First burner... Critique?

[Light Hammer]

Hopefully the video works...

I finally fired my new burner. Can you guys critique the flame? 

Ok. Video didn't attach. Let me try another route. 

forge burner.MOV

 

Ok, it's upside down but attached lol

 

I've since added a choke to the intake though I'm not exactly sure how/when to use it. The flame will sustain up to around 20 psi then blows out. It starts "huffing" around 3-4 psi. 

[Light Hammer]

Youtube link in case the above attachment doesn't work for some:

https://youtu.be/XJ6VLs90NEU

[Mikey98118]

Light Hammer,

In the first place, that isn't a half bad flame for a burner running out in the open air. I would suggest replacing the tapered flame nozzle with a straight nozzle one size larger with a spacer between it and the mixing tube, but first, try moving your tapered nozzle back and forth on the mixing tube to see if performance changes for the better.

 

[Light Hammer]

1 hour ago, Mikey98118 said:

Light Hammer,

In the first place, that isn't a half bad flame for a burner running out in the open air. I would suggest replacing the tapered flame nozzle with a straight nozzle one size larger with a spacer between it and the mixing tube, but first, try moving your tapered nozzle back and forth on the mixing tube to see if performance changes for the better.

 

On moving the nozzle, what should I be looking for? 

As is, the burner has a .023" tapered mig tip that is set almost even with the transition from the bell reducer to the 3/4 pipe. That setting isn't adjustable as I drilled a hole through the reducer to mount the gas tube. I read Frosty's design description which indicates that the tip should, in my case, be about .412 from the 3/4 pipe (if I read it correctly). The tapered nozzle is set at 1.5" from the end of the mixing tube.

I'll try moving the nozzle tonight and see what happens. Again, what should I look for to call it a "better flame"? 

[timgunn1962]

3 hours ago, Light Hammer said:

 

I've since added a choke to the intake though I'm not exactly sure how/when to use it. The flame will sustain up to around 20 psi then blows out. It starts "huffing" around 3-4 psi. 

Try the burner in the forge, either without the choke fitted or with the choke fully open. Give it the beans and see whether or not it gets hot enough to do the hottest thing you will ever want to do with it. At the same time, check whether or not there is visible Dragons Breath (it really helps to do this in the dark).

If it gets hot enough and still has DB, great.  You then have 2 adjustments for reducing the temperature when you don't want it that hot.

Reducing the gas pressure will reduce the amount of gas/air mixture being burnt. Less gas burnt generally means a lower temperature, all else being equal. It's worth pointing out that it's not a linear relationship and the pressure varies as the square of the gas flow.

If you normally run at 10 PSI for example, doubling the flow will take 4 times the pressure: 40 PSI. Halving the flow will take one quarter the pressure: 2.5 PSI.

For many, the gas pressure is all the adjustment they need.

Reducing the choke opening will alter the flame temperature and with it the forge atmosphere. This is the bit that most of the websites I've seen do not seem to explain well.

If you still had some DB when you gave it the beans, you can be reasonably sure that you had a reducing flame even with the choke fully open. Closing down the choke will make it more reducing still. 

A reducing forge atmosphere helps to reduce scale formation. I don't think I've seem many gas forges that don't run with some DB.  Also, while adjusting the temperature so that the forge is only as hot as you can safely allow the workpiece to get may be totally unnecessary for the experienced smiths, for a beginner, being able to leave the workpiece in the forge without it suffering damage can save a great deal of frustration. 

Once the choke is adjusted to give a particular mixture, varying the gas pressure adjusts the amount of that mixture being admitted. The mixture composition tends not to vary much as the gas pressure is adjusted: the change in airflow closely follows the change in gasflow.

Where the ability to vary the mixture can really pay off is for bladesmithing. Heat-treat needs a consistent, controlled temperature and being able to bring the flame temperature down while keeping the mixture flow high can allow the temperature gradients to be minimized. To gain the full benefit needs the forge to be designed with this in mind. 

For most non-forge applications, the air:fuel ratio tends to be a set-and-forget thing and is usually done by tuning the gas jet size, perhaps followed by fine-tuning the gas jet position.

If you have no DB at your initial run, you probably need to try a bigger gas jet. If you have DB but cannot get the temperature as high as you need it, you should try a slightly smaller gas jet.

 

 

 

[Mikey98118]

Light Hammer,

Adjusting the flame nozzle position affects the flame; making it harder and softer; the more overhang the softer and visa versa. A tapered nozzle's position will affect the flame much less than a straight nozzle with spacer ring, BUT, not every burner develops sufficient mixture speed to support this second nozzle design. Therefore, first see if you can get the result you seek with the tapered nozzle. Your reducer is sufficiently large, but you would also need a MIG tip in your gas pipe; not a side hole. to support the nozzle.

As has been stated elsewhere, the minimum performance you need is a neutral flame, which is recognized primarily by flame color; a light blue flame without the slightest tinge of green in it. You can self-teach what that means by using your choke while watching the flame.

After you get that done, your next goal is to see how much you can reduce the secondary flame envelope; 'nough said for now.