Air Compressor Silencer Vibration Issues

[YungPlantEng]

Hello everyone - chemical engineer by trade so be gentle.

At a plant where whomever installed this air compressor decided to install the silencer outwards rather than up above as designed. Presumably because of the piping arrangement which would make changing the silencer filter very difficult.

As you can see by the photos, there is excessive vibration on the silencer that is causing the makeshift support for it to be uprooted and cause further strain. This silencer's vibration is causing the bolts holding the lid to shear off on a monthly basis.

Is there some simple solution? There doesn't appear to be anything online that I could just buy as a replacement for the makeshift support. Halfway tempted to just put some bungee cords around the lid and call it a day but this looks awful and I can't imagine this vibration isn't affecting the motor.

https://files.engineering.com/getfi...b592-4a56-a3d8-5d14593b6a58&file=IMG_1295.jpg

https://files.engineering.com/getfi...0575-4dea-8f25-08d037972682&file=IMG_1294.jpg

Thanks guys!

 

[TugboatEng]

Two choices:

1) Attach the support bracket to the same platform the compressor is on so they move together.

2) Build the support bracket so it can entirely support the silencer housing and connect the silencer to the compressor with a flexible duct/hose.

 

[Tmoose]

I'm suspicious the filter vibration may originate with a wimpy structure supporting the motor and compressor. Both are purely rotational machines that should run pretty sm0oth.
If the compressor is roots type it can have wicked pressure pulsation frequencies in the discharge piping.

The motor and compressor appear to be bolted to a maybe 1" thick table welded to a fancy frame with six very stout legs, just resting on the floor.
Please describe the table top construction. Thickness, material , reinforcement, welded (as it appears in pix) or bolted to the main frame, etc.

Do you have any vibration measuring gear to quantify vibration amplitude and frequency on 50 or so pints on the system ?

 

[YungPlantEng]

Actually just checked and it looks like it’s not done on our vibration route. It’s done by a contracting company and we unfortunately don’t have equipment/training to do it ourselves, but I’ll make sure it’s included

 

[Tmoose]

Do I understand correctly the plant runs some "vibration routes" on its own?
If you have portable vibration data collectors for your vibration route, what make and model are they?

If they are capable of some level of off-route "analysis" measurements, there are documents available online that have instructions how to set up for custom measurements.

There are tons of posts about system vibration problems here -

https://www.machineryanalysis.org/

 

[electricpete]

+1 for machineryanalysis.org There are a lot of rotating machinery vib analysts

It looks like a strap is run over the top of this thing and bolted down to eyebolts on both ends of the top of the Tee support. And then there is some soft spacer between the silencer and the top of the tee support. Although I got a little confused it looked like the strap was missing from the left side in the end view (can you explain what's going on there?)

If you get some vibration measurements you may get more data for an informed approach.

From your senses can you tell anything about the motion pattern. primarily in the H or V direction? Does it get bigger as you move from the rigid mount of the silencer towards the free(ish) end? To what extent is the free end T support moving?

Absent that, I'd be inclined to try a few different trial-and-error tweaks to the end support configuration and see how the vibration changes.

Random things to try:
[ul]
[li]change the strap tension - looser or tighter[/li]
[li]adjust the spacer. Thickness may be critical since it affects what degree of bending occurs when the strap is tightened.[/li]
[li]jam a 2x4 under each end of the horizontal tee to stiffen it[/li]
[/ul]


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(2B)+(2B)' ?