Tray

A tray basically acts as a mini-column in which each of it performing a fraction of the separation task. From this we can conclude that the more trays there are, the better the level of separation and that overall separation efficiency will rely fundamentally upon the design of the tray. Trays are designed to amplify vapour-liquid contact by considering the liquid distribution and vapour distribution on the tray. This is because better vapour-liquid contact means better separation at each tray and lead to a better column performance. Less trays will be needed to achieve the same level of separation. The benefits include less energy consumption and lower development costs.

Tray Tower

Sieve Tray

Advantages:
  • Liquid tight construction
  • Suitable for low liquid rate service
  • Fouling resistance
  • Wide operating range
Disadvantages:
  • Poor vapor/liquid contact efficiency
  • Moderate/high pressure drop
  • Most expensive type
  • More tray weights

Valve Tray

Advantages:
  • Good vapor/liquid contact efficiency​
  • Low/moderate pressure drop​
  • Less expensive
  • Easy maintenance
Disadvantages:
  • Narrow operating range
  • High vapor escaping momentum that can cause liquid entrainment
  • No protection for liquid weeping
  • Possible fouling

Bubble Cap Tray

Advantages:
  • Good vapor/liquid contact efficiency
  • Minimized liquid weeping
  • Moderate pressure drop
  • Most common tray type for new column
Disadvantages:
  • Possible fouling
  • Possible valve displacement
  • Difficult maintenance for valves