equation, but this is not the correct, real (V/F) ratio. Before starting any flash calculation, it is vital that one checks to see that the pressure and temperature given are such that the feed mixture is in the two-phase region. That is, the system pressure must be between the bubble-point pressure and the dew-point pressure for a mixture with a composition equal to the feed composition and at the given temperature T.
Since T is known, both PDP and PBP can be calculated explicitly with no iteration involved.
Was this article helpful?