In a vessel, the downcomer is best described as which of the following?

In a vessel, the downcomer is best described as which of the following?

• A. A pipe path that transports liquid from one tray to the next
• B. A gas outlet filter
• C. A drain for bottom liquid
• D. A vent for off-gas

Answer: (A)

Liquids move between trays in a column through a downcomer, which is a vertical passage that carries the liquid downward from one tray to the tray below. This dedicated pipe or channel directs the downward flow while allowing vapor to rise through the tray perforations, helping prevent flooding of the upper tray and maintaining proper separation. That’s why the downcomer is best described as a pipe path that transports liquid from one tray to the next. It isn’t a gas outlet filter, a drain for bottom liquid, or a vent for off-gas.

Liquids move between trays in a column through a downcomer, which is a vertical passage that carries the liquid downward from one tray to the tray below. This dedicated pipe or channel directs the downward flow while allowing vapor to rise through the tray perforations, helping prevent flooding of the upper tray and maintaining proper separation. That’s why the downcomer is best described as a pipe path that transports liquid from one tray to the next. It isn’t a gas outlet filter, a drain for bottom liquid, or a vent for off-gas.