| 摘要 |
Logs which are difficult to bark can be pretreated by impacts in order to reduce the bond of the bark to the wood prior to a frictional debarking of the logs. In order to avoid the strength problems which arise at the journalling points of beaters journally mounted on a rotor the invention instead uses rotors (11) having preferably block-shaped teeth (13) attached along helical lines to the surface (21) of the rotor (11). The rotors (11) are included in a roller conveyor (7) and are rotated at a peripheral speed of 20-30 m/s which is also 20-30 times greater than the feeding speed of logs through the pretreating apparatus. In order to reduce the speed there are included in the roller conveyor (7) braking rotors (23), such as spiked rollers, and flexible means (19, 19') comprising rubber flaps (27, 27') which press the logs down to the rotors (11 and 23). |
