×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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.

Students Click Here

surface coating/finish and impact on paste dryer performance?

surface coating/finish and impact on paste dryer performance?

surface coating/finish and impact on paste dryer performance?

(OP)
I am debottlenecking a continuous dryer which fouls at high production rates.  The dryer is 316 stainless steel

Adhesion (cohesion) of the sodium organic salt to the mill finished stainless steel is very high at the operating temperature 300 F.  It is highly agglomerating and forms crust if not mechanically disturbed.  

The dryer is built as a heated horizontal cylinder (16 in dia, 60" long, containing a 3" center shaft with a spiral of blades that intermesh with stationary hooks, to clean the heated blades (~ 3 mm clearance).  

Heat transfer surface cannot be added.  What coatings and/or surface finish will limit fouling allowing me to push the heat transfer higher?

If I only modify the cylinder interior, I imagine sliding but the hooks would result in surface renewal.  Is there a negative to not coating the hooks, shaft and blade?  Poor forced convective surface renewal? Poor bulk turnover? Increased stress on the hooks?

If I modify all surfaces, can I be too slick?

RE: surface coating/finish and impact on paste dryer performance?

Sputter-deposited molybdenum disulfide or tungsten disufide would work -- both are low friction coatings that generally resist chemicals -- but it would not be easy to coat the interior of your cylinder.  You might have to add a base hard coating.  Coating the blades would depend on whether or not they can be detached.

Jim Treglio

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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