# Misting Nozzle Gas Jet Experiment



## Steve Shyvers (Jan 2, 2008)

After reading about using a misting nozzle as a Ruby gas jet in this forum a few weeks ago, I ordered two 0.006" orifice nozzles online from Inyo Pools, and received them by US mail within a few days. This weekend I got the time to fabricate a jet holder for my Ruby that was threaded to match the misting nozzle (10-24). I made the holder so that the face of the nozzle would be at the same position within the burner asembly as the stock jet was. I also added a 2-56 set screw to the burner assembly to hold the new jet holder in place, because I used a short length of silicone tubing to connect the jet holder to the Ruby gas tank instead of a rigid length of copper tubing as on the stock setup. The set screw also will allow me to position the jet fore and aft to see how the flame characteristics might change. This afternoon I tested the new jet in the Ruby.

Well, the fire certainly is controllable now, but there doesn't seem to be enough of it! Even with the gas valve wide open there wasn't enough flame to raise a decent amount of steam. The fire was controllable, and lit straight off, so I don't believe that the jet is clogged. The needle on the gauge barely rose throughout the "run".
The Ruby did crawl along for a while pulling two heavy cars, however, but its heart wasn't in it.

Can't blame the outside temperature, it was an the mid 60's, mild and sunny. With the stock jet the Ruby would have had no trouble pulling those two heavy cars with vigor, and typically the safety would have been blowing off unless the gas valve had been critically adjusted just so. One thing I did note was that the silicone gas tubing is a good thermal insulator, and the stock Ruby copper tubing gas line would have conducted heat back to the gas tank thereby increasing the gas pressure. I did check the gas tank by touch today, and it was at least warm and not cold.

Today there was time for only one trial. Next time I'll swap between the stock Ruby jet and the misting nozzle to get a comparison. I'll also monkey with the jet fore and aft position and note any changes to flame characteristics and burner sound.

Steve Shyvers


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## HeliconSteamer (Jan 2, 2008)

Sounds interesting, Steve.


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## xo18thfa (Jan 2, 2008)

What are the nozzles made from Steve?


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## Steve Shyvers (Jan 2, 2008)

Bob, 

The nozzle body is brass, and the orifice is in the center of a stainless steel insert. If you look at the Inyo Pools website you can find a picture of one. They are available in several orifice sizes. Link: http://www.inyopools.com/Products/17800022044299.htm 

The nozzle OD is 3/8", which has to be turned down to fit into the Ruby burner assembly. This means the knurled portion gets removed. However gas pliers and a strip of leather to protect the nozzle finish will serve to tighten/loosen the modified nozzle in the jet holder. 

I have two Ruby nozzles from two Ruby kits. I plan to set up the two Ruby nozzles and one of the misting nozzles side-by-side under some magnification to see how they compare. 

Steve


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## Totalwrecker (Feb 26, 2009)

Most hardware stores carry these nozzles. I know Ace and HD do, but at HD they are 'seasonal', out here they are used as summer cooling misters. You can usually find them year round at Ace. 

I did have the screw thread break off one recently.... just from water pressure. 

John


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## Steve Shyvers (Jan 2, 2008)

John, 

Thanks for the tip regarding retail sources for these things. I suspect that the demand is less out here in the San Francisco Bay Area, but I'll check around HD, Ace and Lowes since summer is coming. 

Steve


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## xo18thfa (Jan 2, 2008)

I did not know the holes in those misters were so small. This is definitely going in the old shop notebook.


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## Phippsburg Eric (Jan 10, 2008)

Does this work? 

I thought the burner needed a "jet" or stream of gas through the venturi to pump in (and mix with) the right amount of air for proper burning. does the atomizer do this? does it work with the stock burner?


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## Steve Shyvers (Jan 2, 2008)

Eric, 

My experiment with the 0.006" orifice misting nozzle was with the stock Ruby burner. The misting nozzle does have a "diffuser" (forget if that's the correct term) behind the orifice. Since the misting nozzle is intended to be used with liquids, the "diffuser" probably impedes the liquid flow and creates turbulence behind the orifice so that the misting nozzle produces a diffuse spray instead of a fine stream. When used as a gas jet, however, the "diffuser" may have a minimal or no effect because the gas density is a lot less than the density of a liquid. I encourage anyone else to share more info and explain what's really going on. 

Whatever was the shape of the butane gas stream out of the misting nozzle it had no problems mixing with enough air from the stock burner air ports. The flame was easy to light, was colored blue, and stayed on the burner. 

I really need to try a couple of more nozzle orifice sizes, but haven't gotten around to looking for some locally. Internet searches found other suppliers, but most were either distributors (i.e. not retail) or the nozzles were plastic. I have a hunch that when I do find some locally that are sold for home use they're going to be plastic and unsuitable for this application. 

Steve


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## Phippsburg Eric (Jan 10, 2008)

I guess that makes sense! 

I often think the standard orifices make too strong a jet...thus the flames tend to fly off the burner or just work at the end. something to "slow" the gas jet down makes sense. 

On my Frank S i made a new "poker" burner using the stock orifice...at the far end of the burner I inserted a christmastree like device which slows and defuses the stream of air/gas so that it burns (more) evenly at each of the slots. 

the screen on the misting nozzle probably does the same thing...better?


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## Brooks (Jan 2, 2008)

Steve - I'd remove the diffuser behind the orifice. You don't want a diffuse, low pressure jet because that will not entrain oxygen well. For example, I clean my jets (backblast of gas, never a wire) when the fire is not hot enough, or has other problems. Rarely do I see the dirt, and never do I see the orifice plugged. The problem caused by the "invisible" dirt is that it destroys the column of gas that should be issuing out at a good clip. It's like putting your thumb over the hose: you don't stop the water, but it sprays out asymmetrically. I suspect the diffuser is doing the same, namely destroying the zippy column of gas that you need to shoot out the orifice. 

Phippsburg - yes slowing the mixed air and gas after mixing will help. But not before mixing. I stuff a twist of wire into the poker, probably similar in effect to your Christmas tree device. Slowing the gas mixture converts it's velocity into pressure. The first slots in the poker don't produce their fair share of flame because of Bernoulli - fast gas has low pressure. By slowing the fast gas mixture, we increase it's pressure (conservation of energy), and now all slots get a shot at the mixture.


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## Phippsburg Eric (Jan 10, 2008)

Those were my thoughts too


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## Steve Shyvers (Jan 2, 2008)

Brooks, 

I was all wet about the "diffuser". My error. There is none. Last night I got a good look into the back of the nozzle and what I thought was a solid piece actually had a tiny hole in the center that I could only see with a jewelers loupe. I missed seeing the tiny hole before (long-term bifocals wearer) and jumped to the wrong conclusion. The hole looks even smaller than the hole in the front of the nozzle so I don't know if it's partially obstructed or an illusion because of my eyesight limitations. Whatever, I still plan to try a couple of other sizes. 

I apologize for the "diffuser" confusion, and hope it doesn't put anyone off trying one of these things. 

Steve


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## Brooks (Jan 2, 2008)

No problem, Steve. I was going to look for the part locally, after reading your results. Thanks for making the experiment, and figuring out how to make the new nozzle work. It needs tuning, certainly, but I think you'll work it out.

Regarding the 2 orifices: I wonder if the pair causes a problem with generating enough heat. The original purpose of the new nozzle was to produce mist. Breaking up the water flow twice may be necessary to achieve this. But you'd not want to slow the gas mixture until it enters the poker. Maybe you could measure the the 2 holes, figure out which one most closely approximates the desired diameter, and then drill out the other. If it goes blooey, you're out the $5 cost plus postage, so probably want to wait before grabbing the drill, I realize.


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