Questions about the bottom-of-tower circulation rate
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In our process, there is one absorption tower; the solvent in the bottom of the tower fills up to only about 10 cubic meters. In addition, there is a bottom-loop heat exchanger, with circulation pipes of DN600 and a circulation volume of 1800 cubic meters. Why is the circulation volume so high? Even though the pipes and heat exchanger are filled to capacity, the volume isn’t that much
Cycle, cycle – think carefully about this word
A water tank can hold 1 cubic meter of water, but its circulation capacity could be 1000 cubic meters; it’s a matter of flow rate. A person weighs 50 kg, but they can consume 1000 kg of food; it’s a matter of time.
This is the circulation volume; for example, in a space of 10 cubic meters, there are 180 entries and exits within one hour.
In other words, the liquid in the tower bottom is circulated every 20 seconds! ! The more times the cycle is repeated, the better the effect theoretically will be—this applies to your process of cyclic absorption. The key is to ensure that your circulation pump does not pick up air (to prevent gas from entering the pump).
The circulation rate depends on phase equilibrium and thermal equilibrium, while the bottom volume of the tower depends on the required residence time.