Flash Drum Vapor Liquid Separation Stripping Gas

The patent applies preliminary action by introducing a stripping gas (such as steam or nitrogen) into the flash drum before the vapor-liquid mixture enters the pyrolysis furnace. This pre-stripping operation removes non-volatile components from the liquid phase, preventing them from reaching the furnace where they would form coke. The stripping gas bubbles through the liquid in the flash drum, carrying volatile components into the vapor phase while leaving non-volatiles behind, thus preparing the feedstock in advance to avoid coke deposition problems.

The patent applies the taking out principle by extracting non-volatile components from the feedstock stream before it enters the pyrolysis furnace. The flash drum with stripping gas separation removes these harmful non-volatile components (which would otherwise form coke) from the vapor phase. The stripped vapor, now free of coke-forming contaminants, proceeds to the furnace for efficient cracking, while the non-volatiles are separated and removed, thus protecting the furnace and maintaining system reliability without sacrificing cracking efficiency.

The patent applies the intermediary principle by using a stripping gas (steam or nitrogen) as a mediator in the flash drum separation process. The stripping gas bubbles through the liquid phase, selectively carrying volatile components including light hydrocarbons into the vapor phase while leaving non-volatile components in the liquid bottoms. This intermediary gas facilitates the separation process, ensuring that light hydrocarbons are not lost in the bottoms but are instead transferred to the vapor stream for subsequent cracking, thus preventing both coke formation and hydrocarbon loss simultaneously.