BROOMAN, J. H. P.; http://lattes.cnpq.br/6315622114836736; BROOMAN, John Henry Percival.
Résumé:
The requirements for control in an industrial plant in a global point of view goes beyond simply
keeping the desired process conditions and production rate. A capacity for emergency control is
also required to mitigate the effects and avoid disatrous consequences.
Last in order of demand there's the pressure emergency relief system. Its basic function is to
direct process streams to a safe destination, condition or treatment avoiding rupture of the
equipments.
The design of relief systems, due to associated high risk and social responsability, has been
improved over decades. A much used code is the API RP-520 "Sizing, Selection, and Instalation
of Pressure-Relieving Devices in Refinerie". For two-phase relief the subject is still in
development today, for example by Leung, Lenzing and Darby.
To design a relief system capacity required for equipment safety, a model of the process at the
emergency moment is necessary.
A computer program for relief valve capacity design was developed for vinyl chloride
polimerization reactors, coupling a kinetic model with a two-phase flow model. The kinetic
model for homogeneous reactions in two phases in equilibrium is based on Xie et alli (Polymer,
vol. 32, n° 3, pp. 537-557, 1991) and includes semibatch feed and temperature programing. The
flow model used is the well established Omega Method.
The model reproduces qualitatively the expected events. The use of the Mathcad platform
including semibatch features and temperature programing easies its use in the industry for relief
design, operations optimization and training.
