×
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!
  • Students Click Here

*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

Jobs

Pneumatic Conveying -High P. Low V.

Pneumatic Conveying -High P. Low V.

Pneumatic Conveying -High P. Low V.

(OP)
I need to determine an economical velocity, supply air pressure, supply air quantity SCFM and friction loss per unit pipe length for:
Material: e-s precipitator dust containing copper 32.8 LB/FT3,
620 F material temp
80% @ 0.05 microns, remainder up to 1 inch
1-2% moisture by weight
Material Flow 3,100 - 27,000 LB/HR
Assume 200 FT straight delivery length plus bends.
My main concerns are: What is a typical weight ratio LB Air/LB Material?
What is a desired transport velocity?
Where can I obtain friction factors?


ttracewicz@atsspartec.on.ca

RE: Pneumatic Conveying -High P. Low V.


I presume with the problem statement development that you are in the conceptual phase of your project. If you are in the detailed phase I would need considerable more information to provide a sizing.

The air ratio is determined by whether economics dictate dense or dilute phase conveyance. You do not give a mineral breakdown of the dust. If it is mostly copper the erosion would be low against steels, therefore you could use either dilute or dense phase conveyance. Material to air ratiios can vary from 2:1 to 10:1 between dilute vs dense phase conveyance. With 200 feet of horizontal (?) conveyance length, dense phase may be the method of choice. In your case the pressure drop will be low and dense phase is not out of the question.

Desired transport velocity also is determined by selection of dilute or dense phase conveyance. If you are in the study phase of your project you should probably consider 5000-7000 fpm. This is a reasonable assumption.

Determination of friction factors for special materials may require laboratory modeling. If your preciptator is installed this may be the most cost effective way to assure project success.

I would consider with caution the particle size distribution you have listed. I do not know the basis of your numbers. The conveyance system should be designed with the "worst" case scenario in mind. But if you are in the scoping study phase your distribution looks rather good for conveyance. You can alleviate concerns about feed stream variation with some conditioning equipment. This is a normal precaution.

Regards

Dan Price

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