We inject steam in VB furnace coil as velocity steam to reduce the furnace tube coking. It also surpresses the vapor pressure of heavy resid and causes to boils at lower temperature (stripping effect). It has helped us to improve the conversion and unit run length.
Corrosion problem in this section will be reduced if operate the reflux return temperature about 10-15F above the water dew point. According to my experience, monel trays also last not more than 3-4 years in this region of tower (we always order new trays before T/A). Keeping the return...
