Vapor generated during rewetting/quenching of hot vertical surfaces/tubes by a falling liquid film forms
countercurrent flow to the quench front propagation. This vapor in addition to the possibly rising vapors
from other sources resist the downward propagation of the quench front and may cause partially or
complete flooding of the injected liquid. The present work develops a semi analytical model to parametrically
study the rewetting/quenching rate of a hot vertical tube by a falling liquid film in terms of
initial tube temperature, flow rate of rising vapors, tube thickness and cooling water injection and
penetration rates. Momentum, energy and conduction-controlled equations are used to find the model
governing equations. Correlations for liquid penetration rate and interfacial friction factor driven from
experimental data were incorporated in the model. The resulting governing equations were solved
iteratively to study the effects of the controlling parameters on the quench front propagation velocity.
Conditions of onset of flooding and complete flooding in terms of the controlling parameters are deduced
and discussed. Results are compared with available experimental results and good agreement was
obtained.