TY - JOUR
T1 - Analysis of moisture purge in high purity gas distribution systems
AU - Yang, Tian Shiang
AU - Wu, Chuan Hsieh
AU - Yeh, Chia Feng
N1 - Funding Information:
The authors wish to thank Drs. T.-K. Lin and C.-H. Lin (both with the Industrial Technology Research Institute, ITRI) for a number of fruitful discussions on the subject of moisture purge/drydown. This work was supported by ITRI and the ROC National Science Council (the latter through Grant No. NSC-89-2212-E-006-104).
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/5
Y1 - 2006/5
N2 - Moisture can easily adsorb on the inner surface of high purity gas distribution systems for semiconductor manufacturing processes, when the inner surface is exposed to the ambient air during regular or troubleshooting services. Before restarting the equipment, the adsorbed moisture has to be removed, typically by purging the gas distribution system with a high purity gas. An important system design issue therefore is to minimize the required moisture drydown time, so as to increase the productivity of the equipment. Here, the moisture purge/drydown process is analyzed using a simple phenomenological model, in which the moisture desorption kinetics is extracted from experimental data for moisture drydown in a single straight pipe. Based on that model, we also propose to minimize the overall moisture drydown time of a gas distribution system by properly allocating the purging gas flowrates in all branches of the system. It is demonstrated by a case study that, without altering the piping network design and total flowrate, our flowrate allocation scheme substantially reduces the overall moisture drydown time of the gas distribution system.
AB - Moisture can easily adsorb on the inner surface of high purity gas distribution systems for semiconductor manufacturing processes, when the inner surface is exposed to the ambient air during regular or troubleshooting services. Before restarting the equipment, the adsorbed moisture has to be removed, typically by purging the gas distribution system with a high purity gas. An important system design issue therefore is to minimize the required moisture drydown time, so as to increase the productivity of the equipment. Here, the moisture purge/drydown process is analyzed using a simple phenomenological model, in which the moisture desorption kinetics is extracted from experimental data for moisture drydown in a single straight pipe. Based on that model, we also propose to minimize the overall moisture drydown time of a gas distribution system by properly allocating the purging gas flowrates in all branches of the system. It is demonstrated by a case study that, without altering the piping network design and total flowrate, our flowrate allocation scheme substantially reduces the overall moisture drydown time of the gas distribution system.
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U2 - 10.1016/j.ijheatmasstransfer.2005.12.004
DO - 10.1016/j.ijheatmasstransfer.2005.12.004
M3 - Article
AN - SCOPUS:33645881063
SN - 0017-9310
VL - 49
SP - 1753
EP - 1759
JO - International Journal of Heat and Mass Transfer
JF - International Journal of Heat and Mass Transfer
IS - 9-10
ER -