×
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

Reduce industrial stack discharge noise

Reduce industrial stack discharge noise

Reduce industrial stack discharge noise

(OP)
Looking for suggestions as how to reduce high velocity stack discharge noise without reducing the velocity.  Discharge velocity is needed to meet AAQS for dispersion.  Noise at property line is above maximum 60 dBA.

RE: Reduce industrial stack discharge noise

What are you discharging? Is it clean, dry, high-temp, etc.?

RE: Reduce industrial stack discharge noise

(OP)
Thanks dvd for your interest to comment/help resolve. To answer your question ----- Discharge is combustion exhaust from a 2,000kW peaking generator, #2 diesel fuel, 16" dia stack, 15,200 acfm at temp of 835 F.  Stack height is 35 feet and unit already has a hospital critical grade silencer.

RE: Reduce industrial stack discharge noise

How much attenuation do you need?
Do you have an enclosure on the genset?  What's the rating?  XXdBA @ X feet etc.
What's the rating (insertion loss) of the silencer?
How close are you to the air quality standards?
What's the set-back distance from the stack to the prop. line?

A 2MW genset, I estimate, to have an exhaust sound power level around 130-140 dB.  That's ignoring casing noise and radiator noise.

As well, if the numbers you gave are correct (i.e. the duct is 16" dia and flow is 15,200 cfm, that's a air velocity of ~10,000 fpm.  I'm amazed the silencer is working at those high velocities!
I'd imagine the self-noise would be horrendous, not to mention the material in the silencer won't last long.

A few suggestions:
There are outfits that can make low pressure-loss, ultra-high velocity silencers that may outperform the existing one.  
If you have the length (and other constraints allow for it), consider re-orienting the exhaust away from the prop. line.

Lastly,
You mention that you need the velocity due to dispersion concerns.  What dispersion model did you use? Can you use a more refined/advanced model? And I'm assuming your emission rates were based on manufacture's data, and not on emission factors.

-
Aercoustics.com

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

White Paper - How ESI is Helping Move New Medical Device Product to Market Quicker & More Cost Effic
Early Supplier Involvement has long been a strategy employed by manufacturers to produce innovative products. Now, it almost seems like a necessity. Because decisions made in the design phase can positively affect product quality and costs, this can help add value to OEM bottom lines. This white paper will discuss many facets of ESI, including why it’s so valuable today, what challenges limit the benefits of ESI, how cost is impacted, and more. Download Now
White Paper - Moving to a Driverless Future
This white paper describes what we see as the best practices to support a sustainable engineering process for autonomous vehicle design. It exposes how to use simulation and testing in common frameworks to enable design exploration, verification and validation for the development of autonomous cars at a system, software and full-vehicle level to drive a mature product development process for automated driving. Download Now
Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. 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