抽吸孔结构对喷气涡流纺喷嘴气流场的影响

Effects of air suction hole structure on nozzle airflow of air jet vortex spinning

研究负压抽吸式喷气涡流纺喷嘴中抽吸孔直径与抽吸区长度对喷嘴气流场分布特征的影响。采用数值模拟的方法,结合纺纱试验结果,阐明了抽吸孔直径与抽吸区长度对喷气涡流纺包芯纱成纱过程中的落纤量及成纱断裂强度的影响机制。研究发现,纺锭内引纱通道入口端面处气流径向速度和轴向速度的方向与大小对成纱过程中落纤量的大小起关键作用,气流轴向速度和径向速度值越大,落纤量越小;靠近纺锭入口位置的抽吸孔中气流径向速度的大小对成纱断裂强度的大小起关键作用,气流径向速度越大,成纱断裂强度越高。气流场模拟结果表明:抽吸孔直径0.3 mm和0.4 mm时降低落纤量的效果优于抽吸孔直径0.2 mm,抽吸孔直径0.2 mm时成纱断裂强度较高;抽吸区长度25 mm和34 mm时降低落纤量的效果相似,抽吸区长度34 mm时成纱断裂强度略低于抽吸区长度25 mm。气流场的数值模拟结果解释了纺纱试验结果,可为喷气涡流纺喷嘴结构的改进提供理论参考。

Effects of air suction hole diameter and length of the air suction region on the airflow patterns in air jet vortex spinning nozzle with negative pressure air suction were studied.Numerical simulation method was adopted.Combined with the results of spinning experiment,the effect mechanism of air suction hole diameter and length of the air suction region on the fiber loss during the air jet vortex spinning process of core-spun yarn and yarn breaking tenacity was explained.It was found out that both radial and axial velocities of the airflow at the inlet plane of the yarn passage inside the spindle played a key role in affecting the amount of lost fibers.The higher the axial and radial velocities of the airflow were,the less the lost fibers were.The radial velocity of the airflow in the suction hole near the inlet of the spindle played a key role in the value of yarn breaking tenacity.The higher the radial velocity of the airflow were,the higher yarn breaking tenacity of the yarn was.The simulation results of the airflow showed that the fiber loss with the hole diameter of 0.3 mm and 0.4 mm was lower than the case of 0.2 mm.The yarn breaking tenacity was the highest when the suction hole diameter was 0.2 mm.The fiber loss was similar when the zone length of suction holes were 25 mm and 34 mm.The yarn breaking tenacity with suction zone length of 34 mm was slightly lower than that with suction zone length of 25 mm.The numerical simulation results of airflow explained the results of the spinning experiment.It could provide theoretical reference for the modification of the nozzle structure in air jet vortex spinning.