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ISSN Online: 2377-424X

ISBN Print: 0-89116-130-9

International Heat Transfer Conference 6
August, 7-11, 1978, Toronto, Canada

DIRECT CONTACT COOLING OF A CRYSTALLIZING BRINE

Get access (open in a dialog) DOI: 10.1615/IHTC6.4040
pages 61-65

Resumo

The application of a direct contact heat exchanger to crystallization is examined. Experimentally, the operation takes place in a vertical column where cooling kerosene droplets flow upwards, counter-currently to a saturated, crystallizing magnesium-chloride brine. The crystals deposited upon the brine cooling form a suspension with the brine. Crystallization of up to 6% is obtained with a temperature change of 20 С in the brine. Volumetric heat transfer coefficients, at kerosene holdups of 7-42% vary within the range of 9-22 kW/m3K. The mechanism of heat transfer in the crystallizer is studied by testing the applicability of a model based upon the phenomena of wake formation and shedding behind droplets. Two flow parameters, the wake volume and its rate of shedding are needed for the model to be operable. The wake volume is obtained using dimensions reported in literature. The wake shedding rate is related to the boundary layer flow on the droplet and calculated on the basis of a reference experiment in the specified system. The temperatures predicted through the wake model agree with the respective values measured in the crystallizer.