In recent models of semiconductor manufacturing clean rooms, air washers are used to remove airborne gaseous contaminants such as NH3, SOx and organic gases introduced from outdoor air into clean room. Meanwhile, there is a large quantity of exhaust air produced from clean room. It is desirable to recover heat from exhaust air and use it to reheat outdoor air. In the present study, an experiment was conducted to investigate heat recovery, particle collection, and gas removal in a heat recovery type air washer system for semiconductor manufacturing clean rooms.

The 2nd landfill of Sudokwon landfill site has been collecting landfill gas flowing into vertical wells using the vacuum generated by blowers. The vacuum applied to the wells enables the landfill gas within the collection boundary to be collected and the air in the atmosphere to be penetrated through landfill cover soil, as well. In this study, we tried to investigate the impact of active landfill gas collection with vertical wells on landfill aeration. The pressure changes and the compositions of landfill gas, measured at the wells and 4 bore holes made in the landfill for this study, showed the air penetrates the landfill cover and inflows into the vertical wells. The concentration of nitrogen in the landfill gas collected from the 2nd landfill site has been increased to 14 ~ 15% as of February 2013, indicating 18 ~ 19% of the air is being included in the landfill gas.

This study was carried out to investigate the collection Efficiency of mass in collector step at the different of physical gas characterization. This work has focused on the dependence of the collection efficiency of mass in the collector zone of a two-stage set up field with gas temperature T and the dew point tmeperature. To identify the dependence of the mass collection efficiency on the grounded plate of the collector zone M_P,k by the specific electric resistance of dust ρe and the relative humidity φ, 20 attempts have been made with three different gas temperature (50℃, 80℃, 110℃) at different dew point. At the specific electric resistance of dust ρe=10^6Ωm which relative humidity corresponds to φ> 15%, a easy rise of the grounded plate secluded dust mass share was measured again. As the result of the higher cohesion imprisonment power due to the adsorbtion of particle, the rise of the relative humidity developed on the particle surface. Therefore, the collection efficiency of mass was not predominant the high temperature T in the collector zone, neither was the pecific ellectric resistance of dust dependent.