Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
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.
Ishiyama, Shintaro
Kagaku Kogaku Rombunshu, 41(2), p.95 - 99, 2015/02
Times Cited Count：0 Percentile：0(Engineering, Chemical)Chemical interface controlled dispersion and high-speed shearing water washing tests were implemented for the purpose of optimization of processing conditions with highly radioactive contaminated soils of over 570,000 Bq/kg in Fukushima and the following results were obtained. (1) Dispersion of the radioactive contaminated soil over 570,000 Bq/kg was enhanced in alkalized washing solution at babe equilibrium point of pH=10-11. (2) Refinement of contaminated soils was also promoted by collision of contaminated soil particles toward washing machine walls and inter-particle collision during soil washing process and remarkable washing performance was achieved under the combination of dispersion and high-speed shearing washing condition with 50% solid density in wash solution.
Ishiyama, Shintaro
Kagaku Kogaku Rombunshu, 40(6), p.462 - 465, 2014/11
Times Cited Count：0 Percentile：0(Engineering, Chemical)For the purpose of performance evaluation of new water circulating system (Amount of evaporation: 40 kg/h) in radiation contaminated soil washing process, decontamination water washing and water circulating tests for the system were conducted with over 570,000 Bq/kg radiation contamination soil in FUKUSHIMA and the following results were derived;(1) Interfusion of fission product due to dissociation from contaminated soil into filtrate was observed after filter press, and interfusion amount of FP for contaminated moor soil and village road soil reached to 35% and 0.01%, respectively. (2) Condensation water with very low contamination and impurity was produced by the water circulating machine and 86-88% recovery rate from filtrate was achieved. (3) Almost FP was concentrated in concentrated solution and concentration rate of solution reached to 7.2-8.6.
Ishiyama, Shintaro; Otani, Kazuhisa*; Yamashita, Manabu*
Kagaku Kogaku Rombunshu, 40(6), p.466 - 469, 2014/11
Times Cited Count：0 Percentile：0(Engineering, Chemical)For the purpose of performance evaluation of the field portable (360 mmD 
360 mmH 800 mmW) and fixed mount type filter presses(1880 mmD 2140 mmH 9085 mmW) for soil consolidation in radiation contaminated soil washing process, decontamination water washing test and radiation assessment for these filter presses were conducted with over 570,000 Bq/kg radiation contamination soil in FUKUSHIMA and the following results were derived; (1) About 10% volume reduction was achieved in soil consolidation process by the field portable filter press with 1.3-6.7 times high condensation of radiation density. (2) During soil consolidation, core dose in the field portable and fixed mount type were evaluated as 2.5 and 196 
Sv/h, respectively, and exposed dose in ordinary maintenance and inspection in excess of radiation protection guide level, especially for the fixed mount type in terms of radiation protection.
Ishiyama, Shintaro; Oba, Hironori; Yamamoto, Shunya; Shobu, Takahisa
Kagaku Kogaku Rombunshu, 40(2), p.131 - 136, 2014/03
Times Cited Count：0 Percentile：0(Engineering, Chemical)New micromachining technique of unworkable sapphire was demonstrated by highly coalesced ion implantation and eximer laser irradiation methods. After proton implantation by 0.3 MeV H
up to 110
/cm
into sapphire, damaged region was formed beneath 1m depth from the surface of implanted sapphire and blistering was observed by 0.3
3 MeV H over 110/cm. Ion implanted sapphire behaves peculiar wavelength absorption at 200 nm and ion implanted sapphire by 0.3 MeV H up to 110/cm was irradiated by ArF laser with 3.4 J/cm1 shot and micro trench shape with 1m depth and 5080 m width was observed on the surface of ion implanted sapphire. These results mean that micromachining of sapphire on the order of m width with arbitrarily depth can be possible by highly coalesced ion implantation and laser irradiation techniques.
Ishiyama, Shintaro; Mamitani, Masataka*; Kondo, Mitsunori*; Hiki, Akinori*
Kagaku Kogaku Rombunshu, 39(6), p.545 - 552, 2013/11
Times Cited Count：3 Percentile：13.49(Engineering, Chemical)Chemical interface controlled dispersion and high speed shearing (CDS) washing verification test of high level radioactive contaminated soil over 570,000 Bq/kg was conducted using three kinds of radioactive contaminated soils of school ground, moor and road in Fukushima and the following results was obtained. (1) Washing rate of three kinds of contaminated soils reached up to 60-98% after 60 minutes CDS water washing. (2) Recovered amounts of reclamation soils of three type of soils(less than 8,000 Bq/kg) were 60-82 wt.%. Especially, 506 Bq/kg 33wt.% was achieved in the case of contaminated soil of moor. (3) Volume reductions of 60-85wt.% were achieved in every case of contaminated soils. (4) Contain recoverable quantities of total radioactive sources contained in soils was over 90%. (5) Main FP trapping minerals contained in contaminated soil of school ground is lamellar silicate and that of moor and road is mordenite.
Ishiyama, Shintaro; Mamitani, Masataka*; Kondo, Mitsunori*; Hiki, Akinori*
Kagaku Kogaku Rombunshu, 39(4), p.405 - 410, 2013/07
Times Cited Count：3 Percentile：13.49(Engineering, Chemical)Ion plating ceramic coating technique was applied for prevention of radioactive contamination and attrition of chemical interface controlled dispersion and high speed shearing washing machine during water washing with high level radioactive contaminated soil over 570,000 Bq/kg and the following results were obtained. (1) No contamination of AlO
courted coupon with 5 m thickness installed in plunger was found after 3 hours water washing process of slurry contained 50% contaminated soil and uniformed attrition of the coating surface was observed, whereas contamination of SUS coupon due to FP particle attack and implantation during washing was observed. This contamination source is attached to SUS surface and not removable. (2) Attrition rate of surface of coated coupon during washing was estimated as 0.14 m/hr in the case of installation on rotor of plunger and attrition of SUS exhibits 7 times higher than that of coated coupon in initial stage of washing process.
Iwatsuki, Jin; Watanabe, Yutaka*; Terada, Atsuhiko; Onuki, Kaoru
Kagaku Kogaku Rombunshu, 37(5), p.441 - 446, 2011/09
Times Cited Count：1 Percentile：6.72(Engineering, Chemical)The thermochemical IS process for hydrogen production involves the use of highly corrosive sulfuric and hydriodic acids at high temperature and pressure, and the development of corrosion-resistant materials for main components is therefore crucial to process development. This paper concerns the development of a sulfuric acid transfer pump, an important component in transferring high-temperature concentrated sulfuric acid in the sulfuric acid decomposition step of the IS process. A reciprocating plunger pump made of SiC ceramics and common metal alloys was designed to meet the required corrosion resistance, thermal resistance and compressive strength for the transfer of high-temperature concentrated sulfuric acid. The pump was test-fabricated, and its performance in an IS test plant with a hydrogen production capacity of 30m
/h was verified in terms of the pressure resistance and the transfer performance.
Iwatsuki, Jin; Tanaka, Nobuyuki; Watanabe, Yutaka*; Terada, Atsuhiko; Onuki, Kaoru
Kagaku Kogaku Rombunshu, 36(4), p.413 - 419, 2010/07
Times Cited Count：3 Percentile：16.48(Engineering, Chemical)A key issue for realizing the thermochemical IS process for hydrogen production is the materials of construction working under high-temperature acidic solutions of sulfuric acid and hydriodic acid dissolving iodine. Glass lining material is a promising candidate, which is composed of steel having good strength and glass having good corrosion resistant performance. Since, the applicability of glass lining material depends strongly on the service condition, corrosion tests using glass used in glass lining material and heat cycle tests using glass lining piping were carried out to examine the possibility of using the glass lining material at high-temperature acidic solutions of sulfuric acid. It was confirmed that the glass lining materials exhibited sufficient corrosion resistance and heat resistance in high-temperature sulfuric acid of IS process.
Imai, Yoshiyuki; Nakajima, Hayato; Kubo, Shinji; Onuki, Kaoru
Kagaku Kogaku Rombunshu, 36(1), p.70 - 73, 2010/01
Times Cited Count：5 Percentile：23.19(Engineering, Chemical)Effect of sulfur dioxide partial pressure and reaction temperature on the composition of the poly-hydriodic acid solution produced in the Bunsen reaction, which is a unit reaction in the IS process for thermochemical hydrogen production, was studied experimentally under iodine saturation. The ratio of (HI/(HI/HO)) of the poly-hydriodic acid solution assuming an ideal desulfurization was increased with sulfur dioxide partial pressure and reaction temperature. The experimental equation on the ratio of (HI/(HI/HO)) was obtained as a function of sulfur dioxide partial pressure and reaction temperature.
Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Kubo, Shinji; Onuki, Kaoru
Kagaku Kogaku Rombunshu, 33(3), p.257 - 260, 2007/05
Times Cited Count：5 Percentile：24.7(Engineering, Chemical)Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water, which is a unit reaction of thermochemical hydrogen production IS process, was studied experimentally at 323K under iodine saturated condition. Quasi-equilibrium state was observed in the presence of sulfur dioxide gas of constant pressure. The composition of the poly-hydriodic acid solution was discussed assuming an ideal desulfurization using the reverse reaction of the Bunsen reaction. The value of HI/(HI+HO) of the desulfurized solution was high in great sulfur dioxide pressure and reached the maximum of 15.7
0.3 mol%.
Iwatsuki, Jin; Ijichi, Masanori; Kubo, Shinji; Onuki, Kaoru; Hino, Ryutaro
Kagaku Kogaku Rombunshu, 32(6), p.524 - 527, 2006/11
Times Cited Count：0 Percentile：0.01(Engineering, Chemical)In thermochemical IS process for hydrogen production, key issue for realizing high thermal efficiency is to develop an efficient route for the separation of hydrogen iodide from poly-hydroiodic acid. Extractive distillation using phosphoric acid proposed by General Atomics was preliminarily examined by the sequential operation of the extraction and the distillation. It was confirmed that concentrated hydrogen iodide can be separated by the procedure.
Nakajima, Hayato; Ikenoya, Kazuhiko*; Onuki, Kaoru; Shimizu, Saburo
Kagaku Kogaku Rombunshu, 24(2), p.352 - 355, 1998/00
Times Cited Count：49 Percentile：86.77(Engineering, Chemical)no abstracts in English
solution by electrodialysisOnuki, Kaoru; Nakajima, Hayato; Shimizu, Saburo
Kagaku Kogaku Rombunshu, 23(2), p.289 - 291, 1997/00
Times Cited Count：5 Percentile：42.35(Engineering, Chemical)no abstracts in English
*; Sato, Osamu;
Kagaku Kogaku Rombunshu, 20(6), p.902 - 911, 1994/00
Times Cited Count：1 Percentile：33.9(Engineering, Chemical)no abstracts in English
Hori, Takahiro*; Saito, Kyoichi*; Furusaki, Shintaro*; Sugo, Takanobu; Okamoto, Jiro
Kagaku Kogaku Rombunshu, 13(6), p.795 - 800, 1987/12
Times Cited Count：7 Percentile：57.81(Engineering, Chemical)Chelating resins containing amide
Kagaku Kogaku Rombunshu, 8(3), p.225 - 231, 1982/00
Times Cited Count：3 Percentile：50.26(Engineering, Chemical)no abstracts in English
