Abstract: The present invention relates to an arrangement for introducing black liquor into a furnace of a recovery boiler, said arrangement comprising an elongated tube having an interior surface and an exterior surface, through which tube the black liquor being fed into the furnace is supplied, whereby the black liquor is taken into contact with said interior surface prior to being sprayed into the furnace. The interior surface of said elongated tube is provided with heat transfer elements and surfaces, such as fins or grooves. The heat transfer element or surface increases the heat conductivity between the tube and the black liquor above the conductivity achieved with a normal tube passage.

Abstract: The present invention relates to an arrangement for introducing black liquor into a furnace of a recovery boiler, said arrangement comprising an elongated tube having an interior surface and an exterior surface, through which tube the black liquor being fed into the furnace is supplied, whereby the black liquor is taken into contact with said interior surface prior to being sprayed into the furnace. The interior surface of said elongated tube is provided with heat transfer elements and surfaces, such as fins or grooves. The heat transfer element or surface increases the heat conductivity between the tube and the black liquor above the conductivity achieved with a normal tube passage.

Abstract: A sharpening device for the blade of a cross-cutting roller (1) is disclosed in which the cross-cutting roller (1) includes at least one blade plate (4) which is located in the angle formed by the two machined surfaces (2,3) of the cross-cutting roller in such a way that the original blade bevel (5) is outer and that the blade is sharpened by grinding the original bevel (5) of the blade plate (4) to form a less sharp bevel (6) at the edge of the blade plate (4), and in which the sharpening device includes support wheels (7,10), a grinding stone (8) and devices rotate it. The intention of the this invention is to achieve a new kind of sharpening device for the blades of cross-cutting rollers, which makes it possible to sharpen them without removing the blade plates. In accordance with the invention, at least one support wheel (7) is adapted to be supported on the original bevel (5) of the blade plate (4) and on the free side surface of the blade plate (4).