The dynamic (velocity) seal is a simple innovation which ensures significant cost savings over time. The reverse conical baffle design reduces flow area in the flare tip while simultaneously increasing purge gas velocity. In combination with the dynamic seal, a constant flow of purge gas will maintain a seal in flare system, ensuring that air infiltration does not occur. A vortex effect is created as the exiting purge gas inspirates intruding air. This intruding air is drawn out of the boundary layer and into the exiting purge gas flow column, thus purging the flare tip. This technology is a standard on various flares.
Continuously sweeping a stack with purge gas can result in exorbitant operating expenses over time; especially for large diameter stacks. The Molecular Seal is a purge reduction device which allows the flare system operator to use 98% less purge gas while continually sweeping the system. The savings in daily purge gas consumption over the long run makes for a short payback period on the initial capital investment of the molecular seal, which can also be referred to as labyrinth or density seal.