PROFILE BAR SCREEN FOR DIGESTER VESSELS

摘要

The invention relates to an improved profile bar screen for draining treatment liquor from a suspension of comminuted cellulose material and treatment liquor in an essentially cylindrical digester vessel. Withdrawal screens for digesters are conventionally made either as profile bar screens or machine slotted screens. Profile bar screens are typically made as a sturdy self supporting screen with the only load support from a surrounding frame bed. Slotted screens on the other hand are rather weak and instead use a multitude of supporting pins behind the screen plate, resting directly onto the vessel wall. According to the invention is a profile bar screen designed with horizontal support arches (11) that have expansion slots (16) allowing the otherwise rigid structure of the support arches to flex and adapt to any unevenness of the vessel wall (1), thus allowing support shoulders (12) to rest against the inside of the vessel wall (1).