Corrosion prevention issues in multi-media filters
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Our factory has just installed a system for reusing treated water; there are 4 filters in the filtration room, two of which are multi-media filters and two are multi-chamber activated carbon filters； The design calls for applying an anti-corrosion primer twice inside the container. Today, the workshop said that lining with rubber or applying resin is necessary; applying just the anti-corrosion primer is not sufficient. So, is it necessary to use rubber lining or resin, or will that still not meet the requirements? Thank you!
It mainly depends on the quality of the reclaimed water – what is its pH level?； Another factor is your requirements regarding iron ions in the reuse water. If the reclaimed water is neutral or alkaline, and there are no requirements regarding iron ions in its subsequent reuse, then the original primer-based anti-corrosion treatment is sufficient. As for using resin-based anti-corrosion methods, they offer little advantage over primers; if possible, it is better to use rubber lining. However, a regular water treatment primer is sufficient; if the equipment has not yet been processed, it is recommended to use a rubber lining ； If it has already been installed, it is recommended not to make any further modifications, as that corrosion does not have a very significant impact on the filter’s lifespan.
Since water quality changes in a fluctuating manner, with significant variations occurring especially with seasonal changes, such changes in the quality of the incoming water can affect the operating conditions of the equipment. Therefore, it is necessary to take preventive measures; starting with proper anti-corrosion treatment for the equipment is certainly the best way to protect it, and I believe it is something that should be done.
It is usually lined with rubber, and it doesn’t cost much either; it’s a one-step solution that saves a lot of hassle
What is the purpose of reusing treated water? Is it used to produce pure water? If it is intended for producing pure water, then anti-corrosion measures are necessary; at least epoxy resin should be applied to prevent iron from contaminating the water again.
Personally, I think using epoxy resin for anti-corrosion is feasible.
What determines the quality of water? Wastewater generally has a certain degree of corrosiveness, especially water from chemical plants. Is the reclaimed water derived from domestic wastewater or industrial waste water? If the water doesn’t have an obvious acidic or alkaline nature, then applying epoxy resin will suffice
The equipment is now in place, and the filter tank is equipped with filters and a distributor; it’s unlikely that lining will be applied externally. Is it possible to apply lining on-site? That would also be very difficult. The original design called for only two coats of anti-corrosion primer. After passing through the filter, it goes to UF and RO, with the output water going to the boiler.
Apply epoxy resin on site. If possible, fiberglass laminate is better.
Determine which prevention method to use based on the quality of the incoming water
Applying an anti-corrosion primer will also meet the requirements; using rubber lining is of course better. Use as little resin as possible; it tends to crack.
It can be said that this is just a way to deceive you; strict requirements exist regarding water quality in boilers, especially in power plant boilers. Iron ions can cause tube explosions. Gasketed ones are better