making a reil burner

Any welding supply or refrigeration place can tell you all about silver solder and probably sell you some. ;-)

Basically, it's just soldering, but with silver solder instead of lead solder. Yes, you have to get it MUCH hotter, but it holds MUCH better. That's probably why they use it on A/C units - especially the high pressure lines.

Al

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Alp> Hi,

If you make 1 "down & dirty" burner, you could use it to braze a second one.

Personally, I dont like the venturi type burners. They wont get as hot as a burner with a blower. You can pull a small blower out of an old microwave or many other appliances. All you need is a tube, blow air through it, inject propane at some point, and use some type of flame holder at the tip. Thats it. You'll be cookin'in no time. I tried running some motor oil through mine, and the were so many BTU's being released very rapidly I thought she was gonna blow ! I was moderately frightened by what I saw that day.

Will

I think the somewhat dissapearing myth that venturi burners don't get hot enough comes from people who never used a decent one. I've done extensive work with combustion engineers and making good fire from plumbing parts ain't like fixing your drain.

Burners made from off the shelf junk have a very small envelope of proper operation. I didn't want to do all that screwing around with cobbling flares and nozzles and testing (I'd rather be making something more interesting) so I was happy when I found a blacksmith who happens to be a combustion engineer, too, and sells burner kits. For about $30 you get an adjustable burner made from plumbing parts that will actually work perfectly.

Case in point, I cast some refractory inside forms made from heavy c-chanel and fired in in the forge. When done I was surprised to find a large portion of the heavy steel c-channel had *MELTED*. I'd say that's hot enough wouldn't you?

The other advantage besides less parts and no electricity to monkey with is that the burners can be run from sitting on the 0 peg up to over 25 psi without adjustment. Ron has alot of hoopla about "Super Duper Rocket Burners" but ignores the fact that that these cheapies do all you ever need. Some people just like fooling with fire I guess.

Good luck,

Ed

P.S. you can get the burner kits from Jay Hayes http://home.earthl> >

It may be a myth, it may not be. Guess I'd have to crunch numbers to prove one way or the other. And I'd certainly agree that you can melt steel with a venturi type, depending on your refractories.

But I do believe that you will get a greater release of energy in a shorter amount of time by forcing the air and gas together with a blower. I got one that resembles a large welding tip when it's burning, and makes one hell of a noise. Probably consumes more fuel, but definately a greater release of energy than what you'd get from a venturi type. Has to be.

It has only one limitation, and that would be the velocity of the gas fuel mix. If you crank it up too high it will blow itself out, but with a good flame holder it should be able to go higher.

I think that the higher pressure you have on your air fuel mix, the more BTU's you are going to release - by definition - assuming stoichometric balanced bla bla bla. If you use a blower, you can force your burner to consume fuel at a faster rate than a similar sized venturi burner. Yes, they will both get things hot, but the one which burns fuel faster will get things hot sooner. Has to be.

True - to some extent.

The biggest factor is not the burner, but the furnace. If your energy input is greater than your losses, then things will continue to get hotter until equillibrium is reached. If the equillibrium point is too high, you will melt your furnace and everything it's made of. You can do this by burning fuel at a very high rate.

Once things are hot enough, you dont even need a burner. Just fuel input, and oxygen input, and some type of mixing of gasses, and if it's balanced it will.

Lets say you took a car engine and put a blower on it. You are forcing more fuel/air mix into the "burner" and therefore get more horsepower. Lets say instead of a blower, you use a compressor. Run compressed air into your intake manifold. Assuming you can cen the right fuel / air mix, you are burning more fuel, and you should be able to get more horsepower because of that, not to mention the increase due to the fact that yoru input is compressed already. Disregarding increases due to gasses being compressed, you are burning more fuel and you should get a bigger bang.

That's all I'm saying.

It dosent matter what kind of furnace you use. If you crank up the rate of combustion by compressing the fuel/air mix, you will be throttling up the rate of energy release and it will get hotter faster.

Maybe it can be done with a venturi burner as well, if you can achieve the same volume of air being pushed through your orifice as you would get with a blower. Never seen such a thing, but might be possible.

At some point, a venturi will probably exhibit a flow reversal, which you would not get from a blower arrangement. Basically, instead of sucking air into the tube due to suction from your jetstream, if you crank up the pressure high enough the flow will probably reverse and flow back OUT of your air intake ports, depending on your design. So, you may have some limitations in that respect, but a venturi which is large enough WILL funtion properly and compete with any blowered unit out there - it just has to be bigger.

Lou,

I wasn't compairing the heat of a venturi to a blown. If we're discussing if venturi burners get hot *enough* then it *is* a myth that they don't.

My forge is 8" ID x 24" long (tube) with 3 burners. I can run all 3 over 25 psi. For normal forging I run 1 or 2 burner at 5 to 8 psi. This gets me a yellow heat on multiple 1/2" to 3/4" bars, so I always have one ready. I also use a throttling circuit Jay suggested to idle at less than 1 psi when I'm not putting cold work in. I never run all burners over 25 psi. Simple enough, I have excess capacity so they are hot enough.

As far as your reasoning with the blower goes, I'm not going to try to argue physics, there's more than meets the eye, and I'm no combustion engineer but mixing and gas ratios are one complication to your comparison. If you're blowing air through that doesn't get mixed well or is excess then it cools the flame.

Have you seen a good venturi burner? They look like a mamoth rosebud and can scream as well, (although the jet-like screaming indicates the tuning is wrong).

Again, I understand being proud of your equipment but it seems like whenever I hear criticism of venturi burners it's from someone who hasn't seen a good one in action (and is proud of their blown burner). Since most of us aren't combustion engineers we have to rely on experience or study ejector theory and combustion mechanics.

In this case I'm going with experience. It's simple that way. And it just confuses people to complicate this. Believe me or not, they get plenty hot.

Ed

This is definately true, and sometimes tricky to adjust them.

I have seen some real nice burners online - really well made ones - not just pipe parts but stuff turned on a lathe.

My motto is if it gets things hot it's got to be good.

To further Ed's comments, pipe parts work just fine. My three Reil burner forge (since sold) got to a nice yellow heat at 10psi. The interior was 10" diameter and 24" long (14" diameter exterior). My single burner does about the same; it is 10" diameter and 15" long. The heat isn't quite uniform at the ends if you don't have the ends fully covered with bricks.

By the way, this was at 5000 feet elevation.

Steve Smith

Lou wrote: