Design for maintaining the stability of gas-liquid interface in the reflux drum or the steam condensate pot

Both the reflux drum of the pressure hot vapor bypass control system and the condensate pot of the reboiler system in distillation column system at least have a gas and a liquid feed line, the gas feeding medium is condensable and the liquid feed medium is usually sub-cooled. This characteristic determines the gas-liquid interface in the drum or the pot must be stable to ensure the normal operation of system. Examples are introduced to show the significant fluctuation of the tower pressure under the hot vapor bypass control system, and the water hammer occurred frequently in the condensate pot if the gas or liquid nozzle positions are not well designed, which can lead to the gas-liquid interface instability. The design principle of gas into the gas phase space and liquid into the liquid phase space were put forward finally.