Quiet Blower Recommendation?

[kingsley9]

Hello, I am trying to select blowers for an air sparging and soil vapor extraction application, and one of the constraints is that they must be as quiet as possible. Typically, a Roots 32 rotary lobe would be used for air sparge, and a Roots 36 for soil vapor extraction, but the noise produced by these blowers is unacceptable for the project location. Does anyone have a recommendation for certain models/types of blower of similar performance to these that would produce the least noise?

 

[crjones]

Tuthill has a new noise reduction blower that has been at some shows.

 

[JRLAKE]

Quiet Roots type lobe blowers are an oxymoron.

I would consider a rotary screw type blower, like this:

http://www.efficiencyblowers.com/efficiencyblowersus/

 

[JRLAKE]

Forgot to mention...noise for these units are about 72 dba.

 

[zdas04]

JRLAKE,
Good information. I'm always leary of dry screws because the timing chain is just noisy and prone to failure. Copco's timing gear looks like a real improvement (wish their site mentioned the gear material, steel gears can still be noisy). 72 dba is pretty good, but what distance and how loaded was it measured at?

David

 

[JRLAKE]

I'm not sure. There are sound level testing standards for air compressors and I assume they are used here too, but I cannot confirm this. See below:

Measured according to PNEUROP PN8NTC2.2 test code (ISO 9614.2 Sound Intensity scanning method) The emission
sound pressure level refers to free field conditions at 1 m distance (Operators position). A total correction factor for
uncertainties of 3 dB(A) has to be added, conform the test code. Possible noise from discharge line, accessories and/or
ancillary equipment is not included.

 

[Warpspeed]

Performing high horsepower acts of extreme violence upon air is never going to be a completely silent process.

But acoustic muffling, sound proofing and enclosing the blower may offer more in total noise reduction than just trying to find a silent blower.