I am in the midst of relieving a constraint in the steam condensate system in a butadiene plant.
As attached. exchanger, Steam condensate system in the aromatics plant and butadiene plant are integrated.
E-940 is heated up steam codensate from D-982. During normal operation, steam condensate from the aromatics plant and butadiene plant is sent to D-982. Steam condensate undergoes flashing at 5.6 kg/cm2G and steam condensate ( ~ 160 degC) is used to heat up E-940.
Under normal operation of D-982 level control, LCV2 is closed and D-982 level is controlled by LCV1.
During the shutdown of the aromatics plant, the amount of steam condensate sent to D-982 decreased significantly. Subsequently, LCV2 (Recycle valve) is opened in order to maintain D-982 level, introducing "cold condensate" to the drum. As a result of the lower steam condensate temperature, E-940 heat duty is affected and the tower tray temperature cannot be maintained.
I have a proposal to heat up the steam condensate by injecting medium pressure steam ( 14.5 kg/cm2G, 280 degC) into condensate drum (with the help of some distributor or spray nozzle) to heat up the steam condensate. The heat transfer principle i imagine is similar to the stripping steam in a deaerator where the steam heats up the boiler feed water (Although the stripping of O2 in the boiler feed water is not similar).
Can anyone advice on the feasibility of such an operation and what are considerations to take note ?