| 摘要 |
<p>A pelletizer particularly useful for pelletizing water-dispersible melt-extrudate, among other materials, delivered from an extruder through a die positioned in communication with the interior of the pelletizer housing. The pelletizer includes a rotor disposed inside the housing and knives mounted around the periphery of the rotor. The knives pelletize the melt-extrudate as the rotor rotates. A fluid supply system selectively delivers a fluid, such as air, to the knives when the knives are at a selected location in the housing. The selected location is preferably just past the inlet and can extend in a circumferential direction around the housing in the area of the housing which is near the outlet. The circumferential extent can vary according to the configuration of the knives and the fluid supply system. The fluid supply system supplies fluid in a radially outward direction and tangentially along the cutting edge of the knives so as to sweep the pellets from the knives, as well as cool the knives, the pellets and the interior components of the pelletizer. The selective delivery of fluid sweeps the pellets off the knives as close to the outlet as possible. This prevents fouling, as well as avoids undesirable cooling of the knives in proximity to the die, which could lower the temperature and interrupt the flow of the extrudate.</p> |
