Hydraulic head box for fiber web manufacturing machine, has throttling bushes rotated around longitudinal axis of manifold to regulate pressure loss of fiber suspension flow during turning of flow into manifold

摘要

The head box has a manifold battery (9) whose manifolds (11) are provided with throttling bushes. Each bush is partially inserted into an interior of one manifold at an end of a distributor (10) of the manifold. A part of the bushes is asymmetrically designed and rotatable around a bush longitudinal axis. Pressure loss of a fiber suspension flow is regulatable during turning of the flow into the manifold by rotating the bushes around a longitudinal axis of the manifold. Each bush has an asymmetrical inlet section whose curvature and/or taper are formed asymmetric to the bush longitudinal axis.