Patent ID: 6030500
Filing Date: 2000-02-29
Classification: D21F

Abstract:
An apparatus for feeding diluted paper stock to a papermaking machine, said apparatus comprising:a multi-layer headbox for producing a fibrous web having three layers, said multi-layer headbox defining pluralities of spaced apart openings arranged in first, second and third rows extending in a cross machine direction for receiving stock for the respective layers, said openings of said second row being spaced apart by a distance less than the distance between the respective openings of said first and third rows;a first stock header for supplying stock to said first row of openings of said multi-layer headbox to form a first, top layer of the fibrous web, said first stock header having an inlet for receiving stock and a plurality of outlets permitting stock to leave said header;a first set of stock conduits each connected to one of said first stock header outlets for permitting stock to pass to the papermaking machine, each of said first set of stock conduits having an upstream end connected to the respective stock header outlet and a downstream end structured and arranged to be attached to the first row of openings in said headbox, said first set of stock conduits having a predetermined inner diameter;a second stock header for supplying stock to said second row of openings of said multi-layer headbox to form a second, middle layer of the fibrous web, said second stock header having an inlet for receiving stock and a plurality of outlets permitting stock to leave said header;a second set of stock conduits each connected to one of said second stock header outlets for permitting stock to pass to the papermaking machine, each of said second set of stock conduits having an upstream end connected to the respective stock header outlet and a downstream end structured and arranged to be attached to the second row of openings in said headbox, said second set of stock conduits having a predetermined inner diameter;a third stock header for supplying stock to said third row of openings of said multi-layer headbox to form a third, bottom layer of the fibrous web, said third stock header having an inlet for receiving stock and a plurality of outlets permitting stock to leave said header;a third set of stock conduits each connected to one of said third stock header outlets for permitting stock to pass to the papermaking machine, each of said third set of stock conduits having an upstream end connected to the respective stock header outlet and a downstream end structured and arranged to be attached to the third row of openings in said headbox, said third set of stock conduits having a predetermined inner diameter, wherein the inner diameter of said second set of conduits is smaller than the inner diameter of said first and third sets of stock conduits;a dilution header for feeding a diluent to at least said second set of stock conduits, said dilution header having an inlet and a plurality of outlets permitting the diluent to leave the dilution header; anda diluent conduit connected to each of said dilution header outlets and permitting a diluent to pass from the respective dilution header outlet through said diluent conduit to one of said stock conduits of at least said second set for diluting the stock passing therethrough, each of said diluent conduits having an upstream end connected to the respective dilution header outlet and a downstream end connected to the respective stock conduit.