Abstract: A method and an apparatus for washing a solids-containing suspension 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 the frame of the suction drum washer. A washing liquid stream is introduced by a first washing tube is directed to contact the pulp layer on the surface of the drum in a point below 10 degrees after the surface of the suspension and a vacuum of at least 0.1 bar greater than the main vacuum source, i.e. intensified suction is applied by means of a separate vacuum source to filtering surface at the contacting point of the first liquid stream and the pulp layer or maximum of 10 degrees before the contacting point. The intensified suction may be utilized also for boosting end of filtration stage (II) and drying stage (IV). Filtrate from the drying stage (IV) can be used at the same washer as a washing liquid at the first or the second washing tube.

Abstract: A method and an apparatus for washing a solids-containing suspension 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 the frame of the suction drum washer. A washing liquid stream is introduced by a first washing tube is directed to contact the pulp layer on the surface of the drum in a point below 10 degrees after the surface of the suspension and a vacuum of at least 0.1 bar greater than the main vacuum source, i.e. intensified suction is applied by means of a separate vacuum source to filtering surface at the contacting point of the first liquid stream and the pulp layer or maximum of 10 degrees before the contacting point. The intensified suction may be utilized also for boosting end of filtration stage (II) and drying stage (IV). Filtrate from the drying stage (IV) can be used at the same washer as a washing liquid at the first or the second washing tube.

Abstract: A method and apparatus for fibrous suspensions in the wood processing industry and more specifically to a so-called drum cylinder, the basic construction of which comprises a vessel, into which suspension being thickened is supplied and a wire-surface cylinder rotating in the vessel. The drum filter is characterized in that the closure member of the drum filter has a channel for leading gas from the filtrate tubes through the compartments of the distribution chamber to the outside of the closing member. The method is characterized in that the operation phase of the filter cylinder is divided into five separate stages. In the first stage, when the cylinder descends on to the vessel, air and the initial filtrate are discharged from the filtrate components and the formation of the pulp web on the wire surface begins. In the second stage, filtrate is discharged with vacuum and the formation of the pulp web continues.

Abstract: A disc filter and method of operating same is provided in which a liquid jet is intermittently used to detach pulp cake from the disc filter. In operation, mechanical or electrical means actuate a nozzle to spray pressurized fluid at a portion of the boundary between the surface of each disc filter segment and its associated pulp cake. The nozzle is actuated to begin spraying as respective segments move into register with the nozzle and are cause to discontinue spraying prior to moving out of register when the loosened pulp cake falls from the segments by gravity. the improved control of pulp cake removal reduces use of washing fluid and results in improved pulp cake consistency.

Abstract: A method for improving the operation of a disc filter used for the filtering of fluids containing solid matter such as fibers. Known filtering methods have the drawback that the rate of water exhaustion is limited, because a vacuum tends to be created inside the sectors when the filtered fluid is drained by suction from the central channel of the disc filter. This drawback is an obstacle to increasing the speed of rotation and therefore to increasing the capacity of the disc filter. With the method of the present invention, this problem is solved by providing the disc filter with a means of admitting ambient air into the disc sectors and the central shaft channel and/or with equipment for blowing air into the sectors and the channel to remove the filtered fluid from them.

Abstract: The present invention concerns a feed and accept duct system (4) for hydrocyclones (1), comprising common feed and accept ducts (7,8) which have by connecting tubes been connected to the parallel hydrocyclones. This type of construction is used, for instance, in purifying fiber suspensions, in which process the suspension is fed into the hydrocyclones (1) and the purified suspension is removed therefrom as a so-called accept fraction into the accept duct (8).

Abstract: A method and apparatus for fibrous suspensions in the wood processing industry and more specifically to a so-called drum cylinder, the basic construction of which comprises a vessel, into which suspension being thickened is supplied and a wire-surface cylinder rotating in the vessel. The drum filter is characterized in that the closure member of the drum filter has a channel for leading gas from the filtrate tubes through the compartments of the distribution chamber to the outside of the closing member. The method is characterized in that the operation phase of the filter cylinder is divided into five separate stages. In the first stage, when the cylinder descends on to the vessel, air and the initial filtrate are discharged from the filtrate components and the formation of the pulp web on the wire surface begins. In the second stage, filtrate is discharged with vacuum and the formation of the pulp web continues.