Abstract: The invention relates to a process for recovering alkali and heat from a black liquor (5) containing silicate from a soda cook of e.g. grass, reed, straw and bagasse. In the process the black liquor (5) is treated with a gas (6) containing carbon dioxide to precipitate silica and lignin, the precipitate (9) is separated (2) from the black liquor, which is evaporated (3) and burnt (4) to generate heat and to recover a sodium carbonate melt. In the invention the black liquor (5) containing silicate is neutralised with a surplus of the gas (6) containing carbon dioxide, which preferably contains over 60% by volume of carbon dioxide. The evaporation (3) of black liquor mainly takes place after the precipitate (9) rich in silica has been separated (2).

Abstract: The invention relates to an apparatus for heat exchange between two liquids without solid matters contained in the liquids. The apparatus comprises a pressure vessel which is divided into a plurality of compartments, each compartment comprising an inner space having an open end and an outer annular space. A baffle having a closed upper end is provided around the upper portion of each inner space with an annular slit between the baffle and the wall of the inner space. The baffle extends to a level below the upper end of the inner space. Injection nozzles for the heat-receiving liquid are provided in the upper portion of the outer space of each compartment, and an outlet pipe is connected to the lower end of the outer space. Inlet and outlet pipes for the heat-delivering liquid are connected to the upper and lower ends respectively of the inner space.

Abstract: Heat exchanger for the heating or cooling of a liquid, in particular of a suspension, comprises of a container provided with an inlet and an outlet and wherein there is disposed at least one rotatably mounted, substantially horizontal heat exchange unit having two end pieces between which heat transfer pipes have been fitted, and a conduit for conducting a heat-accepting or heat-releasing fluid through the end pieces and the heat transfer pipes of said heat exchange unit, a central tube concentrically disposed in relation to the rotational axis of the heat exchange unit between the end pieces among the heat transfer pipes, the diameter of the central tube being not less than 40% of the greatest distance between any two heat transfer pipes, measured at right angles to the rotational axis and that at least the lower edge of the outlet from the container in which the heat exchanger unit has been disposed being located at a level lower than the topmost part of the central tube so that the latter can be held above

Abstract: A process for the wet carbonizing of peat, wherein the peat is diluted and screened to become a raw peat suspension in a suspension preparing apparatus, the peat suspension thus obtained is preheated in series-connected heat exchangers and in a preheating tower, the preheated suspension is wet carbonized in a reactor into which steam is introduced from a steam boiler, the wet carbonized peat suspension is cooled in the preheating tower, mechanically dewatered in a dewatering apparatus and dried in a drying apparatus with the aid of hot drying gas, the exhaust gases from the boiler being employed as drying gas in the drying apparatus and the dust and water vapor containing exhaust gas emerging from the drying apparatus being purified and cooled in a wet separator, wherein part of the water vapor in the exhaust gas condenses and wherein there is used as washing water, polluted water coming from the dewatering apparatus and being cooled by heat exchange with the raw peat suspension in the heat exchanger, and the

Abstract: Suspended solid particles are separated from a fluid flow by dividing the flow into partial fluid flows in flow channels having an upper filter surface travelling upstreams and a lower filter surface travelling downstreams, controlling the flow velocity in the channels such that the flow is turbulent but at the same time low enough to allow for sedimentation of the suspended material to form a clear top layer off so that more than half of the liquid fed to the channel is filtered through the upper filter surface, suctioning less than half of the liquid fed into the channel through a sediment formed on the lower filter surface, and finally removing the sediment from the lower surface.

Abstract: A method and device for the continuous mixing and removal of pulverous or fragmentary material from a container, such as a silo or the like, so that the various layers of material simultaneously become mixed with each other, in which case material is removed at a level below the feeding level, essentially over the entire silo width, the material being removed so that its sinking rate in the silo increases towards the line between the feeding and the removal points in order to slant the material layers towards the said line so that the material can be removed in a controlled manner from the slanted layers by means of a removal member or members directed across the layers.