Abstract: The present invention relates to a method of confining pollution generated in the top volume and/or in the bottom volume of an enclosure filled with a fluid, i.e. either a gas, which is in general air, or a liquid, which is in general water, the method confining the pollution by thermal stratification. In said method the mean temperature of said top volume is maintained higher than the mean temperature of said bottom volume by an amount that is sufficient to ensure that said two volumes are separated by a turbulent intermediate zone of narrow width, referred to as the “mixing zone”, within which a steep temperature gradient is maintained; said intermediate zone constituting a virtual confinement barrier in a horizontal plane. The present invention also relates to apparatus associated with the method.

Abstract: The present invention relates to a method of confining pollution generated in the top volume and/or in the bottom volume of an enclosure filled with a fluid, i.e. either a gas, which is in general air, or a liquid, which is in general water, the method confining the pollution by thermal stratification. In said method the mean temperature of said top volume is maintained higher than the mean temperature of said bottom volume by an amount that is sufficient to ensure that said two volumes are separated by a turbulent intermediate zone of narrow width, referred to as the “mixing zone”, within which a steep temperature gradient is maintained; said intermediate zone constituting a virtual confinement barrier in a horizontal plane. The present invention also relates to apparatus associated with the method.

Abstract: 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.

Abstract: In order to ensure a bidirectional dynamic separtion between two zones (10,12), between said zones is formed a gas curtain constituted by three juxtaposed gas streams or jets (28,30,32). The central stream or jet is relatively fast and serves to stabilize the two relatively slow lateral streams or jets (30,32). The latter ensure the relative confinement of the two zones by means of their tongues (30a,32a) and their flow rate is determined in such a way as to supply the relatively fast stream with the gas necessary for its full development. In the case where one (10) of the zones has a reduced volume, a low flow rate, additional gas flow can be injected into the said zone.

Abstract: In the method disclosed for filtering a contaminated gas laden with liquid vesicles (or aerosols) through a filter medium arranged around a center hollow through which the aerosol enters, the filter medium is heated to a temperature above the aerosol's dew point by a radiant heat source arranged in said center hollow. The inventive filter enables the said method to be practiced.

Abstract: An apparatus for isolating an enclosure from external pollution includes a tube (2) with one end opening out into the enclosure and with its opposite end (5) being open. At least one slot (6) is provided in the inside wall of said tube in the vicinity of its opening (5), the slot being disposed in a plane perpendicular to the axis of said tube and sloping towards the opening. The slot is fed with gas so as to blow a continuous sheet of gas into the tube. At least one porous plate is disposed on the inside wall of said tube between the slot (6) and the opening (5), and the plate is fed with a gas which forms a small flow of gas suitable for overcoming the pressure reduction formed by the sheet of gas leaving from said slot (6). The enclosure is maintained at a pressure which is slightly higher than its surroundings so as to create a flow of gas running along said tube (2) and deflecting the sheet or sheets of gas leaving the slot (6) towards the opening (5).