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1.
A method of using laser induced fluorescence(LIF)technique was applied to two-dimensional measurement of the liquid concentration distribution in the 250Y structured packing sheet. The experimental structured packing sheet was made of perspex so that the laser could pass through it. The visualization of the distribution of the liquid concentration in the structured packing sheet was realized. The calibration of the thickness and liquid concentration was carried out firstly and the regression formula I=kcd was acquired, in which concentration c and the liquid film thickness d were both considered. Then the liquid feed of uniform tracer(rhodamine)concentration entered the perspex structured packing from the top under different spraying densities. The corresponding thickness of liquid film on the packing was calculated. Finally, tracer(rhodamine)with a high concentration was injected only at one fixed point of the structured packing under different spraying densities of the liquid. With the known liquid film thickness, the concentration distribution of the tracer can be calculated inside the structured packing sheet. 相似文献
2.
1996年初 ,教育部启动了“高等教育面向 2 1世纪教学内容和课程体系改革计划”。“化工类专业人才培养方案及教学内容体系改革的研究与实践”是这次改革计划中 2 2 1项教学改革项目之一。该项目的牵头单位是天津大学 ,主持单位是华东理工大学、浙江大学和北京化工大学 ,参加单位包括大连理工大学、四川大学和华南理工大学。从 1 996年 1月召开的第1次研讨会开始 ,至 2 0 0 0年 4月召开的第 1 0次研讨会结题总结为止 ,项目组在总负责人余国琮院士领导下 ,以天津大学为牵头单位的 7所学校 ,先后有 2 0 0多名骨干教师和 80 0多名学生 ,历经 4年… 相似文献
3.
It is propsed that double level programming technique may be adopted in synthesis strategy ,Optimi-zation of heat exchanger network sturctural configuration (the master problem )may be solved at the upper level ,leaving the rest operaing conditions (the slave problem)being optimized at the lower level ,With the uniqueness in mind,an HEN synthesis expert system may be employed to address both the logical constraints and the global operation parameters‘ optimization using enhanced sequential number optimization theory,Case studies demonstrate that the synthesis strategy proposed can effectively simplify both the problem-solving and the synthesis process,The validity of the strategy recommended is evidenced by case studies‘ results compared. 相似文献
4.
过程系统综合问题通常是非线性和多峰的 ,求解该类问题的确定性方法通常会陷入局部极值陷井 ,随机方法则只能以一定概率得到全局最优解 .基于此 ,提出一种并行序贯寻优 (SNTO)方法 .该方法中 ,可行点均匀散布在可行域内 ,并行搜索模式为小样本条件下获得全局近最优解提供了可能 .对测试函数的有效求解验证了该方法的有效性 . 相似文献
5.
对乙醇－水－４Ａ分子筛体系的气液固三相平衡关系进行了研究．结果表明，吸附剂的加入不改变气相与主体液相间的平衡关系．给出了计算气液固（吸附剂）三相平衡关系的计算方法 相似文献
6.
沙勇 成弘 袁希钢 刘春江 孙志发 余国琮 SHA Yong CHENG Hong YUAN Xi-gang LIU Chun-jiang SUN Zhi-fa YU Guo-cong 《天津大学学报(英文版)》2002,8(1)
利用激光作光源 ,通过光学纹影仪系统 ,系统观测了不同质量传递过程中浓度驱动的Rayleigh B啨ｎａｒｄ Marangoni对流结构 .在应用不同吸收剂的基础上 ,考查了密度梯度和表面张力梯度在RBM对流中的作用 .结果表明 ,实验过程中溶剂蒸发所导致的表面冷却和溶质吸收、解吸的热效应是影响RBM对流产生的重要因素 .在实验结果的基础上 ,定性地分析了RBM效应的观测结果 ,为进一步的理论分析提供了依据 相似文献
7.
化工学科的发展态势与高等人才的培养 总被引：2，自引：0，他引：2
化工学科的发展态势与高等人才的培养天津大学余国琮化工学科一般是指用化学在应或化学／物理分离方法改变原料的化学组成、状态或微观结构而成为产品的一门技术科学。化工学科所涉及的领域很广，不仅覆盖了整个化学工业，而且也渗透到许多工业及技术部门，如能源、环境、... 相似文献
8.
This paper is focused on the Marangoni effect in the gas-liquid mass transfer systems. A series of experiments were conducted to observe Marangoni effect by a laser Schlieren system. Experimental investigations of the occurrence of Marangoni convection were presented. The typical polygonal patterns and even the reaching of chaotic interfacial flow were observed. The visual evidences were discussed and the characteristic time and scale of Marangoni convection were obtained approximately as 0.5 s and 1 mm according to the Schlieren images. From the perspective of hydrodynamic instability, the mechanism of the Marangoni convection was investigated. Though many external factors have influence on the interfacial instability, the local surface-tension gradient is the primary reason for the Marangoni convection. The small-scale interfacial flow increases the surface renewal rate. Consequently, due to the occurrence of the Marangoni effect, the mass transfer rate can be significantly enhanced. 相似文献
9.
Axialmixing ,or“longitudinaldispersion”and“backmixing”interminology,isanimportantnon idealflowphenomenoncommonlyoccurringinchemicalengi neeringprocess,suchasdistillation ,absorption,extrac tion,etc.Thisphenomenonrepresentsadeviationfrompistonflowandusuallyformsaparabolicaxialconcentra tionprofilealongtheflowdirection.Theunfavorableef fectofaxialmixingisthatitdecreasesthemasstransferdrivingforcesandfinallyleadstopoorerseparationeffi ciency.Instructuredpackedtower,althoughtheaxialmixingcanbe… 相似文献
10.
Marangoni effectis of interestto the chemical en-gineers from both scientific and practical points ofview[1—6]. The Marangoni convection contributes tothe renewal of the interfacial surface and is capable ofincreasing the mass transfer rate, resulting in intensi-fication of separation processes such as distillation,extraction, absorption, and desorption. The theoretical studies of Marangoni instability inthe past were focused on determining the critical tran-sition point. The critical condit… 相似文献