True volumetric vapor content and thickness of the film in the boiling of liquid metals in channels

Results are presented for an experimental study of the thickness or volume fraction of a boundary film of liquid in a two-phase flow of steam and potassium in high vapor content regions under conditions encountered in steam generators and reactor piping systems. The flow occurred in a straight horizontal adiabatic tube. The tube was located immediately after the heated or flowpreparation section. It is shown that as the heat-transfer crisis nears in the heated section the thickness of the liquid film continuously decreases and approaches zero at the inlet. Data for the true volumetric vapor content of two-phase flows of liquid metals are generalized.