An Investigation of Vapor Concentration during Boiling of Liquid Mixtures : (Measurement of Bulk Vapor Concentration in Pool Boiling System)

Abstract

The objective of the study is to clarify experimentally the variation of the vapor concentration of binary mixture generated during nucleate boiling in a saturated pool under the various boiling conditions. The generated vapor concentrations in the bulk vapor layer were measured for the binary mixtures of water-ethanol and ethanol-acetone under various liquid concentrations, the heat fluxes and the liquid layer heights from the thin wires at the atmospheric pressure. Two methods of measuring concentration, i.e. the dew point method and the laser absorption method were adopted to confirm the reliability of the results. The measured results by using both methods coincided well with each oher. The measured concentrations of the bulk vapor for various superheats of heating wires, the depth of liquid layer and liquid concentrations were almost independently of those parameters and were almost in equilibrium with bulk liquid conditions even under the higher heat fluxes and lower liquid heights.