陶瓷膜冷凝器用于烟气脱白烟过程的中试研究

The tubular ceramic outer membrane with average pore diameters of 5, 20 and 50 nm was made into a membrane condenser, and a membrane condensation pilot test device with a membrane area of 0.3 m² was set up to carry out the recovery of water and waste heat resource from flue gas using ceramic membrane condensers. The recovery performance of two-stage membrane condensers with different installation types was investigated. The effects of relative humidity of inlet gas, inlet gas temperature, inlet gas velocity and average pore size of membranes on mass and heat transfer performances were systematically studied. The results showed that the higher flux and recovery ratio can be achieved when the gas and water flowed within the membrane condenser in a tandem way. The water flux increased with the increasing of relative humidity, temperature and velocity of the inlet gas. The water recovery ratio can be enhanced by increasing relative humidity, temperature of the inlet gas and decreasing gas velocity. In addition, a three-stage condenser installed with 50 nm pore-sized ceramic membranes displayed a better water and heat recovery performances. The average pore size of ceramic membranes had remarkable impact on the mass transfer process rather than the heat transfer process. In this work, the highest water flux and recovery ratio of three-stage membrane condensers were 38.5 kg•m^-2•h^-1 and 50.6%, respectively. Compared with conventional heat exchangers, ceramic membrane condensers can recover water and heat simultaneously, during which the overall heat transfer coefficient could reach as high as 415 W•m^-2•℃^-1. The ceramic membrane condensers can not only effectively relieve the visible pollution known as "smoke plume", but also have great potential applications in the resources recycling and environmental protection.