Improvement in drying performance through sample movement change in tumble dryers

To improve the drying performance of a tumble dryer, the movement of sample clothes as a function of the mechanical action of the dryer was analyzed. The movement of cotton shirts inside a tumble dryer, represented by sample movement patterns, occupancy, and velocity distribution, were quantitatively analyzed using sample movement indices. The differences in the sample movement and the subsequent drying performance were evaluated by varying the drum rotational speed and direction. A drum rotational speed of 50 rpm produced the best sample properties and a short drying period, as the samples actively moved primarily in the center of the drum. Changes in the direction of the drum rotation reduced the drying period and minimized wrinkles in the samples when the frequency of changes to the rotational direction was minimized; however, the change aggravated shrinkage and damaged the samples. The best drying performance was observed when the direction of the drum rotation was changed every 2 seconds. The correlation and regression analysis demonstrated that the sample movements occurred at the center of the drum and that the drying period decreased while the drying performance improved, as the samples were subjected to complex movements and the mixing between them increased.