Abstract
While the gravitationally drained bed of ice crystals was washed, a part of the crystals melted in the upper part of the liquid which was unsaturated. As the washing proceeded, a part of the washing water froze on the surface of the crystals in the lower part of the liquid which was saturated.
However, under such experimental conditions as those that temperature of the washing water was lower than 5°C, the flow rate was less than 0.22 cm/sec and the room temperature was around 1°C, those effects to be exerted by the melting of the crystals and the freezing of the washing water upon the apparent axial dispersion number were so small that the displacement type washing of the ice-crystal bed could be done in the same treatment as that of the bed packed with such inert particles as glass beads.
