the material to be contained within the enclosure.

18. An enclosure according to any preceding Claim with particular reference to any one of the Figures.

19. An enclosure for the secure containment and handling of noxious materials substantially as hereinbefore described.