Abstract

Positron emission particle tracking (PEPT) has been used to investigate the motion of radioactively labeled tracer particles attached to fabrics and solid fabric enhancer (SFE) delivery articles, such as dryer sheets, in the domestic clothes dryer. This work examines the dynamics of motion within the dryer across a range of operating conditions. Six regions within the dryer drum are identified, demonstrating the range of movements experienced by items during tumbling. These show clear correlation with existing flow regimes describing behavior of granular media in rotating drums. Fabric motion is primarily cataracting to maximize the surface area of fabric available to interact with drying air in the falling region, with some conditions moving toward centrifuging or cascading flows. Movement in the axial direction was significantly slower than the primary radial flow. Dryer sheets were more prone to centrifuging than fabrics, with significant time spent in contact with the drum wall. Conversely, a wool dryer ball was more likely to cascade, spending time mixed into the top of a fabric bed which forms in the impact and lifting regions. Behavior in this bed is primarily determined by frictional interactions with the drum wall, which subsequently affects behavior in the 5 remaining regions. The most significant changes to this behavior were observed when changing fabric moisture content and volumetric fill ratio, with wet fabrics and smaller load sizes both exhibiting faster falling speeds and spending more time in the fabric bed. The changes were most significant in the lifting, falling and detachment regions, with varying acceleration and shearing likely to influence both fabric wear and SFE delivery.

摘要

正电子发射粒子追踪 (PEPT) 已被用于研究在家用干衣机中附着在织物和固体织物增强剂 (SFE) 输送物品（如干衣片）上的放射性标记示踪粒子的运动。这项工作检查了干燥机在一系列操作条件下的运动动态。确定了干燥滚筒内的六个区域，展示了物品在翻滚过程中所经历的运动范围。这些与描述旋转滚筒中粒状介质行为的现有流态有明显的相关性。织物运动主要是白内障，以最大化织物的表面积，可用于与下降区域中的干燥空气相互作用，一些条件向离心或级联流移动。轴向运动明显慢于初级径向流动。与织物相比，干燥片更容易离心，与滚筒壁接触的时间很长。相反，羊毛烘干机球更有可能级联，花费时间混合到在冲击和提升区域形成的织物床的顶部。该床的行为主要由与滚筒壁的摩擦相互作用决定，这随后会影响其余 5 个区域的行为。当改变织物水分含量和体积填充比时，观察到这种行为最显着的变化，湿织物和较小的负载尺寸都表现出更快的下降速度和在织物床上花费更多时间。上升、下降和脱离区域的变化最为显着，