Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: kiwimodeller on July 17, 2016, 06:31:24 am
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Has anybody come up with a way to stop boilers making "moaning" noise when operating? Several of my boats do it, differing from a low moan to a high pitched whistle. Some of the boilers are home made but a couple are commercially made ones. Adjusting the gas jet does make some difference but it also reduces temperature as the spot that gives the hottest flue temperature also seems to give the loudest noise. Coincidentally while measuring gas temperature today I ran one of the loudest boiler without its funnel and it was much better so obviously funnel length makes a difference but I cant run without it or I will set fire too the suoerstucture. Any suggestions? Thanks, Ian.
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Bonjour Ian,
I fully understand what you mean, listen to the boiler Saito of the Rohinet launch : https://www.youtube.com/watch?v=UFI7QyIkM50
My friend Didier partially solved the problem by pulling back the torch of the boiler.
I also have the problem on several of my boilers, I did not find a solution but noticed the sound decreases after a while when the boiler is hoter.
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clevedon steam make a burner that is gauze, rather than the usual ceramic. they claim it is more efficient, and eliminates the howl in chedder locomotives. if your boilers have the same flue size, (28mm) you could try one.
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I have two of the Clevedon burners and one is in a boat but I cant remember whether that boat is noisey or quiet. Will take it out for a test next weekend weather permitting. It certainly seems to run hotter and more efficiently than the original Cheddar ceramic burner. Cheers, Ian.
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I'm using a Clevedon burner which works very well but starts to howl at 20psi input with a No 5 jet. Once the pressure falls slightly the howl disappears.
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The smaller the jet the greater is the velocity for the same tank pressure.
So if you are using a No 5 jet try a No 8.
I have a ceramic burner in my Vertical test boiler and with a No 3 Jet is screams but it's O.K. with a No 8 jet.
Hope this helps.
George.
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Thanks for that, I did some tests today and the Clevedon burners are among those that make a noise but the sound from each is quite different in the two different boilers. The thermometer also tells me that when the noise is loudest almost always coincides with when the exhaust temp at the top of the funnel is highest. I do have one boiler from ACS which seems to run quietly and the one small vertical boiler I have is the noisiest. I will be ordering some spares soon so I will get some more jets to play with. Cheers, Ian.
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That howling noise is a resonance in the tube system formed by the flue and funnel which depends on the overall length of the system. Besides moving the burner, another cure can be shortening or lengthening the funnel. Try to pull it out a 1-2 cm if it allows and see if it makes a difference.