Reynst pot help

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Fileeraus
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Reynst pot help

Post by Fileeraus » Thu Apr 21, 2016 5:40 am

What defines a reynst pot?
I made mine from an empty fire extinguisher https://www.youtube.com/watch?v=HF76iIa1c4g
I've tried some different fuels and I explain the best one in the video too.
I would like to weld a snorkel to it but none of the tubes I've got don't work. I have used tubes that are (almost) equal size to the original hole in the extinguisher.

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Mark
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Re: Reynst pot help

Post by Mark » Thu Apr 21, 2016 8:20 pm

I would try a snorkel about 2 centimeters in diameter. Certainly not much more than 2.5 cm if that for just a simple tank and snorkel arrangement. And I wouldn't try any snorkel that's longer than the tank. Shorter snorkels are more forgiving and as far as fueling methanol (CH3OH) is better than ethanol or turpentine I should think. If you get it running with a snorkel you'll be surprised how much more energetic it can be. I can't tell the diameter of the tank but it looks about 13 - 15 cm?
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Re: Reynst pot help

Post by Fileeraus » Fri Apr 22, 2016 10:04 am

Thanks for replying, its a 10L tank and I'll measure it in a couple of days. (been busy) I once had a short snorkel in ja small jam jar and it was indeed more energic, I was surprised how loud it can be!

If I get it running good with the snorkel, me and my friend will attach it to his pickup and drive trough a cruise night of classic cars lololol

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Re: Reynst pot help

Post by Mike Everman » Fri Apr 22, 2016 11:02 am

that was a very cool technique of starting on the side and standing it up. I would normally have considered the start a fail. I'll have to try that. how did that occur to you?
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Re: Reynst pot help

Post by Mark » Fri Apr 22, 2016 1:17 pm

Sometimes a 30-45 degree angle of the tank instead of straight up works best for me like with my paintball tank snorkelers. If held straight up they don't often sustain and if completely horizontal even with a modest amount of fuel they become breif flamethrowers, the sudden compression or extra confinement of having a snorkel will eject the fuel as soon as you light the engine. I've never been able to get a snorkeler to run with a flare on the end like a typical pulsejet exhaust end. A straight tube without any burrs or rough internal edges will help too. If you cut a piece of pipe for a snorkel, file the inside edge where you cut it so it won't dampen feedback when the air rushes to and fro.
One thing when experimenting with smaller sensitive snorkelers is that the combustion is quite violent and that causes the fuel to slosh a great deal which then causes the engine to flameout. So with my paintball tanks I have to be careful not to add too much fuel.
With my 2.5 gallon/9.5 liter piglet snorkelers I have used a 1.25 inch plumbing pipe or 3.175 cm diameter snorkel but it was really hard to get it to sustain so I typically use a 1 inch diameter pipe on the 8 inch diameter tank. But when it did stay lit with the largest snorkel it was so loud you couldn't hear a person next to you talking. It's quite impressive. In summer in Florida these things refuse to run. As is, they like cool weather and dry air.
Methanol is probably the easiest fuel for getting these engines to run if you can find it.
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Re: Reynst pot help

Post by Fileeraus » Fri Apr 22, 2016 2:58 pm

Mike Everman wrote:that was a very cool technique of starting on the side and standing it up.
If it was on sideways, the revs would come down soon and it would shut off, so I thought that it needs to be in up position, just like jam jars. Tested the theory and it worked out.


I'll cut the old snorkel away and try without it in 45 degree angle :)

Is HEET fuel line antifreeze methanol?

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Re: Reynst pot help

Post by Mark » Fri Apr 22, 2016 4:24 pm

HEET in the yellow bottle is what you want, not the red bottle that says iso-heet. The yellow bottle is methyl alcohol and the red isopropyl alcohol. I think you'll find methanol to be quite a perky fuel. But methanol is a lot cheaper if you can go to a speed shop or racing fuel store. Also if there is a bio-diesel fuel place they use methanol to make bio-diesel fuel. Last time I bought 5 gallons/19 liters of methanol it was less than $25.00, I think $4.50 a gallon. Compare that to $3.00 a bottle of HEET in some places here in the U.S.
When you angle a tank you often expose more fuel surface area to the flame and also alter the sloshing of fuel, for better or worse.
https://www.youtube.com/watch?v=y76r-3RV64U
http://jwbasecamp.com/Articles/SuperCat ... 13-600.jpg
http://4.bp.blogspot.com/-tif1itirnTE/T ... +Label.JPG
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Re: Reynst pot help

Post by Fileeraus » Fri Apr 22, 2016 6:39 pm

I've found methanol from another fuel line antifreeze product from my country.
If methanol car-gas works, I suppose ethanol gas works too?

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Re: Reynst pot help

Post by Mark » Fri Apr 22, 2016 10:12 pm

Ethanol works but it has other chemicals in it to denature it. I've used both but find methanol more energetic and cheaper to buy. You might find one does better with a different size snorkel using different fuels. Methanol has a lower boiling point and higher vapor pressure than ethanol. Methanol also has a wider window in which it will run rich or lean.
https://www.youtube.com/watch?v=TLB_oVPaW10#t=1m10s
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Re: Reynst pot help

Post by Fileeraus » Wed Apr 27, 2016 1:39 pm

Ok, the pot is 40cm tall, 15cm wide and the hole is 3cm.
I cut the old pipe away and now it runs like this with the mix of turpentine and spirits: https://www.youtube.com/watch?v=8c5hO53nbDM
I did not try methanol yet because I don't have much of it left, but I did try it with the good fuel mix which is spirits and turpentine.
I believe it lost revs because it would rev too much and the hole starts to get too small? I remember seeing identical extinguisher laying in a forest near, I'll go grab that if this is junked :P

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Re: Reynst pot help

Post by Mark » Wed Apr 27, 2016 2:45 pm

There's not enough confinement of the hot gases to get it up to a sustained speed. While I can't say what size hole is going to function with your blend of fuels, with methanol it should run fine with a 2.5 cm diameter snorkel or one just slightly smaller in diameter. Even with a short snorkel of 10 cm in length would pep it up quite a bit. If you could weld a fitting to the hole like this one, then you could try various lengths of the same pipe diameter to see what works the best instead of being stuck with what you've got.
If you do find a welder, be sure you aren't welding onto a zinc coating fitting or avoid any fumes from that type of fitting because zinc fumes are harmful to breathe. Black iron fittings would be better. Also the first whoosh can be quite screechy and loud especially with methanol, so some hearing protection would be a good idea.
http://www.downwindmarine.com/images/P/891187.jpg
Or something like this http://image.made-in-china.com/4f0j00AB ... eaded-.jpg

This one is a rough approximation of what your tank size is, although it's 7 inches or 17.78 cm in diameter. The tank in the video seems rather tame and all but it's really fairly loud and throwing a fair amount of air even though the hollow steel balls barely seem to be held up by the exhaust, maybe because of the way the air is ejected in donuts or vortex rings perhaps. It's running with a 2.5 cm diameter snorkel. It would be fun to have a small hot air balloon lift off the ground attached to this "burner". I ran it about a week ago for some company and it ran full grease for about 4 minutes on less than a liter of methanol. The engine stopped prematurely in the video because of the steel balls and there's always some fuel that remains in the tank even if it dies a natural death. I wear hearing protection when I run this one, I want to save my hearing.
https://www.youtube.com/watch?v=YlXaCQXZ9zU
Last edited by Mark on Wed Apr 27, 2016 7:22 pm, edited 1 time in total.
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Fileeraus
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Re: Reynst pot help

Post by Fileeraus » Wed Apr 27, 2016 6:54 pm

I'll see what I can rig up, thanks!

Fileeraus
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Re: Reynst pot help

Post by Fileeraus » Wed Apr 27, 2016 7:54 pm

I measured an old pipe that I used as a snorkel in another extinguisher, which was a bit wider and the pipe is 2,5cm. In the a-bit-wider tank, the 2,5cm pipe was too small, it only pulsed three times and then shut off. Should I try the same piping in the new tank?

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Re: Reynst pot help

Post by Mark » Thu Apr 28, 2016 12:48 am

I don't know what you mean by a bit wider in another extinguisher, but I have used a 2.5 cm diameter snorkel on a 20 cm diameter tank as seen here. You can see it more clearly about half way into the video the lighting improves. Perhaps it is the case that with turpentine and spirits you can't get away with using this diameter snorkel as your mixture is going to require a greater ratio of air to fuel. Believe me I have tried a lot of different fuels and I prefer methanol which is the best common fuel you can find. Things like ether, acetone, other alcohols, gasoline, turpentine all are very fragile when trying to get the right fuel/air mixture. With these types of engines you need all the help you can get, and nearly all my snorkelers refuse to run or run very poorly and then die out quickly in summertime in Florida. You might as well not even try to experiment when it's hot and humid out. Just having cool dry air can make all the difference with my simple snorkelers.
https://www.youtube.com/watch?v=XRaGP6FlZw4

Another thing to consider is the length to diameter ratio of your tank. This will affect results too of course. I still would consider finding a source of methanol because it is often the case that other fuels quickly become too rich inside a tank and the initial starting doesn't perform well. You will need a way to refresh your tank if it doesn't start on the first try. I have a foot pump with a long tube that I can put inside a tank to air it out quickly. If it doesn't start standing straight up after several tries, you can also try a 45 degree angle. Maybe you have something like that airing out device already.

The next size down from what's called a 1 inch pipe here in the US is a 3/4 inch common threaded pipe. You could get away with using a 2 cm diameter pipe on that tank you are trying now. Be sure to wear some hearing protection because the first whoosh can be very harsh if you have a good fuel/air mixture. Even a short snorkel will likely help improve the amplitude of combusiton so you can start out with short lengths at first. Short lengths are often more forgiving.

I was reading that for turpentine it has a lower explosive limit of .8% and an upper explosive limit of 6% by volume in air. That's a very fragile range to maintain compared to methanol which is 6.7% to 36%.

"The minimum concentration of a particular combustible gas or
vapor necessary to support its combustion in air is defined as the
Lower Explosive Limit (LEL) for that gas. Below this level, the
mixture is too “lean” to burn. The maximum concentration of a gas
or vapor that will burn in air is defined as the Upper Explosive
Limit (UEL). Above this level, the mixture is too “rich” to burn.
The range between the LEL and UEL is known as the flammable
range for that gas or vapor."
"The values shown in this table are valid only for the conditions
under which they were determined (usually room temperature
and atmospheric pressure using a 2 inch tube with spark ignition).
The flammability range of most materials expands as temperature,
pressure and container diameter increase."
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Fileeraus
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Re: Reynst pot help

Post by Fileeraus » Thu Apr 28, 2016 10:00 pm

Here is my older tank, it is a bit wider and I had a 2,5cm pipe in it, which was too small for it. Image I did some research and found out that none of the gas station fuels are methanol based, so I'll stick with HEET. Will try methanol as soon as possible.
So should I weld that 2,5cm pipe to the tank which was shown in the videos?

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