When heat exchangers are an essential aspect of your operation, it's important that they're working at top efficiency. Dirty or fouled exchangers can slow down your processes, contaminate your product and lower your company's overall efficiency. To avoid these negative consequences, it's important to be vigilant about shell and tube heat exchanger maintenance and proper cleaning.
Here are five factors to keep in mind to make your shell and tube heat exchanger maintenance as effective as possible:
1. Have a plan
When it's time to clean your shell and tube heat exchanger, there's a good chance that you'll need to shut down operations temporarily. This is lost production time, which translates to reduced output and efficiency. However, there are ways to minimize the effects of a plant shut-down. One of the most effective ways to lower the impact is to prepare for it.
Have a dedicated date for planned maintenance, Ethanol Producer Magazine suggested. This way, you can plan ahead in preparation for the event, allowing you to choose an inconsequential day for the shutdown. Additionally, since contractors who specialize in equipment maintenance often have busy schedules, planning ahead can help you choose the date and time that suits you best – not when the contractor has a free space in his schedule.
Make sure that any spare gaskets or replacement tube bundles are ordered in plenty of time to arrive by your scheduled maintenance date. Without a predetermined date for planned maintenance, it's all too easy to let this important task get pushed back. When this happens, your equipment is more likely to run into problems. Sooner or later, you'll either have to shut down your operation yourself, or a piece of equipment will fail and you'll have to quickly schedule reactive maintenance. There's no predicting if or when this will occur, and it may not always be in your favor.
2. Inspect your equipment
Excessive fouling is never a good thing for your heat exchanger. If not identified or addressed in a timely manner, it could result in a number of problems, including contaminated or unusable product, corrosion or leaks. Ethanol Producer Magazine pointed out that, in some cases, material buildup can become a fire hazard.
To prevent these issues, it's important to note when fouling begins to form and to remove it promptly. Check your tube bundles as well as the shell side for signs of material buildup or corrosion.
3. Test your heat transfer fluid
Another area of concern is the heat transfer fluid. When using chemical-based HTFs, it's inevitable that the material will eventually become degraded and less effective. When this happens, it can reduce the efficiency of the exchanger and, depending on the chosen fluid, can adhere to the surface of the tubes, become a more volatile solution or create a fire hazard, Processing Magazine reported.
Regularly testing the HTF will tell operators where in the lifespan the fluid is. Take the fluid from several different places to get a more complete idea of how good the fluid still is. Additionally, be sure to test the fluid while it's in operation; cooled HTF will display different properties than the HTF in action, making the reading of fluid from a shut down machine a less informative sample. Additionally, shutting down a piece of equipment for the purpose of taking a sample will slow down operations, put undue stress on the equipment and HTF, and takes more time out of your workday.
Test the fluid periodically; Processing Magazine noted that quarterly testing typically provides the best results.
4. Collaborate with the right people
Shell and tube heat exchanger maintenance is no small task, so it's important to include any and all relevant personnel in planning it. Work together to identify maintenance needs, a day that works best for the company and the right professionals to assist or carry out the job.
"Approach your planned maintenance day with a checklist."
"Myself, the maintenance manager and the environmental health and safety coordinator typically work together on scheduling and making sure we have the proper documentation, training records, etc.," Tyler Edmundson, the plant manager at ethanol plant Mid-Missouri Energy, told Ethanol Producer Magazine. "Safety is the No. 1 priority – making sure contractors have proper credentials and understand our policies and expectations."
When you include people from different departments, such as your environmental health and safety team, you'll be able to collaborate on smart decisions that are good for the company overall. Additionally, when you approach your planned maintenance day with a checklist, you're more likely to have as productive a shutdown day as possible.
Edmundson noted that working with different people to plan out the maintenance day also allows them to collect all the necessary documentation that any incoming professional would need to know. For example, Matt Werzyn, maintenance manager with Louis Dreyfus Commodities, Elkhorn Valley Ethanol LLC, told Ethanol Producer Magazine that he creates and sends an informational packet to any contractors that will work on their equipment. It includes the company's safety rules and requests items from the contractor, like employee training records, to demonstrate their credentials. Then, after arriving on-site, but before they get their hands on the equipment, the team goes through a contractor orientation.
Other information you may want to provide any contractor that will be working with your equipment is a maintenance log, documentation from the original equipment manufacturer or information about the products or fluids used in the equipment.
5. Post-cleaning cleanup
Depending on your cleaning method, there may still be necessary tasks to carry out once everything is all cleaned. Whether you used chemical or mechanical cleaners to remove fouling, there could be debris left over. This could contaminate your product if left unaddressed. Give your equipment a rinse to ensure there are no leftover chemicals or dirt.
Your shell and tube heat exchanger is designed to be closed up tight most of the time. As such, opening it can sometimes cause damage to the gasket, Marine Insight explained. Be sure to double-check your gasket and gasket cover before wrapping up your heat exchanger maintenance. Make sure that you have spare gaskets on hand and replace them if necessary.
Heat exchanger maintenance and cleaning can be a time-consuming task, but it's not one that's worth putting off. By being proactive, you can help your equipment perform more efficiently and last longer. When you have questions about proper care for your heat exchanger, need replacement parts, or when you're ready for a replacement unit, reach out to the helpful heat exchanger experts at Enerquip.