Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology, Wuhan, China.
Sci Rep. 2023 Jul 18;13(1):11554. doi: 10.1038/s41598-023-37804-8.
Hand dryer in public washroom has been reported likely to be a reservoir of drug-resistant bacteria. When a hand dryer being used, the high-velocity air jet from the dryer outlet can carry aerosol particles to hand surfaces, the user, and indoor space. This in silico study considered the effect of different airflow speed of hand dryers on the dispersion of particles in different diameters with and without the user. The aim of this study was to apply the computational fluid dynamics (CFD) method based on the discrete phase model to investigate the trajectory of indoor particles from the hand dryer in public washroom. The CFD results showed that, when the user was using the hand dryer, 42.3% of the particles were distributed on the wall against the user, and 31.6% were distributed on the user's body, including their hands. When no one was standing in front of the hand dryer, 87.6% of the particles fell on the ground. The blocking of user's hand dispersed the particles to a wide range, particularly for the larger diameter particles which were scattered on the user's body or on the ground. In addition, the dispersion proportion of particles did not vary with the speed of airflow, but the area of particles distribution became larger as the speed increased. Our findings suggest that the contamination of the indoor environment caused by the hand dryer could not be ignored, incorporating filters into hand dryers is essential. Furthermore, our work offers valuable insights for optimizing the design of hand dryers.
公共洗手间的干手机据报道可能是耐药菌的蓄水池。当使用干手机时,干手机出口的高速气流会将气溶胶颗粒带到手部表面、使用者和室内空间。这项计算机模拟研究考虑了不同干手机气流速度对有用户和无用户情况下不同直径颗粒的分散效果。本研究旨在应用基于离散相模型的计算流体动力学 (CFD) 方法,研究公共洗手间干手机内室内颗粒的轨迹。CFD 结果表明,当使用者正在使用干手机时,42.3%的颗粒分布在使用者对面的墙上,31.6%分布在使用者身上,包括他们的手。当没有人站在干手机前面时,87.6%的颗粒落在地上。使用者手的阻挡将颗粒分散到更广泛的区域,特别是对于较大直径的颗粒,这些颗粒会散落在使用者的身体或地面上。此外,颗粒的分散比例与气流速度无关,但随着速度的增加,颗粒分布的区域会变大。我们的研究结果表明,干手机可能会导致室内环境的污染,不容忽视,将过滤器纳入干手机是必要的。此外,我们的工作为优化干手机的设计提供了有价值的见解。