1 Copyright © 2015 by ASME Proceedings of the ASME 2015 International Mechanical Engineering Congress & and Exposition IMECE 2015 November 13-19, 2015, Houston, Texas, USA IMECE2015-50479 PRELIMINARY INVESTIGATION OF NOVEL DIRECT CONTACT ULTRASONIC FABRIC DRYING Ayyoub M. Momen Oak Ridge National Laboratory Oak Ridge, TN, USA Edem Kokou Bronx Community College Bronx, NY, USA Pradeep Bansal Oak Ridge National Laboratory Oak Ridge, TN, USA Kyle R. Gluesenkamp Oak Ridge National Laboratory Oak Ridge, TN, USA Omar Abdelaziz Oak Ridge National Laboratory Oak Ridge, TN, USA ABSTRACT Thermal evaporation of moisture from clothes is the main technique used in clothes dryers today. Most of the energy supplied is spent to provide the latent heat of evaporation of water (2.5MJ/kg). This paper presents a novel direct contact ultrasonic system to mechanically remove water from wet fabric. The vibrations from the transducers are transferred by direct contact to the water inside the narrow pores of the clothes. Breaking the capillary adhesion of moisture at the interface between air and water allows water to exit the clothes as cold mist. The cold mist also carries with it most impurities such as minerals or detergents. This cannot be achieved in thermal dryers where water evaporates and leaves the impurities behind. Mechanical extraction of water is expected to be more efficient since thermal processing is not required. The majority of the supplied energy is used to mechanically separate water from the fabric. Initial testing has revealed that it is possible to dry a 1 cm 2 piece of fabric from full saturation to a mere 0.4 % moisture content in just 14 seconds. INTRODUCTION Oak Ridge National Laboratory is developing a novel ultrasonic clothes dryer [1]. Ultrasonic drying of porous materials had been developed and used in the food conservation industry [2-3]. The systems involved in the drying process use piezoelectric transducers to generate high frequency vibrations. In most cases, the ultrasonic waves are transmitted to the materials to be dried through air or a solid medium. In direct- contact ultrasonic drying, the fabric is placed directly in contact with the vibrating transducer to increase ultrasonic energy transmission (Figure 1). A thorough understanding and characterization of the mechanical and acoustic phenomena, occurring when a transducer vibrates, is crucial to this drying technique. A few parameters were studied to understand how ultrasonic drying could be implemented: drive signal wave form, operating temperature, relation between transducer dimension, and the water atomization process, which underpin fabric drying in a direct-contact configuration. Figure 1: Direct contact ultrasonic drying process A: Atomization occurring inside pores of the fabric The mechanical oscillations generate heat. However, transducers lose their piezo-electrical properties when operated at temperatures higher than their Curie temperature. Even though some of the heat generated during operation is dissipated to the environment, the temperature was monitored to ensure that the transducers never exceed their safe operating temperature. As transducers lose their properties they fail to vibrate as intended. It was observed that being able to atomize