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Author Topic: Silencer idea  (Read 12946 times)

Bottleveg

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Silencer idea
« on: March 19, 2010, 08:51:03 PM »
I’ve had an idea for an underground silencer for Listers ext.
What about feeding the exhaust into an existing foul drain manhole or into the top of an existing soil pipe?
The manhole would be vented on one side by the soil stack and by the main sewer on the other. It would also remove the smell from wvo and soot ext from wmo.
Anyone tried this?

oliver90owner

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Re: Silencer idea
« Reply #1 on: March 19, 2010, 08:59:38 PM »
And when the water utility find you are the origin of the oil in the system?

Regards, RAB

Bottleveg

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Re: Silencer idea
« Reply #2 on: March 19, 2010, 09:50:19 PM »
Good point but why oil in the system? I thought it all got burnt on a properly working engine. I don’t have oil in my silencer box so I wouldn’t expect any to leave the tail pipe.  :-\

DRDEATH

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Re: Silencer idea
« Reply #3 on: March 20, 2010, 12:45:39 PM »
One thing you might get buy with would pipe it through your sewer drain. Not the gray water or curb or some call it storm drain. Your sewer line go to the turd farm where it is processed and unless you have a really bad problem with your engine no one should know. The only thing is if you notice people working on the line don't start it because most of those lines do not operate under positive pressure. Yours would have pressure until it hit a larger area of the drain. Also you want to make DARN sure you exhaust is not hot. Sewer gas is highly explosive. Just food for thought. Mike
Breast cancer kills. It takes money to save lives.

westcoaster

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Re: Silencer idea
« Reply #4 on: March 20, 2010, 03:02:27 PM »
I wouldn't use either one.
You are now introducing carbon monoxide into the sewer system. The next city worker that opens a manhole a few blocks away might not be able to purge the hole to an acceptable level before entering.

mike90045

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Re: Silencer idea
« Reply #5 on: March 20, 2010, 03:19:33 PM »
I wouldn't use either one.
You are now introducing carbon monoxide into the sewer system. The next city worker that opens a manhole a few blocks away might not be able to purge the hole to an acceptable level before entering.

I don't recall for sure, but I don't think a properly running diesel produces carbon monoxide.   And the workers in manholes have several vents running at a time, at remote manholes, because the sewer fumes are much more problems. 

But I'd be worried about them tracking down the source of the "thump thump thump" more than anything else.

buickanddeere

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Re: Silencer idea
« Reply #6 on: March 20, 2010, 04:47:28 PM »
I wouldn't use either one.
You are now introducing carbon monoxide into the sewer system. The next city worker that opens a manhole a few blocks away might not be able to purge the hole to an acceptable level before entering.

I don't recall for sure, but I don't think a properly running diesel produces carbon monoxide.   And the workers in manholes have several vents running at a time, at remote manholes, because the sewer fumes are much more problems. 

But I'd be worried about them tracking down the source of the "thump thump thump" more than anything else.

   A diesel engine produces CO. At light load the amounts are reduced. If the engine is working hard enough to smoke, where there is unburned carbon soot blowing out the stack. You can bet there is also invisible unburned carbon vapour going out the stack as CO.

  b&d

Bottleveg

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Re: Silencer idea
« Reply #7 on: March 21, 2010, 11:10:41 AM »
Good point about the CO. I didn’t realise that diesels produced CO.
 I live in semi countryside so the bore of the sewer pipes are relatively small, not the ones that can be walked in, all the way to the sewer farm which is a few miles away.
I have a manhole right next to what will me my engine shed so it seems ideal to make use of it. The soil stack is about 30ft away and goes up above the roofline of my house. My thinking was that any ‘lighter than air’ gasses would flow up the soil stack whilst heavier matter would be washed away.
Mike, the idea of the ‘thump thump thump’ made me chuckle, I wonder if reverberations could be achieved on the toilet pan water?
How come nobody posts in the alternative fuels section now? I was interested in making a still like Listeroidusa1’s but I’m getting no replies. Using diesel now in the UK is no longer practical but I’ve had unsuccessful results from using filtered WMO in a car engine. I’m not sure if Lister injectors are more tolerant?

Mark.

buickanddeere

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Re: Silencer idea
« Reply #8 on: March 21, 2010, 01:40:19 PM »
  How much filtering of the wmo was done before using in the car? What made and model of car? What ratio was the wmo to diesel? Isn't kerosene cheaper in GB than diesel? Can you obtain off-road diesel?

Bottleveg

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Re: Silencer idea
« Reply #9 on: March 21, 2010, 08:34:36 PM »
  How much filtering of the wmo was done before using in the car? What made and model of car? What ratio was the wmo to diesel? Isn't kerosene cheaper in GB than diesel? Can you obtain off-road diesel?

1 micron filtered, admittedly through a bag filter so not as efficient as a cartridge filter would be. I tried 10/40/50 petrol/diesel/wmo and 50/50 wmo/wvo in a 1.7 Isuzu IDI engine that is normally run on 100% wvo. All worked well for a week and then poor starting and running so I guess the injectors started to coke as it still had the same problem on diesel for a time. I can do some 0.5 micron cartridge filtered to try in the Lister or even take it down to 0.1 but I did like the idea of the vacuum still. Our kerosene and off road (red) diesel is around 46ppl so best avoided if possible. If we use wmo (on road) in the UK then we have to pay 56ppl duty on it. >:(
« Last Edit: March 21, 2010, 08:36:09 PM by Bottleveg »

DRDEATH

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Re: Silencer idea
« Reply #10 on: March 21, 2010, 08:58:48 PM »
Bootleveg, I would guess in most areas that was not in major cities like LA or NY the sewer lines are small. In our area the only way they have of checking them is a very big truck that caries a very long camera. It just unwinds and takes pictures of the sewer. That is why I said if you saw someone around you might want to shut her down until there gone. The chance of any exhaust from you engine causing an explosion would be minimal campared to sewer gas, as long as it was cool or even cold when it hit the pipe you should be OK. I suppose some politic an at the city might think different. I plan my exhaust to run 20 or 30 feet under ground and the slope of our ground I will build a little place for it to exit like you would a water drain. The pipe in some places will be about 30 inches under ground. That should absorb most of the noise and with the pipe sloping down any build up should flow out of the pipe. I plan for my pipe to run under my green house to claim a little heat from the exhaust. I also plan to build a heat exchanger but that will not be until next year. I still haven't decided how I would like to make it. Mike
Breast cancer kills. It takes money to save lives.

Peter C.

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Re: Silencer idea
« Reply #11 on: March 22, 2010, 05:37:32 AM »
Silencer Box???
Please explain and a design drawing would be outstanding. I am depsperate to quite down my st3.

Combustor

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Re: Silencer idea
« Reply #12 on: March 22, 2010, 11:02:40 AM »
Hello PeterC,
                 The exhaust will not be the main source of noise from your ST3, or any highspeed aircooled diesel. A good car or truck muffler will take care of most
exhaust noise, but the whole engine radiates noise very effectively from its cooling fins, shrouds and other surfaces. This is unavoidable, and the alternative is to
screen the unit with sound reflective or absorbent surfaces while not restricting air flow. Silenced generator packs use metal panels clad inside with sound absorbent foam
and baffled air intake and outlet grilles. A stationary set can use brick, concrete, masonry panels to just above engine height to reflect sound upward. Again, air circulation
must be provided for. Lister handbooks detail the requirements plainly.  Regards,  Combustor.
Toys include- Lister CS 8/1, Lister VA SOM plant and some Aussie engines.
   "Old iron in the Outback" Kimberley, West Australia.

Peter C.

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Re: Silencer idea
« Reply #13 on: March 22, 2010, 04:24:23 PM »
Hey Combuster-
"The exhaust will not be the main source of noise from your ST3" That's for sure! But quieting that and intake noise will help a little...
Do you have a recommendation for an "off the shelf" muffler size? I don't want to restrict exhaust more than required and I also want to produce required back pressure for good operation. Short of calculating all the little holes in the stock ah, "muffler?" I haven't seen anything that will work. I can build any bracket I need so that not an issue.

Thanks!
Peter

buickanddeere

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Re: Silencer idea
« Reply #14 on: March 22, 2010, 06:41:19 PM »
Bootleveg, I would guess in most areas that was not in major cities like LA or NY the sewer lines are small. In our area the only way they have of checking them is a very big truck that caries a very long camera. It just unwinds and takes pictures of the sewer. That is why I said if you saw someone around you might want to shut her down until there gone. The chance of any exhaust from you engine causing an explosion would be minimal campared to sewer gas, as long as it was cool or even cold when it hit the pipe you should be OK. I suppose some politic an at the city might think different. I plan my exhaust to run 20 or 30 feet under ground and the slope of our ground I will build a little place for it to exit like you would a water drain. The pipe in some places will be about 30 inches under ground. That should absorb most of the noise and with the pipe sloping down any build up should flow out of the pipe. I plan for my pipe to run under my green house to claim a little heat from the exhaust. I also plan to build a heat exchanger but that will not be until next year. I still haven't decided how I would like to make it. Mike

  Going to a corrigated pipe with a larger dia keeps the back pressure down. The corrigations absorb the sound energy.