Profile bar screen for digester vessels
AssigneeValmet Corporation
InventorsMikael Vinje, Jerk Söderman
Life of this patent
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Abstract
The improved profile bar screen is for draining treatment liquor from a suspension of comminuted cellulose material and treatment liquor in an essentially cylindrical digester vessel. The profile bar screen is designed with horizontal support arches that have expansion slots allowing the otherwise rigid structure of the support arches to flex and adapt to any unevenness of the vessel wall, thus allowing support shoulders to rest against the inside of the vessel wall.
Claims10
A profile bar screen for draining treatment liquor from a suspension of comminuted cellulose material and treatment liquor in an essentially cylindrical digester vessel, said profile bar screen being arranged inside the outer wall of the digester vessel forming a withdrawal chamber between the wall of the digester vessel and the profile bar screen, the profile bar screen comprising:
- vertical profile bar elements facing the suspension of comminuted cellulose material, said vertical profile bars arranged in parallel to each other and forming a withdrawal slot for treatment liquor between neighboring profile bars;
- several horizontal support arches having vertical mounting slots for holding a profile bar element in said mounting slots, the horizontal support arches having integrated support shoulders resting against the inside of the outer wall of the cylindrical digester vessel;
- said horizontal support arches being equipped with additional expansion slots having an open end facing towards the interior of the digester vessel and a closed end in the area of a support shoulder, allowing a flexibility of the horizontal support arches such that support shoulders rest against the wall of the digester vessel despite any local deviations from a perfect cylindrical shape of the digester vessel wall.
A profile bar screen as claimed in claim 3, wherein the depth (X) of the expansion slots exceeds 50% of the total depth (Z) of the horizontal support arches, as counted from the inwardly facing surface of the support arches and to the outwardly facing surface of the support shoulder of the support arches.
Dependencies are inferred from the claim text.