3D printed plastic burner experiments (photo heavy)

[D.Rotblatt]

On 10/15/2019 at 9:28 AM, Frosty said:

It acts in the same manner as a flare by increasing the area of the cross section in the mixing tube. Lengthening it increases the length of the flare and lowers pressure in the tube. This increases how much combustion air is drawn leaning the flame down.

That sounds reasonable.  Yes, it's a step nozzle (3/4" black pipe into 1" schedule 40 pipe).  Basically what you are saying is it acts as a wasp waist?  Increase in diameter is lessening pressure thus draws more air.  Though I thought the burner was running from lean to rich (it has a choke), this may have allowed it to go richer at it's "sweet spot" increasing flame temp.  I'll take a look when I get to play with it.  Thanks for the input Frosty!

On 10/15/2019 at 7:06 PM, Mikey98118 said:

So, I'm not saying anything about your method, just reminding us all--including me--not to overlook the obvious again

I got it, thanks!  Basically, since it's out of our range to measure forge temps, the best we can do is surmise changes in flame temps from the forge temp by keeping other variables constant.  In my case, the burner has a choke, so the constant was the gas pressure/jet size, while I was changing mixture via choke to get hottest forge temp.  Then I moved the burner out (adding another variable) and pow - temps skyrocketed.  

In the 60's a psychological scientist working with rats in mazes discovered that the rats where following their own scents to get through the maze...thus invalidating decades of psychological research preceding him (or her).  By changing the flare length on the burner, I just realized I've invalidated all my burner tests up to this point....  I really didn't pay any attention to how deep the burner was into the flare.

DanR

[Frosty]

19 hours ago, D.Rotblatt said:

Basically what you are saying is it acts as a wasp waist?  Increase in diameter is lessening pressure thus draws more air. 

No. Wasp waste is a venturi, a decrease in diameter followed by a widened one. I meant to say your sleeve mount is an adjustable "step" flare as described by Mike, where the thread protector I put on Ts is a fixed step flare. The effect on induction is as you describe for said reason, just not a wasp waste. 

I've never owned nor had the use of a pyro so if I'm curious beyond perceived color I put a 1" cube of cold steel in the forge and time it till color equalizes. I found using long bars wasn't consistent as different parts of the bar were in different temp zones. However in a ribbon burner forge this may not be an issue.

Frosty The Lucky.

[D.Rotblatt]

On 10/17/2019 at 6:07 PM, Frosty said:

No. Wasp waste is a venturi, a decrease in diameter followed by a widened one.

I was kind of thinking of the reducer as the decrease in diameter, and the flare as the increase in diameter...it just has a long straight tube in-between.  So no, not a wasp waist, but the same principle?  The furthest the burner goes in is pretty much the depth of the flare, so I was going from no flare to a couple inches of flare.

I like you solution to no pyro. The pyro has it's issues as well - placement in the forge is the main one.  When working where temps are critical (like heat treating) I use the color of the pyro as a known temperature to gauge the ballpark of where the metal is.  It's always different.  

DanR

[Frosty]

Yeah, I don't see a resemblance with wasp wasted in a reducer to a straight pipe to a flare sequence, dragon fly body maybe. I think of generally hour glass shape when I hear wasp wasted. I THINK that's generally true for most folk though maybe not.

You are right that increasing diameter in the direction of flow reduces pressure and velocity increasing induction. I just have trouble calling the flare on the end of a burner outlet making it wasp wasted. Yeah, it's that long straight mixing tube screwing up the picture. I think it's confusing and names should clarify where possible.

Frosty The Lucky.

[D.Rotblatt]

1 hour ago, Frosty said:

I think it's confusing and names should clarify where possible.

I agree, and as usual you are right: precise nomenclature is very important.  I think what I should have said is: "Basically what you are saying is that the principle behind what's going on is parallel to that in a wasp waisted venturi?"  This would have been clarified in moments if we were actually talking to each other in like....the real world!  The internet is a great clearing house for ideas and confusion 

DanR

[Another FrankenBurner]

On 10/13/2019 at 11:44 PM, pnut said:

So it's more a matter of justifying the expense and finding time.

I understand.  If you are looking to justify the build, one thing I can say is about the time savings.  I like both solid fuel and gas forges.  In terms of not having much time but wanting to smite some steel, the gas forge is a time saver.  I can forge more often because of the simplicity and ease of the gas forge.  It's an unfair comparison but liken it to cooking dinner over a camp fire vs a gas stove.  No time spent building or managing the fire, no clinkers, no shoveling fuel, no smoke.  Light it, let it preheat, do your work, shut it down.  I have done it several times in one day.

On 10/14/2019 at 9:29 AM, D.Rotblatt said:

Latest cast burner.  Works great.

And it looks good.  Nice job.  

As to the step flare talk, I like the term nozzle which I think I picked up from Mike's book.  Flare makes me picture an expanding taper on the end of a cylinder.  Like bell bottoms, the flare with flair.  Now we have 3D printer nozzles to add to the confusion.  

I suspect you are tinkering with plenum pressure.  The definition of Venturi effect that I find most often is a decrease in fluid pressure as a result of passing through a constricted section.  This would apply to any burner using a reducer as the inlet and it is part of why so many use a reducer.  The outlet taper from the throat of a Venturi tube is for the opposite effect, pressure recovery.  Converge to drop pressure and diverge to recover as much as possible.  This is where the 1:12 angle comes from, it is the fastest expansion possible that does not cause turbulence which would hinder this recovery.  While you are stepping, which is a faster expansion, it is still better than the huge immediate expansion at the plenum.  More plenum pressure, more push, more induction.  Leaning out the flames a bit.

This is what I suspect but I could easily see the opposite being true instead.  Your flames being too lean, you increase nozzle length, which increases drag and decreases induction.  

Either way, as Frosty stated, it is a final tuning by making small changes to the fuel/air ratio.  One reason Mikey controls the overhang on his sliding stepped nozzles.

[Mikey98118]

Yes; I called them nozzles in the book. It was short for flame retention nozzle, which I make sure to write out completely at least once be before going back to using the shortened "nozzle" term whenever writing on the subject these days, after realizing that others didn't get the fact that I meant to refer to flame retention nozzles every time

[D.Rotblatt]

1 hour ago, Another FrankenBurner said:

And it looks good.  Nice job

Thanks!  It's pretty  much as cast with about 15 minutes cleanup - cast really clean.  I was pleased!

1 hour ago, Another FrankenBurner said:

I suspect you are tinkering with plenum pressure.

I don't know if the pressure in the plenum is comparable to venturi theory.  The gas is flowing into a box rather then a larger tube, so you have weird turbulence issues, a right angle turn, back pressure from the number of outgoing holes...so many variables.  I played today and did notice that the flame is leaning out a bit as I pull out the burner tube/lengthen the nozzle.  Also sounds like it's pulling more air.  The pitch of the air flow also changes, but that's just like pulling the tube on a trumpet.  It may be more sensitive to nozzle length being that it's flowing into a box rather then into the open air or a forge.  Either way, it works.  No way to play with it more without cutting up my NARB, and thats now my go-to burner, so I may have to make a new one that has a larger opening on it that can take different sized tubes.

DanR

[pnut]

1 hour ago, Another FrankenBurner said:

No time spent building or managing the fire, no clinkers, no shoveling fuel, no smoke.  Light it, let it preheat, do your work, shut it down.  I have done it several times in one day.

Very compelling argument. 

 How do you think the forge would hold up outside covered by a plastic tote or box of some sort when not in use. I'm in northern KY so it snows, rains, and gets hot. Sometimes all in the same week

Pnut

Edited October 20, 2019 by pnut

[Mikey98118]

That will fine, so long as you remember to warm up the forge slowly to drain any build up of moisture in the refractory, before using the forge.

[pnut]

I'm running out of  excuses it seems.I only have tofind the cash now. It's not at the top of the list though. I just bought a Buffalo blower and had it shipped without the stand so I have to come up with the money to get the stand and pedestal shipped. It weighs more than the blower which was 41 pounds. By next spring I expect to have a gas forge built.... Until then I bask in the warmth of solid fuel.

Pnut

I had no idea a blower and stand weighs about a hundred pounds.

[Another FrankenBurner]

8 hours ago, Mikey98118 said:

It was short for flame retention nozzle

When I write the term nozzle, your "flame retention nozzle" is implied.  At least in my head, which others don't have access to.  I suppose I should write it out in full as well so that there is less possibility for confusion.

8 hours ago, D.Rotblatt said:

I don't know if the pressure in the plenum is comparable to venturi theory.

I was more so meaning that the connecting tube which you are sliding the burner in and out of is responsible for the pressure changes.  I am with you on the plenum being it's own monster as far as variables and what is happening to the stream once it exits the connecting tube into the plenum.  I have a mental picture of what may be happening in there but it is speculation at best.

8 hours ago, D.Rotblatt said:

It may be more sensitive to nozzle length being that it's flowing into a box rather then into the open air or a forge.

It doesn't sound like it.  My burners can go from lean to rich by changing the nozzle overhang alone.  I am not sure if it is changing induction dramatically or if the fuel/air ratio has a small range of happy.

8 hours ago, D.Rotblatt said:

so I may have to make a new one that has a larger opening on it that can take different sized tubes.

More speculation, I wonder if you made dramatic changes here, if the burner wouldn't like it.  To the point that you may need to increase/decrease the quantity of ports.  Mikey's stepped flame retention nozzles are stepped to make a more dramatic expansion to slow down his high velocity FAM stream.  To put on the brakes as he puts it.  Your port quantity is balanced to your stream velocity and volume.  If you slow it down too much, maybe you get to flashback territory.  I am not sure how picky the NARB's are with this.  Especially yours since it seems to be below the quench distance.  I should probably get off my butt and start playing with ribbon burners a bit deeper.

9 hours ago, pnut said:

How do you think the forge would hold up outside covered by a plastic tote or box of some sort when not in use.

I once had my forge directly rained on for quite a while, which upset me greatly.  I started it in bypass flame for a nice low heat.  After the steam stopped billowing out and the forge got to a low red, I turned up the heat and all was good.  

Somewhere I read that the refractory is hygroscopic.  If this is true, you heat the forge regularly which keeps it bone dry and when you shut it off, it absorbs moisture from it's surroundings.  I have no idea if it's true but I start my forge with full heat and have not had any problems.  If my forge has been off for weeks, I give it a few minutes in bypass before I kick on full heat.  Not sure if it is needed but it only costs me a few minutes.

[D.Rotblatt]

54 minutes ago, Another FrankenBurner said:

More speculation, I wonder if you made dramatic changes here, if the burner wouldn't like it.

Its true, too many variables.  It's a pretty forgiving burner, but I may have just gotten lucky on the first try.  I was just blown away that moving the burner tube 2" increased the temp 100F...Now I'm just thinking, "What if I just...."  I'm just chasin' that rabbit down his hole, I do need to actually use the darn things and make a few knives!  ...or a sword...or a seax.....hmmmmm.....

DanR

[Another FrankenBurner]

Yeah, I too am guilty of spending too much time on burners/forges and too little on the fruits of that labor.

[Mikey98118]

Too lmuch time spent? We will pass; our improvements remain in the world. Too much time? I don't think so.

[Another FrankenBurner]

I should have stated that differently.  What I meant was that I am guilty of not balancing my time well.  I fully intend on spending much more time on burners.  I just have to fit forging in.  For me, forging is therapeutic.  If I start to get grouchy and life seems to not make sense, I need time at the anvil.  Then all is well again.  At least it's a manly binky.  

[Frosty]

On 10/19/2019 at 5:49 PM, D.Rotblatt said:

"Basically what you are saying is that the principle behind what's going on is parallel to that in a wasp waisted venturi?"  This would have been clarified in moments if we were actually talking to each other in like....the real world!  The internet is a great clearing house for ideas and confusion 

Exactly, the flared end functions the same as the expanding section of a wasp waste Venturi inducer. Oh yeah, face to face wouldn't be an issue, at worst a piece of scrap paper and a crayon. Face to face is much more information dense, we communicate with our whole body in person. I was blessed with outstanding reading comprehension and I miss the obvious regularly, it's one reason I push for a unified jargon so regularly. 

 

On 10/19/2019 at 9:30 PM, Mikey98118 said:

It was short for flame retention nozzle,

Ah yes. I think we talked about the accuracy of the term once. Holding the flame at the end of the burner is a secondary effect though desirable. It's primary is to increase induction, lowering flame velocity is secondary. If I recall correctly we decided to stop talking about it do to the confusion we were sowing.  Most folk just want something that'll work well, as good as we can make is for a different crowd and they can email us on the side. 

 

On 10/19/2019 at 9:38 PM, D.Rotblatt said:

I don't know if the pressure in the plenum is comparable to venturi theory.

Nope, a gun burner multiple outlet burner all to often is run at way too high pressure. Watch some of the videos of ribbon burner forges with 3-4' FEET! of dragon's breath. I balanced the static pressure developed by the NA,  T inducer with the available outlets to keep the velocity in the outlets high enough they don't burn back but low enough individual flames aren't any longer than possible. 

The transition from the mixing tube to the plenum is a significant increase in room for flow so pressure doesn't increase. The impact with the opposite side of the plenum doesn't seem to effect things until it back fires. THEN the increase in volume caused by combustion shoots flames as much as 6" out the intake ports in the T. 

Back pressure from placing a burner nozzle too close to an opposing wall in the forge IS an issue because there is an ongoing explosion in a relatively confined space. Yes, the space between nozzle and opposing wall is relatively confined. We to feed this air fuel mixture through the right shape combustion chamber and nozzle we'd have a jet engine. Yes?

17 hours ago, Another FrankenBurner said:

At least it's a manly binky.

Oh so well said! Just think, your anvil says it's name every time you strike, "Bink, bink, bink! I'm with you, time at the anvil is very therapeutic for me as well, it's very meditative. I think the common belief that we get out aggression out at the anvil is mistaken. You can't do good work if you're angry, you can beat the gravy out of things but not accomplish much.

Blacksmithing requires control over strength and you can't control anything else if you can't control yourself. Everything about time at the anvil is about control, you can't build a working fire if you don't do it right, it takes personal control. If you aren't paying attention you burn your iron or try to forge it too cold. Fire management is nothing BUT control. While striking iron on the anvil our brains are processing information from every part of our body and making microscopic adjustments to our swing, placement, hammer angle, etc. in microseconds. 

It's control on all levels, from how we hold our feet to planning our next step.

Hmmm?

Making tools is as addictive as using them and in many ways as or more therapeutic. It's why I miss a good 2D cad program so much, I see the things I draw and take little mental journeys with them to find and correct or tweak things. 

One of the few things that is as good as doing is teaching next down the list is brainstorming and scab picking with a like minded bunch of folks. 

Frosty The Lucky.

[D.Rotblatt]

5 hours ago, Frosty said:

It's primary is to increase induction, lowering flame velocity is secondary.

I think that has gotten lost over time, at least for me.  I'll put it in the variable toolbox! (toolbox of variables?...sigh...I'll just remember it.)

5 hours ago, Frosty said:

It's control on all levels, from how we hold our feet to planning our next step.

Well said!  It's being in a world of our own making; no disturbances, just figuring out where we want to go, and how to get there.  It is complete control over ourselves and our environment...except when I can't find what I just put down....

DanR

[Another FrankenBurner]

I definitely agree with not bringing anger to the anvil.  This was one of my early on learnings, right in there with tapers.  Meditation is a great word to describe it.  Finding Zen with hammer in hand.

Now every strike I am going to hear it.  Bink, Bink, Bink.  

Making tools is addictive.  I always made tools before I found forging but forging gave me more reasons to make more, more tools to make more tools and a deeper understanding of all the tools I already owned.  Got an idea, figure out what tools you need to make it happen, make the tools and make it happen.  It is rewarding and fulfilling.  

The tools make the craftsman but the blacksmith makes the tools.  I don't remember where I read that one.  Probably on IFI somewhere.

 

[Mikey98118]

A craftsman's reach will not exceed his tools.

[pnut]

Most tools outreach the craftsman.

Pnut

On 10/21/2019 at 3:44 PM, Frosty said:

One of the few things that is as good as doing is teaching

Teaching surpasses doing in some respects. When teaching you have to explain the why and not just the how, which has always lead me to be more thoughtful about what I'm trying to teach and gives me a deeper understanding of the subject. Sometimes doing is nearly automatic. While teaching you have to explain why you're doing what you're doing. 

Pnut

[Frosty]

Ayup, you learn often more than the student. 

I don't know Mike, I think you have that backwards. Except in narrow definition I haven't seen many tools the human can't out perform. We may be thinking different definitions of "reach," I think of "reach" as a level of "desire" in this context. Different context?

Frosty The Lucky.

[pnut]

56 minutes ago, Frosty said:

We may be thinking different definitions of "reach," I think of "reach" as a level of "desire" in this context. Different context?

Frosty The Lucky.

Yep, I think I could have said it better,most craftsmen can't use their tools to the tools full potential. I know I sure can't. I'm not skillful enough to use my best air rifle to it's full capabilities. At 10m it's capable of putting ten shots through a hole barely larger than a pellet. I can't use it at that level but it is capable of doing it. 

How's this, " Most craftsmen never let their tools reach their full potential."  Someone with more skill could make beautiful things with lesser tools easier than someone with lesser skills could make beautiful things with better tools. 

Pnut

 

 

[Frosty]

You said it fine pnut, I was looking for clarification with Mike. 

I don't think anybody can use almost any tool to it's full potential, for example a hammer. On the other hand when we find something our current tool list doesn't cover we make new ones till we find one that does. Often the early attempts that don't cut it turn out to be perfect for something else. I have a couple buckets of, "wonder what I can do with THAT" tools, they gotta be good for something, I put WAY too much work into them to toss. 

Of course if a person who passes hovers around in the afterlife keeping an eye on their survivors I want to watch folk at the estate sale trying to figure things out. Heck I'm sure they'll think of something. 

I have a 5mm Sheridan pellet rifle, not the one I grew up with, that one is somewhere in the boxes of stuff in my parent's garage. Anyway, I shot it so much I could make some pretty long shots and tight groups. I darn near shot the lands out of the barrel though, a 500 pellet can didn't last long. 

Frosty The Lucky.

[pnut]

My name is also Mike, hence the confusion.

Pnut