Removal of Inorganic Gas Contaminants via the Air Washer of a Make-Up Air Unit in Clean Rooms

摘要

Set up a hydrophilic eliminator on an air washer to increase the gas-liquid contact surface, and incorporate with smaller droplet spray nozzles to increase the removal efficiency of contaminants. The chemical contaminants such as ammonia (NH_3) and sulfur dioxide (SO_2) were discharged upstream of the make-up air unit, and the removal efficiency downstream was evaluated. Experimental results show that coupled with the hydrophilic eliminators, the air washer can increase SO_2 removal efficiency up to 13.4% and utilizes fine water fog nozzles of about 65 μm to control the outlet concentration of NH_3 effectively. Under the liquid/gas ratio value 0.08, the removal efficiencies of sulfur dioxide and ammonia were 59.58±1.50% and 71.99±6.41%; for a liquid/gas ratio value 0.12, the removal efficiencies of sulfur dioxide and ammonia were 73.91±2.66% and 82.23±4.91%, respectively. Both efficiencies can be predicted by a theoretical model, and also presented.