【作者】 王玉栋；

【导师】 葛明桥；

【作者基本信息】 江南大学 ， 纺织工程， 2010， 硕士

【摘要】 旋流纺纱是在利用喷射气流加工纤维的技术、并针对克服喷气纺纱方法所存在问题的基础上发明的一种新型纺纱方法。它以梳辊牵伸机构代替喷气纺纱中的罗拉牵伸机构,具有牵伸速度快、效率高,牵伸部件磨损小等优点。本文在大量前期实验和理论分析的基础上,重新设计了闭合式旋流纺的纺纱工艺流程,设计了压辊、纤维引导管道和纤维气流引导装置,将纤维集聚装置汇聚好的纤维引导出来。纤维气流引导装置内部流场的速度和压强分布状态决定了涤纶长丝和纤维在纱道内的运动状态,对纤维的引导至关重要。本文应用流体计算软件ANSYS CFX对纤维气流引导装置内气流流动特征进行三维数值模拟,根据计算结果对其内部的气流速度和压强分布进行分析;并选择喷射孔出口速度和喷射孔倾角作为研究参数,考察它们对纤维气流引导装置内气流流动特征的影响。最终得出如下结论:1、纤维气流引导装置与纤维引导管道和压辊配合,可以较好地将汇聚后的纤维引出闭合式纤维集聚装置。2、压缩空气经过喷射孔后在纤维气流引导装置内部形成旋转气流,向纱道出口螺旋推进。3、切向速度沿纤维气流引导装置纱道的轴向与径向存在差异,会造成涤纶长丝上的捻度不匀,对引导纤维不利。4、轴向速度在靠近管壁处较大,对包缠纤维的自由端可以起牵伸作用;同时容易引起涤纶长丝和纤维与壁面碰撞,造成引出的纤维的伸直平行度恶化。5、径向速度较小,波动较大,这有利于包缠纤维的边缘自由尾端在气流作用下膨胀,从而使纤维在切向气流作用下获得更多的包缠捻度。6、随着喷射孔倾角的增大,纤维气流引导装置纱道进气端的负压减小,不利于吸入纤维和涤纶长丝;对应截面内的最大切向速度随着增大,对涤纶长丝的旋转加捻增强。当纤维气流引导装置的喷射孔倾角为45°时,对纤维的引导较为有利。7、喷射孔出口速度增大,切向速度和轴向速度随之增大,纤维气流引导装置纱道进气端的负压也越大。更多还原

【Abstract】 Swirl spinning is a new-type spinning process. It uses jet air to process fibers in order to resolve the matters in air-jet spinning. It substitutes roller drafting system with combing roller drafting system, which ensures the drafting system of swirl spinning with high speed, high efficiency, little abrasion, and so on.On the basis of large former experiment and theoretical analysis, loading roller, fiber guiding pipe and fiber-guiding device were designed and the closed swirl spinning process was improved.The flow field’s distribution of fiber-guiding device are very important for guilding fiber. A three-dimensional computational fluid dynamics model was developed to simulate the flow field inside the fiber-guiding device with ANSYS CFX. Flowing state, distributing of static pressure and velocity and so on were characterized and analyzed.Finally, results were got as follows:1. Fiber-guiding device working with fiber guiding passage and loading roller can well guild the converged fiber.2. Compressive air through the jet orifice comes into being three-dimensional whirly airflow.3. The reason of twist irregularity of filament is that the tangential velocity at different position is different.4. The axial velocity near the wall is larger,which can draft to the free end wrapped fibers;At the same time it also easily leads to collision among polyester filament yarn, fiber and the wall,and leads to deteriorate of the straight parallel for derived fibers.5. The radial velocity is small and volatile.It makes the edge open-trail end fibers in the main nozzle begin to expand to let filament get more wrapper fibers.6. The negative pressure in the inlet decreases with increasing the jet orifice angle.The tangential velocity increases along with increasing the jet orifice angle.It is better when jet orifice angle is 45 degree.7. When the velocity at the exit of jet orifice enhances, the tangential velocity,the axial velocity and the negative pressure in the inlet are greater.更多还原