3 replies to this topic

[Dudee]

Hi all,

I have a question: Is it always needed to install a flash drum separator after a partial condensation? if not, in which cases is it applied?

Any help is welcome. Thanks.

[shan]

Hi all,

I have a question: Is it always needed to install a flash drum separator after a partial condensation? if not, in which cases is it applied?

Any help is welcome. Thanks.

The question is why you want to condense the stream. If you want or don’t want gas/liquid, you have to install a separator to obtain or get rid of the phase desired/undesired. If your purpose is to lower the stream temperature, you do not need a separator. For example, there is no separator needed, if you want to lower a stream temperature to less than 120 F for avoiding personal protection insulation downstream.

[Dudee]

Hi all,

I have a question: Is it always needed to install a flash drum separator after a partial condensation? if not, in which cases is it applied?

Any help is welcome. Thanks.

The question is why you want to condense the stream. If you want or don’t want gas/liquid, you have to install a separator to obtain or get rid of the phase desired/undesired. If your purpose is to lower the stream temperature, you do not need a separator. For example, there is no separator needed, if you want to lower a stream temperature to less than 120 F for avoiding personal protection insulation downstream.

Sorry if I wasn't clear: I do want to separate the gas/liquid streams, what I don't konow is if I can make it just with the heat exchanger (shell and tube) or if I need the flash drum... It's a general question , just to know.

[djack77494]

Sorry if I wasn't clear: I do want to separate the gas/liquid streams, what I don't konow is if I can make it just with the heat exchanger (shell and tube) or if I need the flash drum... It's a general question , just to know.

Dudee,
To achieve effective separation of the liquid and vapor phases, you will need to design you equipment for that. The normal practice is to have some sort of flash vessel, often called an accumulator or a reflux drum, downstream of a partial condenser. Is one absolutely required? NO! You could design the exchanger to achieve the separation. For example, kettle type exchangers do just that. But that is not the normal practice for the situation you describe. And, my opinion in all such matters is that if you don't have a good reason to change that which has been used successfully in the past, don't change it. Would you like a long career?

Edited by djack77494, 12 November 2009 - 10:12 AM.