| 摘要 |
A pressure screen is disclosed for use in screening pulp suspension, utilizing the principle of a cylindric screen provided with a pulse generating device such as hydrofoils (34). As is usual, the screen has a cylindric housing (12) but instead of a single cylindric screen arrangement concentric with the axis of the chamber, it has at least three smaller cylindric screens (16, 17, 18, and 19) disposed about the axis (22) of the housing. The invention provides a significant improvement over known pressure screens in that it substantially increases the screening area while not requiring enlargement of space required for the cylindric housing. The high capacity is provided by smaller size screens which are easier to manufacture, have better strength properties compared to large cylindric screens and are less expensive to replace. The increased area of screening can be utilized by provided smaller apertures in the screens while maintaining the same overall output of the screen despite the lower capacity per area unit caused by smaller passages. This results in a significant improvement of the quality of the accepts.
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