Low-temperature methanol wash tower: How to prevent oxidative corrosion during inspection and testing
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Dear sea friends: Will severe oxidative corrosion occur when the manholes of the low-temperature methanol washing tower are opened again for inspection and testing? How to prevent it? Which sea friend has done it? Could you give an introduction? Thank you!
However, maintenance is generally not recommended, as it may lead to more problems. Iron sulfide, when exposed to air, oxidizes into iron oxide, which is akin to the formation of a layer of scale; such oxidation can cause blockages or leaks after maintenance. This issue mainly occurs in carbon steel equipment, while it’s not a big problem with stainless steel. During maintenance, it’s important to rinse and clean thoroughly, and areas that do not require maintenance should be protected with nitrogen.
The scrubber tower is located in a low-temperature area, so the conditions there are much better compared to those in the hot area; if maintenance is indeed necessary, it can be carried out after draining and replacing the contents
I’m struggling now; when the inspection period arrives, I’m worried about corrosion if I open the tower for inspection.
Which sea friend can give some good advice?
The principle is to avoid opening it whenever possible; if it must be opened, then make sure to be well-prepared to do so.
What is your maintenance goal? Just go in for an inspection; if you do that, there’s positive nitrogen pressure protection, so just wear the appropriate protective equipment and go in to take a look. If maintenance is needed, specific plans should be developed after examining the particular issues; this approach is too general
For internal inspections of special equipment, the Technical Supervision Bureau requires inspections of the interior, but the process engineering team says it’s not possible to open the tower due to concerns about corrosion.
What they said is right; for this kind of inspection, one has to wear protective gear to go in
One sample can be taken: the methanol inside the tower is drained, nitrogen is used for purging, and the manhole most likely to suffer corrosion or have its packing washed away is opened; a diver wearing a self-contained breathing apparatus then enters to conduct an inspection.