Patent ID: 7485206
Filing Date: 2009-02-03
Classification: D21F

Abstract:
1. A headbox dilution apparatus, comprising; a device body, having a first plate, a second plate, and a tube bank; a first facing plate mounted to the device body arranged to match the device body to an inlet header of a headbox; wherein the first plate mounts to the first facing plate, the first plate having a stock inlet header facing surface; wherein the second plate is connected to the first plate in spaced parallel relation by a plurality of ribs; a second facing plate having a tube bank facing surface, the second facing plate connected to the second plate to define a plurality of mixing chambers therebetween; the plurality of mixing chambers located side by side in a cross machine direction, and each mixing chamber of the plurality of mixing chambers being limited by a covering wall (T wherein the tube bank is formed of a plurality of inlet ducts extending from the stock inlet header facing surface of the first plate through the second plate, the inlet ducts arranged in adjacent vertical rows, the vertical rows arrayed in the cross-machine direction, wherein there are at least two vertical rows arranged through which stock can flow to each mixing chamber, the inlet ducts extending into the mixing chambers a selected distance; wherein the second facing plate forms a plurality of outlet ducts, one outlet duct for each inlet duct of the plurality of inlet ducts, each outlet duct aligned with said each inlet duct, the outlet ducts starting on the outlet side wall formed by the second facing plate, and extending through the second facing plate to the tube bank facing surface of the second facing plate, whereby an annular gap is left between each inlet duct and each outlet duct, so that when a communicating mixing chamber of said plurality of mixing chambers is filled by dilution water the dilution water is conducted through the annular gap to join stock flowing through the outlet ducts; a single valve connected to each mixing chamber arranged to control a dilution flow; and wherein the headbox dilution apparatus is arranged to be connected between a stock inlet header and a tube bank of an existing headbox.