Patent ID: 8308536

Claim:
A ventilating device for providing in a room a zone of clean air between the ventilating device and a workplace region in the room, which ventilating device comprises air supply units adapted to generating laminar air flows intended to constitute said clean air zone, wherein the ventilating device comprises at least three air supply units disposed in a closed pattern so that the extent in cross-section of the clean air zone below the air supply units substantially corresponds to the surface delineated by said closed pattern of air supply units and the surface situated within that pattern, and a corresponding number of air stop and guide units disposed between, and substantially filling the space between each pair of mutually adjacent air supply units, each air stop and guide unit having at least one air stop surface which faces outwards away from the clean air zone and prevents or hinders air surrounding the clean air zone from being drawn in between adjoining air supply units and into the clean air zone, at least two first air guide surfaces which run from the air stop surface in between adjoining air supply units, converge towards one another and guide parts of the air flows from adjoining air supply units that are directed towards one another away from one another and outwards from the centre of the clean air zone, and at least two second air guide surfaces which face inwards towards the centre of the clean air zone and converge towards said first air guide surfaces and towards one another and guide other parts of the air flows from adjoining air supply units that are directed towards one another away from one another and inwards towards the centre of the clean air zone.