Muffler/silencer for high pressure gas exhaust

[patdh1028]

Howdy,

I am working on a gas system that operates at about 500 psig with N2. We have a relief valve, a bleed valve and an electronic regulator with exhaust outlets that tie in to an exhaust line.

On the end of the exhaust line I want to put a silencer or muffler, but the pressure is too high for any standard-service silencer I know of or have seen in my research and it is not nearly important enough to warrant the heavy industrial exhaust mufflers used in big plants. SO I threw together a design and I figure I'll post it up here to get some input.

It is a series of concentric tubes. I figure the high pressure gas will have room to expand and lose velocity and pressure as it flows through larger spaces, and I have some hard foam inserts in there (the dark khaki stuff) to take some energy out of the pressure wave. Probably not very good for continuous-operation processes, but for the intermittent pressure-relief I think it would do a lot to make dumping some pressure less aurally unpleasant. And it looks like it will cost about $75.

Am I way off or what?

 

[GregLocock]

It should make things quieter, and it won't increase your back pressure much. The length of each chamber is rather important.

Cheers

Greg Locock


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

http://eng-tips.com/market.cfm?

 

[Tmoose]

http://ecx.images-amazon.com/images/I/41O6BJYZDuL._SL500_AA300_.jpg

If I use an air gun to blow out my funnel from the small end before use it is so loud it scares the doggies.

If I blow it clean from the large end it is MUCH quieter.

Mr Beranek probably discusses reflection and dissipation of chambers with different end treatments.

Is this a closed loop? Or is the N2 released to atmosphere?

 

[Strong]

I don't see this design as being very effective. It looks more appropriate as a engine exhaust muffler rather than a high pressure relief valve silencer. Of course you can make it and try it out to see if it works adequately. Most commercial silencers for your application have a gas diffuser section and a sound absorber section. In some applications a diffuser alone can be used with a discharge pipe oriented away from the receptor location.

Walt

 

[patdh1028]

Unfortunately I don't have to put my design to the test; I found a silencer in the size and pressure-handling range I was looking for. Thanks for your input, if ever it does come down to trying out my design I would probably tweak it a bit.

 

[DLite30]

Well, it seems you found a solution...I was going to suggest one of these. It's a high pressure gas muffler used on valve actuators.

http://www2.emersonprocess.com/site...ts/Shafer/Misc/RV/Exhaust_Muffler_MIS_R10.pdf