MEASUREMENT OF INTERFACIAL AREA AND MASS TRANSFER COEFFICIENTS BY CHEMICAL METHOD OF C02 ABSORPTION INTO AQUEOUS SOLUTIONS OF NaOH IN A MODEL COLUMN WITH EXPANDED METAL SHEET PACKING

The theory of gas absorption accompanied by fast pseudo-fast order reaction which considered dependences of diffusivity, kinetic constant and Henry's law constant on absolute temperature and ionic strength was used to obtain values of effective interfacial areas and mass transfer coefficients in gas and liquid phase.

Experimental measurement of carbon dioxide absorption from mixture with air was performed in a pilot-plant column with expanded metal sheet packing irrigated with sodium hydroxide solution.

Resulting liquid and gas-side mass transfer coefficients are compared with values obtained from physical Absorption measurement of carbon dioxide into water and with measurement of gas-side mass transfer coefficient for sulphur dioxide in the same column.

The differences between determined values are discussed.     

化学法测定鼓泡塔中的相界面积和传质系数

本文开发了一种新的物质，用Na2SO3溶液吸收空气中的O2，并伴有物理解吸C2H4来同时测定α和kL，以保证α和kL的测定在同一流体力学条件下进行，在单气泡时，将Na2SO3-O2-C2H4系统测得的αchem与通过气泡大小及上升速度经计算而得到的αgeo进行了比较，校核了αchem的准确性，并将此系统测得的kL,C2H4与化学法测得的kL,o2进行了比较，得知它们十分接近，且其关系符合Danckwerts模型。将该物系用于气泡群，测定了不同空塔气速下的α、kL和ε，并进行了数据关联，取得了相当满意的结果。通过对不同清液层高度下传质系数的测量，发现喷嘴附近的传质系数比全塔平均值高3－5倍，说明有相当比例的传质发生在喷嘴附近。     

SIMULTANEOUS MEASUREMENT OF INTERFACIAL AREA AND MASS TRANSFER COEFFICIENT FOR RISING BUBBLES BY Na2S03—o2ABSORPTION METHOD WITH C2H4 DESORPTION TECHNIQUE

A new system of sulfite oxidation accompanied by C ₂H₄ desorption was proposed to determine interfacial area and liquid side physical mass transfer coefficient in bubble column. The method ensures that K ₁, and a are measured under identical hydrodynamic conditions.

The interfacial areas determined from the new system and from geometrical calculation show reasonable consistency. The values of physical mass transfer coefficient kc₂H₄comparable and they agree well with Danckwerts surface renewal model     

伴随化学反应的液液相间传质现象

液液体系中形成动态相间分散层 (IDZ)的观点合理解释了伴随化学反应的传质动力学特性 .研究表明 ,用 3 - (正十二烷基 )胺萃取HCl时发生的萃取速率突变现象 ,可用由于局部反应平衡常数的变化和浓度梯度增长 ,在有机相边界层内形成W/O型IDZ过程予以解释 .添加少量表面活性剂可以改变IDZ的液滴数量与尺度 ,进而显著地改变通过相界面的扩散系数 .如果表面活性剂能够稳定IDZ和 (或 )促进反应剂在液滴表面上的吸附 ,则呈现正效应 ;如果表面活性剂使IDZ的稳定性降低和 (或 )减弱液滴表面对反应剂的吸附 ,则观察到负效应 .上述现象在 2 -羟基 - 5 -辛基二苯甲酮肟萃取和反萃Cu²⁺的过程中得到了证实 .     

化学吸收法测定多级离心雾化旋转填料床有效相界面积及体积传质系数

对多级离心雾化旋转填料床的有效相界表面积及体积传质系数,用化学吸收法做了实验测量。实验结果表明：多级离心雾化旋转填料床不仅具有超低气阻,而且可产生良好的喷雾扩展相界面积的作用,体积传质系数比传统填料塔提高一个数量级,接近气液逆流型旋转填料床。多级离心雾化旋转填料床开拓了新的气液传热传质途径。     

DETERMINATION OF MASS TRANSFER COEFFICIENTS AND THEIR BEHAVIOR IN PERMEABLE MEMBRANE PROCESSES BY LIMITING DIFFUSION CURRENT METHOD

The mass transfer coefficient k is an important parameter for predicting the concentration polar-ization of reverse osmosis and other membrane separation processes.In order to determine the k valueprecisely,a limiting diffusion current method with specially designed porous electrode has been devel-oped.This method can be used to determine the k values for both one dimensional and two dimensionalflow.It seems that the actual situation of membrane process is closely approached,so the dimensionlessempirical equations obtained have a practical significance.The equations of present work have been compared with the data of previous authors,and manyresults seem to be in good agreements.Therefore this paper offers useful reference for the investiga-tion and design of diversified membrane separation systems in future.     

细鳞片石墨化学氧化法制备可膨胀石墨技术问题探讨

采用分步氧化法制备了80目细鳞片可膨胀石墨。通过L9（3^4）正交试验确定了最佳工艺条件。在液固比-5：1，C：KMnO4=1：0．12，Ⅰ H2SO4：Ⅱ H2SO4=4：1，H2SO4：H2O2=12：1（均为质量比g／g）条件下获得膨胀容积为290mL／g。对制备过程中液固比、硫酸浓度、双氧水的加入方式、可膨胀石墨烘手温度、原料粒度等因素对膨胀容积的影响以及可膨胀石墨的稳定性的改善方法进行了探讨。