摘要 |
A refiner (1) comprising a stator (2) and a rotor (6) that comprise a planar portion and a conical portion after the planar portion, which in turn comprise refining surfaces (4, 8) provided with blade bars (15, 18, 24) and blade grooves (16, 19, 25) therebetween, and the planar portions (4', 81) of the refining surfaces (4, 8) of the stator (2) and the rotor (6) comprising at least two refining zones (14, 17, 23) in the direction of the radius (R) of the planar portion. At least the planar portion (8') of the refining surface (8) of the rotor (6) is provided with blade bars (18) in its outermost refining zone (17) in the direction of the radius (R), the blade bar angle (a) of the blade bars being arranged so as to provide pumping blade bars, and their blade bar angle (a) being greater than the blade bar angle (a) of the blade bars (15, 24) in the previous refining zone (14, 24) in the direction of the radius (R) of the planar portion (8') and that the blade bar angle (a) is 5 - 50 degrees so that the blade bars (18) in the outermost refining zone (17) have an overall pumping effect on the material to be refined. |