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[malkio]

Is there a way to chemically clean this type exchanger from graphite impurities (tiny particles) ? we clean it with xylene but that doesn't help
tnx

[Art Montemayor]

Malkio:

In colloquial USA English, you have "bought the ranch".

What this means is that when you decided to apply a brazed (100% seal welded) plate heat exchanger, you instantly committed yourself and your process to a situation where the internal maintenance and cleaning of such a piece of equipment is either very difficult or nearly impossible without physical disassembly - which is often cost prohibitive. Therefore, you must accept the consequences of allowing foreign substances or contaminants to enter the PHE.

This is the major issue whenever the question of applying a 100% sealed (or welded) heat exchanger is debated. And it is a wise and experienced engineer that sees to it that if such an option is decided upon, then a very efficient and dependable solids removal (or filtering) system is always introduced immediately upstream of such units. This, of course, means that it takes more capital $, maintenance, and pressure drop to operate such a system. Of course it does! It's called a TRADE OFF and is associated with everything related to engineering. You don't get any good things (like a 100% leak-proof heat exhanger) for free.

Once you have contaminated the sealed exhanger, you are on your own. Your only option is to keep trying to loosen up all the deposited solids and sweep them out with purging fluids. But your only tools are a very high Reynolds number, agitation, and a fluid that has solvent-type qualities. It of course means that the unit must be taken out of service for the attempted clean-outs. This is a pain in the backside and in the operation's pocketbook. Welcome to the world of trade offs. If you don't succeed in removing the solids you may have to buy and install a new unit. If so, be smart: always install an efficient and dependable filtering system immediately ahead of the sealed exchanger.

This is the only credible, practical advice I can offer.