Dynamic Simulations of the Impact of Depressurization of a Vessel on an Interconnected Vessel

Effluent handling systems such as containment vessels along with scrubbers and flare system are used for the storage and treatment of the emergency discharge from the relief system. In case of a runaway reaction or blowdown of a pressure vessel, the relieved stream is usually directly directed to a containment vessel also known as catch-tanks or dump tanks which have several benefits including moderation of the flow for later treatment process and returning the process vessel to service in a shorter time. Many researches have been conducted on the depressurization of a pressure vessel and vent sizing, but only few take into account the impact of depressurization on the catch-tank. The objective of the thesis is to present a dynamic simulator capable of simulating the depressurization of a pressure vessel which is connected and vented to a catch-tank. To achieve the goals of the study, the capabilities of an existing dynamic simulator for the simulation of venting and leaks from pressure vessels were enhanced. The simulator was limited to the simulation of a single vessel which was extended to the simulation of multiple vessels. A one dimensional transient heat transfer model was included in the simulator assuming the vessel is insulated from outside. Furthermore, an experimental study was conducted by depressurizing non-reacting gases from a pressure vessel to a catch-tank where the pressure and temperature were measured during the process. Moreover, a study of the impact of variation of the parameters such as initial pressure in the vessel, nature of the gas, composition in a mixture of gases and diameter of the tube connecting each vessel is conducted. The experimental data generated from these experiments are used to validate the dynamic simulator, and is presented in the results