2024 Spring Meeting and 20th Global Congress on Process Safety
(158d) Learnings from Cold Box Core Exchanger Replacement on Existing Unit
Beaumont Chemical Plant required replacement of a cold core exchanger due to a long-term fouling issue. The fouling caused high DP and poor heat transfer leading to lost recovery of valued molecules. Graphs of this will be included. This is a brazed aluminum heat exchanger (BAHX) inside of a perlite filled cold box.
The first attempt to purchase a new core used a non-OEM exchanger supplier but the exchanger had to be disposed due to manufacturing issues. The site then utilized another vendor and successfully manufacture the new core. There were multiple learnings due to the fact that neither vendor provided an identical replacement in kind for a 30+ year old exchanger. Details will be provided on some of the technical quality checks and design evaluations.
Installation was successful without issues. A general overview of the process, typical hold points, inspections, leak testing, and findings will be provided. Discussion of the perlite changeout typical process and safety concerns will be included.
Base improvements were made during the outage to prevent future fouling. The paper will discuss some standard cold box exchanger protection elements.
The old exchanger was dismantled by cutting in a fabrication shop to determine the root cause of the fouling. Multiple cuts were made on the old exchanger over the course of three days. This was a unique experience and pictures will be provided. The shop work helped identify particulates as the source of the exchanger performance issues. This method of troubleshooting may have a low probability of success depending on the choice of cuts on the exchanger pieces. Learnings from the process will be provided. The cutting required a lot of senior technical people observing and discussing the issues to find the fouling in the cut exchanger pieces.
Post start-up performance on the new core exchanger was very good and returned the unit back to design performance. Graphs of the performance change will be provided.