Separation · Refining
Desalter
A vessel where heated crude is mixed with water and demulsifier and the salty water is separated out with a high voltage electrostatic field before distillation.
What it does
Removes mineral salts, mainly chlorides, that would otherwise cause corrosion, plugging and fouling in the crude unit and heat exchangers.
Basics
| Crude temperature | About 65 to 175 °C (150 to 350 °F) |
| Added | Water and demulsifier |
| Separation | High voltage electrostatic field |
Common failures
- Water and salt carried over into the crude unit
Troubleshooting
- Symptom
- Chlorides rising in the column overhead water
- Likely cause
- Poor desalting
- What to check
- Check water and demulsifier rates and the electrostatic grid