Process Description
Unstabilized condensate from LP Condensate Recovery Separator D-321 flows through isolation valve XV-331 and on to the top tray of Condensate Stabilizer T-331. The condensate is heated as it contacts warm vapor rising from the bottom of T-331. At the lower pressure of T-331 (25 PSIG) and the warmer conditions in T-331, the lighter compounds in the condensate feed are vaporized and sent overhead through control valve PV-331 to the Offgas Header of Vapor Recovery Compressors K-301A/B. Normally, the flow rate of vapor to K-301A/B is 1.125 MMSCF/D.
Condensate reaching the base of T-331 is routed by gravity to the Stabilizer Reboiler E-331. Vapor from E-331 is returned below the bottom tray in T-331 and flows upward through the 10 trays in the Condensate Stabilizer.
Stabilizer Reboiler E-331 is a kettle-type reboiler that uses circulating hot oil to generate vapor from condensate flowing in from the base of T-331. The reboiler has an overflow baffle to form a sump for stabilized condensate. This baffle ensures that the tubes with hot oil flowing through them are fully submerged in condensate on the outside of the tubes. The vapor from Stabilizer Reboiler E-331 is returned to the bottom tray of T-331. The temperature of the vapor from E-221 is normally 160 DEG F. Hot stabilized condensate flows over the baffle and into the sump of E-331 and is sent to Condensate Cooler E-332.
Stabilized condensate is cooled in Condensate Cooler E-332 which cools the condensate using ambient air supplied by an electric motor-driven fan. Air flow is adjustable by the pneumatically driven louver. The condensate is cooled from 141.3 DEG F to 90 DEG F before being sent through control valve LV-331 to the Atmospheric Condensate Recovery Separator D-341.
The normal flow rate of condensate is 0.942 MBPD.
Instrumentation
Hand switch XV-331 opens and closes isolation valve XV-331. XV-331 is locked in the CLSD position when interlock I-331 is activated by high level in the bottom of T-331. TI-331 indicates the temperature of gas flowing from the top of T-331.
FI-331 indicates the flow rate of gas from the top of T-331.
PIC-331 controls the top pressure of gas from T-331 by adjusting the position of PV+331.
PDI-335 indicates the pressure drop across all the trays of T-331.
LAH-322 indicates the level of condensate in the bottom of T-331 and is a trip input for interlock I-331.
TI-334 indicates the temperature of the condensate flowing from the bottom of T-331 to the Stabilizer Reboiler E-331.
TIC-335 controls the temperature of the vapor leaving E-331 by adjusting the position of TV-335.
FI-335 indicates the flow of hot oil to E-331.
TI-337 indicates the temperature of hot oil leaving E-331.
LIC-331 controls the level of condensate in the collection sump of E-331 by adjusting the position of LV-331.
FI-332 indicates the flow rate of stabilized condensate through LV-331 to D-341.
Hand switch HS-332 starts and stops the electric motor of E-332’s fan. TIC-332 controls the outlet temperature of E-332 by adjusting the air louver positioner TV-332.