| 摘要 |
PURPOSE: To provide a downcomer for a distillation column which prevents upwardly flowing vapor from entering the downcomer even when an abnormality occurs in the distillation column by providing an arcuate bend at the lower edge part of an apron of the downcomer. CONSTITUTION: A liq. in the downcomer 10 is passed through a gap 22A between the tip end 8 of the apron 14 above a perforated plate 18 and a seal pan 16, and reaches a tray 24. The apron 14 is provided with an arcuate bend 8 extending along a radius R centered in the downcomer 10 at an angle of approximately 60 deg. to 120 deg.. The length R of the radius and the angleβof a curved line determine the gap 22A which remains after the bend 8 is formed. The gap 22A not only does not permit the vapor to enter the downcomer 10 but also shows the pressure drop same as or lower than the pressure drop at the time when the vapor is passed through the gap 22A between the apron 14 and the seal pan 16 of the downcomer, as compared with a linearly bent bend, as the shape of the bend 8 is substantially arcuate. The smaller the gap 22A, the higher the downcomer 10, thereby bringing about a unit having more flexibility.
|
