Search

Abstract: In this study, an original method for production of ice slurry from ethanol solution without using a refrigerator is proposed. As was introduced in the first report, this system has advantages compared with similar existing systems using materials other than ethanol solution. In this paper, the process of producing ice slurry using this method was observed, and the relationship between ethanol concentration of the solution and that of the vapor, which evaporated from the ice-solution mixture, was measured. It was found that the ethanol concentration of vapor was lower than that in the condition that did not produce ice. The composition of vapor was found to be affected by the sublimation of the ice produced. Finally, the COP of this system was estimated and the effect of sublimation of ice was investigated. [Copyright &y& Elsevier]

Abstract: In this study, an original method for the production of ice slurry from ethanol solution without using a refrigerator is proposed. This system has advantages compared with similar existing systems using materials other than ethanol solution. In this paper, the vapor–liquid equilibrium data of ethanol solution at 20°C and at the freezing temperature are measured, which is necessary to calculate the COP of this ice slurry producing system. In the experiments, two experimental methods are proposed to measure the saturated pressure and the vapor composition of ethanol solution. Each method has an advantage in their operating temperature range. As a result, the vapor–liquid equilibrium diagrams of ethanol solution at 20°C and at the freezing temperature, and approximations of saturated pressure of various concentrations of ethanol solution for varying liquid temperature, are obtained. [Copyright &y& Elsevier]

Abstract: In order to clarify the effects of electric charge on freezing of supercooled water, experiments were carried out. Two kinds of shapes were used for tips of electrodes. One was the sharp end surface. The other was the flat end surface. Aluminum was selected as the material. Water sample was kept in a test tube and cooled down at a constant cooling rate. When the water sample was maintained under a supercooling state, an electric charge was applied to the water sample with a small electric current. The degree of supercooling and the electric current were measured, continuously. Then the degree of supercooling at freezing was determined. It was found that the effects of electric charge were distinct according to the shapes of electrodes. The degree of supercooling at freezing was the lower in the case of flat end surface of the anode than that in the case of sharp end surface of the anode. [Copyright &y& Elsevier]

Abstract: In this study, latent heat of fusion of ice in aqueous solutions was measured to understand latent heat of fusion of ice slurries. Propylene glycol, ethylene glycol, ethanol, NaCl and NaNO3 solutions were used as aqueous solutions. For measurements, pure ice was placed into solution, and temperature variations of the solution due to melting of ice were measured. Effective latent heat of fusion was calculated using an energy balance equation. Concentration of the solution varied due to ice melting, and dilution heat was considered. Therefore, latent heat of fusion of ice in aqueous solutions was predicted by considering the effects of dilution and freezing-point depression. We found that effective latent heat of fusion of ice decreased with increasing concentration of the solution, and effective latent heat of fusion was derived from latent heat of fusion of pure ice, effects of freezing-point depression, and dilution heat. [Copyright &y& Elsevier]