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Sano, Yuichi; Sakamoto, Atsushi; Takeuchi, Masayuki; Misumi, Ryuta*; Kunii, Kanako*; Todoroki, Kei*; Nishi, Kazuhiko*; Kaminoyama, Meguru*
Kagaku Kogaku Rombunshu, 44(6), p.335 - 340, 2018/11
Concerning an annular centrifugal contactor which has high throughput and separation performance, the effect of operational condition on fluidic and dispersion behavior, which are important to improve the contactor performance, was investigated by computational fluid dynamics (CFD) analysis based on the turbulence model, and the calculated results were validated by experimental data. The liquid phase in the annular zone was gradually divided into two regions vertically with increasing the rotor speed and decreasing the flowrate, and the liquid flow moved toward the center of the housing bottom was generated in the lower annular zone under any operational condition. The droplet size of the dispersed phase in the annular zone decreased with increasing the rotor speed and decreasing the flowrate. These calculation results showed a good agreement with experimental data. The CFD analysis considering mass transfer between aqueous and organic phases was also attempted, and it was confirmed that the change of extraction performance with the rotor speed showed the same tendency as the experimental result.
Misumi, Ryuta*; Todoroki, Kei*; Kunii, Kanako*; Nishi, Kazuhiko*; Kaminoyama, Meguru*; Sano, Yuichi; Sakamoto, Atsushi; Takeuchi, Masayuki
Kagaku Kogaku Rombunshu, 44(5), p.285 - 291, 2018/09
Annular centrifugal extractors have been anticipated for use as extractors in spent nuclear fuel recycling. The extraction rate and the liquid-liquid dispersion are related to the flow pattern in the vessel. However, no study has clarified flow patterns in vessels of various scales. For this study, flow pattern characteristics are quantified for extractors of two scales. An extractor has a mixing zone around the vessel bottom and a separation zone in the cylindrical rotor. For this experiment, distilled water was fed into the vessel. Flow behavior in the mixing zone was observed from a side view using a digital video camera at various rotor speeds and supply flow rates for extractors of two scales. In some cases, the liquid horizontal velocity vectors in the mixing zone were measured using particle image velocimetry. Results demonstrate that flow behaviors in the mixing zone in both scales of extractors are classifiable as three types, changing with operational conditions: Type A, Type B, and a Transition regime. For the Type A state, the mixing zone is fully filled with liquid from the vessel bottom up to the lower edge of the rotor. In the Type B state, the zone with existing liquid is vertically divisible into two regions. Lower rotor speeds and higher flow rates tend to produce Type A state flow behavior. The boundary operational condition between Type A and the Transition regime are correlated with the normalized supply flow rate and pumping capacity of the rotor, which is evaluated from liquid surface level in a rotor formed by centrifugal force. Furthermore, the fluid velocity in the mixing zone is roughly proportional to the rotor surface circumferential speed irrespective of the vessel scale.
Misumi, Ryuta*; Kunii, Kanako*; Todoroki, Kei*; Nishi, Kazuhiko*; Kaminoyama, Meguru*; Sano, Yuichi; Sakamoto, Atsushi; Takeuchi, Masayuki
Kagaku Kogaku Rombunshu, 44(3), p.135 - 141, 2018/05
Times Cited Count：1 Percentile：4.87(Engineering, Chemical)Annular centrifugal extractors have been used in spent nuclear fuel reprocessing, but the relation between the extraction rate and flow pattern in the vessel remains unclear. This study quantifies characteristics of the flow pattern to clarify this relation. An extractor produces a mixing zone around the vessel bottom and a separation zone in the rotor. The horizontal velocity of the liquid in the mixing zone was measured using particle image velocimetry at various rotor speeds and supply flow rates. Flow behaviors in the mixing zone are of three types, changing with operational conditions: Type A, Type B, and a transition regime. At lower rotor speeds and high supply flow rates, the mixing zone is fully filled with liquid from the vessel bottom up to the lower edge of the rotor: the Type A flow state. At high rotor speeds and low supply flow rates, the zone with existing liquid is vertically divisible into two regions: near the vanes and around the bottom of the rotor, which is the Type B flow state. A transition regime is also observed between Type A and Type B state. In each region surrounding the two vanes on the vessel bottom and the vessel wall, the liquid flowed in the direction of rotor rotation along the vessel wall. Liquid flow altered by the vane flowed toward the center of vessel bottom. The liquid then entered the separation zone through the orifice at the rotor bottom. For the Type A state, the horizontal velocity distribution was roughly proportional to the rotor speed. For the Type B state, the horizontal velocities around the vessel bottom were lower than those of Type A and were not proportional to the rotor speed. Presumably, the liquid fed into the vessel went directly to the rotor instead of passing between the two vanes attached to the vessel bottom.
Narita, Hirokazu*; Maeda, Motoki*; Tokoro, Chiharu*; Suzuki, Tomoya*; Tanaka, Mikiya*; Motokawa, Ryuhei; Shiwaku, Hideaki; Yaita, Tsuyoshi
Analytical Sciences, 33(11), p.1305 - 1309, 2017/11
Times Cited Count：11 Percentile：40.7(Chemistry, Analytical)Naganawa, Hirochika
Bunseki Kagaku, 66(11), p.797 - 808, 2017/11
Times Cited Count：6 Percentile：22.86(Chemistry, Analytical)A new liquid-liquid extraction method, called the emulsion-flow method, has recently been developed at Japan Atomic Energy Agency (JAEA). The emulsion-flow method, where low cost, simplicity, high efficiency, compactness, safety, and eco-friendly go together, has attracted attention, and has been expected to bring innovation to liquid-liquid extraction technologies. Compared with conventional industrial apparatuses, an emulsion-flow apparatus successfully combines the lowest cost superior to a spray column and the highest performance (the highest efficiency and the highest processing speed) comparable to a centrifugal extractor. Furthermore, the emulsion-flow method can also be used for collecting particulate components by utilizing their aggregation onto a liquid-liquid interface and for purifying water polluted by oil with its remarkable phase-separating ability.
; ; Tachikawa, Enzo;
Bunseki Kagaku, 37(1), p.7 - 11, 1988/01
no abstracts in English
; ; Mohammad Abdullah*; ; Yamamoto, Katsumune
Nihon Genshiryoku Gakkai-Shi, 29(1), p.58 - 63, 1987/01
Times Cited Count：1 Percentile：19.35(Nuclear Science & Technology)no abstracts in English
Naganawa, Hirochika
no journal, ,
Liquid-liquid extraction (solvent extraction) is a method for extracting a target component from an aqueous solution into an organic solvent immiscible in water, which is very popular in industry especially in metal refining. In the emulsion flow extractor, the flow of an emulsion, which is a fine mixture of aqueous and organic phases, arises by generating micrometer-sized liquid droplets with a nozzle head, and the emulsion flow then promptly disappears by itself with a drastic change of the cross-section area of its passing in the extractor vessel structure. In short, aqueous and organic phases can be effectively mixed to an emulsified condition and then these two liquid phases can be quickly separated to their perfectly clear condition by only sending liquids. Therefore, the emulsion flow extractor is markedly low-cost and simple compared with conventional apparatuses (mixer-settler, etc.) despite showing the highest performance.
Naganawa, Hirochika; Nagano, Tetsushi; Yanase, Nobuyuki*
no journal, ,
A new liquid-liquid extraction apparatus, named, emulsion-flow extractor, where low cost, simplicity, compactness, high processing speed, high efficiency, and safety go together, is introduced. The emulsion-flow technique can actualize very efficient liquid-liquid extraction with its high two-phase mixing ability to an emulsion by spraying micrometer-sized oil droplets into a counter-current aqueous solution. Meanwhile, this technology can also actualize more than tenfold processing speed in its very rapid phase separation and less than one fifth cost with its very simple structure workable by only solution sending in comparison with mixer-settler that is the most popular industrial liquid-liquid extraction technique. In addition, the emulsion-flow extractor having no drive part in its main body has less trouble and is safer than the conventional extractor.
Motokawa, Ryuhei; Endo, Hitoshi
no journal, ,
no abstracts in English
長縄 弘親; 永野 哲志
not registered
JP, 2019-234265 
Patent licensing information Patent publication (In Japanese)
【課題】正抽出部100、洗浄部200、及び逆抽出部300が一体となり同期して機能する循環送液システムにおいて、複数回の循環回数によって発現する多段に相当する効果を利用して分離精製される特定物質の製造装置を提供すること。 【解決手段】正抽出部100、洗浄部200、及び逆抽出部300が一体化して同期的に機能する構成を備え、正抽出部100の水相(多くの場合、重液相)が正抽出部100のみの単独部内で循環送液すると同時に、正抽出部100の油相(多くの場合、軽液相)が洗浄部200から逆抽出部300を経て再び正抽出部100に至る横断的な循環送液を行うように構成され、正抽出部100の水相の単独部内循環を複数回行うことによって分離精製される特定物質を得る。
