Numerical Study on Effect of Suction Slot Geometric Parameters on Airflow Field in Compact Spinning

The airflow field in the condensing zone is crucial as it affects the fiber condensing, additional twists, and consequently yarn properties. Parameters of spinning and suction slot geometric were found to be key factors influencing the airflow characteristics. To develop a better understanding of the complex airflow field within the pneumatic compact spinning system with lattice apron, a 3D numerical simulation model was built and the influence of negative pressure and geometric of suction slot was investigated. The results reveal that the accelerating air from the top of the suction slot generates transverse condensing force and downward pressure on the fiber strand. The inclination angle has a small effect on airflow velocity. The absolute z -velocity and x -velocity in the positive x -axis were both increased with increasing the slot width from 1.0 mm to 1.5 mm. An arc suction slot increased the absolute z -velocity and x -velocity compared with a linear one, thus benefiting fiber condensing. By decreasing the outlet negative pressure to −3kPa, the airflow velocity increased significantly.