INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Leaching considerations with reactive heat sink materials...

Leaching considerations with reactive heat sink materials...

(OP)
I need to cool a slow moving small flow of hydroponic plant water, at most 1000 ppm nutrients, with a pH of typically around 6.

I'd like to use aluminum or copper heat sink directly in that fluid stream to drop temp 10 or 20 degrees F down to 50-60F neighborhood.

My concern is I don't want to contaminate my fluids with copper or aluminum reacting to and leaching off into the fluid.

Is that likely an issue and if so, is there any spray coating or other such treatment onto the surface of the heat sink to minimize that happening that does not greatly degrade the materials thermal conductivity?

Thank you for any thoughts.

- Shane

RE: Leaching considerations with reactive heat sink materials...

Don't use Cu, at least not pure Cu.
IF the flow is slow then your heat transfer will be very low.
Any Al should work fine.
Are there any other metals in the system, in contact with the water?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Leaching considerations with reactive heat sink materials...

(OP)
EdStainless,

Thanks for comments.

No other metals, other than perhaps some micro nutrients in that nutrient solution.

- Shane

RE: Leaching considerations with reactive heat sink materials...

Aluminum leaches out easily into solution over a wide range of pH, and is a potent biological poison. However, there are some aluminum grades good for seawater application - check if these marine grades are compatible with the nutrient slate at these low concentrations you've got, in what appears to be a fully aerated solution stream.

RE: Leaching considerations with reactive heat sink materials...

(OP)
IRStuff & georgeverghese, thanks both for comments.

Elsewhere I'd also read that there are conformal coatings with good thermal conductivity
and that a coated aluminum part is probably a good balance between cost and performance.

- Shane

RE: Leaching considerations with reactive heat sink materials...

Bronze is used for marine application and may be an answer.

RE: Leaching considerations with reactive heat sink materials...

Of course, make sure you use lead-free grade of bronze.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close