Pulping method

摘要

1,116,940. Disc refiners. BELOIT CORPORATION. 5 Nov., 1965 [4 Feb., 1965]. No. 46999/65. Heading B2A. [Also in Division D2] Cellulose-bearing materials, e.g. wood chips, sugar cane, straw, prairie grass, waste paper and rags, are mechanically pulped by depositing the material in a continuously-vented distributing zone 61, Fig. 2, subjecting the material to mechanical breaking action in a prebreaking zone 58, Fig. 3, continuously feeding the material to a continuously-vented initial defibrating zone 59, and continuously feeding the undeveloped separated fibres to a final defibrating zone 60. The refiner comprises a housing 50, Fig. 2 having an upper stator 54 and a lower rotor 56 with attrition surfaces 55, 57 defining between them the zones 58, 59, 60. The distributing zone 61 comprises a conical member having vanes 62, and is in open communication with the entrance portion 52 and thence with atmosphere. The material prebreaking zone 58 comprises radially extending bars on the stator and rotor and is relatively wide at its entrance portion 63, and gradually decreases in width radially outwardly. The zone 59, Fig. 3, has generally parallel grooves and ridges on the rotor and stator and the final zone 60 has angularly spaced grooves and ridges on the upper and lower outer annular portions of the stater and rotor. The system employed in refining paper pulp in a single continuous pass comprises a bin 10, Fig. 1, feeding a screen 15 and thence a second bin 16 which supplies refiners 19, 20, 21 via quantity control devices 25, 27. The material may be subjected to further refining in a second bank of defibrators 31 . . 33, or bypassed via line 38. Material which does not initially leave the supply line 18 to the banks of defibrators may be returned via line 39 to the bin 16 for later processing.