Question

As a chemical engineer who involves in the process design, you need to propose three (3) parameters which can be manipulated to prevent flooding occurs in gas absorption tower during the process. Justify your proposal to your superior.

Answer 1

To discuss about the preventive methods of flooding, we first need to understand what is flooding.

Flooding is a situation which arise whenever the liquid or gas flow is above the allowed limits. This would result in accumulation of liquid. Liquid starts flowing in upper direction instead of flowing downward. This condition is not recommended and it also increases the pressure drop in the column due to which the column efficiency is reduced.

The methods that can be used for prevention of flooding can be-

The operating velocity should be maintained about 50%-60% of flooding velocity so that the liquid hold up cannot occur. Here the flooding velocity is the upper limit of gas flow.

The other method that can be used in prevention is reducing both the feed rate and reflux rate so that the the hold up is controlled and pressure drop rise can be avoided.

We can also prevent flooding by reducing liquid in the column and also vapour by reducing the steam from the reboiler. This would help in reducing accumulation of liquid in the column to a great extent and will also increase the efficiency of the column.

Hope you liked the answer and it resolved your doubt.