The Experimental Study Of Rising Film Evaporation In Desalination Device

Just like power, water is the essential matter for the development of society, and the shortage of water can also cause crisis like energy crisis. More and more eyes are focus on the crisis. China is rich in water sources, the whole scale is in the front of world, but when it is small averagely. It is only one forth of that around the world. So the situation is urgent. Desalination, as the best key to this puzzle, receives more and more concern. It is popular acknowledged that desalination will be crucial to the Chinese littoral's 'water crisis'.In this paper, a desalination device made up of a rising film evaporator was set up. During the designation, the length and ratio between length and diameter are referred to those of industry. In this paper, the L=2000 millimeter, ratio L/d-125.Experiments were carried out under vacuum(absolute pressure 0.01MPa-0.015MPa), and the ratio between the liquid height and length of tube were h/H=0.3 and 0.6, temperature difference between heating water and liquid were 5-15 centigrade. Under these situations, a series of experiments in order to study the effects of h/H and temperature difference on in-tube coefficient of heat transfer were done. The experimental figure is between 926 and 1861 W/(m~2·K). The augment of temperature difference and diminution of h/H can make the coefficient of heat transfer increase. The vacuum mast be hold.At last, the experimental figures were compared to the calculated ones, all of those can make some favor to increasing the yield rate of water in rising film desalination devices.