ON THE PROBLEM OF LIQUID ENTRAINMENT

THe problem of liquid entrainmment by a gas phase is considered with the purpose of gathering, presentinf, and correlating available information which may be useful for predicting the liquid carry-over in a boiling water reactor at high pressure. Correlations which predict water carryover as a function of pressure, of the height of the vapor dome, and of the vapor mass flow rate are presented and discussed. Because entrainment depends upon the hydrodynamic conditions and upon the expansion of a two-phase bubbling mixture, the transportation 0f vapor through such mixtures is also discussed. Equations which relate the volumetric vapor fraction to the reduced (superficial) vapor velocity in bubbling at high pressures are presented, and some inconsistencies are noted. Experimental data and correlations which predict the location of the liquid-vapor interface in bubbling at high pressures are also givna. Experimental data on water carry-over at high pressures reported in the literature are summarized. The problems of drop formation for bursting bubbles and of drop ballistics are discussed together with some analytical formulations of the entrainment problem. The bibliography may prove useful as a source of additional information on the problems of carry- over, corrosion and on the purity of steam and of water at high pressures. (auth