Impurities separating method for fibrous material suspension in paper production, involves holding set of openings of filter freely by temporal changes of difference of pressure arising in sorter openings

摘要

The method involves introducing a fibrous material suspension (2) into inlet area (17) in housing (11) of a pressure sorter (1), where a portion of the fibrous material suspension is diverted to overflow stream (4). A set of openings of a filter (7) are freely held by temporal changes of difference of pressure arising in sorter openings, in such a manner that the temporal changes of the difference of pressure takes place by the low pressure or high pressure, which is produced outside the filter areas and transferred to the sorter openings.