Abstract: A contact tray for use in a mass transfer or heat exchange column and having multiple baffles walls that cause the liquid flowing on an upper surface of a tray deck tray to change its direction of flow and narrow its flow path width and extend the length of the flow path when the liquid flows from an inlet area to an outlet on the tray deck. By narrowing the flow path, the volumetric flow rate of the liquid at any portion of the deck increases and reduces the opportunity for vapor entrainment of the liquid at low liquid flow rates. A downcomer extends downwardly from the outlet to receive liquid when it enters the outlet and then convey it downwardly to a discharge outlet located at a lower end of the downcomer. The downcomer includes an inclined or horizontal portion that causes the discharge outlet to be positioned beneath and in vertical alignment with the inlet area on the tray deck.

Abstract: A contact tray for use in a mass transfer column and having a tray deck for receiving a liquid stream and a plurality of valves distributed across the tray deck through which vapor ascends for interacting with the liquid stream. Each valve has an opening in the tray deck in the form of a central segment and extensions that extend outwardly from opposite ends of the central segment. The valves each include a valve body with a valve cover positioned in covering relationship above and extending outwardly beyond the opening and legs that are attached to the valve cover at recesses located at opposite ends of the valve cover. The legs extend downwardly through the extensions in the opening and include stops in portions of the legs positioned below the tray deck to permit limited vertical movement of the legs to allow the valve body to move between open and closed positions in response to ascending vapor pressure against an undersurface of the valve cover.