Help! Ruby vs Edrig burner information and Edrig jet size.

[brianthesnail96]

<p>Hi again all, does anyone know if a stock Ruby burner is the same as an Edrig's? Found some useful articles on MLS (heading in a slightly different direction, but on similar lines- they suggest that the flow through a standard burner is too fast, but deal with it by reducing the jet size and also partially blocking the air holes on the burner- however this should have broadly the same effect as fitting a holed burner I believe. Also I'm not sure reducing the air side of the mixture is a great way to achieve higher efficiency personally!) that are Ruby related and I'd like to know if I can use the information directly or rescale to suit. </p><p>Also (more importantly in fact) what size the standard Accucraft gas jet as found in an Edrig please?</p><p>Cheers folks
</p>

 

[Doug]

Have you been in contact with Mr Pearse? I'm sure he would be interested to hear about your experiments.

 

[brianthesnail96]

No I haven't (I see his name works now though!) although I probably should be.

Thus far we've worked out it's all down to primary air/ fuel air mix flow- there's too much primary air for the free flowing burner design which is what causes it to lift off- the exit velocity of the mixture from the burner is faster than the flame can propagate which is why instead of sitting on the burner it ends up in the smokebox. On MLS they've cured it with a combination of a bunsen burner style valve sleeve over the primary air holes on the jet holder and a meshed burner. But I think the MLW burner has the same effect, but by slowing the mixture flow leaving the burner. This should actually be more efficient I think. I'm worried that by reducing the air in too much it'll make it less efficient when the gas it turned up (loco on a heavy train) or when it's cold- it'll start acting like a bunsen with the valve half shut off ("liquid flame" IIRC from my school days) but I'm going to try an adjustable sleeve anyway- it should be easy enough to do and gives me another option to test without having much more work to do! The holed burner should slow down the exit speed and hence reduce the flame lifting effect without the bunsen burner effect at higher gas regulator openings. I'll be trying both together to see what happens- it might be that Accucraft can improve performance with simply reducing the size of the primary air inlet holes by the jet a bit.

Yes, I am just thinking aloud here and yes, I am hoping you lot will tell me if this makes sense or if I'm totally barking- it's based on a combination of David's assumption that the holed burner reduces the through flow rate, MLS forum articles regarding the throttling of the primary air, and a few US patents and journals on similar matters in industry, obviously on a larger scale.

 

[Ferrysteam]

Just turn the gas down!..

 

[brianthesnail96]

Shh! Still doesn't work as well as it should. A roaring burner is a sign of the flame lifting, which they do tend to do regardless of how low the gas is turned down. That's inefficient whichever way you look at it. Also, "turn the gas down" is unlikely to get me many marks

 

[New Haven Neil]

They don't boil enough water when turned right down......the L&L runs heavy trains....

 

[brianthesnail96]

There probably is an optimum where you can make sufficient steam for a heavy train without "lifting" but I've yet to find it.

The challenge is to have a burner which will function well and efficiently for both those who run 2 coach trains on a flat circuit, and for Neil too- ideally without having to adjust anything bar the gas regulator. I think the MLW burner is more effective at this than the MLS idea as it throttles the outlet mix not the primary air inlet. Restricting the inlet will mess up the fuel/ air mix when working hard- you'll end up with less primary air than desired.

I think.

No idea how I'm going to calculate this... hopefully I can merely use discussion with example calculations as opposed to having to do an accurate theoretical analysis 'cos I'm not that smart...

 

[johnsaintjim]

<p>Isn't the lifting due to the draught ripping the flame off the burner as it's at 90 degrees to the flame?</p><p>Remote control of the gas valve is a doddle and it means you can have more steam when you need it on the up gradients and not waste as much gas on the down.</p><p>I'm with you on the heavy trains Neil </p><p>PS She's coasting down past Bluebell Wood here, gas right down and regulator nearly shut too.</p>

 

[Doug]

Regarding the primary air inlet (the holes eotherside of the jet), i assume that they are that big to allow enough air for when the burner is turned right up, but then wouldn't they allow too much air when the burner is turned down? Maybe they don't have that much effect (ie supply an 'inifinite' supply of air) as the change in the supply of gas has a much bigger effect. (Hence the flame front leaving the burner face due to the change is gas velocity). Maybe you also need to look at the effect of the gas jet has on sucking air in through the primary air slots.

Also is the accucraft/roundhouse design a 'balanced flue' design so external effects are minimised?

 

[brianthesnail96]

No idea Doug.
Yes I assume they are that big to allow enough primary air for operating at full chat. Which is why I'm not particuarly keen on the idea of restricting them, and instead restricting the outlet, i.e. the Milton burner.

Graham, that was my first thought but according to this link http://www.patentstorm.us/patents/5104311/description.html it's a result of too much (or too high a velocity of) primary air, which I suppose makes some sort of sense- if the fuel/ primary mix is leaving the burner faster than the flame can grow back towards the burner then the flame will lift? But I think too much draught would have the same effect- however there isn't one really other than what is created by the burner itself affecting the secondary airflow- there's no draught created by the exhaust for example. If it had a sealed smokebox and a proper blastpipe as on a coal fired loco then I think that would be the case.

 

[Ferrysteam]

<p>

New Haven Neil - 23/11/2009 11:47 AM They don't boil enough water when turned right down......the L&L runs heavy trains....

</p><p>My Wrekin was blowing off all the time when she was steaming at Annieshalt and you couldn't hear the burner!</p>

 

[brianthesnail96]

Maybe yours is a good 'un... What sort of a load did it have behind it? I think that's a fairly flat raised line also?

 

[Ferrysteam]

<p>

brianthesnail96 - 23/11/2009 4:40 PM Maybe yours is a good 'un... What sort of a load did it have behind it? I think that's a fairly flat raised line also?

</p><p>About 8 axles I think (mixed).It is a bit up and downy though with tight curves.</p>

 

[New Haven Neil]

I think it must be an exceptional one, Allan - I've had many Accu locos run here, Lawley, Wrekin, Caradoc, Edrig etc, and they all scare the birds away......the quietest in my fleet by far is the Roundhouse Jack.

Despite much fiddling my Mortimer is still pretty noisy in comparison if set to keep sufficient steam while running continuously with those big trains and coping with a couple of 1 in 40's. It's very powerful though, and chuffs beautifully with the summerlands pipe.

 

[Ferrysteam]

<p>

New Haven Neil - 23/11/2009 4:48 PM I think it must be an exceptional one, Allan - I've had many Accu locos run here, Lawley, Wrekin, Caradoc, Edrig etc, and they all scare the birds away......the quietest in my fleet by far is the Roundhouse Jack. Despite much fiddling my Mortimer is still pretty noisy in comparison if set to keep sufficient steam while running continuously with those big trains and coping with a couple of 1 in 40's. It's very powerful though, and chuffs beautifully with the summerlands pipe.

</p><p>Well Neil,I've got six Accucraft and don't turn the heat up on any of them.All still have shiny smokebox doors.</p>

 

[New Haven Neil]

So does mine Allan, but it's noisy in comparison! Bradypus's Accu's with meshed burners are pretty good in terms of noise and steaming, but for some reason I can't get the identical mesh to work on my loco - more research needed.

 

[Ferrysteam]

<p>

New Haven Neil - 23/11/2009 4:58 PM So does mine Allan, but it's noisy in comparison! Bradypus's Accu's with meshed burners are pretty good in terms of noise and steaming, but for some reason I can't get the identical mesh to work on my loco - more research needed.

</p><p>Tried the mesh,took them off again,they didn't seem to make any difference:thumbdown: </p>

 

[Ferrysteam]

Like the picture of Mortimer Neil,a lovely engine.

 

[brianthesnail96]

Made a big difference with my Caradoc. My Edrig doesn't seem too bad as is, haven't fitted mesh yet. Annoying almost- would have made my life easier if it had been a bad one! It's fairly noisy though- far noisier than it should be. And no, I run it with the gas turned down fairly low, in fact I think when I ran it at Tag's the only time the safety valve lifted was when it was stationary for a while.

I'm sure I can do better!

 

[Ferrysteam]

<p>

brianthesnail96 - 23/11/2009 5:06 PM Made a big difference with my Caradoc. My Edrig doesn't seem too bad as is, haven't fitted mesh yet. Annoying almost- would have made my life easier if it had been a bad one! It's fairly noisy though- far noisier than it should be. And no, I run it with the gas turned down fairly low, in fact I think when I ran it at Tag's the only time the safety valve lifted was when it was stationary for a while. I'm sure I can do better!

</p><p>Mind you Matthew,my Edrig kept running out of breath and never blew off until I adjusted the valve settings.</p>