×
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

Pressure and Flow Measurement

Pressure and Flow Measurement

Pressure and Flow Measurement

(OP)
I have a system which conveys powder in an air stream. The air is conveyed by a fan in the middle of the system
The system goes through a number of unit stages and pipework.

I need to develop a number of system curve and understand the pressure profiles and velocity through the system on different powders and at different flowrates.

The system currently has no measurements at all.

What is the best way of measuring pressure throuh the system and then how do I calculate the associated velocity. I am comfortable to do the pressure drop calcs for the pipes, but have no real data to establish pressure drop accross cyclones and filter bags etc. The cheaper solution, the better

I have heard of pitot tubes but not too sure if this would be applicable and how they work and what calcs I would need to do.

Any suggestions?

RE: Pressure and Flow Measurement

bif
You need to get the static pressure at the fan inlet and outlet. From this you can deduce the flow if you know the fan speed and have the fan table from the fan manufacturer.
It is important however that you have straight piping at the inlet and outlet of the fan. Otherwise you may not get an accurate number for your flow.

Measuring static pressure is a matter of drilling a 1/8" hole into the pipe and placing the end of a 1/4" flexible hose over the hole and pressing it against the pipe/duct such that the hose end is sealed up tight to the wall of the pipe/duct. The other end of the hose is connected to a gauge or manometer which can read pressure in inches of water.

Add the static pressure you measure at the inlet to the pressure you measure at the outlet, ignoring whether the pressures you measured are positive or negative. This number is your fan static pressure.

Armed with the fan static pressure and the fan speed which you can measure with a tachometer, you can now enter the fan table to determine the volume of air that is being moved.

I am assuming standard air density for this process. If the temperature or humidity is elevated or your altitude is significantly above sea level you will have to do some additional calculations.

Good luck.

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