Noise Reduction in Assembly department 1

[Lars90]

Hi all,

I'm trying to find solutions to reduce the noise in the assembly department. Basically, the department consists of 25 assembly machinery which include vibrating bowl feeders, pneumatic equipment and ultrasonic welding machines. So far i could observe that the majority of the noise is coming from the pneumatic equipment. Different types of silencers have been installed to reduce the amount of noise however, there is still a high level of noise. On the other hand, bowl feeders are enclosed in special cases to reduce the noise. Does anyone know what should be done more to reduce the noise level in the department ? does anyone ever had any similar situation ?
Thanks.

Regards
Lars

 

[Tmoose]

I'd start by identifying the frequency content of the noise.

lacking fancier instruments it can be done with a Microphone plus PC sound card plus freeware FFT software.

Some report success with guitar tuning phone apps, but I do't have a phancy phone, so can only suspect that maybe noise with pure tones/discreet frequencies might be required.

 

[GregLocock]

Android phones or tablets can use an excellent free spectrum analyser.

There are many alternatives for noise reduction, but typically you are wasting your money unless the problem is obvious, or you have done some analysis. An industrial 'expert' will recommend treatments but won't guarantee outcomes.

Cheers

Greg Locock


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[SomptingGuy]

You can sometimes address the noise sources, mostly in obvious cases such as air emission from pneumatic systems. But containment (enclosures) and absorption (room treatments) are going to be most likely. An assembly area will have a whole range of impulsive noises (clanking, banging, shots of air), so I think it's unlikely that you'll learn much from a frequency analysis.

Depeneding on where you are, there will be environmental noise limits imposed for employee safety. This has given rise to industrial noise consultants who will come in, assess your risks and then probably offer some (seemingly obvious) solutions.

I did visit an assembly plant once where the noise problem had been addressed by letting the employees turn their radios up.

- Steve

 

[Lars90]

Hi all, first of all thanks for your feedback.
This noise pollution issue is a project requested from the management so, such improvements to minimize noise have to be found. I just took the measurements of the noise level at different areas in the department and the highest noise level is 89dB. This noise is manly coming from an assembly machinery which includes pneumatic equipment, vibrating feed bikes and robots. I have also checked the legal notices and found out that the exposure noise limit has to be 87dB maximum. Thus, this issue has to tackled in a way. Does anyone have any suggestions for such solutions to minimize noise ?
Thanks

Regards
Lars

 

[SomptingGuy]

Yes, call in the professionals. There are many of them. If management is serious and you are operating at a noise level that could attract lawyers, there will be a budget. Spend it.

E.g (unlikely local to you, but typical):

http://www.advanced-noise-solutions.co.uk/industrial-noise-reduction.html

- Steve

 

[GregLocock]

I assume you mean 89 dBA, yes it would be wise to fix that if you have people working there for more than an hour a day. Depending on your location and industry you may get away with issuing ear muffs, but that is distinctly less effective than curing the noise at source.

A reasonably cheap and cheerful solution is to build a large heavy box around the noisy machines and line it with foam. However given the likely cost it is probably worth getting a consultant in.

Cheers

Greg Locock


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[BrianE22]

I used sound absorption panels in our air compressor room. They helped quite a bit. Sorry, no numbers for you - it was just cheap, quick and easy to try.

 

[Lars90]

Hi guys, thanks once again for your help. My manager just asked me to figure out this issue so i have to find solutions for this although i dont have such experience in this area. However, i was thinking a bit and getting around the shop floor and since the vibratory bowl feeders are one of the equipment which is causing a high level of noise i was focusing on them to find solutions. All the bowl feeders have an enclosed case to reduce noise however, i could notice that the operators are leaving the lid of the enclosed case open so, as a solution i was thinking to do a sensor so whenever the lid will be open it will give an alarm or blink a lamp thus the operators will close it. In your opinions what kind of sensor should use ?

Another possible solution which i found from my research is to paint the inner bowl feeder by urethane coating. As i could see from the info online this coating reduce the acoustic level. Do you know if its good or not ? anyone used it ?

regards
Lars

 

[GregLocock]

I think coating the inside of the bowl (and indeed the outside) is an excellent idea.

Just use a typical square D limit switch for the lids, they are two a penny in most assembly shops.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[Strong]

Lars,

I would not consider damping a vibratory bowl feeder unless you are prepared to stop production while you remove the material! Vibration and surface friction are key to bowl design, so be careful about changing them to reduce sound emissions. You can make sure that bowl does not have broken or loose components (springs, fasteners, and vibration mounts), impacting at in/out feeds, and is properly tuned for the product being conveyed. You may find that repairs/upgrades to the bowl will maintain or improve performance while producing lower sound emissions. Make sure that any sound enclosure or barrier wall has adequately sized and located inspection windows, so operators can view bowl operations without opening enclosure. The best advise already given is to seek professional assistance.

Walt

 

[Tmoose]

http://www.bksv.com/doc/bn1299.pdf

 

[Lars90]

Thanks for the helpful information guys.

Lars