(563h) Refinery Vacuum Ejector Systems: A Process Engineer's Perspective

The largest refinery vacuum systems are on the crude vacuum tower overhead. The vacuum system is a utility system that lowers the vacuum tower pressure to allow more of the feed to the tower to vaporize. They are required to handle a mixture of water vapor, hydrocarbons, and other gases from the vacuum tower. Steam jet ejectors are the dominant vacuum equipment used in these systems. The entire vacuum system includes more than just the ejectors. It includes the ejectors, condensers, and hot-well. How these components interact determines overall system performance. When dealing with vacuum systems designers, operators, and troubleshooters must have a fundamental understanding of how the components work and interact.

Topics covered here include:

• Vacuum process type (wet versus dry/damp systems)
• Load factors
• Basic component operation
• Component interaction
• Common alternate configurations