Journal of Civil and Environmental Engineering

Water Vaporization from Deposited Sand by Microwave Cavity Resonator

Abstract

Hiroshi Yokawa ,Hirokazu Mutou ,Shuntaro Tsubaki ,Naoto Haneishi ,Takashi Fuji ,Norio Asano ,Keiichiro Kashimura *,Tomohiko Mitani ,Satoshi Fujii ,Naoki Shinohara ,Yuji Wada

In this study, water-soil moisture heating behavior, water vapor rates, and the effect of soil-aggregating agent permittivity under a 2.45-GHz microwave cavity resonator were investigated. The conducted experiments indicated different orders of magnitude than the drying furnace process in the water evaporation rate; moreover, the water vapor rate increased in accordance with the microwave power. The microwave absorption properties indicated that microwave selectively heated water into vaporized moisture, and the vaporization conformed to an energy balance between water evaporative latent heat and microwave power. Furthermore, soil-aggregating agents showed minimal effects on the vapor rate at low microwave power, whereas sand deposited with an aggregating agent indicated a higher vapor rate than that without an agent at a high microwave power. When sufficient energy was supplied to moisture, water transfer was dominant in the vaporization process. In this case, the soil-aggregating agents significantly affected the efficiency of the vaporization process.