Thread Content
I would like to ask some questions regarding the operation of the flash tank. Under normal circumstances, the operation of a flash tank involves adiabatic flashing, or it may be operated at specified temperatures and pressures. I would like to ask how these two methods of operation are chosen? And how is it achieved to operate the flasher at specified temperature and pressure? Is there external heat exchange?
Adiabatic flash: A liquid feed with known flow rate, composition, pressure, and temperature (or enthalpy) is throttled to a lower pressure, resulting in partial vaporization. Adiabatic flash calculation: Determine the flash temperature as well as the vapor and liquid phase compositions and flow rates. Isothermal flashing: I. The vapor-liquid equilibrium constant is independent of composition. The bubble point temperature and dew point temperature of the feed mixture at the flashing pressure are calculated using the bubble point equation and the dew point equation respectively, and then it is checked whether the flashing temperature lies between these bubble and dew points. II. Flash calculation related to composition using vapor-liquid equilibrium constants
In our factory, a coil-type heating system is used for concentration.
I saw in the literature that a flash tower is used to separate two components; so when simulating this in Aspen, should I use the Flash module or the Radfrac module? The literature also mentions that the outlet temperatures at the upper and lower ends are different; so it should be the radfrac module that is used, right? Are a condenser and reboiler needed for that?