Abstract: A gas cleansing arrangement comprising a vessel (1) partially filled with liquid (32) and a gas distribution means (14) beneath the liquid surface (34). The gas distribution means (14) comprises obliquely and downwardly extending distribution pipes (26) with upwardly facing inlet openings (64) for contaminated gas and a lower opening (22). The inlet openings are each connected to a venturi device (28) having an outlet opening (31) and suction openings (29) facing the liquid (32). In use, pressurized gas urges an inner liquid surface (46) downwards in the distributor means (14), until the liquid surface (46) reaches and exposes the uppermost inlet opening or openings (64). The gas is then forced through respective venturi device (28) at a pressure drop corresponding to the height difference (h) between the inner liquid surface (46) and respective outlet opening (31).

Abstract: Method for cleansing gas from solid, liquid and/or gaseous contaminants, by bubbling the gas through a liquid bath (32), and by introducing the incoming gas into a distribution means (14) and causing the gas to pass in part-streams through a multiple of inlet orifices (64) located at progressively increasing depths beneath the surface (34) of the liquid (32). With increasing inlet pressure an increasing number of inlet orifices (64) are utilized for an increasing number of part-streams. The gas flow is passed from respective inlet orifices (64) through connecting means (24, 26, 28) to outlet orifices (31) located at a considerably higher height level (h) than corresponding inlet orifices (64). The gas flow is caused to flow out through venturi nozzles (28) and/or to strike against impinger or striking surfaces (39) with a minimum pressure drop corresponding to said height differential (h).

Abstract: A method and apparatus for producing a continuous web of material (36) on an endless belt (24). Fibers suspended in a carrier gas are transported from a transport conduit (12) through a transition part (38) of zig-zag configuration, having cross-section which tapers or narrows in the flow direction. Arranged at the outlet aperture of the transition part is a coarse-particle separator means (22) which incorporates a curved, convex surface (60), an accept outlet (48), and a reject outlet (54). The carrier gas is deflected around the convex surface, as a result of the ensuing Coanda Effect, and transports acceptable fine fibers to the accept outlet (48), while coarse reject particles, due to their greater kinetic energy, pass in a straighter path to the reject outlet (54). The accept outlet leads directly to a distribution chamber (52) which is located above the endless belt (24), and opposite which there is provided a suction box (32) for extraction of the carrier gas.

Abstract: A paint-spray chamber having a grate-like floor with an outlet for particle-laden air below said floor, said outlet comprising water reservoirs along the periphery of the spray chamber and a venturi outlet disposed centrally of said chamber between the water reservoirs. Water is continuously supplied to said reservoirs to fill the reservoirs to overflowing and cause the water to flow into said venturi so as to provide a body of water underlying the floor. The venturi is formed by opposed venturi sides converging toward the central axis of the venturi outlet in the direction of the gas flow to a venturi throat. A pair or a series of pairs of guide plates extend inwardly from said opposite venturi sides adjacent said reservoir means and converge toward one another in the direction of air flow with a greater angle of convergence than said venturi sides and terminate in one or more noise-muffling zones along said venturi axis above said throat.

Abstract: An apparatus and method for removing dense impurities, such as sand, from a fluid, such as liquids use in the production of cellulosic pulp. A vertically upstanding tank substantially circular in cross-section is provided including a top wall, bottom wall, and side wall. The fluid with dense impurities is introduced into the tank with a whirling motion. Vertical stagnation of the dense impurities against the side wall interior (which can result in damage to the tank wall) without dampening the whirling motion imparted to the fluid is prevented by mounting a perforated funnel in the tank at the area of the tank where the vertical stagnation is likely to occur.

Abstract: A web is formed from particulate material, for example, wood fibers, by depositing the fibers on a conveyor surface in a distribution chamber. The particulate material is introduced into the distribution chamber at its top by a carrier air stream which is caused to oscillate across the surface by impulses from separate control blow boxes on the opposite sides of the stream. The particulate material is thoroughly dispersed in the air stream by passage through a transition zone where the carrier air stream is deflected into a zigzag path and its flow velocity is reduced. The effect of static electricity on the particles in the carrier stream is reduced by lining the transition zone with nonconductive material and providing ionizing devices in the blow boxes for the air flow passing through the control boxes, or in the chamber adjacent the boxes.

Abstract: A web is formed from particulate material, for example, wood fibers, by depositing the fibers on a conveyor surface in a distribution chamber. The particulate material is introduced into the distribution chamber at its top by a carrier air stream which is caused to oscillate across the surface by impulses from separate control blow boxes on the opposite sides of the stream. The particulate material is thoroughly dispersed in the air stream by passage through a transition zone where the carrier air stream is deflected into a zigzag path and its flow velocity is reduced. The effect of static electricity on the particles in the carrier stream is reduced by lining the transition zone with nonconductive material and providing ionizing devices in the blow boxes for the air flow passing through the control boxes, or in the chamber adjacent the boxes.

Abstract: Apparatus for forming and controlling high-velocity air curtains in a room such as an auto-body painting booth, which room is also provided with ventilating air flowing inwardly through perforations in a ceiling in response to pressure developed by a fan in a chamber above the ceiling. Rather than using a permanent custom-designed arrangement of nozzles separately supplied with pressurized air through special ducts to form the air curtains, the curtains are formed and controlled by air guiding means located on the room side of the ceiling and open to the ceiling perforations, so configured that the flow through the perforations is converted to one or more air curtains of desired velocity and direction. Quick-disconnect fastening means insertable into the perforations through a flange on the air guiding means enables installation, removal or shifting of theair guiding means, as desired for different purposes.

Abstract: A web is formed from particulate material, for example wood fibres, by depositing the fibres on a movable deposition surface in a chamber. The particulate material is carried to the surface in an air stream to form a composite material flow which is caused to oscillate across the surface by impulses from separate control means preferably disposed on opposite sides of the stream. The control means is preferably opposed control flows which are caused to vary alternatingly between a minimum and a maximum impulse by use of one or more fluidistors. The fluidistors may be controlled by self-oscillation or by measuring the evenness of the particulate material deposited on the deposition surface. The control may also be effected by adjusting the walls of the chamber to utilize the coanda-effect. The particulate material may be admixed with additives from the control flow and may be charged electrostatically.

Abstract: A method and apparatus for dewatering a suspension of comminuted fiber material and liquid. A suspension is passed in a given direction in a container of generally circular cross-section having a hydraulic piston mounted generally concentrically therein. There are no movable components extending between the piston and the walls of the container in which it is disposed, therefore leakage from the container is minimized. The piston has screens for separating liquid from the suspension associated therewith, and is movable in the same direction as the suspension flow during removal of some liquid from the suspension, and is movable in a direction opposite to the direction of fluid flow to facilitate cleaning of the screens and to return the piston to a position wherein it can move in the direction of flow again.