The downcomer from the bottom tray is submerged in a seal pan (see Fig. 8.3), to preserve its downcomer seal. I always set the horizontal dimension between the over-flow lip of the seal pan, (dimension y) the downcomer at four inches, so I never have to worry about restricting liquid flow from the bottom tray.… Read More »
To summarize, the total height of clear liquid in the downcomer is the sum of four factors: • Liquid escape velocity from the downcomer onto the tray below. • Weir height. • Crest height of liquid overflowing the outlet weir. • The pressure drop of the vapor flowing through the tray above the downcomer. Unfortunately,… Read More »
Liquid flows across a tray deck toward the outlet weir. The liquid overflows the weir, and drains through the downcomer, to the tray below. Vapor bubbles up through the sieve holes, or valve caps, on the tray deck, where the vapor comes into intimate contact with the liquid. More precisely, the fluid on the tray… Read More »