Burners 101

[Mikey98118]

I stumbled across SSTs for use with fan-induced vortex burners, but they work just fine for plain old vanilla linear burners too.

Not that I want to encourage people do do things the easy way--as a rule--but we all slip up and lower our standards once in a while

[Mikey98118]

As to "juicing up a T burner..." "If it aint broke, don't fix it."

[Another FrankenBurner]

I hear Tim Allen grunting again. 

[The Jeff]

Frosty and Tim Allen are now the same person in my mind

[Mikey98118]

Remember the Home Improvement episode, where Tim 'souped up' his garbage disposal? I worked with a few guys like that over the years

[The Jeff]

I do vaguely remeber that one. 

I work in a local hardware store and we sell Stihl products, well there are some lumber jack shows in town that use Stihl. So we get people in here wanting the biggest saw we have occasionally. The "soup it up" remionded me of that.

 

[Mikey98118]

I was NEVER that young; never! That's my story, and I'm stickin to it...

[The Jeff]

This may be obvious or just a stupid question but Im ignorant enough to not really know what I am asking, but since we are talking about souping things up would a 2" tee burner be feasible? 

[Frosty]

I'm shocked you'd get the classic old blacksmith saying, "If it ain't broke fix it till it is," wrong, Mike. Shocked, SHOCKED I say!

Dr. Frankenburner: Coming from you I take that as sort of a society handshake. On the more serious side, how do we work "burner guru" into something Allen?

There really isn't a reason not to make a T burner any size you'd like, just remember output increases geometrically with size, double the diameter = 4x the output. 

Just increasing the size isn't souping a burner up. Souping them up is increasing output, ambient temp or BTUs for a given quantity of fuel. The Frankenburner is a wonderful example of a successful up-souping of a linear burner. 

What kind of furnace/forge/melter/? are you thinking of heating with a 2" burner?  The forge that'd reach welding temp volume that jumps to  my mind is 2,800 cu/in plus.

Frosty The Lucky.

 

[Mikey98118]

4 minutes ago, Frosty said:

On the more serious side, how do we work "burner guru" into something Allen?

Okay; I'm going to go lay down and be very still, until my brain shuts up!

[Frosty]

Don't be THAT still Mike! That reminds me of a nurse that promised me she'd get my blood pressure down as far as it'd go!   

I got that wrong, I meant how do we work a Tim Allen mem (or whatever) into for the title of burner guru. Wait, that probably didn't do much if anything to reduce the spinning in your head did it? Oh well, don't worry, spinning helps keep my head stable, I'm sure it'll work for you too. 

Frosty The lucky.

[Mikey98118]

I just got up, and after that I'm going right back down. In the morning I'll down a big cupa Joe before reading anything more outta you

[Mikey98118]

• Below are some available SSTs for easy linear burners:

Smokehouse Chef #606 SST ($26.50) is the smallest stuffing tube size on the market; it has a 6-3/4” long 3/8” O.D. tube, with 0.295” I.D., which is about 0.025” larger inside diameter than 1/8” pipe.

Smokehouse Chef #606A SST ($26.75): This stainless-steel sausage stuffing tube is used on 1/4” burners; it has a 5-3/4” long 1/2” O.D. tube, with 0.375” I.D; about 0.010” larger than the inside diameter of 1/4” pipe

LEM #606 SST ($17): This stainless-steel sausage stuffing tube ($16 from LEM; $23 from Amazon.com) has a 5-3/4” long 1/2” O.D. tube, with 0.422” I.D. (about 0.063” larger inside diameter than 1/4” pipe).

LEM #606 SST ($17): This stainless-steel sausage stuffing tube ($16 from LEM; $23 from Amazon.com) has a 5-3/4” long 1/2” O.D. tube, with 0.422” I.D. (about 0.063” larger inside diameter than 1/4” pipe)

Gvode SSTs: Two stainless-steel sausage stuffing tubes for $11. These two SSTs are good for a 1/2” burner (0.625” O.D. x 0.575” I.D. X 2.78” long tube), and a 3/4” size burner (0.750” O.D. x 0.700’ I.D. X 4.770” long tube); both tubes are too short, and should be slid inside of longer mixing tubes.

FAMKIT #32 SST ($15) is very well made, and has an extended bell-shaped funnel section, which has a 4.126” diameter at the flange, and 3.25” opening diameter, by 1.800” length; this is roughly a sixty-degree cone,1” burners. The pouring spout (tube) diameter gradually narrows from 1.111” outside diameter at its base, down to 0.927” O.D. at its end; its tube section is welded to its funnel base, for a smooth transition; and thus, good mixture flow. This funnel is a bargain through Amazon.com, but slow to ship.

[Mikey98118]

Keeping the flame retention nozzle simple

Whether the SST you choose has a long enough tube to use as your burner's mixing tube, or you push it into a pipe, the flame retention nozzle will end up being the slide-over stepped nozzle kind; that is an outer stainless-steel tube, with an inner stainless-steel (or mild steel) 1" long spacer ring. To the length of the spacer ring is added an additional length equal to the inside diameter of the outer tube, plus an extra 1/8" to provide the total length of the flame retention nozzle's outside tube.

Stainless-steel hex socket 8-32 set screws, as short as 1/4" long are used to hold these nozzles in place (or the closest metric equivalent). It is necessary that the screws be stainless-steel, because mild steel will seize-up, after a few heating cycles in a forge.

While the screw holes are threaded completely through both the outer tube and the spacer ring on most flame retention nozzles, there is an exception to this practice. When the flame retention nozzle will slide back and forth on a very thin mixing tube, such as some of these SSTs provide. Then, the spacer tube is slit, and only the outer tube has threaded holes made, for the set screws; this way the screws squeeze the whole spacer ring against the mixing tube, instead of only pressing their small points against it. Thus the mixing tube won't be dented in by the screws, but sufficient pressure can still be provided to keep the nozzle in position.

If your flame retention nozzle ends up a little over size to the mixing tube (even up to 1/8" of space between these parts), it will still work just fine, so long as you keep it centered and axially true with the mixing tube. I suggest placing two rows of three equally spaced screws at 1/4" and 3/4" away from the rear edge of the flame retention nozzle's outer tube.

Frosty,

Solomon said that "there is nothing new under the son." Before Tim Allen came along to fill the gap, we had Loony Tunes. Your thoughts?

 

[Hefty]

May I slightly hijack to ask a relevant burner question, please?

I've searched the site (using site:iforgeiron.com) to find some threads and images to clarify, but I'm trying to find clear examples of each type of NA burner by their most common names.

Can all of you people-in-the-know please tell me if I have all of these correct? (I've underlined where I'm not sure, or don't know)

Frosty T burner: NA jet induction burner where air is induced by gas from (usually) a mig tip through a 2 to 1 reducing T pipe fitting into the mixing tube, originally designed/discovered by Frosty with detailed instructions in its own thread in the gas forges section of this forum. (I know this one - I've built two)

Mikey burner: NA jet induction burner where air is induced by gas from (usually) a mig tip through 3 (ideally - beveled edged) slots into the mixing tube. Designed by Mikey and presented with detailed instructions in his book.

Linear burner: NA jet induction burner where air is induced by gas from a gas orifice, through a reducing funnel into the mixing tube with the direction of induction parallel/linear to the gas jet direction. (Does a Ron Reil burner fit this description even though the original design has the gas delivered by a pipe at right angles to the orifice itself, or am I just splitting hairs?)

Vortex burner: Is this the name used for AnotherFrankenburner's design that he has been experimenting with in the 3D printed burner design thread? NA jet induction burner, similar in concept to the linear burner, where air is induced by gas from a gas orifice (mig tip or 3d printer nozzle) through a trumpet bell shaped funnel into the mixing tube. An "Aerospike" and vanes encourage vortical ??? (is it "spin" or "flow" here) in the induced air as it enters the funnel, causing better mixing of the gas and air in the mixing tube.

Fan-induced vortex burner: I haven't seen one of these but have seen Mikey reference the concept often in this thread. Mikey, have you (or anyone) made one of these, or is it currently a thought-experiment yet to be carried out? NA jet induction burner where air is induced by gas from a gas orifice, through a reducing funnel into the mixing tube with the direction of induction parallel/linear to the gas jet direction. A computer-style fan is used, not to force air, but to encourage vortical ??? (again, not sure if it's "spin" or "flow" here) in the induced air as it moves through the funnel into the mixing tube.

What other types of NA burners have I forgotten? I haven't included NARBs because I was mainly focussing on the NA aspect of the burner, not the flame itself.

With any necessary corrections, and maybe some pictures, I thought this might make a good starting point/reference for people learning about the different types of NA burners to find the info all in one place.

Let me know how I did.

Cheers,

Jono.

[Mikey98118]

Well, Jono, you did pretty well. You have your concepts and terms pretty straight as far as I can tell. The only departure I noticed in terms was when you called called the Frosty "T" burners, and My tube burners "jet inducers": Frosty calls them "jet ejectors." Perhaps he will see no difference; that isn't for me to say. Frosty and Frankenburner may have further comments on their burners, but your summery of mine is correct.

Your view of linear burners is right on track. To answer your question about Reil burners; yes they are linear burners too. The departure from a gas hole drilled into their cross pipes, to gas orifices on the end of pipes that are kept axially inline with the mixing tube, is a refinement which doesn't change linear burners to jet ejectors (or jet inducers)

You also have a firm grasp of what constitutes the difference between a plain vanilla linear burner and what I call a vortex burner; that is the added vortex motion given by moving (and to a lessor extent, still) impeller blades. Yes, I did put an axial computer fan (with impeller blades) on one of these burners, and know whereof I speak. At present, I have several half finished vortex burners in the garage awaiting both fans, and still blades (they require very different gas assemblies); to be mounted this summer. Yes, there will be photos of them all.

Frankenburner's design is also definitely a vortex burner. However, I am not qualified to speak on his burner; its subtleties are beyond me. I kinda get it, almost, but not quite...I just know that it works. And how would I know it works, since I don't really understand its design? Because I see the affects in its flame. utterly superior flames are what vortex flow in burners is all about. Do computer fan induced burners output flames identical to Frankenburner's design? NO; but they make flames like Mikey burners on steroids (total combustion in a single primary flame, but bigger and faster flames from the same burner size).

Finally; no, your examples do not exhaust the list of good burner designs-- far from it! Hybrid burners were an excellent design, but they seem to have gone out of business. Modified side-arm burners and "Z" burners are both good designs, and still available. There are still others; they come and go...some are even available as kits. The Burner Guru (I forget what site that is) started selling a modified version of a Mikey burner that is supposed to be quite good, and Mister Volcano forge appears to have very hot burners, which also look to be a modified version of Mikey burners. I totally approve of such burners, so long as they burn hot
 

[Hefty]

Jet ejectors, that's right!! I knew it was "jet something" and I knew they induce air so I cobbled the wrong words together!

You're right, I forgot about side arm burners, and I've heard of z burners but don't think I've seen one (or if I did, I didn't realise what it was).

I'll do some more research and see if I can write up some more descriptions and add some photos (with credit where it's due) and maybe I'll start a new thread so it's easy for newbies like me to find.

Cheers,

Jono.

[Mikey98118]

The only thing I would suggest is to consider anything a seller claims about the wonderfulness of his or her burner be automatically discounted, and that you only believe half of what you see (Photoshop).

[Mikey98118]

About Vortex Burners

    Let us start by clarifying what is meant by the term “vortex burner.” Burners that swirl the flames they make are often touted as vortex burners. But causing a flame to swirl happens far too late in the air/fuel mixing process to provide much benefit; used this way, the description is hype.

    Vortex is a fluid dynamics term, describing a region where the flow of gas or liquid revolves around an axis line.  The vortices generated on the trailing edge of plane wings only create drag. At the other extreme, a tornado’s funnel is powerful, but only for destruction. The gentle current of a bathtub drain effectively employs vortex flow to good purpose, and so should your burner.

    Vortex burners are simply advanced linear designs; linear burners are chosen over jet-ejector types, to supply the greatest amount of vortex motion in their gas/air mixture flow. For good combustion, it is necessary for incoming air to mix sufficiently with a burner’s fuel. A swirling motion provides the most mixing for the least drag on your burner’s air flow.

    When incoming air passes through a constricting tubular shape (ex. pipe reducer or kitchen funnel), vortex movement is generated, becoming an excellent air/fuel mixing aid. Most successful burners, whether linear or not, create at least some vortex flow. My high-speed tube burners are an exception; they gain swirl from three (fore and aft beveled) rectangular side air entrances; nevertheless, if you place a pipe reducer between their air entrances, and a smaller diameter mixing tube, even their performance will be enhanced.

   Since most successful burner designs create vortex flow, why bring it up? Because the people who designed those burners, only pictured them as swirling incoming air into a stream of fuel gas, and thought no further. Both passive and fan-induced “V” burners, are designed to enhance vortex flow, and then to derive maximum benefit from it.   

    Any device that provides lateral air movement at a funnel opening, will increase vortex flow; this includes the two opposed air openings on “T” plumbing fixtures, disc shaped choke plates near funnel entrances, or (my favorite) impeller blades in front of the opening. If you strip the blades from a cheap or worn-out axial computer fan, and mount them on a linear gas tube at a burner’s air opening, they will significantly increase vortex movement through the funnel, even though they are still, because they start lateral air movement (spin) at the funnel’s entrance, instead of somewhere within it.

    Installing axial computer fans on linear burners will supercharge vortex flow, but this requires an intricate gas assembly, and an electrical power source. So, it is easier for novices to move from passive to powered “V” burners in stages.

    Some part shapes used for air entrances on naturally aspirated linear burners, also work well with moving fan blades, while others do not. However, the limits on shape and size imposed by use of moving impeller blades, do not apply to motionless blades; these can be mounted on gas pipes without worry.  

    Straight or curved wall pipe reducers, kitchen funnels, and other constricting tubular shapes provide convenient ready-made entrances for incoming air to revolve its way through, and into the burner’s mixing tube; its spiral path increases its rotational speed, along with its forward velocity (by about one-half of its rotational speed). Also, the faster the incoming air’s rotation, the lower the pressure of the incoming air flow through the mixing tube; this is all very good for mixing, but requires the mixing tube to be lengthened enough to stabilize the flame (by allowing friction within the tube to slow the mixture’s swirl and forward velocity, before it exits into the flame retention nozzle).

    Or, internal vanes near the tube’s exit can be made to slow air spin, in order to keep the mixing tube’s length shorter. A larger diameter flame retention nozzle can break the flow’s exit speed sufficiently. Thus, you would need to exchange your smaller flame retention nozzle, used at lower gas pressures and fan speeds, for a larger one, when running a fan-induced burner full-out.

    The first thing to keep in mind about funnels and other constrictive shapes, is the greater the ratio between the air opening’s diameter and the mixing tube’s diameter, the stronger the vortex created.

    Secondly, the shorter the length of the funnel the greater the drop in air pressure it creates at its opening. This drop in the pressure of incoming air is not sufficient to create a problem in naturally aspirated burners, but the low-pressure zone created at the opening with moving impeller blades, can draw some fuel gas into the fan. Then, the fan’s electrical sparks will ignite the fuel/air mixture.

    So, a maximum 3:1 ratio between entrance diameter to the mixing tube’s internal diameter, becomes the first safety margin with fan-induced burners; another safety margin is provided with sufficient length in the funnel shape, or the addition of a short tube section between the funnel opening and the fan; this produces the same effect as a longer funnel shape (in avoiding back-flow of fuel gas into the fan). The SE HQ93 Stainless Steel Flask Funnel is an excellent example of such a shape being used as a safer air entrance for fan-induced burners.

Note: The moving fan blades you are concerned with here are impeller blades, which have become standard on axial computer fans; not the old-style flatter blade designs that are meant to push air forward; those increase the pressure of incoming air. Impeller blades lower the pressure of incoming air.

    Of course, this leaves us wondering how long a funnel is long enough. Only experience can answer that question, but I suggest a minimum length of one and a half times the diameter of the air opening. Furthermore, fan strength, constrictor shape (straight, convex, or concave wall) all come into play. Add to that how much curvature at what point in a funnel shape, and we are reduced to trial and error. Always remember that, if the burner you design starts backfiring into its fan, there is very little work needed to change it to a naturally aspirated design. You do not have to rebuild the whole burner.

 

[Another FrankenBurner]

7 hours ago, Mikey98118 said:

Frankenburner's design is also definitely a vortex burner. However, I am not qualified to speak on his burner; its subtleties are beyond me.

I’m not qualified either.  While I studied what I could, trial and error led most of  the way.

The burners don’t really have a name.  The first time I heard the term vortex burner was in this thread and it was referring to a new Mikey design.

 How about twirly birds?

[Mikey98118]

1 minute ago, Another FrankenBurner said:

I’m not qualified either.  While I studied what I could, trial and error led most of  the way.

The burners don’t really have a name.  The first time I heard the term vortex burner was in this thread and it was referring to a new Mikey design.

 How about twirly birds?

Be carefull what you wish for; some wag is likely to change that to twirly burners; it might catch on...

What is Allen doing? I haven't heard a peep outa him today.

Maybe we should call him Mister Allen; he being such a serious guy, and all

[Another FrankenBurner]

AFB’s twirly monster 

I always figured a name would come about on its own.  Whatever sticks.  Until then, that guys 3D printed thingy works.

Someone suggested AFB’s AFB but repeating what is stood for would violate the rules.  

[Mikey98118]

11 minutes ago, Mikey98118 said:

Be carefull what you wish for; some wag is likely to change that to twirly burners; it might catch on...

What is Allen doing? I haven't heard a peep outa him today.

Maybe we should call him Mister Allen; he being such a serious guy, and all

I was a little surprise to find someone classifying your burners as  vortex burners--until I thought things through. Then, I had to agree with whoever it was; they are vortex burners. The proof is in the flame.

[Mikey98118]

Further notes on "V" burners

To install Vortex burners in horizontal tube, oval, or “D” shaped forges, they should be aimed with the flame retention nozzle angling somewhat upward from a position that is low in the forge (or furnace) body. If installed facing downward, and/or high on a box forge’s side wall, a Vortex burner’s plastic fan can easily be overheated by the chimney effect, after shutdown; this is also true, when the burner is installed in a casting furnace. You must be able to easily remove such burners from heated equipment, immediately after shutdown. Even when properly positioned, you still need to leave the fan running after shutdown, until the equipment cools to room temperature; Even though removed, the burner’s fan should be kept running until its flame retention nozzle is cool.

Note:  Fan-induced burners used in any position other than horizontal need an axial fan with ball-bearings. Motors with sleeve bearings should only be run in a horizontally placed burner, to prevent the lubricating oil from seeping out, letting the bearings run dry (and ruining the motor). You will find this information listed on any manufacturer’s site, but not on those of most retailers.

[Frosty]

Not a bad summary Hefty. 

The term "Jet Ejector" comes from the induction devices I modified into the T and Robert Groman built the first sidearms. He was visiting Alaska and I described the T burner while driving down Turnagain arm and he rotated the T 90* when he made a version. 

If you do a web search for "Jet Ejector" you'll find literally thousands of device for drawing vacuum, the hangar size vacc chamber NASA uses to test pace craft is drawn down by jet ejectors large enough to park busses in.

Detuned enough they make dandy NA (Naturally Aspirated) burners.

Frosty The lucky.