(47ci) Beyond Phi Factor: Qualified Experimental Data for Emergency Relief Sizing

Emergency relief system design of runaway reactions requires using bench-scale adiabatic calorimeters to evaluate thermo-kinetic data of a full-scale reactor. The well-known method to correct bench-scale experimental data is the Phi correction (thermal inertia) method. However, it does not consider the effect of vaporization on thermo-kinetic data. The Calorimeter fill ratio, an important parameter directly relating to vaporization effect, is discussed in this presentation. For a 60% fill ratio, a case study shows that the measured reaction heat would be 7% less than the actual value for a reaction with heat release of 800J/g, 5% less than the actual value with heat release of 600J/g, and 2% less than the actual value with heat release of 300J/g. Self-heating rate is far more sensitive to fill ratio. A higher fill ratio is required to get more reliable data for a more exothermic reaction for a tempered system. Too less fill ratio would give a misleading thermo-kinetic interpretation of a full-scale reactor. Applying the same fill ratio of full-scale reactor to adiabatic calorimeter test to get thermo-kinetic data for emergency relief sizing, not just considering thermal inertia equivalence, is recommended.