Side Stream Cooling Water Treatment
Side Stream Cooling Water Treatment
(OP)
I am moving to a plant which suffers from terrible cooling water problems. The source of make-up water is from a waste treatment system and loaded with solids (biological and other), which are further cycled up by the cooling towers. Water is very precious there so no other make-up source is practical.
At present I have no quantitative detail on % solids or their nature. The water is described as being "thick" with solids, and from previous work in units on the same site I have on occassion observed the cooling water to have the color and consistency of chocolate milk- YIKES! I envision some side stream (or feed water) treatment for solids removal. I am seeking recommendations in advance on the type of equipment, packages, and suppliers normally used for such cooling water treatment. Any advice is appreciated.
best wishes,
sshep
At present I have no quantitative detail on % solids or their nature. The water is described as being "thick" with solids, and from previous work in units on the same site I have on occassion observed the cooling water to have the color and consistency of chocolate milk- YIKES! I envision some side stream (or feed water) treatment for solids removal. I am seeking recommendations in advance on the type of equipment, packages, and suppliers normally used for such cooling water treatment. Any advice is appreciated.
best wishes,
sshep





RE: Side Stream Cooling Water Treatment
We installed a self-flushing rotary screen filter in the condenser cooling water lines to our steam turbine. In our application we are only concerned with removing solids down to about 5mm diameter because below this level we do not experience tube-blocking problems. Do I sense that your problems are more of a silt-like nature?
If it is of interest, the equipment was built by a French company, Beaudrey & Cie, and has proven very reliable. We installed it ourselves. They are not a large company, but showed great flexibility and worked well with us to customise our equipment. I've just learned while looking for their url that they have a US subsidiary too.
http://www.beaudrey.com/english/indexEn.html
http://www.beaudreyusa.com/
----------------------------------
I don't suffer from insanity. I enjoy it...
RE: Side Stream Cooling Water Treatment
How much NH3? If you have Cu alloy tubes you can expect alot of issues usnless the NH3 is nitrified or removed otherwise.
How much P? The P and NH3 will feed the bugs that have the nice warm and wet environment of the cooling tower to live in. Left unchecked your fill will have lots of slimey things hanging. Hmm...a giant trickling filter.
Any residual surfactants will cause foaming.
You will need to provide more detail for more complete opinions but you won't likely get a complete design package.
RE: Side Stream Cooling Water Treatment
In the meantime a rather interesting theory was presented in that some biological solids are healthy for cooling water. The rationalization is that scaling from water hardness will adhere to suspended solids rather than tube walls (all are carbon steel by the way). I am skeptical- any opinion on that?
On the otherhand when I arrived considerable work was under way to hot tap high volume caustic batch injection nozzles in the inlet piping for purposes of improving heat transfer. I would not have bet 2 cents on that and yet when we did the injection today there was an dramatic positive effect. Any suggestions on why that works?
best wishes,
sshep
RE: Side Stream Cooling Water Treatment
I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int./JCI
RE: Side Stream Cooling Water Treatment
Pure nonsense is my opinion.
"On the otherhand when I arrived considerable work was under way to hot tap high volume caustic batch injection nozzles in the inlet piping for purposes of improving heat transfer. I would not have bet 2 cents on that and yet when we did the injection today there was an dramatic positive effect. Any suggestions on why that works?"
It is a well known phenomena in the water treatment business. A change in the composition of the water will frequently shell off the old scale right down to the bare metal. Don't worry however, the scale will quickly reform.
RE: Side Stream Cooling Water Treatment
The bio-solids theory would not be too far off, if you had huge volumes of sediment to deal with.
Actually the particulate (non-disolved solids) are of little concern to me.
You need to focus on scaling, pH and biocide are where I would start. You may need to knock the solids down in order to control biological growth, since that may be what is feeding it.
You also need a good inventory of what metals are in the systems that use this water. Much copper an brass? What about carbon steel? stainless (check clorides).
I have seen similar plants, but in there case the incoming grey water was very much dead. Still lots of organic content, but no biological activity.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Side Stream Cooling Water Treatment