Effects of microbubble addition on the sophistication of solid/liquid separation processes

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04176
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Properties in chemical engineering process/Transfer operation/Unit operation
• Research Institution: Osaka Prefecture University
• Principal Investigator: IWATA Masashi 大阪府立大学, 工学(系)研究科(研究院), 教授 (10151747)
• Co-Investigator(Kenkyū-buntansha): 田中 孝徳 大阪電気通信大学, 工学部, 講師 (30581889) ; 安田 昌弘 大阪府立大学, 工学(系)研究科(研究院), 教授 (40264808)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 加圧溶解方式 / 気泡径 / 収縮 / 膨張 / プリコート濾過

Outline of Final Research Achievements

Effects of microbubble addition to solid/liquid separation have been investigated. A pressurizing dissolving system was used to generate microbubble. The larger the discharge pressure of the generator, the smaller the median diameter of the bubble. There exists the critical diameter of the bubble; i.e., a bubble larger than the critical size always grows, while a bubble smaller than the critical size surely shrinks. The critical size depends on the dissolved gas concentration. Colloidal particles attached to a shrinking microbubble approach each other as the bubble shrinks, resulting in agglomerates of particles. This process requires several minutes when the bubble size is several ten micrometers. In precoat filtration using diatomaceous earth as precoat material, the addition of microbubble increases dramatically the filtration capacity of the precoat layer, provided that the precoat layer is carefully prepared.

Free Research Field

工学