| 摘要 |
In continuous pulping processes for cellulosic fiberous material pulp, a changeover from deciduous wood raw material to coniferous wood raw material without interruption of the production process, and with a minimum waste of pulp, is provided. The pulp mixture during changeover, having a consistency of about 8-15% is fed to a screen in which the pulp is separated into two pulp fractions depending upon fiber length. A fiber length analyzer is placed in the pulp stream between a treatment or storage vessel and the screen, and controls the rejects line from the screen to determine the amount of pulp passing out the screen rejects conduit. The screen may be directly in a production line from a continuous digester, refiner, or like device for producing the pulp, or it may be connected to a storage vessel to which pulp from a digester or the like has been fed. The accepts conduit from the screen is connected to a first vessel while the rejects conduit is connected to a second vessel, with valves allowing for by-pass of the screen in feeding the pulp directly into either the first or second vessel when only a single type of pulp is being produced. |
