(34a) Vacuum Distillation: Wash Zone Configuration

Refinery vacuum units include a deentrainment, or wash zone, for removal of heavy material from desired products. Wash zone reliability problems often shut vacuum units down, causing significant losses. The review of wash zone operations cover;

• Operating objectives
• Fractionating versus deentraining wash zones
• Wash zone terminology
• Operating configurations
• Hot-wash versus cold-wash
• Wash oil distributors
• Conventional configurations
• Spray chambers
• Multiple stage wash systems
• Recycle wash systems
• Wash zone modeling and reliability

 Elements of case studies from multiple units are included to illustrate key points.