Community Research and Development Information Service - CORDIS


The discharge of a reactor vessel containing a subcooled liquid at high pressure through a vent line may produce a rapid depressurisation of the fluid. When this occurs, the liquid flashes soon after the pressure reaches the saturation condition and thereafter flows as a two-phase mixture. With a sufficiently high stagnation pressure upstream of the vent line, the flow through the vent line reaches the critical condition whereby the flow rate becomes a maximum and is independent of the conditions downstream of the throat. The critical flow rate through the vent line depends on the state of the fluid upstream of the throat and on the characteristics of the vent line itself. A non-equilibrium separated flow model is described in this paper. It has been applied to steam-water mixtures, where reliable experimental data are available, in an attempt to understand better the phenomena governing critical two-phase flow processes, especially the increase of the interfacial area and the mechanism of the interfacial mass transfer.

Additional information

Bibliographic Reference: Paper presented: 25th European Two-Phase Flow Group Meeting, Varese (IT), May 21-23, 1990
Availability: Available from (1) as Paper EN 35572 ORA
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