WET-END SECTION OF A PAPER MACHINE WITH A CONSISTENCY CONTROLLED HEAD-BOX AND A TWIN-WIRE FORMER

摘要

The invention relates to a wet-end section of a paper machine with a head-box (1); a wire section (2) comprising 2 continuous screens - a first screen (40) and a second screen (42), forming together a twin-wire former on a part of their perimeter; at least one former-cylinder (50) placed in the area of the twin-wire-former zone acting as a supporting body in the twin-wire-former zone and which surface area acts as a supporting surface, whereby at least one part of the supporting surface of the first screen (40) provides support on its interior surface and one part of the second screen (42) provides support on its exterior surface; at least one pressure element (58), wherein the pressure elements (58) pres s on certain points only (pressure points), so that areas remain where pressure is reduced and fit closely on the first screen (40) touching the pressure elements; and with a roll (52), which is arranged downstream of the former-cylinder (50). The invention is characterized in that the head-box (34) is consistency controlled and comprised of means to produce controlled sectional flows (30) by means of at least two controlled flows, a main sectional flow (16) and a subsidiary flow (22).