Paper making stock inlet jet - delivers fibre suspension in a stream which opens out without micro-turbulence

摘要

The fibre suspension for papermaking, delivered by the stock inlet, emerges through a jet assembly as a stream across the machine width which, as seen from the side and in the flow direction, opens out after leaving the jet by an opening angle of at least 3 deg. The fibre suspension stream strikes a long fourdrinier or is directed into the wedge gap between two fourdriniers or the wedge gap between a fourdrinier and the rotating mantle of a roller. The opening angle of the fibre suspension stream is pref. 30-60 deg. the dimensions of the surface where the stream of fibre suspension strikes and is caught are n X d X a, where d is the stream thickness, a the stream width and n is a value greater than d. The jet has an abrupt narrowing at the outlet zone. A flow body is in the jet, generally parallel to the stream surface, ending at the outlet zone so that, at the outlet, the two partial streams come together again. An air inlet is fitted to one of the jet lips, while the other lip has a hump across the machine width with its peak at about the point of the air inlet. ADVANTAGE - The system gives an even delivery of the fibre suspension, without micro turbulence, to give a consistence paper prod..