Pressure Relief Sizing Using Area to Charge Scaling Method and Automatic Pressure Tracking

Several vent sizing methodologies have been developed and presented in “The Design Institute for Emergency Relief Systems (DIERS) Project Manual”. These include analytical, experimental, and computational methods using bench-scale apparatus. This paper discusses a direct scale-up technique for sizing pressure relief systems under thermal runaway conditions of reactive systems. The study utilizes direct empirical scaling of experimental data obtained from an instrument with very low thermal inertia. The technique applies an automatic pressure tracking adiabatic calorimeter (APTAC^TM) to conduct tests with different vent areas to reflect actual process designs. Applicability to various flow regimes will be discussed. An example pressure relief sizing for maleic anhydride will be presented.