January 2013
Publication year: 2013
Source:Building and Environment, Volume 59
Airborne Molecular Contamination (AMC) has become one of the major problems in nano-technology development and manufacturing facilities. To deal with this problem, a prototype Ultra-Pure Air (UPA) system with a targeted air quality level of 10 ppt impurity was experimentally developed. The prototype UPA system presently composes two process modules; pre-treatment and post-treatment. In order to deal with the hard-to-remove airborne organic molecular substances, UV185+254nm is first used in the pre-treatment module to provide the energy needed for breaking the molecules into smaller transitional compounds. Meanwhile aerosol water droplets are introduced; these combine with the transitional compounds to form hydrophilic substances. After the “Immersing Photochemical Oxidation” reaction, the hydrophilic contaminants go through compression and condensation processes, which comprise the post-treatment module. During the air compression and condensation processes, the collision probability of the contaminants and aerosol water droplets is highly increased. Later, a dehumidification process removes the water droplets within the condensed air; this removes both the water and the dissolved contaminants. These pre and post-treatment processes yield air quality levels of less than 1 ppb of volatile organic compound (VOC); the minimum detection limit for a measuring analyzer. The purpose of this paper is to introduce the developed UPA system and to present its experimental results.
► Ultra-Pure Air System (UPA) was experimentally established for solving AMC problems. ► The UPA used UV185+254nm to pre-treat insoluble AMCs into hydrophilic substances. ► The hydrophilic substances were post-treated by dehumidification processes. ► Xylene was used to exemplify the UPA with a removal rate of 99.99%. ► The UPA process obtained air quality less than 1 ppb within 10 s.
Publication year: 2013
Source:Building and Environment, Volume 59