Abstract: A hydrofoil impeller wherein the tip edge is straight and has a right angle with a radius extending from the central axis to the tip edge. In the central hub and in each of the blades the number of holes in each group of first and second holes is at least five. The pattern in which the holes are arranged in each of the respective groups of holes is elliptical having a center and a major axis which is substantially parallel to the radius and placed at a distance therefrom. The leading edge is, in the direction of rotation, behind an imaginary radial line intersecting the central axis of the shaft and the center of the ellipse, the leading edge being at an angle of 50°±2° in relation to the radial line. The area of the blade is divided into four planar portions by three straight bends.

Abstract: A hydrofoil impeller wherein the tip edge is straight and has a right angle with a radius extending from the central axis to the tip edge. In the central hub and in each of the blades the number of holes in each group of first and second holes is at least five. The pattern in which the holes are arranged in each of the respective groups of holes is elliptical having a center and a major axis which is substantially parallel to the radius and placed at a distance therefrom. The leading edge is, in the direction to rotation, behind an imaginary radial line intersecting the central axis of the shaft and the center of the ellipse, said leading edge being at an angle of 58°±2° in relation to the radial line. The area of the blade is divided into four planar portions by three straight bends.

Abstract: A method and an arrangement for collecting and removal of acid mist from an electrolytic cell. The arrangement includes a cover for covering an open top of a container of the electrolytic cell so that a space is formed between a surface of electrolyte contained in the container and the cover, a decontamination system provided with an acid mist suction channel terminating in an upwards facing inlet opening in the space, and a cleaning arrangement for spraying the upwards facing inlet opening with washing fluid. The cleaning arrangement has a fluid nozzle. The fluid nozzle is in the acid mist suction channel. The fluid nozzle is arranged to spray washing fluid at least downwards into the acid mist suction channel.

Abstract: A method and an arrangement for collecting and removal of acid mist from an electrolytic cell. The arrangement includes a cover for covering an open top of a container of the electrolytic cell so that a space is formed between a surface of electrolyte contained in the container and the cover, a decontamination system provided with an acid mist suction channel terminating in an upwards facing inlet opening in the space, and a cleaning arrangement for spraying the upwards facing inlet opening with washing fluid. The cleaning arrangement has a fluid nozzle. The fluid nozzle is in the acid mist suction channel. The fluid nozzle is arranged to spray washing fluid at least downwards into the acid mist suction channel.

Abstract: The invention relates to dimensioning rules for a blade of an axial flow impeller. The dimensioning rules relate to: (i) the lengthwise dimension from the axis of rotation of the impeller to the tip of the blade; (ii) the widthwise dimension of the blade perpendicularly to the lengthwise direction; and (iii) respective angles for a plurality of folds of the blade. The invention also relates to an axial flow impeller having such blades.

Abstract: The invention relates to a turbine-type high-power impeller, to be used for mixing slurry in hydrometallurgical process reactors. The impeller is formed of at least five blades, each of which blades comprises a front edge, trailing edge, root and tip; the roots of the impeller blades are permanently attached by a joint to the hub or axis of the impeller, so that the front edge of the impeller blade is straight, and the trailing edge is chamfered, in which case the blade is narrowed towards the tip, and the blade is provided with two longitudinal folds arranged in parallel with the front edge of the blade.

Abstract: The invention relates to a blade (4) of an axial flow impeller (1). Dimensioning rules for the blade (4) are presented: A=0.2R; B=0.2Wb; C=0.2R; D=0.2Wb; E=0.5R; F=(0.1 . . . 0.2)R; G=0.2Wb; H=0.25R; I=0.1R; J=0.4R; K=0.1Wb. The first angle ?1=6°±1°, the second angle ?2=8°±1° and the third angle ?3=19° to 25°. R is the lengthwise dimension from the axis of rotation (x) of the impeller to the tip (7) of the blade (4). Width Wb is the widthwise dimension of the blade perpendicularly to the lengthwise direction. The invention also relates to an axial flow impeller (1) having said blades (4).

Abstract: The invention relates to a turbine-type high-power impeller, to be used for mixing slurry in hydrometallurgical process reactors. The impeller is formed of at least five blades, each of which blades comprises a front edge, trailing edge, root and tip; the roots of the impeller blades are permanently attached by a joint to the hub or axis of the impeller, so that the front edge of the impeller blade is straight, and the trailing edge is chamfered, in which case the blade is narrowed towards the tip, and the blade is provided with two longitudinal folds arranged in parallel with the front edge of the blade.