051 Day 2 of Industrial Water Week (Boilers) - Scaling UP! H2O
Day 2 of Industrial Water Week is here! Today we celebrate by answering a few questions about boilers and I am joined by one of my mentors, Bruce Ketrick, CWT.
Here are the questions we are answering today.
- What causing foaming in a boiler? David
Foaming is primarily caused by high solids. As the boiler concentration increases, the boiling bubble cannot “pop” as quickly and they begin to build up on each other. Forming a creamy foam. This can be solved by lowering the concentration or reducing other items that may be cause high solids in the boiler water like product over feed. The bigger issue is when the foam level increases, the boiler water sensors get a false sense of where the water level is. This can cause the boiler to cut off on low water. Another issue is the foam can get up into the steam line and cause wet steam. Water only has 180 btu’s on its best day, where steam has a 1150 btu’s on its worst. If we get water in the steam, we don’t have enough btu’s to get the job done.
Many will try to treat this issue with a defoamer, but a true water treater will investigate the real reason for the foam and correct the cause. So the exact issue needs to be investigated, but hopefully this information will get you off to a good start.
- How can you reduce corrosion in a boiler? David
Again, knowing the exact issue with the exact system is key. With out knowing exactly what the issue is, let me answer that very generally. When ever anything happens in a boiler that bad, water treatment is always blamed first. Weather it is the issue or not. Water treaters are guilty until proven innocent. It has been my experience that most issues dealing with boiler corrosion are more operational than water treatment based.
Many times companies purchase boiler that are too big and they get underutilized. Or maybe they have 2 boilers on a lead/lag operation, but never rotate them. Boilers are meant to run at the pressure there were designed to run at, straying from this can make a corrosive situation. Among the biggest issues I see are seasonal operations. When a boiler is not being used continuously, it needs to be wet or dry stored. Wet storage is preference when there is a short period of time the boiler will be down and the owner may need to put the boiler back online quickly. This is where you will purge all of the air out of the boiler to the steam header with treated water. Normally with high sulfite and caustic.
Dry storage is for more long-term storage. This is where the boiler is opened and completed dry. I’ve seen this done with desiccants left in the boiler, fan blowing into the boiler so the air can circulate a drop light hung in the boiler to allow for some heat to drive away moisture and a combination of all of these. My preferred method is to use some of the volatile amine products out there the help protect the boiler during dry storage.
No matter which method you choose, none are set it and forget it. You need to periodically check to make sure the conditions you created to store the boiler stay within range.
- What is the maximum concentration ratio for low pressure boilers using high purity makeup water such as RO or DI water?
- What resources do you use to differentiate between low pressure and high-pressure boilers? How do treatments change as boiler operate from low to high pressure? (Mark Juhl)
Have a great Industrial Water Week!
Industry Water Week
Join me each and every day this week for a special themed episode.