Abstract: A flow distributor capable of forming a defining wall of a duct or chamber having further defining walls comprises a profiled, apertured plate. The plate is provided with profile sections or wall sections which extend transversally of the direction of the main flow immediately downstream one or more apertures. The profile sections form baffle means for dividing the main flow of medium into a plurality of part flows and for deflecting said part flows through respective apertures to the opposite side of said defining wall. Located between the profile sections are substantially planar, apertured sections which extend in parallel with or are inclined to the direction of the main flow, while forming an arrangement of step-like or shoulder-like protrusions. Alternatively, the plate may exhibit adjacent one or more of said apertures corrugations which curve inwardly or outwardly towards and away from said flow, a part of which corrugations forms said profile sections.

Abstract: In a method of removing contaminated air by suction, ejector air is blown towards a tangentially directed inlet slot (3) in a cylinder (2a) comprising part of an air extractor (1). The contaminated air is entrained in this way to form a rotating air stream in the interior of the cylinder, said air stream also being imparted an axial movement component as a result of underpressure prevailing in the interior of the cylinder. The cyclone effect of the air stream in the cylinder is used to separate contaminated particles from the air and to deposit the particles on the inside of the cylinder. The air stream can also be caused to pass through a cylindrical filter (11) arranged centrally in the cylinder (2a). Blow-openings (8) for ejector air are suitably located in the vicinity of the end of a tangentially directed cylinder-extension portion (2b). The cylinder can be flushed to remove adhering particles therefrom, e.g.

Abstract: A flow-distributing device comprises a perforated plate (1) which forms a defining wall of a passage or chamber arranged to accommodate a flow of fluid and provided with at least one further defining wall. Deflecting means (1a; 3) extend into the path of said flow adjacent the perforations (2) which are evenly distributed over at least a part of said wall. The deflecting means divide the flow into a plurality of part-flows which pass in mutually the same direction to the other side of the plate via the perforations. The deflecting means may comprise separate nozzles (3) or lips (1a) which have been pressed out of the material when forming the holes. The flow-distributing device may be incorporated in an air-supply device for a furnace, a fluidized bed, an air cooler or heater or the like. In one important application it is used in a substantially box-shaped air-intake screen (10) having a perforated side surface (10b) and an air-supply pipe (11).

Abstract: A screen for improving the environment of separate working areas in a working place having a plurality of such working areas, e.g. a factory floor, a workshop, an office or the like, is provided with a mechanism for connecting the screen to an air-supply line and exhibits at least one perforated side surface. The screen is hollow and accommodates a perforated supply and distributing pipe for fresh air. So as to evenly distribute the air, the pipe in a preferred embodiment has a number of nozzles which project into the path of the main-flow in the pipe and deflect uniform part flows therefrom in a direction substantially transversally of the direction of the main-flow and at substantially the same speed as the speed of the main-flow before the first nozzle. The screen may serve as a combined acoustic and air-supply screen which enables personnel to work close to the screen without being subjected to draughts.