Recovering fibres from white water in pulp, paper or board making process, by filtration using a pulp fraction taken from the pulp mixing vessel

摘要

A pulp fraction taken from the pulping process, which has better infiltration properties than the pulp obtained from the pulp mixing vessel (10), is used to assist filtration in the fibre recovery device (24). A method for treating white water obtained in a pulp, paper or board making process as a filtrate containing fibrous material separated from a fibrous suspension, comprises supplying the white water to a fibre recovery installation where the useful fibrous material is separated from the filtrate using a fibrous layer formed by an auxiliary pulp. This material comprises a pulp fraction taken from the pulping process, which has better infiltration properties than the pulp obtained from the pulp mixing vessel. The recovered fibres are then returned to the process. Independent claims are also included for white water treatment installations.