共查询到15条相似文献,搜索用时 468 毫秒
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该研究跟踪国际先进水平,首次在我国进行折流板环形脉冲柱应用研究。采用5cm柱径,板间距2cm,开孔率25%,正弦脉冲波。水力学性能研究结果表明,液泛通量高达2.7cm/s,可采用V_c(1-X)+V_d/x=V_0(1-x_e) ̄(KX)关联分散相存留分数。其K值为4.5一6,大于零,为Ⅱ型柱;U传质结果表明,理论级当量高度为70cm,当在振幅a=2cm,频率f=1.5s ̄(-1)的脉冲条件下操作时,其理论级当量高度将降至50cm。同脉冲筛板柱的对比试验结果表明,其传质性能优于脉冲筛板柱。与相同工艺条件下的串级结果对比,在a=2cm,f=1.5s ̄(-1)条件下,200cm的萃取柱可达4个理论级。 相似文献
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脉冲萃取柱中正辛醇-硝酸体系流体力学性能研究 总被引:5,自引:0,他引:5
研究了喷嘴板脉冲萃取柱中正辛醇-0.5mol/L硝酸体系的液泛通量、分散相存留分数等流体力学特性.用改进的Pratt公式对两相流体力学参数进行了关联,得到水相连续时的n值为1.15,有机相连续时的K值为5.64.特性速度可用下述经验公式关联Vo(Vo′)=11.7e-0.693Af.有机相连续时柱内液滴以聚集为主,水相连续时柱内液滴以分散为主.在相同的脉冲强度下,该体系水相连续时液泛通量较小,有机相连续时液泛通量较大.经验公式计算得到的水相连续时的液泛通量与实验值的相对误差在±15%以内. 相似文献
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当脉冲萃取柱处于液泛操作状态时,理论分析表明,吹气法所测量的柱重时均压降信号随时间延长而增大,这一结果在以30%TBP/煤油溶液和1mol•L-1HHNO3溶液为体系的50mm折流板脉冲萃取柱中得到了验证。在此基础上,给出了工业上应用吹气法直接确定液泛特征的实验步骤。 相似文献
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The performance of
COBRA/TRAC code in predicting the flooding, the counter-current flow limit, is evaluated in three geometries important to nuclear reactor loss-of-coolant accident evaluation; a vertical pipe, a perforated plate, and a downcomer annulus. These flow limits are computationally evaluated through transient conditions. The flooding in the vertical pipe is compared with the classical Wallis flooding limit. The flooding on the perforated plate is compared with the Northwestern flooding data correlation. The downcomer flooding in 1/15th and 1/5th scale model is compared with the Creare data. Finally, full scale downcomer flooding is compared with the UPTF test data. The prediction capability of the code for the flooding is found to be very good. 相似文献
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Horst Glaeser 《Nuclear Engineering and Design》1992,133(2)
The limitation of vertical steam-water countercurrent flow, called flooding, is important for the operation of Emergency Core Cooling (ECC) Systems in Nuclear Reactors. The ECC water injection flooding behavior is scale dependent and the reactor size behavior cannot be extrapolated from small scale data.A new flooding correlation is presented, based on the classic flooding equation where the effects of gravity, interphase momentum exchange, and instability of the gas/liquid interface are considered. Development of a new correlation was necessary in order to correlate the reactor scale downcomer and upper tie plate countercurrent flow data gained in the Upper Plenum Test Facility (UPTF). The new correlation is an extension of the well-known Wallis-type and Kutateladze-type correlations. Each of the three correlations is valid for the experimental facilities on a certain scale. The range of applicability for each of the three correlations is defined for the case of downcomer and tie plate countercurrent flow. 相似文献
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氢-水液相催化交换(LPCE)是处理大量含氚废水的有效途径,而疏水性载体苯乙烯-二乙烯基苯共聚物(SDB)是LPCE的关键材料,对活性组分Pt起到承载作用。采用30mm×400mm玻璃柱模拟催化反应床,研究了SDB疏水性载体与填料的填装方式、气体流速、液体流速、温度以及分层装填高度等工艺条件对床层压力降和持液量的影响。结果表明:当不锈钢θ填料与SDB疏水性载体的体积比为4∶1时,无论采用混合装还是分层装,床层压力降均随气体流速、液体流速和温度的增加而升高,而动持液量随气体流速的增加而减小,随液体流速的增加而增大;混合装的压力降低于分层装,不同分层装对应的床层压力降大小为:四层装三层装一层装两层装。 相似文献
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D2/DT低温精馏分离动态模拟 总被引:3,自引:0,他引:3
本文建立了氢同位素低温精馏分离的动态模型,利用该模型针对D2/DT体系计算获得了精馏柱上DT浓度的动态变化和空间分布;研究了再沸器滞留量、回流比等参数对系统分离性能的影响.回流比的提高可以显著地提高脱氚率;再沸器中DT浓度不但与滞液量存在显著的依赖关系,而且随时间增长而增长.在理论板数为80时,塔顶与塔底DT浓度相差约3个数量级,分离效果明显. 相似文献
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梯形脉冲筛板萃取柱性能的研究 总被引:1,自引:0,他引:1
梯形脉冲柱在分散-聚合状态下操作。两相流体周期性地聚合与再分散能增强表面更新速率和有效地抑制返混现象。柱内流体系单一分散,液滴尺度分布比较均匀,在有机相连续、V_d/V_c=0.5时,液泛速度达1.8cm/s。同样情况下所需的脉冲强度约为正弦波脉冲柱的一半。其萃取效率比正弦波脉冲柱约高30%。在1.1m高的板段内,用钍作为传质核素,用配制的后处理废液进行了回收钍的模拟试验,钍回收率大于98%。 相似文献