Study on Fixed Salt Removal Effect by Fine Bubbles

¹ Advanced Course of Material Engineering, National Institute of Technology (KOSEN), Kochi College, 200-1 Monobe, Nankoku, Kochi 783-8508, Japan
² Ligaric Co., Ltd, 15-1Shimizu, Suita, Osaka, 565-0805, Japan
³ Department of Social Design Engineering, National Institute of Technology (KOSEN), Kochi College, 200-1 Monobe, Nankoku, Kochi 783-8508, Japan

^* Corresponding author: thata@ms.kochi-ct.ac.jp

Abstract

In recent years, it has become clear that 1 μm or less sized fine air bubbles have different properties from those of mm or cm sized air bubbles. This study examined the effect of fine bubbles on the removal of salt fixed in the gap of aluminum plate as a verification of cleaning action by fine bubbles. As a result, it was confirmed that the removal effect of fixed salt is higher in fine bubble water than in control water, and that the degree of effect depends on the concentration of fine bubbles. It was also confirmed that less than 1 μm sized ultrafine bubble water has a higher removal effect than the control water. As a mechanism of removing fixed salt, it is conceivable that peeling effect, like lifting up part of fixed salt, in which fine bubbles are dissolved by pressure change around the fixed salt to become supersaturated, causing further bubbling around there, and/or physical collision effect of microbubbles. In addition, it was confirmed that the removal effect of a system in which fine bubbles were regularly introduced was much higher than the one that does not introduce fine bubbles regularly. In addition, even when the gap between fixed salt and aluminum plate was narrowed, the superiority of fine bubble cleaning was confirmed.