Characteristics of an ice wash column was investigated under non-washing condition. Ice crystalsproduced by the second refrigerant freezing method were used in this experiment. The hydraulic piston bed (HPB) formed in the wash column showed a zigzag upward movementby the effect of the wall friction. The average velocity was in proportion to the pressure drop ofthe solution flowing in the driving section, but this relation was remarkably changed by thesaturation of the residual solution in the washing section. Under the higher pressure drop, theaverage porosity of the bed in the driving section was nearly the same as that of the top bed inthe washing section, but under the lower pressure drop, the former was a little larger than thelatter, while those values of the porosity were distributed in the range of ±10% in the relationwith the pressure drop. Therefore, the HPB was considered to consist of the bed in which theporosity was not uniform, and especially it was considered to consist of a compressible one underthe lower pressure drop. Under the non-washing condition, it may be assumed that the saturation of the residual solutionof the top bed just equalled to the unit when the HPB moves upward with the maximum allowancevelocity. From the relation between the average velocity of the HPB and the saturation of theresidual solution of the top bed, it was found that both the maximum allowace velocities of the HPB were about 24cm/min and 30cm/min, respectively, when the porosity of the top bed was 0.4 and 0.5
Direct-contact heat-transfer between steam and single liquid column was studied at 0.35--0.89 ata. As the result, nearly constant value of overall heat-transter cofficient was obtained. This valuewas about 1000 (kcal/m2hr0C) and was nearly constant independently of steam pressure, liquidcolumn diameter and liquid flow rate. This fact suggests that the interface resistance of direct-ontact heat-transfer was unexpectedly large.
Melting points of NaOH·3.5H2O in the NaOH-KOH-H2O system were measured at various ratios of potassium hydroxide to total hydroxides in the range of 33-43wt. % of total hydroxide concentration. The result showed that the melting point could be expressed by a polynominal the coefficient of which was calculated by the least square method. The measured values well agreed with the calculated values with a power of 3-5 in the polynominal, and the mean relative error was 0.1% when the power of the approximation was 4. The authors published similar contents to this paper at the 23rd Annual Meeting of the Chemical Society of Japan held in April, 1970.