ISSN : 2233-8292
In this paper, the liquid air was selected as the refrigerant in artificial ground freezing to be used for rapid ground freezing and to reduce the risk of suffocation and the applicability of liquid air was verified. In order to evaluate the stability of the liquid air, the oxygen concentration of mixtures with liquid nitrogen and liquid oxygen was experimentally examined to meet the oxygen concentration criteria in the Occupational Safety and Health Act. In addition, the effects of the mixture ratio of liquid nitrogen and liquid oxygen, pressure and flow rate change in the storage vessel on the oxygen concentration in the liquid air were investigated. As a result, the ratio of liquid nitrogen and liquid oxygen 8: 2 was shown to meet the oxygen concentration standards. Pressure and flow rate change in the storage vessel did not have significant effects on the oxygen concentration in the liquid air.
1. Daesung Industrial Gases Co. LTD (2008), DOA-3000R Oxygen Analyzer Manual.
2. Giancoli, D.C. (1984), General physics, Prentice-Hall, New York, p. 892.
3. Harris, J.S. (1995), Ground freezing in practice, Thomas Telford, London, p. 264.
4. Ministry of Employment and Labor (2013), Occupational Safety and Health Act.
5. Sharp, D.A., Lee, J.M., Yeo, Y.K., Lee, S.C. (2008), Process design using HYSYS, A-Jin, Seoul, p. 207.
6. Son, Y.J., Lee, K.W., Ko, T.Y. (2014), “Studies of application of artificial ground freezing for a subsea tunnel under high water pressure - focused on case histories -”, Journal of Korean Tunnelling and Underground Space Association, Vol. 16, No. 5, pp. 431-443.