FIELD: chemistry.
SUBSTANCE: invention relates to washing a suspension of fibrous material such as pulp mass by means of a suction drum washer. Method for washing a suspension containing solid matter by means of a suction drum washer, comprising a drum provided with a filtration surface, a main vacuum source such as a drop leg, and washing tubes connected to frame of suction drum washer. Washing liquid stream is introduced by a first washing tube is directed to contact pulp layer on the surface of drum in a point below degrees after surface of suspension, and a vacuum of at least 0.1 bar greater than main vacuum source, that is, intensified suction is applied by means of a separate vacuum source to filtering surface at contacting point of first liquid stream and pulp layer or maximum of 10 degrees before contacting point. Intensified suction may be utilised also for boosting end of filtration stage and drying stage. Filtrate from drying stage can be used at same washer as a washing liquid at first or second washing tube.
EFFECT: invention enables more free adjustment of duration of stages, performed in vacuum drum filter, and conditions, dependent on both treated pulp mass, and process requirements, to effectively and continuously optimise production.
15 cl, 6 dwg
