Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

EFFECT OF ULTRASOUND PRETREATMENT ON MICROSTRUCTURE AND DRYING CHARACTERISTICS OF FIBROUS POROUS MEDIA

Get access (open in a dialog) DOI: 10.1615/IHTC16.mtr.023846
pages 5869-5875

Abstrakt

Ultrasound is an effective pretreatment way to increase the moisture transfer rate in fibrous porous media drying process by changing the micropore structure. Pretreatment tests are implemented in six pretreatment times and seven ultrasound power. After pretreating, all samples are dried at 20°C and 45%RH to determine the effect of ultrasound pretreatment on fibrous porous media dehydration rate and a microscopic observation is carried out to analysis the variations of pore structure . Results show that, after the ultrasound pretreatment with the power of 630W for 60min, the surface fractal dimension, obtained by box-counting method, increases from 1.7538 to 1.8736. Besides, the area ratio of gaps between yarns increases from 0.48 to 0.62. Due to the change of micropore structure, the dehydration performance of fibrous porous media is improved. The experiment data obtained in drying process is fitted by the Modified Page model and the time required reducing the dry basis moisture content from 3 kg water/kg dry solids to 0.5 kg water/kg dry solids is calculated, which is decreased from 690 min to 504 min.