Apparatus for producing pulsed liquid flow in a distillation column

In combination with a fractionation tray a fractionation tray downcomer which comprises in cooperative combination:

• a. a liquid-transfer conduit defining an enclosed liquid flow path, the liquid-transfer conduit having an upper portion with the shape of an inverted U located in an upper first half of the liquid-transfer conduit, the upper portion having a horizontal section which divides the liquid-transfer conduit into a shorter first leg and a longer second leg, the liquid-transfer conduit having a first opening located in the first leg and a second opening located in the second leg;
• and,
• b. a curved, siphon-breaking vapor conduit defining an enclosed vapor flow path, the siphon-breaking conduit being joined to the upper portion of the liquid-transfer conduit and operably communicating with the liquid flow path, the siphon-breaking conduit passing downward through a first plane perpendicular to the second leg of the liquid-transfer conduit and passing through an outer surface of the horizontal section of the upper portion of the liquid-transfer conduit which is closest to said second opening in said second leg of said liquid-transfer conduit, said siphon-breaking conduit having an opening located between the first plane and a second plane perpendicular to the second leg of the liquid-transfer conduit and passing through said first opening in the first leg of said liquid-transfer conduit, whereby liquid is transferred from said fractionation tray in a periodic pulse-like manner, said periodic transfer commencing when the liquid level on said fractionation tray initiates siphonic flow through said liquid-transfer conduit, said liquid flow being terminated when the liquid level on said fractionation tray descends to said opening of said siphon-breaking conduit and vapor flow is initiated in said siphon-breaking conduit.