Back to results
US 4,784,726 AGranted
Paper machine head box with adjustable perforated plate flow ducts
AssigneeA. Ahlstrom Corporation
InventorOsmo Evalahti
Life of this patent
Estimating the term…
Abstract
A paper machine head box includes perforated plates being used as a distributor and a turbulence generator and having flow ducts, of which the ones at the edges are of different size than the remaining flow ducts. According to a preferred embodiment, slides, which are movable sideways, are provided at the ends of slice ducts at both edges of the perforated plates in order to regulate the flow. The slides and the perforated plates define the outermost flow ducts of the turbulence generator and the distributor.
Claims20
A head box, including side walls, for a paper-making machine, comprising:
- a cross header in communication with a perforated plate having a plurality of flow ducts extending through the head box, the plate having a pair of side edge areas, each of said side edge areas having a plurality of outermost flow ducts of substantially uniform size relative to one another;
- the size of the outermost flow ducts in at least one of said side edge areas of the plate being different than the size of the non-edge area flow ducts in the perforated plate;
- means carried by the head box for substantially uniformly altering the size of the outermost flow ducts in said at least one of said side edge areas;
- and a slice.
1 more element
A head box, including side walls for a paper making machine, comprising:
- a cross header;
- means defining a distributor for spreading pulp supplied into the head box evenly over the whole width of a paper making machine with which the head box is associated;
- said distributor means including a perforated plate having a plurality of flow ducts extending through the head box, the plate having a pair of side edge areas;
- an expansion chamber;
- said perforated plate communicating with said cross header and with said expansion chamber wherein pulp flows through said flow ducts from said cross header to said expansion chamber;
- and a slice;
- and wherein each of said edge areas has a plurality of outermost flow ducts, the size of the outermost flow ducts in at least one of said side edge areas of said plate being different than the size of the non-edge area flow ducts of said perforated plate, the outermost flow ducts in said one side edge area being substantially uniform in size with respect to each other and means carried by said head box for substantially uniformly altering the size of the outermost flow ducts in said at least one side edge area.
4 more elements
A head box, including side walls, for a paper making machine, comprising:
- a cross header in communication with a perforated plate having a plurality of flow ducts extending through the head box, the plate having a pair of side edge areas, each of said side edge areas having a plurality of outermost flow ducts;
- the size of the outermost flow ducts in at least one of said side edge areas of the plate being different than the size of the non-edge area flow ducts in the perforated plate;
- the edges of the perforated plate being provided with projections, and grooves defined between said projections, and corresponding gliding projections of the slides being disposed in said grooves so as to define the outermost flow ducts between the perforated plate and the slides, so that the width of the outermost ducts is adjustable, the outermost flow ducts along each side edge area being of substantially uniform cross-sectional area each with the other in their adjusted widths, and a slice.
A head box, including side walls, for a paper making machine, comprising:
- a cross header;
- means defining a distributor for spreading pulp supplied into the head box evenly over the whole width of a paper making machine with which the head box is associated;
- said distributor means including a perforated plate having a plurality of flow ducts extending through the head box, the plate having a pair of side edges areas, each of said side edge areas having a plurality of outermost flow ducts;
- an expansion chamber;
- said perforated plate communicating with said cross header and with said expansion chamber, wherein pulp flows through said flow ducts from said cross header to said expansion chamber;
- and a slice;
- and wherein the size of the outermost flow ducts in at least one of said side edge areas of said plate is different than the size of the non-edge area flow ducts of said perforated plate;
- slides provided in both of said side edges of the perforated plate and said slides being movable sidewardly and forming with the perforated plate the outermost flow ducts, the edges of the perforated plate being provided with projections, and grooves defined between said projections, and corresponding gliding projections of the slides being disposed in said grooves so as to define the outermost flow ducts between the perforated plate and the slides so that the width of the outermost ducts is adjustable, the outermost flow ducts along each side edge area being of substantially uniform cross-sectional area each with the other in their adjusted widths.
5 more elements
Dependencies are inferred from the claim text.