MRI measurement of a small amount of water which passes a zeolite packed column before a breakthrough

Abstract

In order to clarify the mechanism by which water adheres to the oxygen discharge side of the zeolite packed column composing a compact adsorption-type oxygen concentrator, the mass of a small amount of water absorbing to the column was measured by MRI (Magnetic Resonance Imaging). The zeolite particles used were Li-X type molecular sieve OXYSIV-700. The result of the MRI measurement showed that the mass of water adhering to the oxygen discharge side of the zeolite packed column increased almost linearly with the operating time of the oxygen concentrator. The experimental equipment comprised a thin zeolite packed column (inside diameter 8 mm, length 200 mm) and a thick zeolite packed column (inside diameter 30 mm, length 80 mm) connected in series. Even if the zeolite packed column had not reached the breakthrough point, water vapor contained in the gas passed through the thin zeolite packed column in the upper stream, and adhered to the thick zeolite packed column placed downstream. The amount of water absorbing to the thick zeolite packed column was about 1/150 as compared with that adsorbed to the thin zeolite packed column. This research showed clearly that the water adhering to the oxygen discharge side of a zeolite packed column is the water which passed through the column and reached the oxygen discharge side.