Modelling Temperature of Separators

[Buchi]

Hi gangs,

I am trying to set up a model for an Oil processing facility (FLOWSTATION) consisting of three separators stages at different conditions. I am using HYSYS. If the first stage separator is operating at 100 psig and 50 degree C (say), and the second stage is operated at 50 psig and 80 degree C (say), how can I ensure that the stream leaving the first stage separator enters the second stage at 50 psig and 80 degree C. My first guess would be to use a valve dowstream of the first stage separator to letdown the pressure from 100 psig to 50 psig and subsequently use a cooler or heater as the case maybe to take the temperature to 80 degree C from whatever it was downstream of the letdown valve.

This looks too complicated an approach, does anyone think differently?

Buchi

 

[PraveenBajaj]

I suppose the use of a pressure let down valve is common and also economic.

Praveen

 

[TD2K]

I'm not familar with Hysys but that is the way you did it with Hysim. Pro/II allows you to go from one flash vessel to another and lower the pressure and raise/lower the temperature, they essentially have the valve and heater built into the flash separator model.

Heck, for all I know, you can raise the pressure in Pro/II going from one separator to another.

But back to your question, that is how I would do it.