Residential Silencer - Underground !

[VeggieDiesel]

Has anyone built (or have experience with) an underground exhaust silencer
like to one used in this video.

http://www.youtube.com/watch?v=xLxUbLznTug

I understand they were very popular at one time.
Another solution I read about was to insert a 10 gallon drum inside a 20 gallon drum and fill
the area between them with sand, then set the 20 Gal. drum into the ground, and have the exhaust
enter and exit the 20 gal drum.

I need to silence a single cylinder Changfa for residential use and thought the Lister experts may have some tricks.
Anyone know a soution to building a sound deadening silencer ?

Cheers,
Veggie

[mjn]

In addition to dealing with the exhaust noise, you will need to muffle the intake as well.  My Changfa makes nearly as much noise on the intake as the exhaust.   Once you get the intake and exhaust quieted down, then you can work on getting the mechanical clatter silenced.

[lendusaquid]

Nope,never come across an exhaust like that before.

[SCOTT]

I have an underground exhaust.  The exhaust is routed outside of the gen shed via 2" black pipe into the top of a buried 30 gallon drum.  The exhaust exits out of the top and into a gentle bend into 4" black corrugated drainage pipe.  After a run of 51 hrs the plastic was only warm to the touch.

This system quiets the noise enough for me to run at night.

Scott

[lendusaquid]

My underground exhaust was not as quiet as i had hoped.It sounded very nice to me, but the addition of a lorry silencer was required before i was happy with the sound level. 

[VeggieDiesel]

lendusaquid,

Your system is beautiful. I found your YouTube video a month ago when I was researching Listeroids.
That's a really nice job you did there.

Your login name reminds me of a comedy Monty Python poem that I heard as a kid entitled:
" Can you lend us 10 quid till Tuesday".    :-)

Cheers,
Veggie

[VeggieDiesel]

Scott,

Thanks for the description of your sub-terranian noise suppression system. :-)
Is the pail empty inside ? Or perhaps 1/3 full of sand ?.
Anything unique about the way it is set in the ground (concrete vs. dirt)?

If you are getting good results, it seems like the solution for me.

Thanks,
Veggie

[lendusaquid]

Well my login name does not work cos not a single person has lent me a quid.

[diyer]

Has anyone put the exhaust into a bucket of water to heat the water and dampen the noise?

I was thinking about a large 55 gallon drum.  This would dump the condensation into the drum, but probably would evaporate several gallons a day.  I can have an auto water feed to keep up the level.  Also, there could be a sump area for draining the sludge.

This would eliminate the expensive heatexchanger and muffler.  I believe that the heat transfer would be greater than a heat exchanger.

Carl

[Stan]

Might create too much back pressure.  I don't know how to test for that other than to run it and see if it burns out your exhaust valve. 
Stan

[biobill]

diyer,
  I think a lister would blast the water out of the drum. A changfa maybe to a lesser degree but I think you would have to do something to mitigate the pulses. Perhaps a perforated pipe?
  I'm hard pressed to see the advantage. Why create contaminated water in large quantities?
                Bill

[rbodell]

Well my login name does not work cos not a single person has lent me a quid.

Not quite sure what a quid is, but I could send you a Squid. Might smell a little by the time you get it though.

[lendusaquid]

A quid = £1 .

[Doug]

1 looney = 1 dollar........

[lendusaquid]

So the USA is full of Looney's  and people who want to send me smelly squid