looking for air velocity criteria for frp duct/pipe used 4 foul air?

[brazilianjj]

I'm currently working on the design of odor control facilities for a wastewater treatment plant. We plan to use FRP pipe for convey foul air to odor control scrubbers.

I've seen guidelines that limit the air velocities in pipes/duct to less than 2500 fpm or 3000 fpm to reduce the problem of noise.

Does anyone know where these criteria orginate and how they were established?? I'd like to find the background.

Thanks,
ppalencia@lacsd.org

 

[julia]

Check out the chapter called Sound and Vibration Control in the ASHRAE Applications handbook.

 

[UtilityLouie]

The velocity limit that you have seen is typically used for ductwork in occupied office areas above ceilings. This velocity is noisy in a commercial office setting. In an industrial setting your fan and the amount of energy you want to spend are the limits to the velocities in ductwork. There are also limited noise concerns.

There have been instances where I have used 4000 to 5000 FPM in ductwork as long as the pressure drop is accounted for in your blower specification. I have found that over 5000 FPM velocity causes outrageous pressure drop.

In conclusion, use ASHRAE for some guidelines on calculating pressure drop, but look at your restrictions on duct size and go from there.

 

[russmech]

The book "Industrial Ventilation" has lots of data concerning air velocieties to use in an industrial setting. I recommend it. Also try the ASHRAE handbooks. In a noisy environment, I would not hesitate to use 3000 FPM minimum, perhaps up to 4000 FPM, depending upon how far you are going with it (total static pressure drop), how many hours per day (energy costs), space available (faster FPM, smaller duct sizes). Don't run a duct with fast moving air over or through the boss' office, the noise may generate a complaint.

 

[joan271273]

How can I estimate the sound level associated to the high velocity air movement within a ductwork. The project I am involved in is installing a dust collection system.


Thanks