新型旋转填料床强化气膜控制传质过程

摘要

A novel rotating packed bed (RPB) with the rotor consisting of nested packing rings is a new efficient apparatus for intensifying the gas-film controlled mass transfer process,and is used in the processes of absorption,distillation and purification for low concentration of industrial gas,which are controlled by gas-film mass transfer resistance. The mass transfer characteristics of the novel RPB were studied experimentally,interfacial area (a) was determined by chemical absorption with CO2-NaOH system and gas volumetric mass-transfer coefficient (kya) was measured by physical absorption with NH3-H2O system under different gas flux,liquid-gas ratio and super gravity factor conditions,and gas mass-transfer coefficient (ky) was obtained. The results showed that a,kya and ky increased with the increase of gas flux,liquid-gas ratio and super gravity factor. The kya of the novel RPB was two times higher compared to that of a conventional rotating packed bed under the same operational conditions. Based on the experimental data,the empirical equations of a,kya and ky were developed.%转子结构为相互嵌套填料环的新型旋转填料床是基于强化气膜控制传质过程的新型高效传质设备，可适用于受气膜控制的吸收、精馏和低浓度工业气体的净化等过程。分别以化学吸收体系 CO2-NaOH 和物理吸收体系NH3-H2O测定了不同气量、液气比和超重力因子条件下的有效比表面积a和气相体积传质系数kya，并由此得到气相传质系数 ky，对其传质性能进行研究。实验结果表明：a、kya 和 ky均随着气量、液气比和超重力因子的增大而增大。通过对比可知，新型旋转填料床的气相体积传质系数在相近操作条件下是文献逆流旋转填料床的2倍。并对实验数据进行了回归，拟合出了 a、kya 和 ky分别与气相雷诺数 ReG、液相韦伯数 WeL和伽利略数 Ga之间的关联式。