Downcomers are used to guide liquid flow from an upper tray to a lower tray. The most common is the segmental-type, which can be either straight or sloped (angled).

What is the purpose of Downcomers?

Downcomers are pipes leading from the top to the bottom of the boiler. Downcomers carry the water from steam drum to the bottom part of the boilers where it enters the distribution headers to be heated in the combustion zone.

What is the function of weir and Downcomer?

During this foaming process, a high interfacial area for efficient vapour-liquid mass transfer is produced. The function of a weir is to maintain a desired liquid level on the tray. Downcomers are used to guide liquid flow from an upper tray to a lower tray.