| 摘要 |
An improved extruder (10) is provided which permits successful introducti on of very high quantities of injected steam into material being processed, on the order of 6-8 % or more by weight steam. The extruder (10) includes an elongated extruder barrel (12) having at least one elongated, axially rotat able, helically flighted extrusion screw (16, 18) therein. The barrel (12) i s equipped with obliquely oriented steam injection ports (44, 46) along the length thereof, housing steam injectors (48, 50). The barrel (12) includes r elatively high free volume steam injection heads (32 and 38, 40) having ther ein screw sections (78, 82) of relatively long pitch length, together with s team restriction heads (30, 34, and 42) on opposite sides of the injection h eads (32, and 38, 40) having therein relatively short pitch length screw sec tions (76, 80, 84). |
