GB941577A - Improvements in or relating to stock-distributor assemblies for paper-making machines - Google Patents

Abstract

941,577. Flow-boxes of paper-making machines. BELOIT IRON WORKS. Feb. 17, 1960 [July 29, 1959], No. 5647/60. Heading D2A. An assembly for distributing stock from a conduit to a flow-box in a paper-machine comprises a header which is connected to the conduit, extends the full width of the flow-box and has a progressively varying cross-sectional area along its length to provide substantially equal stock inputs to each of a plurality of outlet ducts extending upwards from the header in vertical planes parallel to the centre-line of the flow-box to flow stock from the header to a blending chamber extending the full width of the flow-box. The outlet ducts are of uniform substantially circular cross-section and have a ratio of length to mean diameter within the range 7:1 to 25:1. As shown, pulp from a conduit 11 flows to a header 13 supplying a series of risers 14 closely spaced across the machine, providing high-speed flow to a blending chamber 15 and thence through a throat 16 and a deceleration conduit 17, the pulp thus changing its direction of flow by at least 90 degrees twice before entering the flowbox of a Fourdrinier papermaking machine, via a rectifier roll 21. The pulp in the flow-box flows to the wire-cloth through a rectifier roll 21b, and through another 21a at the slice outlet S. White water from the wire pit 30 may be mixed with fresh pulp, centrifugally cleaned, and supplied to the wider end of the header 13 which may be of frusto-conical form, and pulp may be recirculated from the narrower end, the volume recirculated being controlled according to the pressure drop in the header 13. The wall 23c is formed with an upturned flange 23d bolted to the wall 24 by bolts 25 received in vertical slots 24a, so that the cross-sectional area of the throat 16 may be adjusted. Specification 854, 529 is referred to.