HEADBOX OF A PAPER/BOARD MACHINE BY WHOSE MEANS THE BASIS WEIGHT OF THE WEB CAN BE REGULATED

摘要

The invention concerns a headbox for a paper/board machine by whose means the basis weight of the web can be regulated. The headbox comprises a stock inlet header (J1), which becomes narrower towards its end. Tubes (11a1, 11a2...) in a tube bank (11) open in the stock inlet header (J1) across the machine width, which tubes are connected with thickening elements (12a1, 12a2...) across the machine width, in which connection a flow (L1) is removed from the thickening element into the duct (D1) and said flow (L1) to be removed is regulated by means of a valve (V1, V2...). From the thickening element (12a1, 12a2...) a tube (14a1, 14a2...) for a flow (L2) of higher consistency is provided, which flow is passed further in the headbox.