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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

INFLUENCE OF ORGANIC POLYMER ADDITION ON THE STABILITY OF FILM BOILING IN THE CASE OF QUENCHING IN SUBCOOLED WATER

Get access (open in a dialog) DOI: 10.1615/IHTC8.4040
pages 2067-2071

Sinopsis

When a silver cylinder is quenched from 850°C in a subcooled liquid, film boiling takes place randomly. Accordingly, the cooling law recorded versus time in the center of the cylinder is not reproductible. A velocity controlled injection of cold liquid close to the vapor-liquid interface, leads to the destabilization of the film boiling.
Depending upon the temperatures of the solid and the liquid, the velocity necessary to destabilize the film boiling ranges from 0.1 to 5 m/s. In this study the influence of these three parameters is shown and allows us to establish stability diagrams of film boiling.
The stability diagram for water is modified by the type of polymer and its concentration. The mechanisms of film boiling destabi1ization are studied and we point out that there is effectively a wetting of the solid by the liquid after destabilization and an increase of the local pressure in the liquid.
This fondamental study led us to improve aqueous solutions of organic polymer for the quenching of steels and aluminium alloys.