3 replies to this topic

[conan_kaya]

I am now having my attachment in a refining company.

I was posted this question by a senior engineer.

For a tray in the distillation column, is the height of the weir important.

There is generally 2 purposes for the weir. One of them is to maintain a certain liquid level on the tray. What is the second one?

Also, the senior engineer did mention that the height of the weir and the distance between the end of the downcomer(from the above tray) and that of the end of the tray are inter-related and play an important and fundamental role in the designing and working of a distillation column. Can someone advice me on what is the importance?

THank you!

[katmar]

The higher the weir the better the gas-liquid contact and the better the mass transfer, but the price paid for this efficiency improvement is a higher pressure drop.

The weir height must be more than the gap between the downcomer from the tray above and the tray floor because you need to establish a liquid seal under the downcomer to prevent the gas flowing up the downcomer.

[conan_kaya]

Thanks a lot.

Also can i ask what is the consequence of the loss of downcomer seal?

[chem101]

Hi;
the consequence of the loss of downcomer seal will cause Gas to flow through downcomer area.
which can cause flooding inside the column.