Reuse and Relocation: A Case History Part I Reboiler Analysis and Performance

Reboiler Analysis and Performance

Andrew W. Sloley

Potentially, used equipment can save time and money over new equipment in your plant. Occasionally, used equipment can be picked up for very low prices. But getting it to the plant and properly working does require skills that differ from purchasing new equipment.

However, the process requirements for the new service are nearly always different from the original process requirements. Expert-level knowledge may be required to decide if the equipment will really do the required job.

Unless an entire plant is purchased and used as-is, used equipment will have to be integrated with other parts of the plant that will use new equipment. Integration may be difficult as the used equipment may have constraints that makes its use difficult with conventional choices for the new equipment attached to it.

This presentation examines a plant that purchased a 42-inch diameter tower used from a pharmaceutical plant. It had been built and erected but never placed into service. The client purchased the tower and placed it into a completely new service.

The focus on this presentation is on the reboiler system and difficulties with this system. The reboiler chosen was a falling-film evaporator. Once in service, the reboiler could not get the required duty into the tower. Areas covered include:

• Investigating leaks in the reboiler,
• Determining the actual reboiler duty,
• Examining the actual capability of the hot oil system providing heat to the reboiler,
• Inherent limits on the reboiler performance including fouling and liquid distribution problems,
• Steps taken to improve reboiler performance, and
• The alternate best case reboiler type that would have performed better.