Citation

Mcintosh D, Waldram S, Etchells J. Process. Saf. Environ. Prot. 2004; 82(1): 26-36.

Copyright

(Copyright © 2004, Institution of Chemical Engineers and European Federation of Chemical Engineering, Publisher Hemisphere Publishing)

DOI

10.1205/095758204322777642

PMID

unavailable

Abstract

The multi-phase venting of vapour, liquid and glass particles has been studied experimentally on the 1 and 10 l scales. In non-reacting systems, the depressurization profiles of superheated water or water-glycerol mixtures were studied on their own and with added glass particles. The particles were both solid and hollow, with specific gravities both greater and less than 1. Similar depressurization experiments were made during the runaway reaction of acetic anhydride and water, both with and without the glass. Relief set pressures were between 3 and 5 bara. Glass particle concentrations were up to 16% v/v. Nozzle to median glass diameter ratios were between 6 and 500. Experimental design techniques were used to study the effects of many factors efficiently. Depressurization profiles with and without glass present were compared: in general the glass had little statistically significant effect. There was limited evidence that the hollow glass particles could increase depressurization rates slightly. Tests with runaway reactions have highlighted some difficulties when comparing systems with and without glass particles present. In all cases, the vented fluids were less concentrated in glass than those in the reactor. This may have important implications for design and sizing of pressure relief vents. Poor reproducibility of the total amount of liquid carry over was apparent for the 1 l scale tests.