面向应用的膜蒸馏过程再探讨  

Discuss about membrane distillation for application

作　　者：吕晓龙[1] 

机构地区：[1]中空纤维膜材料与膜过程国家重点实验室培育基地,天津工业大学生物化工研究所,天津300160

出　　处：《膜科学与技术》2011年第3期96-100,109,共6页Membrane Science and Technology

基　　金：“863”课题工业循环冷却水膜集成净化过程研究(2008AA06Z303);天津市重点基金课题废水浓缩减排与淡化再利用技术研究(09JCZDJC26300)

摘　　要：讨论了膜蒸馏涉及的膜材料特性和应用中面临的问题.膜蒸馏过程实质属于传热控制过程,研究膜蒸馏过程的重点在于研究膜蒸馏过程中热量的传递与回收.吸收膜蒸馏传质过程无相变热损失,疏水膜兼具有传质与导热双重作用.采用曝气膜蒸馏工艺对反渗透浓水进行了连续高倍率浓缩,膜组件没有发生亲水化和膜污染问题,说明曝气膜蒸馏工艺在高盐度、易结垢的废水深度浓缩方面具有较好的应用潜力.水膜阻力本质是气体穿过多孔膜表面的气/液两相界面所需克服的界面张力,除了与膜材料本体特性、膜表面结构等因数有关外,还与气体传输方向有关.与传统中空纤维膜相比,设计的异形中空纤维多孔膜,断裂强力有很大的提高.将热泵技术与减压膜蒸馏过程耦合,热泵制热系数COP与蒸发器流速、冷凝器流速和膜蒸馏通量之间存在显著相关性.In this paper, the characteristics of hydrophobic membranes used in membrane distillation （MD） and some realistic problems exist in MD process were discussed. MD process is a heat transfer controlled process. The research in heat transfer and reclamation in MD is of great importance for promoting the technique into real application. There＇s no phase inversion heat loss in osmotic membrane distillation and the micro--pores is the channels for mass transfer and the matrix of hydrophobic membranes worked as heat transfer medium. A novel bubbling membrane distillation （BMD） process was designed and used in the continuous concentration experiment of reverse osmosis drained wastewater. No flux declination was observed during the concentration experiment even when the 0. 6 ton wastewater was concentrated to near saturation by the membrane module of 0. 5 m2, and no obvious membrane fouling and scaling was found in SEM pictures of the membranes used in BMD. Water film resistance （WFR）, the resistance for gas to transfer the hydrophobic membrane/solution interracial tension, was discovered in our work. Systemic research showed that, effects including the membrane material characteristic, the surface morphology and gas transfer orientation could through light on WFR. The specially designed abnormity hydrophobic tube membranes illustrated excellent mechanical strength comparing to traditional hollow fiber ones. Vacuum membrane distillation （VMD） was coupled with a heat pump system, for the reclamation and reuse of the phase inversion heat of the vapor produced in VMD process. The coefficient of performance of the heat pump is relative to the velocities of the solutions in the evaporator and condenser and the product flux of VIVID process.

关 键 词：膜蒸馏 疏水膜结构 汽化热回收 疏水膜干燥 

分 类 号：TQ028.8[化学工程]