Headbox for carton or papermaking machine mixes two types of fluid in a profiled chamber incorporating profiled triangular keel with fluid outlets

摘要

A papermaking machine has a headbox with a mixing chamber with an inlet for a first fluid, and a series of further inlets at different heights for a second fluid. The inlets for the second fluid e.g. dilution water are incorporated within a dosing keel located in the mixing chamber. The dosing keel has an essentially right angled triangular form, with the incoming first fluid flowing first over the vertical bevelled edge from which it proceeds to the hypotenuse. The incoming channels for the second fluid emerge from the hypotenuse. The mixing keel thickness is between one third and two thirds of the chamber width which is pref. 50 mm. The mixer chamber sidewalls and keel have profiled surfaces promoting the formation of fluid vortices. Also claimed is a commensurate process for mixing different fluids.