Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips now!
  • 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!

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

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

hgjor (Materials)
9 May 08 10:38
I need a metal (alloy) with the highest possible thermal conductivity to use as heat exchanger. I have tried pure copper, but I noticed severe temperature corrosion at 450°C. I have also tried nickel plated copper, but the nickel comes loose at sharp edges.
Does anyone have a recommendation for a metal alloy with excellent thermal conductivity (preferably the same as copper) and high temperature corrosion resistance ? The metal (alloy) will be used as heat exchanger and should not be excessively expensive.
Many thanks for your help.
Herman
btrueblood (Mechanical)
9 May 08 11:18
Presumably "temperature corrosion" means oxidation in air?  Or can you be more specific about what fluids are going thru your HX.  At 850 deg. F (450 C) you don't have a lot of choices, and no alloys that will survive long at that temp. will approach copper's conductivity (silver is the only metal with better conductivity than copper).  Stainless steels can work (I would suggest stabilized grades like 347 or 321, or duplex alloys), as will superalloys (Inconels, Haynes alloys).
hgjor (Materials)
9 May 08 11:43
Yes, you're right, I mean oxidation in air.  If there are no alternatives, would copper surface treatment help ?  Or replacing the copper by bronze ?
moltenmetal (Chemical)
9 May 08 11:54
Have you analyzed the heat transfer resistances in your exchanger to know that the resistance of the metal itself is so significant as to dominate?  If the metal itself is not a significant fraction of the resistance, you have lots of other options which are only modestly less thermally conductive.
EdStainless (Materials)
9 May 08 12:02
I suggest that you look at high Cr steels, 9% Cr or 13% Cr grades.  They will be a lot stronger and stiffer than Cu so you should be able to use 1/2 the wall thickness of your Cu or even less.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

hgjor (Materials)
9 May 08 12:05
I selected copper because the exchanger temperature uniformity has to be very good.  What other options would you suggest ?
EdStainless (Materials)
9 May 08 12:17
You will have good uniformity with THIN wall steels.
You need to look at the CDA web site and see if there are any Cu alloys that are usable in your temp range.  My guess is that they will have Ni and Cr in them and their TC will be less than 1/4 of pure Cu.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

unclesyd (Materials)
9 May 08 13:44
We used Cu and Cu alloys, mainly Silicon Bronze at your temperatures but we always used a thermally sprayed aluminum on the OD. I don't know if you can get an Al coating on small tubes.
Here are a couple of ideas if you have to get away from Cu and go to a Cu alloy.

Wolverine Tube has various Cu alloy finned tubes available that might work. Using fins will mediagate some of the loss in thermal conductivity from the Cu tubes.

http://www.wlv.com/products/products/Enhanced/enhanced.htm

Ener-Fin makes a Al finned Cu tube that might work and again I don't think you will loose much heat transfer.

http://www.enerfin-inc.com/Fins.html

If you have to get away from Cu or Cu alloys altogather Fin-Fin is another approach to enhance the heat transfer of other metals.

http://www.highperformancetube.com/benefits.htm
metman (Materials)
11 May 08 8:23
You might want to consider Monel, Nickel-Copper alloy(s).

The heat transfer will be considerably less than Cu but the heat resistance much better and as has been pointed out, geometry can be a large factor in heat transfer.  Thinner tube walls plus fins can be used to take advantage of the strength & heat resistance to heat transfer ratio.

GBSC (Materials)
27 Jun 08 8:54
Hi,

I found an interesting content regarding quotation on metal injection molding parts on
http://omnexus.com/rd/?rd=213&lr=postengtips

You might be able to find someone there who can quote/advise on the best material/alloy to use.

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!

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