Internal Pipe Cleaning

[robotengineer]

Thanks in advance
I'm lookiing for a method of removing accumulated scale and sludge form pipe walls/branches in a nuclear plant where removal from service is impossible (one outage/2 years), chemicals canot be used (conductivity is 0.2 microsiemens) and access to the internals to hydrolaze or chemically clean is impossible. I'm looking for a method of flushing which incorporates ultrasonic or other external energy application to loosen a gently adherant iron oxide layer during a flush with water.
Any suggestions?

 

[kenvlach]

Back flush using compressed air (or nitrogen).
Reversing flow a few times, each time flushed out with compressed air (nitrogen) for turbulence, may remove a lot of gunk.

 

[unclesyd]

You might want to checkout this method.

http://www.pipetech.no/hydrokinetics.asp

During any cleaning process you are going to change the physical properties of you system depending on what the soils are.

As posted by kenvlach there are several companies that use water hammer/shock waves to remove materials from pipe walls.

 

[ProcessWaterChemist]

Robot-

I love how you said "to loosen a gently adherant iron oxide layer during a flush with water."

Gently adherant...Inside the steam header of a Nuclear power plant! That makes me laugh!

 

[kenvlach]

ProcessWaterChemist, where do you read 'steam header?'

'conductivity is 0.2 microsiemens' suggests something like Type III water per ASTM D1193.

 

[MikeInSWLa]

unclesyd-

Do you have direct experience with the hydrokinetic cleaning method per the link you posted?

We have a process where we make an alumina slurry, and we have to shut down every 18 months or so to clean buildup on pipewalss, equipment, etc.
Currently we do this by circulating caustic, which is effective, but has its own problems in terms of the downtime, cost, and getting rid of the spent caustic.
Perhaps using thios method in selected areas might be an alternative or at least can make caustic washes less frequent.

 

[unclesyd]

MikeInSWLa

I haven't personally used this service but have had some very good 1st hand reports of the success of it. It looks like time factor is a big selling point. I see also they mention Barium Compounds which are heavy and hard to remove.

Here is the US site for Hydrokinetics. The can move a lot of different materials

http://aimmtechnologies.com/experience.html

 

[unclesyd]

MikeInSWLa,

Here is another company you may want to contact

http://www.aquadrillinternational.com/Markets/Mining_Alumina_Copper.htm