微通道内微细颗粒增强气液传质的研究.pdfVIP

摘 要 微化工技术和颗粒强化技术都是化工过程强化的新兴手段，也是当前化工等 行业的发展方向，目前已经在气液吸收、液液萃取、多相催化反应等过程中有所 应用。因此，在高效节能的时代中，广泛开展两种技术的综合研究工作具有必要 性和重要性。 本文以CO -H O 为气液两相体系，在自制的内径为 1mm 的微通道中，研究 2 2 了 Taylor 流下物理吸附型和化学反应型微细颗粒对气液传质的影响。考察了气 液表观速度和固体微细颗粒浓度对传质增强因子、气泡长度以及微通道进出口压 降的影响，针对不同类型的颗粒进行传质增强机理分析，结果表明，物理吸附型 颗粒主要借助传输机理来增强气液传质，而化学反应型颗粒主要是通过溶液中离 子和溶解气体的反应来达到传质增强。 本文还着重对物理吸附型颗粒建立了非均相传质增强模型。通过实验，明确 了疏水性和吸附性等因素对传质增强有主导作用，由此建立了传质增强模型。此 模型将 Taylor 流下的气液传质区域分为半圆型头部和液膜两个区域，并引入循 环流理论。采用该模型探讨了微细颗粒粒径、无因次传质系数、颗粒吸附能力、 颗粒浓度、溶液表观粘度、气液表观速度等因素对传质增强因子的影响。最后将 实验值和计算值对比，数据十分吻合。因此，该模型对微通道中具有吸附性的疏 水性颗粒有很强的实用性。 关键词：微通道 Taylor 流 微细颗粒 气液传质 强化 ABSTRACT The micro-chemical engineering and particles intensification technology, which have been adopted in gas-liquid adsorption, liquid-liquid extraction, and heterogeneous catalytic reaction, are emerging methods in chemical process intensification and also are the development direction of the current chemical industry. As a result, in the era of high efficiency and energy saving, widely carrying out integrated study on the two technologies is of necessity and importance. This article has chosen CO -H O gas-liquid two-phase as the research system, 2 2 and has studied effects of two types of fine solid particles-the physical adsorption type and chemical reaction type on gas-liquid mass transfer under Taylor flow in the homemade micro-channel for the inner diameter of 1 mm. The paper mainly discussed what the changing gas-liquid rates and solid particles concentration made on mass transfer enhancement factor, bubble length and pressure drop from the channel import to the export, and developed the mechanism analysis for different types of particles. Among t