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Emergency venting requirements for tempered systems considering partial vapor–liquid separation with disengagement parameters greater than unity: Part II: Application



Part 1 of this two-paper series presented closed-form analytical expressions for the two-phase emergency relief requirements of top-vented vertical cylindrical containers when the fluids involved exhibit partial disengagement. Both churn-turbulent flow and bubbly flow fluid behaviors, with disengagement parameters greater than unity, were considered. Energy input from either runaway reactions or uncontrolled external heat was included. The methods are limited to systems that are tempered and do not contain noncondensable components. In Part 2, the models developed in Part 1 are applied to specific points along the venting transient, yielding expressions for the required flow rate under emergency conditions. Part 2 elaborates on the limitations of the models, illustrates the use of the models with numerical examples, and compares the results against previous work. The effect of disengagement parameters greater than unity is illustrated in terms of both the required relieving rate and the mass remaining inside the container when disengagement occurs. © 2004 American Institute of Chemical Engineers Process Sag Prog 23: 86–98, 2004