Burners 101

[TFT]

I hope im not the only one who thinks this but.... Sticky thread please... im just saying its usefull

[Mikey98118]

To get a little more specific about choke sleeves: It is good when a pesky detail can be turned into an advantage. Pipe is a long ways from being round; when trying to fit a pipe over the next size smaller pipe, power sanding, slitting lengthwise, and rotating both pieces are are all standard ploys for dealing with it.

Tubing is more uniform than pipe, and is also available with far more size choices than pipe. Nevertheless, you may not find the most desirable part sizes available from local sources, or inexpensive enough for from online supplier; if you pass those hurtles, there may still be plus/minus tolerances to deal with in a close fit. So sanding, slitting, and turning will likely remain necessary.

The good news is that both pipe and steel tubing have some spring in them. So, if a pipe or tube choke sleeve is split, or if a tube happens to be close enough to the right tolerance, it will slip back and forth on the mixing tube in one position and freeze in place with a small twist, conveniently locking the sleeve in place in another position, without need of further work to achieve that end.

Mind you, old doc Frankenburner is a big fan of doing everything the hard way, but Frosty has been influencing my thinking lately.

[Mikey98118]

You don't need to be told to make the choke sleeve before you layout your air openings do you? After all, you definitely want the choke sleeve to tighten up with the slit over a a rib section; not over an air opening.

Speaking of air openings, the optimum number is three, and they should open far enough so that moving the choke sleeve any farther no longer effects a difference in performance. As for widths, the opening needs to be wide enough so that their widths time their lengths times three amounts to more than one and a half times the area of the mixing tube opening, You can always lengthen the the air openings, but making the openings to wide will result in a loss of smoothness in the flame.

[Johan]

Hey guys I know its been a long time since I last updated on the burner issues. As of right now its working great, I swapped the 1"-3/4" reducer to a 1 1/2"-3/4" reducer and now its good. I also changed up the design of the forge a little bit because the steel plate around the door opening was starting to warp from the dragons breath. Instead I took the plates off and welded some angle to slide firebricks in and out. This is also really handy when it comes to changing up opening sizes and such. Here is a picture  Once again, thanks for everybodys help with the burner!

[Mikey98118]

Johan,

I wish you guys would stop posting photos of cute little box shaped forges; I"m deeply invested in tubular and oval shapes; why tempt me like this? BTW, this photo would like very nice posted in the Forges 101 thread too...hint, hint.

[Mikey98118]

.023 versus .025 MIG contact tips

There where no such thing as ".025" MIG tips sixteen years ago, which you may think is why they don't appear in any list of tips sizes-per-burner-sizes that I ever wrote. But if I where writing such a list today, they still wouldn't appear. The closest appropriate MIG tip size for a 1/2" burner is .023" (and it is too large to be ideal). A MIG contact tip for .023" welding wire has an actual orifice diameter of .030". The optimal orifice diameter would be .028". So, by installing a .025" tip in a 1/2" pipe size burner you assure lousy performance.

[Mikey98118]

Well, that's what my burners do; Other burner designs can vary.

[Johan]

haha well thank you Mikey. I mainly just build a square shaped forge because I figured it would be much simpler to build. I also had nothing cylindrical kicking around and the price to buy some plate at Metal Supermarkets wasn't outrageous  One of these days im sure ill get around to making a tubular version. It seems I spend more time making things to forge then forging itself LOL

[Frosty]

8 hours ago, Mikey98118 said:

Well, that's what my burners do; Other burner designs can vary.

That's because the induction ratio of your burners is significantly better than other home build designs. I don't know of anybody getting even close to a neutral flame with a 0.030 mig tip in a 1/2" T.

Frosty The Lucky.

[Mikey98118]

Back in 2000 NA burners needed to raise there game a bit; today, we are starting to have a glut of good designs; at least if we include some of the better imports in the mix...now if we could only get people to use a little more sense in what they choose to go with, because there are aksi no so many junk burners to choose from...I think the fight to keep people from running off the road with the other parts of a gas forge is making better progress then burners now; after all the improvements, we see seem to be making negative progress!  do you think this will happen to ribbon burners too? We need to recast the old saw about money to "A fool and his heat are soon parted."

That so read "also so many junk burners..."

[Frosty]

Pre 2,000 there weren't many home built NA burners that actually performed worth spit. The basics are starting to penetrate and more guys are discovering how easy it is to make a good one. Unfortunately there is the faction looking for their 15 minutes of fame so they shoot a video cobbling together some "secret" design(?) and uploading it as THE way to make a burner.

Popularity is going to cause a glut of junk and a lot of folk who can't or wont do a LITTLE real reading will be the marks for cheap junk shysters. It's so much easier to buy into a "secret design" than it is to actually learn how something works. It's like the UFOlogist movement. A person can't explain what or how something is so it MUST be alien tech. It didn't take long before they weren't entertaining enough to even drink coffee with so I started sitting farther away at the coffee shop. Have you noticed how many Discovery(?) programs are devoted to aliens, unexplained NASA video, etc? Funny paper intellects.

The only way popular internet EXPERTS won't muddy up the oh so simple to build NA ribbon burner (NARB) is it doesn't gain popularity in the first place. I'll try not to let it crush my spirit either way.

Frosty The Lucky.

[Mikey98118]

I figure they will begin goofing up by trotting out "cheap" homemade castable for the burner blocks

[Frosty]

1 hour ago, Mikey98118 said:

I figure they will begin goofing up by trotting out "cheap" homemade castable for the burner blocks

No, not the "special" blend, Plaster of Paris and sand, castable refractory? Oh NO, tell me it ain't so Mikey!

That's okay I'm not going to let the secret brand of multi port burner casting crayons slip. Bwa ha ha ha ha!

Frosty The Lucky.

[Mikey98118]

Fan-blown burner thoughts:

It is time for an "oh by the by" possibility.  I have felt that regular fan-blown burners were mostly a thing of the past, possibly because so many of them are just cobbled together, but there has always been a question mark in the back of my mind on this subject. three years back I discovered an appropriate use for impeller style micro size fans on a special new burner, and last year I was introduced to ribbon burners, and thought that still another appropriate use for a fan-blown burner had to be added to my very short list.

Now Frosty has  come up with a viable naturally aspirated ribbon burner for torges, and it looks like fan-blown has taken a major hit again...BUT, I am wondering if a tiny flat bladed fan on a funnel entrance might not provide an improvement one more time, via better control of the ribbon burner's flames?

Obviously this is all speculation, so why bring it up here? This thread is meant as a resource for people who want to tinker, and design their own new burners. Us old guys only care that you guys tinker well. So what is the point of re-introducing fans to equipment that have escaped drop cords? Well, a micro fan can be run all day long from a small highly portable battery is what. The march of progress is generally slow because so much of it must wait on a general level of technological improvement. To ignore today's answers to yesterday's deal breakers is monumentally STUPID!

[Frosty]

Ah I didn't come up with a NA multi port burner, commercial ones are available in many shapes. I just adapted one into an easy home build.

You've mentioned the small fan in the intake a few times and I still don't have a handle on how it works and you've explained the idea a few times. Do you have a couple sketches I can take a look at?

Frosty The Lucky.

[Mikey98118]

No, and I don't know how a sketch would really get the idea of what an impeller fan can do to power a vortex across very well; it would take several ne sketches.

However, this would be a standard fan; the kind used to provide push; just not anywhere as much force as were thought needed to do the job on a ribbon burner. For that matter you could use one of the tiny squirrel cage fans to do this job, because the amount of added force needed might only be sufficient to push passed the amount of flow generated by air induction. I visualize the possible benefit coming via the ability to separate gas and air intake amounts in order to gain fine control of the flame; at present it is tied automatically to gas flow. You could think of its possible effect on flame formation as a kind of reverse choke; instead of reducing air to gas amounts this would increase it. Just as oy taked very little choking to greatly change a flame, it should only take minor supercharging to change a flame.

[Frosty]

I get vortices, I LOVE vortices but my experiments with them in burner tubes seriously reduced the over all throughput. My thought was to increase the time in contact of the air and fuel before ignition to improve mixing. I'd thought of inducing a vortex with what the boiler oil burner guys called a "turbulator" which is essentially a "fan blade" that induces a strong vortex in the oil : air in a boiler to prevent the flame from actually touching the furnace walls.

The "turbulator didn't work so I played with intake ports that introduced air at an angle to induce a vortex. I wasn't impressed with that either so I shelved the idea till I felt like tinkering again.

So, is the fan in your design primarily to boost air intake or induce a vortex, both? Making the ratio more adjustable is a given with a super charger/ booster.

How much have you played with the things?

Frosty The Lucky.

[Mikey98118]

First, which design? I use fans with impeller blades to induce strong cortices in a linear burner's funnel opening, but am considering any other fan but one with an impeller blade to create push in the entrance of a ribbon burner. No matter what kind of fan we use, it will provide some vortex formation in air traveling through a constricted opening. The difference is whether most of its energy is powering the vortex or providing forward force. If you wish to talk about vortex burners again, I am willing, but we will most likely be drifting away from ribbon burners...

[Mikey98118]

If you're still primarily interested in improving the ribbon burner, adding a very small amount of supercharging to affect flame formation, than a squirrel cage fan is the most desirable type. I hate to even use the term "supercharger" because it invokes the idea of a powerful input, and that is the last thing I would be aiming for; as previously stated, I would be looking for an anti-choking mechanism, in order to make it possible to fine to the flame; not to introduce a lot of extra air to the mix.

[WayneCoeArtistBlacksmith]

Frosty, have you used a pyrometer with your NARB?  If you are building the burner to be able to forge weld billets without flux you will need to be able to control the heat to about 2315 degrees and have a reducing (oxygen poor) flame.  Whenever I am doing fluxless welds I always use my pyrometer.  For general forging I reduce the temp.

[Mikey98118]

Wayne,

If you want to talk about ribbon burners, including where to get supplies for ceramic heads and forges, now is the time and this is the place...

[Frosty]

Mike: One of the problems having a living language as our first is how muddy meanings get and, my bad, I pursue etymology for fun. By super charged I mean the proper definition not the popular misuse of the term. Anything that is supplied more air than it can naturally draw is charged "ABOVE" the natural. or Super charged. Unfortunately "Super charged" is so . . . (polluted?) by common slang I gave up trying to discuss turbo chargers as super chargers and lord forbid trying to discuss positive flow as opposed to transparent blowers! Eg, Roots type gear compared to fan impeller super chargers.

Pick a term Mike I'll be more than happy to use it for the purposes of discussion. Uh the discussion I don't know what you have in mind for including a fan in burners, that's what I was wondering.

Wayne: I don't have a pyrometer, never used one. Maybe someone will bring one along to the next meeting, I'll ask the club. The orange exhaust plume had me scratching my head about the fuel air ratio. However the practical tests show it's either neutral or slightly reducing and the CO meter doesn't peep. Is doing a fluxless weld a benchmark or a practical method? Getting a gas forge to operate at or abve welding temperature is more a benchmark than something most people actually need.

Frosty The Lucky.

[Mikey98118]

Something about fans and vortical flow:

1) If you create a circular motion in a liquid or gas it creates vortical flow.

(2) If you pass a liquid or gas through a circular constriction ut will create votical slow.

In a vortex burner both effects are deliberately combined to create maximum vortical flow without forward force, as--in these burners--forceful airflow is not wanted.

To create  a small amount of added airflow, a very weak squirrel cage fan will blow air in a straight line into a funnel shape. Much of the forward force will be transformed into vortical flow, but not all of it, as would be the case from an impeller blade. Also, how much of the fans force is transformed into vortical flow depends on how great the amount of constriction is. For vortex burners I recommend no more than a 3:1 constriction (to prevent dangerous back pressure next to the fan). But a little 12V DC squirrel cage computer fan doesn't produce much force to begin with, so a 1-1/2;1 funnel shape would be the maximum I would employ to make a supercharger for a ribbon burner. Add speed variance to the fan, and it should not take many experiments to find a happy result. 

(2) should read" If you pass a liquid or gas through a circular constriction u will create vortical slow."

[Mikey98118]

In a vortex burner both effects are deliberately combined to create maximum vortical flow without forward force, as--in these burners--forceful airflow is not wanted.

this shoild read "... without increasing forward force..."

[WayneCoeArtistBlacksmith]

Frosty, the fluxless weld is practical.  There is no flux to cause inclusions.  As a flux insurance some of the guys do dip the billet in kerosene to further aid in no oxygen to cause scale.  I think that the fluxless welds are also easier to do.