These devices are used to collect liquid from upper bed for redistribution or draw off as side-product or pump around. They are designed to give low-pressure drop and collect all the upper bed liquid. It's very important to mix all the liquid and provide a uniform composition for redistribution. Chevron type and riser type are in common use.
Chevron type collector for large diameter column
Chevron type collector for small diameter column
Φ3800 Orifice pan liquid collect and redistributor