Ice Slurry Generation for Direct Contact Cooling

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Koji Fumoto ◽  
Toshiki Sato ◽  
Tsuyoshi Kawanami ◽  
Takao Inamura
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Direct Contact ◽  
Freezing Point ◽  
Solution Concentration ◽  
Freezing Point Depression ◽  
Ice Slurry ◽  
Supercooling Degree ◽  
Basic Characteristics ◽  
Pressure Shift Freezing

Ice slurry has attracted a great deal of attention as a coolant for direct contact cooling. In this study, we generated ice slurry by the method of pressure shift freezing (PSF), which is based on the freezing-point depression of an aqueous solution at high-pressure conditions. As a result, the basic characteristics of the ice slurry generation are clarified. Moreover, the physical properties of the ice slurry indicate that the shape of an ice particle in the ice slurry is strongly affected by both the supercooling degree and the aqueous solution concentration.

STUDY ON NEW ICE SLURRY GENERATOR USING NaCl AQUEOUS SOLUTION AT LOW CONCENTRATION

2013 ◽  
Vol 21 (01) ◽  
pp. 1350004 ◽  
Author(s):  
KOJI FUMOTO ◽  
TSUYOSHI KAWANAMI ◽  
TAKAO INAMURA
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
Test Section ◽  
Freezing Point ◽  
New Method ◽  
Heat Of Fusion ◽  
Test Fluid ◽  
Ice Slurry ◽  
Slurry Ice ◽  
Experimental Apparatus

A cold thermal energy storage system has been developed for HVAC. There are many ice-based cooling systems operating around the world. Ice slurry, which is a mixture of fine ice crystals and liquid water, is utilized in ice storage systems owing to its good flowability and large latent heat of fusion. For slurry ice production techniques, there are presently a number of commercially available ice slurry generators (e.g., Supercooled slurry ice generator, Scraper type generator, and Vacuum type generator, etc.). In the present study, a new method was developed to generate ice slurry without the deposition of an ice layer on a cooled surface. The basic components of the experimental apparatus is a cooling brine circulating loop, a high pressure pump, a valve, an aqueous solution flow loop containing the test section, which is made of transparent acrylic, and the associated instrumentation. This new method is based on freezing-point depression of the aqueous solution, which is maintained under high-pressure conditions. To control the timing for solidification and to generate ice slurry, we investigated the relationships among the pressure and temperature of the aqueous solution. The freezing phenomenon of the aqueous solution in the test section was observed in detail. As a result, we developed a new ice slurry generator based on the new method that controls the pressure and temperature of the aqueous solution. Experimental results showed that the characteristics of the ice slurry generation were closely related to the pressure and initial stage temperature of the test fluid. Finally, the optimum operation condition of the ice slurry generator based on visualization experiment was discussed.

scholarly journals Generalized enthalpy model of a high-pressure shift freezing process

2012 ◽  
Vol 468 (2145) ◽  
pp. 2744-2766 ◽  
Author(s):  
Nadia A. S. Smith ◽  
Stephen S. L. Peppin ◽  
Ángel M. Ramos
Keyword(s):  
High Pressure ◽  
Stokes Equations ◽  
Freezing Point ◽  
Food Samples ◽  
Navier Stokes ◽  
Freezing Process ◽  
Frozen Foods ◽  
Navier Stokes Equations ◽  
Pressure Shift ◽  
Pressure Shift Freezing

High-pressure freezing processes are a novel emerging technology in food processing, offering significant improvements to the quality of frozen foods. To be able to simulate plateau times and thermal history under different conditions, in this work, we present a generalized enthalpy model of the high-pressure shift freezing process. The model includes the effects of pressure on conservation of enthalpy and incorporates the freezing point depression of non-dilute food samples. In addition, the significant heat-transfer effects of convection in the pressurizing medium are accounted for by solving the two-dimensional Navier–Stokes equations. We run the model for several numerical tests where the food sample is agar gel, and find good agreement with experimental data from the literature.

scholarly journals Activity-measurement by the partition method.—I

1924 ◽  
Vol 106 (737) ◽  
pp. 243-250 ◽  
Keyword(s):  
Aqueous Solution ◽  
Electrostatic Potential ◽  
Special Interest ◽  
Freezing Point ◽  
Activity Measurement ◽  
Freezing Point Depression ◽  
Concentration Cell ◽  
Low Concentrations ◽  
The Mean ◽  
Partition Method

In the light of Milner’s calculation of the mean electrostatic potential in chaos of ions, activity-measurement is of special interest at low concentrations aqueous, and still lower concentrations in non-aqueous solution, owing to the simple and peculiar dilution law which the theory predicts for such consentrations. The methods which have chiefly been relied on for such data—that of the Freezing-point depression and that of the concentration cell-—tend to lose recision at low concentrations, owing, in the former, to the smallness of the depression measured, and in the latter, to polarisation effects.

Depression of freezing temperature of water and water solutions in porous materials

1989 ◽  
Vol 54 (10) ◽  
pp. 2644-2647 ◽  
Author(s):  
Petr Schneider ◽  
Jiří Rathouský
Keyword(s):  
Water Vapor ◽  
Porous Materials ◽  
Inorganic Salt ◽  
Freezing Point ◽  
Freezing Temperature ◽  
Inorganic Salts ◽  
Freezing Point Depression ◽  
Salt Solutions ◽  
Water Solutions

In porous materials filled with water or water solutions of inorganic salts, water freezes at lower temperatures than under normal conditions; the reason is the decrease of water vapor tension above the convex meniscus of liquid in pores. The freezing point depression is not very significant in pores with radii from 0.05 μm to 10 μm (about 0.01-2.5 K). Only in smaller pores, especially when filled with inorganic salt solutions, this depression is important.

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