Sound Abatement on New Project 1

[tduggan]

Im am in the early stages of a large machine which includes pellet handling systems, extruders, large blowers, conveyors ect. We have alotted money for sound abatement. Can anyone recommend the best way to approach the sound abatement issues I will encounter and where to focus to get the most bang for the buck?

 

[Hatch]

Step 1 is to decide what the important paramter is? Is it environmental noise (outdoor noise radiation) or indoor noise (workplace noise exposure, or both that you need to control. Typically outdoor noise may have a limit such as 55 dBA at the property line and indoor noise is 85 dBA at 1 metre.

The best way to assess your situation is to do a site visit to a similar/idential operating machine. Then you can see and hear the "beast".

If that is not possible, I would guess based on my experience that the following systems need to be addressed. Note the order of importance:

1. Fans and Blowers (particularly if the inlet or outlets discharge or intake air where people walk by.
2. Fans and Blowers (casing noise and motors if they exceed 200HP. High efficiency motors are generally quieter.
3. Compressed air discharges and associated equipment.
4. Conveyers are not usually a problem unless you have vibratory feeders, de-magnetizers, belt beaters and/or motors larger than 100hp.
5. If there is a pneumatic pellet transport system, then I would look at that also.
6. The extruder should not be a problem, but assuming that you are extruding a product which is not steel, then material handling is an issue. Parts made of Magnesium are very noisy when they bang together, aluminium is too, and steel is the best of the 3.

Hope the above info helps. Fans/Blowers are the primary noise source. I can't make any more judgements without more info.

 

[tduggan]

Hatch,

In your response to my original email, you mentioned looking at the pellet handling system. Are you talking about the blowers specifically or other parts of the system?

Thanks.

 

[Hatch]

Pellet handling systems can create noise by the blowers, but there are many other mechanisms such as vibration, impact of the material on the ductwork, air discharge points, leaks, etc.