Runaway reactions relief vent sizing

Wang Y-W, Duh Y-S, Shu C-M (2006) Evaluation of adiabatic runaway reaction and vent sizing for emergency relief from DSC calorimetry. J Therm Anal Calorim 85 225-234... 

Vent Sizing Package (VSP) The VSP is an extension of ARC technology. The VSP is a bench-scale apparatus for characterizing runaway chemical reactions. It makes possible the sizing of pressure relief systems with less engineering expertise than is required with the ARC or other methods. 

Experimental data at the actual relief conditions are recommended for sizing relief vents for runaway reaction scenarios. As always, manufacturers technical specifications are used for selection, purchase, and installation. 

When a runaway reaction occurs within a reactor vessel, two-phase flow should be expected during the relief process. The vent sizing package (VSP) laboratory apparatus described in chapter 8 provides the much needed temperature and pressure rise data for relief area sizing. 

Figure 9-9 Nomograph for sizing two-phase reactor reliefs. Source H. K. Fauske, Generalized Vent Sizing Nomogram for Runaway Chemical Reactions, Plant/Operations Progress (1984), 3(4). Used by permission of the American Institute of Chemical Engineers.

J C Leung, "Simplified Vent Sizing Methods Incorporating Two-phase Flow", International Symposium on Runaway Reactions and Pressure Relief Design, 200-236, AlChE, 1995, ISBN 0-8169-0676-9... 

Many methods have been used to size relief systems area/volume scaling, mathematical modeling using reaction parameters and flow theory, and empirical methods by the Factory Insurance Association (FIA). The Design Institute for Emergency Relief Systems (DIERS) of the AIChE has performed studies of sizing reactors undergoing runaway reactions. Intricate laboratory instruments as described earlier have resulted in better vent sizes. 

Gustin, J. L., Choice of Runaway Reaction Scenarios for Vent Sizing Based on Pseudo-adiabatic Calorimetric Techniques, Int. Symp. on Runaway Reaction, Pressure Relief Design, and Effluent Handling, AIChE, pp. 11-13, 1998. 

Boyle [15] and Huff [16] first accounted for two-phase flow with relief system design for runaway chemical reactions. A computer simulation approach to vent sizing involves extensive thermokinetic and thermophysical characterization of the reaction system. Fisher [17] has provided an excellent review of emergency relief system design involving runaway reactions in reactors and vessels. Fauske [18] has developed a simplified chart to the two-phase calculation. He expressed the relief area as ... 

The self-healing rate, which is determined from the experiment, is what is used to calculate the vent size of the relief valve. of the reactor in order to prevent runaway reactions from exploding (see PRS R9.4 on the CD-ROM). 

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