TEMPERATURE, FLOW VELOCITY AND PROTEIN CONCENTRATION NEAR ICE SURFACES IN MINI-CHANNELS

摘要

The aim of this study is to elucidate how additives, such as salt and antifreeze protein, are effective for the inhibition of ice growth in cooled water flow in mini channels. In the case where ice grows from a sidewall of a mini channel (the cross sectional area of which is 2 × 0.3 mm~2), we carried out measurements of flow velocity using tracer particles. We also carried out temperature measurements using a near-infrared camera. Furthermore, we estimated the concentration of antifreeze protein with fluorescence microscopy. It was confirmed that the flow velocity was measured successfully near ice surfaces and it was found that high concentration regions of antifreeze protein appear adjacent to the ice surface. In the case of ice slurry flow, we measured the motion of ice crystals in flow in another mini channel (the cross sectional area of which is 1 × 0.7 mm~2). It was found that aggregation of ice crystals was seen in the ice slurry flow. A second finding was that the antifreeze protein inhibited this aggregation. The velocity of cluster of ice particles in the saline solution with the protein is lower than that in the saline solution only.