| 摘要 |
<p>1482002 Papermaking STOECKLIN & CIE 26 Sept 1974 [4 Oct 1973] 41949/74 Headings D2A and D2B In a papermaking process all of the whitewater is collected for reuse, a first major portion being used untreated for stuff defibring and stuff dilution, and the remaining, second portion being treated with aluminium sulphate and water-soluble, cation-active polyamide and then with the product of reacting an aluminium salt and an alkali metal hydroxide, thereby producing clear water and sludge which, after separation by filtration, flotation or sedimentation, are respectively used in place of fresh water and added without further treatment to the stuff flowing into the headbox. As shown the first major portion is made up of wire-water from vessel I, recycled via pipe 21, and part of the wire-water from vessel II recycled via pipes 22 to pulper 2, pre-screen 4, chests 5 and refiner 6. Another part of the wire-water from vessel II is pumped via tank 12 into tank 16 and then divided into a fraction passing via tank 19 to pulper 2 and a fraction treated with chemicals from pipes 24 before being fed to flotation apparatus 18 for separation, the resulting sludge being fed back into vessel I via pipe 20a and the clear water resulting being fed to a tank 11 for mixing with fresh water.</p> |
