Selection Of Artificial Fog Dissipation Catalysts And Study Of Catalytic Mechanism

The presence of the heavy fog weather not only brings great inconvenience topeople’s production and life, but also influences people’s health. So the fog dispersaltechnology is of much important significance nowadays when the haze weatheroccurs frequently. This paper is aimed at finding some effective warm fog dissipationcatalysts and studying the catalytic mechanism at the same time.Referred to fog chambers reported in published papers and combined with theactual conditions of the lab, a cylindrical fog chamber was designed and set up,14mhigh,1m in diameter. It is equipped with an ultrasonic fog-making machine, wirelesstemperature and humidity sensors, light sensors, lasers, a data acquisition unit, acomputer and a digital microscope. At the same time, a method using the timetransmission recovering to60%, that is t60%to evaluate whether the catalysts’ effecton fog dispersal is good or bad was established.Experiments using catalysts and without using catalysts were conductedrespectively in the cloud chamber described above. Catalysis experiments were toinvestigate how the particle sizes and the dosages of sodium polyacrylate (PAAS) andSodium Chloride (NaCl) influenced fog, how PAAS and NaCl compounds withdifferent proportioning affected fog dispersal and how the dosage of5A molecularsieve worked on fog. Results show that:(1) the average t60%in experiments withoutcatalysts is138min;(2) catalyzed by PAAS, when the particles are smaller than40μmand the dosage is30g, it works the best, with t60%shorting87.7%;(3) catalyzed byNaCl, when the particles are smaller than40μm and the dosage are25g, it works thebest, shortening t60%by83.7%;(4) catalyzed by5A molecular sieve, when the usagesare25g and30g, t60%are prolonged by48.6%and124.3%respectively;(5) whenPAAS and NaCl are compounded with a mass ratio of1:1, they work best on fog,shortening t60%by94.2%.Fog droplet spectrum was inspected using an optical digital microscope and glassslides coated with oil to explain the experimental results, thus to explore the principlesof fog dispersal.Results show that:(1) PAAS powders disperse fog because of theirexcellent water absorption performance and their working as heterogeneous coresafter absorbing water speeding droplets’ touch;(2) NaCl powders affect fog dispersal because they could deliquesce into solution drops and grow by condensing and thenaccelerate coalescence growth of fog drops;(3)5A molecular sieve has no effect onfog dissipation because it can neither work as condensation growth nucleus noraccelerate the coalescence of fog droplets.