Abstract: In a method of preventing snow from bedding into railway switches, air is blown into the area between the stock rail and the movable rail in a switch, and substantially horizontally in a direction obliquely outwards towards the open end between the stock rail and the movable rail. An apparatus for carrying out this includes a blower assembly (8) between the rails in a railway switch, the assembly being supplied by a fan unit (20) and adapted to provide a substantially horizontal air discharge directed obliquely outwards towards the open end between the stock rail and the movable rail in their separated positions.

Abstract: A rigid discharge electrode (2) intended for use in an electrostatic precipitator which, in addition to the discharge electrode, also includes one or more collector electrodes. A voltage source is provided for supplying energy to the discharge and collector electrodes, so as to create therebetween a high d.c. voltage and an electric field, causing dust to be separated from a dust-laden medium passing between the electrodes, this separated dust settling primarily on the collector electrodes. The discharge electrode comprises a rod-like member (10) having attached therealong a plurality of electrode parts (17,18) presenting one or more discharge tips. The electrode parts extend transversely to the longitudinal axis of the rod-like member and project beyond the outer defining surfaces thereof. The rod-like member (10) presents two mutually opposite and mutually parallel surfaces (19,19'), and elonagated electrode parts (17,18) presenting discharge tips (17a,17b) are attached to or fitted on these surfaces.

Abstract: An electrode holding arrangement (11,12,13,14,15) forming part of an electrostatic percipitator and intended for supporting a plurality of discharge electrodes (2). In addition to the discharge electrodes (2) the precipitator also incorporates one or more collector electrodes (25), and a voltage source for supplying energy to the discharge and collector electrodes so as to create therebetween a high D.C. voltage which influences dust carried in a dust-laden medium passing between the discharge and collector electrodes in a manner to separate dust from the medium, this dust falling primarily on the collector electrodes. Respective discharge electrodes comprise a rod-like flexurily rigid member having attached thereto, or formed integrally therewith electrode parts which present discharge tips. A predetermined number of discharge electrodes (2) are attached at their upper end parts (2a) to a common, elongated, horizontallly extending electrode holding device (11).

Abstract: A method and a device for scrap preheating by means of hot steel furnace exhaust gases. A scrap bucket permits passage of gaseous medium therethrough and is closed by a cover with an exterior waterseal by providing an intermediate annular space having a controlled inlet for a purging medium which is connected to a pressure sensing means in the intermediate space. Purging medium is supplied to the intermediate space at a pressure not substantially less than the pressure in the inlet space in the bucket, so that all leakage is primarily the purging medium which flows outwardly to an outlet space. In a preferred embodiment the purging medium is recycled from the outlet space.

Abstract: The invention relates to a discharge electrode (30) produced from metal sheet and intended for use in an electrostatic dust precipitator which in addition to incorporating the discharge electrode also incorporates one or more collector electrodes. A voltage source is provided for supplying energy to the discharge and collector electrodes, so as to create therebetween a high d.c. voltage and an electrostatic field which separates dust from a dust-laden medium flowing through the precipitator, this dust settling primarily on the collector electrode. The discharge electrode comprises an elongated member (30) having distributed therealong a plurality of electrode parts presenting one or more discharge tips (37a, 37b, 38a, 38b). The electrode parts extend transversally to the longitudinal axis of the elongated member and project beyond the outer defining surfaces thereof.

Abstract: A guide vane ring for a return flow passage in axial fans comprises a ring (3) intended for placing in the return flow passage (4) coaxial with the impeller (6). A plurality of guide vanes (7) are formed integral with the ring and distributed round its exterior circumference. In a method of producing such a ring integral with its vanes, separate longitudinal slits are formed in a line one after the other in a metal strip. A cut is made transverse the strip between one end of each slit and one long edge of the strip. Portions of the band thus cut free are bent out from its plane and formed to a desired configuration, whereafter the formed band portions are bent such that the transverse cut lines will extend substantially at right-angles to the unformed flat band portion. This flat band portion is cut to desired length, formed and joined together into a circular ring with the portions formed to desired configuration forming exterior, substantially axially disposed guide vanes.

Abstract: Process for the separation of fine dust which contains impurities from alumina. The contaminated alumina is firstly subjected to a disintegration step in order to liberate fine dust from the alumina, and then the purified alumina is selectively separated from the fine impurity-containing dust in a separation step.

Abstract: The invention relates to a plant for drying a material web. Such plant includes a plurality of upper (3) and lower blow boxes arranged substantially mutually parallel and at right angles to the travelling direction of the web. The lower boxes are intended to support the web and are provided in their surfaces facing towards the web with orifices for blowing air in directions substantially parallel to the plane of the web. The air ejection velocity is thereby sufficient to maintain the web in a specified floating position above said boxes. The upper blow boxes (3) are situated on the other side of the material web and have orifices for blowing air substantially perpendicularly to the plane of the web. According to the invention, the distance (H) between the blowing orifices of the upper blow boxes and the web is variable. It is furthermore adjustable so that the relative energy requirement for the upper blow boxes may be brought closely into the region of the value 1.

Abstract: The invention relates to an arrangement for pulling the tail of a web-like material through a drying or cooling plant. In such a plant the web-like material is floated on air at a given distance from a surface provided with air delivery orifices. The web-like material (10) is thereby caused to pass zig-zag over drivable reversing rolls (2), while an endless traction or pulling member (3) in the form of a belt or rope runs in a separate path through the plant, substantially parallel to the material web, and is provided with means (12,13,14,15) with the aid of which the forward web end or tail (11) is attachable for pulling through the plant. At least one of the reversing rolls (2) is adapted at one end portion for carrying the tail pulling member either directly or over a pulley (9) drivably connected to said end portion. Driving the tail traction member is performed with the same means as drive the reversing rolls.