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小型环隙式离心萃取器的水力学和传质研究 总被引:2,自引:0,他引:2
用单级=10mm小型环隙式离心萃取器研究了水-30%TRPO-煤油体系在不同条件下的水力学特性和硝酸、Fe3+和Nd3+的传质特性。在转速4000—4500r/min、流量<600mL/h、相比(o/a)1/10—10/1情况下,硝酸和Nd3+的传质级效率比较高,为90%左右。由于Fe3+的萃取动力学速率比较慢,因此其萃取级效率比较低。 相似文献
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为将Φ10mm离心萃取器用于Purex流程钚纯化循环反萃段的实验研究中,当水相和有机相流比为1∶4,离心萃取器的重相堰直径分别为6.4、6.6和6.8mm时,考察了两相出口料液的夹带情况以及环隙和转筒内液体体积随转速的变化等水力学性能。研究表明,当两相总流量小于9.0mL/min、转速大于4000r/min时,离心萃取器处于稳定可操作区间。此时两相出口料液均不夹带,两相混合区内液体量约为0.7mL,转筒内液体量约为2.2mL。结合总流量可进一步计算得出两相接触时间。 相似文献
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用十六级分离式混合—离心澄清萃取装置,在20-24℃,30-34℃,45-50℃等不同温度下进行了3B槽硝酸羟胺还原反萃钚的实验。结果表明,钚的收率均可达99.9%以上。在20-24℃时,有机相出口级附近几级的钚浓度较高,实验条件一旦波动,有可能造成钚的流失,且钚在萃取设备中有明显的积累。温度升高,14级反萃(停留时间约18min)时,钚的收率基本得到保证。 相似文献
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本文介绍了一种小型分离式混合-离心澄清萃取器。它由混合器、澄清器及传动部件等组成。进行了该设备的水力学性能试验和铀、酸传质试验。结果表明,该萃取器的适应范围如下:总流通量10—15毫升/分;相密度比(ρ_o/ρ_a)0.64—0.88;流比(o/a)1/10—10/1。试验还表明,该设备也能在总流通量为5毫升/分条件下稳定运行。酸传质效率为98.5%以上,铀传质效率为99.5%以上。两相混合时间最长可达70秒之久。因此该设备可能作为一种高效、快速的小型逆流萃取实验装置的单元设备,并能适应某些反应速度较慢的过程研究。 相似文献
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Φ20 mm离心萃取器的水力学性能 总被引:1,自引:0,他引:1
为将φ20 mm离心萃取器用于Purex流程2A段的研究中,针对2A段的工艺参数进行了φ20mm离心萃取器的水力学性能研究.固定其重相堰直径为10.8 mm,采用30% TBP/煤油-HNO3体系,研究了流比(A∶O)、流速、转速变化对两相出口料液的夹带及环隙和转筒内液体体积变化的影响.研究表明:当流比(A∶O)为1∶1、两相总流速小于70.0 mL/min及流比为5∶1、两相总流速小于28.8 mL/min时,当转速大于3000 r/min时,该类型离心萃取器处于稳定可操作区间;此时两相出口料液均不夹带,两相混合区内液体量约为5.1mL,转筒内液体量约为12.3 mL.结合总流速可算出两相接触时间t=5.1×60/vt,vt为总流速.结果表明,该类型离心萃取器可满足Purex流程中2A段工艺实验研究的需要. 相似文献
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本工作用φ10的环隙式离心萃取器检测了30%TRPO-OK萃取硝酸水溶液及模拟强放废液中的铕的传质动力学。结果表明,这种离心萃取器的传质速度快、萃取率高。在一分钟的停留时间内,其传质效率大于98%。在多级连续逆流萃取模拟料液里Eu的传质实验中,Eu的萃取率分别达到99.99%(六级萃取,0.58mol/L的HNO_3料液)和99.83%(十二级萃取, 2.5mol/L的HNO_3料液),验证了原设计的概念流程。 相似文献
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Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,easy start-up and shut-down, high compact structure.Therefore, ACEs have attracted increasing interest for future nuclear processing schemes, including the partitioning of high-level liquid waste(HLLW). Laboratoryscale and pilot-scale ACEs have been applied in demonstration tests of the trialkyl phosphine oxide(TRPO) process for HLLW partitioning. In this study, an industrialscale ACE(260 mm in rotor diameter) with magnetic coupling and a ‘‘hanging' rotor structure was developed for the TRPO process. Moreover, a series of hydraulic and mass-transfer tests were carried out in the industrial-scale ACE. The maximum throughput can reach 10 m~3/h under suitable operation parameters when kerosene is used as the organic phase, and water is used as the aqueous phase. The influence of the total flowrate, the flow ratio(aqueous/organic, A/O), and the rotor speed on the liquid hold-up volume was determined. The extraction stage efficiency is higher than 98% under test parameters for extraction of Nd~(3+) and HNO_3, using 30% TRPO kerosene as theextractant from an HNO_3 solution containing Nd. All results show good performance of the industrial-scale ACE for the TRPO process. 相似文献
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Advances are being made in the design of the annular centrifugal extractor fornuclear fuel reprocessing extraction process studies.The extractors have been built and tested.Twelve stages of this extractor and 50 stages are used toimplement the TRPO process for the cleanup ofcommercial and defense nuclear waste liquids,respectively.Following advances are available:(1) simple way of assembly and disassembly between rotor part and housing part of extractor,ease of manipulator operation;(2)automatic sampling from housing of extractor in hot cell;(3) compact multi-stage housing system;(4) easy interstage link;(5) computer data acquisition and monitoring system of speed. 相似文献
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The Indian nuclear power programme was conceived with a three-stage structure in order to utilize the resources optimally with at most importance to fuel reprocessing for closing the fuel cycle. The first stage of Indian nuclear power programme is based on natural uranium fuelled pressurized heavy water reactors to produce the plutonium (Pu) feed for the second stage. The second stage consists of plutonium fuelled fast breeder reactors to produce U-233 from thorium. The third stage envisages development and deployment of U-233 fuelled reactors. In the fuel cycle operations, solvent extraction is a major step for the recovery of uranium and plutonium. Centrifugal extractors plays a vital role in solvent extraction due to their compact size and high throughput. In the present work, the experimental studies for the hydraulic performance were reported for a single stage annular centrifugal contactor of ϕ125 mm rotor for two-phase flow. Maximum throughput with entrainment less than 1% of one phase to the other, of the centrifugal contactor was measured with the A/O ratio 1 to 6 for the three different bottom vane heights of 6, 8 and 10 mm and also for three different annular gaps of 12, 15 and 18 mm. The centrifugal extractor was operated at different speeds ranging from 1200 to 2200 rpm. In addition, mass transfer performance of the same unit was evaluated with 30% TBP/nitric acid biphasic systems. 相似文献
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Korean fast reactor scenarios have been analyzed for various kinds of conversion ratios by the DANESS system dynamic analysis code. The once-through fuel cycle analysis was modeled based on the Korean “National Energy Basic Plan” up to 2030 and a postulated nuclear demand growth rate until 2150. The fast reactor scenario analysis has been performed for three kinds of conversion ratios such as 0.3, 0.61, and 1.0. Through the calculations, the nuclear reactor deployment scenario, front-end cycle, back-end cycle, and long-term heat load have been investigated. 相似文献
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Nobuyuki Takenaka Koji Akagawa Terushige Fujii Koji Nishida 《Nuclear Engineering and Design》1990,120(2-3):293-300
Experimental results are presented on flow pattern and heat transfer in the regions from inverted annular flow to dispersed flow in a vertical tube using freon R-113 as a working fluid at atmospheric pressure to discuss the correspondence between them. Axial distributions of heat transfer coefficient are measured and flow patterns are observed. The heat transfer characteristics are divided into three regions and a heat transfer characteristics map is proposed. The flow pattern changes from inverted annular flow (IAF) to dispersed flow (DF) through inverted slug flow (ISF) for lower inlet velocities and through agitated inverted annular flow (AIAF) for higher inlet velocities. A flow pattern map is obtained which corresponds well with the heat transfer characteristic map. 相似文献
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Chaowei MAI Liqun HU Liqing XU Zhengping LUO Shiyao LIN Yiping CHEN EAST Team 《等离子体科学和技术》2021,23(4):30-35
Hard x-ray(HXR) burst is found during internal crash in the flat top current stage of experimental advanced superconducting tokamak(EAST) discharges and it is caused by fast electrons. The generated electrons during internal crashes may be an operational safety issue in advanced tokamaks. During an internal crash, locations of fast electron generation from HXR evolution agree with areas of magnetic reconnection from soft x-ray(SXR) tomographic reconstruction. Further statistical analyses show a 27 μs time difference between SXR crashes and HXR bursts, and the agreement between time broadening of HXR bursts and estimated characteristic time of magnetic reconnection in EAST. The magnetic reconnections during internal crash are proved to generate fast electrons, by both spatial and temporal agreements. 相似文献
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通过分析MURA编码孔成像技术的原理,实现了MLEM重建算法的源物体图像重建。使用数值模拟方法,分析了413keV单能γ面源的MURA编码板成像全过程,通过对比分析重建源物体分布与实际源物体分布,验证了重建算法及程序的正确性。并通过MNCP程序模拟假想的Pu部件模型,在编码孔成像过程中,像平面上射线投影强度分布、直接重建及简单扣本底重建源物体分布,从而论证了MURA编码孔成像测量Pu部件对称性的可行性。数值模拟结果表明,编码孔成像测量Pu部件对称性与小孔成像相比,在保护敏感信息和提高射线利用效率方面,具备一定的优势。 相似文献