Demin. water - Cationic bed filtering laterals

[ruikp]

Hello!

I have a problem with the filtering laterals (regeneration screen) inside cationic bed. They worn after 2 years of work. They are half-pipes (half is a common pipe and the other half is a screen with 300 microns openings) which contact with 3 fluids: 1 - Raw Water; 2 – Air; 3 – HCl solutions of 7% (6800kg/day). The velocity is not expected to be very high.

They are made of 316L SS, previous pickled and passivated – design and the new ones too. I heard that an alloy of more than 6% of Mo would be the best material choice. But is very expensive!

So, I ask:
1 – Does anyone have experience with those mats?
2 – If so, how long did they last?
3 – Companies name that manufacture them.
4 – And what about plastic ones?

Thanks in advance.

 

[TomEun]

What is the operating temperature (normal and maximum with exposure time a year)?

 

[ruikp]

Well, the raw water come from underground. Its always at +-25ºC.
The regenerant solution is a little bit higher. It may vary, lets say, 30+-5ºC.

 

[strider6]

if one of the fluid is HCl @ 7% then SS316 is not suitable and even 6mo.

http://www.outokumpu.com/applications/corrosion/image_viewer.asp?image=hydrochloric1.jpg

S

Corrosion Prevention & Corrosion Control