首页>
外国专利>
Stock inlet for a papermaking or cardboard prodn machine has a blade inserted between the rows of turbulence tubes with a lateral zone of a reduced cross section to reduce force peaks on starting/stopping the stock inlet
Stock inlet for a papermaking or cardboard prodn machine has a blade inserted between the rows of turbulence tubes with a lateral zone of a reduced cross section to reduce force peaks on starting/stopping the stock inlet
The stock inlet (10), for a papermaking or cardboard prodn. machine, has a turbulence generator (12) and a jet (14), with at least one blade (16) to divide the flow zone (14'). At least one blade (16) is inserted between two rows of tubes (12') of the turbulence generator (12), with a reduced cross section (20) at the zone of the tube rows (12'). The cross section reduction (20) at the blade (16) is at least partially between the rows of tubes (12') and at least partially in the flow zone (14') of the jet (14), to form a gap between the blade and the tubes. The two rows of tubes (12') have rounded or chamfered outer edges (26) at the blade side towards the jet (14), with a curve radius of = 0.1 mm. The reduced cross section (20) is formed by a cut-in (28) pref. across the direction (S) of pulp flow, across the blade width, on one or both sides of the blade (16). The cut-in (28) forms convex or flat leading and/or trailing wall (28',28) in cross section in the pulp flow direction (S) and/or a concave base (28') between them, with a base concave curvature radius (R3) of -0.05 mm. The curve radius (R3) of the concave base (28') is generally half the gap between the leading and trailing cut-in walls (28',28). The blade (16) is a plate with a thickness (d) of 0.5-10.0 mm, where the cross section is not reduced. At the thinner section (20) of the blade (16), it has a min. thickness (b) of 0.1 mm to 0.95 times the thickness (d) of the main blade. The length (c) of the cut-in (28) is -0.1 mm, in the pulp flow direction (S). At the ends of the rows of tubes (12'), towards the jet (14), at least one of the two tube rows can have a pref. concave curved blade support surface. The inserted blade between the two rows of tubes can have at least one lateral groove which is engaged by a rib or shoulder at the tube(s).
展开▼
