Abstract: An apparatus for dewatering and squeezing a water containing material comprises a drum with a sieve mantle defining two co-operating drum sections, each comprising a feed screw extending therein. The first section of the drum in the feed direction is formed for dewatering of the material mainly by self-drainage. The first drum section is rotatable and is provided with means for cleaning the sieve mantle holes. The second section is formed for increased compression of the material, and has a thread height for the feed screw smaller at the outlet of the second section than at the inlet to this section.

Abstract: A method of cleaning green liquor of solid particulate impurities by adding caustic lime corresponding to 0.5 to 10% of the amount of caustic lime needed for complete causticizing of the green liquor to the green liquor in a soda dissolving tank or in a separate mixing tank to which the liquor is led directly from the dissolving tank. Calcium carbonate precipitates and forms, with the impurities, particles having better settling and filtration properties than particles in green liquor which has not been treated with caustic lime.

Abstract: In a method and an apparatus for mixing chemicals into a fibre pulp, the pulp passes in a space between a fixed casing and a rotating device through three treatment sections. In the first treatment section a transport screw is arranged for transporting the pulp and impart to it a pressure up to the subsequent treatment section. In this treatment section both the casing and the rotating device are provided with guide elements which cause shearing between the fibre layers of the pulp by alternating velocity gradiants in the pulp and oscillating movement thereof. In the next treatment section the pulp is imparted a retarding velocity in a first part of the section and thereafter an accelerating velocity in a second part of the section during simultaneous oscillating movement and shearing between the fibre layers. This is accomplished by a configuration of both the fixed casing and the rotating device in the form of double-cones having their basis abutting each other.