Author Topic: Three Otto & Langen models  (Read 632 times)

Offline Craig DeShong

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Three Otto & Langen models
« on: November 06, 2020, 05:53:43 PM »
Having just finished my 3rd generation Otto & Langen model; rather than just post it, I though I'd set all three up and get them running together.

My model of a first generation Otto & Langen engine can be seen on the left at the beginning of the video.

My model of a Crossley built third generation Otto & Langen engine can be seen in the middle; it has a build log  that can be found at: http://www.modelenginemaker.com/index.php/topic,9285.0.html

My model of a Gasmotor-Fabrik Deutz built third generation Otto & Langen engine is on the right at the beginning of the video.  It has a build log that can be found at: http://www.modelenginemaker.com/index.php/topic,9856.0.html

« Last Edit: November 09, 2020, 01:19:48 PM by Craig DeShong »
Craig

Online Jo

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Re: Three Otto & Langen models
« Reply #1 on: November 06, 2020, 05:59:54 PM »
 8)

Could you explain a bit more about what you run these on Craig. I know they should be run on town gas  or acetylene, clearly you have worked it out  because they are running well :ThumbsUp:

One of these days i must get round to making my version of the original Otto Langen  Patent Engine  :embarassed:

Jo
Enjoyment is more important than achievement.

Online Jasonb

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Re: Three Otto & Langen models
« Reply #2 on: November 06, 2020, 07:26:18 PM »
A very nice trio indeed, I've been quietly following along and as Jo says it also makes me think about my own one but without the acetylene that you are using I wonder if I may just end up with a big door stop.

Offline Craig DeShong

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Re: Three Otto & Langen models
« Reply #3 on: November 06, 2020, 07:46:18 PM »
Jo, I would be glad to.
I initially tried using propane but couldnít get the engine to fire.  I tried map gas but had the same result.

The full size engines were run on illuminating gas, which was piped into the houses in the 1800ís.  My understanding is that illuminating gas is a mixture of, mostly, methane and hydrogen and I believe the Rough and Tumble group in Kinzers, Pa. uses this mix on their Otto Langen and other early gaseous fueled engines.
 I tried acetylene around the middle of 2015; I can tell you that the results were immediate.  The engine started firing consistently.  Iím convinced all my Otto Langen engines would run on the hydrogen/methane mix but acetylene is easily obtained and works well.  The by-product of hydrogen combustion is water so Iím thinking that a little carbon (from the combustion of acetylene) that needs occasionally cleaned is better for the model.  When you build your engine, build it so it can easily be disassembled and cleaned.

You will need to be able to finely regulate that amount of acetylene your engine uses.  These things really sip fuel; you will be amazed at the small amount of fuel needed to run the engine.  On mine, Iím sure more fuel leaks away that is used to run the engine. 

I use a standard ďtorchĒ regulator to get the fuel pressure down to around 5 PSI.  Then use a water column low pressure regulator to further reduce the fuel pressure to around a half PSI.  Before delivery to the engine the fuel then passes through a restrictor that is drilled out to .020 inches.  Even with all this pressure reduction and restriction, my latest Otto Langen was leaping off the table and consistently pounding the overcharge spring at the top of the column. Jeeeeez !

In desperation I placed a set of vice grips around the rubber acetylene delivery tube and progressively squeezed the tube to even further restrict the amount of fuel available to the engine.  In this way I found a place where the engine would fire consistently, but not be over charged.  I replaced the vice grips with a piece of steel with a hole passing through it for the flexible rubber tube and a blunt end thumb screw that would screw down onto the tube.  A simple valve, but it seems to work quite well.  You can see it in this latest video.
« Last Edit: November 06, 2020, 10:06:51 PM by Craig DeShong »
Craig

Offline Craig DeShong

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Re: Three Otto & Langen models
« Reply #4 on: November 06, 2020, 07:59:07 PM »
Jason, I can tell you that, for me, it was a learning experience.  I had no experience firing an engine with gaseous fuel and tried many different approaches.  While still trying to use propane as a fuel, I managed to set the top of the worktable in the shop on fire; that was an exciting day!

Iíve stated earlier that I finished my first Otto Langen engine in 2014.  It showed NO inclination to run for a year and a half until I switched to acetylene.

About ten, maybe fifteen years ago, Wayne Grenning build some small Otto Langen models (a little over a foot tall) that he sold.  I have a friend that has one of these and he runs it on propane.  Iíve had no luck with that fuel.

Acetylene is a convenient fuel for me.  Most of us have an acetylene torch rig, and I just use the acetylene tank and regulator as the 1st stage regulator to run my engine.
Craig

Offline Chipmaster

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Re: Three Otto & Langen models
« Reply #5 on: November 06, 2020, 09:53:18 PM »
Wonderful models Craig, I have watched the video a few times.

Andy

Offline Alyn Foundry

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Re: Three Otto & Langen models
« Reply #6 on: November 07, 2020, 12:02:54 PM »
These engines ran on Town Gas or Illumination Gas derived from heating Coal in a retort. The fuel is a mixture of mainly Hydrogen, 50+% with other flammable and non flammable gasses making up the rest.

Because of the Hydrogen content the speed of combustion is quite fast and lent itself well to the " carrier flame " ignition system that Otto developed to run his engines.

At the Anson Engine museum there are several examples of Otto's atmospheric engines on working display. The fuel for main combustion is Propane and pure Hydrogen is used only on the carrier ignition system. Geoff Challinor, the curator also has one of Wayne Grenning's models on display but that particular engine has defied all efforts to run on Propane.

Due to the very " wet " nature of Propane combustion in the early stages, the model that uses HT electric ignition for firing actually soaks the sparkplug because of its position in the base of the cylinder.

As both Jo and Jason have not got to a stage of construction perhaps a change of ignition source location could be identified so that Propane could be used as the fuel? I was also thinking on the lines of using a pinpoint burner that could be directed at a port opened just after fuel induction on the upstroke?

Cheers Graham.

Offline Craig DeShong

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Re: Three Otto & Langen models
« Reply #7 on: November 07, 2020, 06:01:28 PM »
Thanks for your comments Graham.  I might also add that I donít use a single, short duration spark as you would get from a magneto, but a buzz coil/box that provides a continuous spark as long as the ignition switch is closed.

You might notice that I have reversed the motion of the slide valve in my models.  On the full size, the slide valve starts in a central location with the exhaust open; it then cycles down to allow fuel and air to enter the cylinder while the carrier flame in the valve is lighted.  The valve then cycles through the center exhaust position and to the top of its movement where the carrier flame is exposed to the cylinder to ignite the fuel in the cylinder.  The valve then return to center, once again opening the exhaust.

I have reversed the motion if the valve and re-ported it.  My valve, like the full size, starts at center with the exhaust port open.  It then cycles up to emit fuel into the cylinder.  I have no carrier flame so the porting is simpler.  The valve then cycles down, through exhaust where the opening to the cylinder is closed.  At the bottom of the valve travel the slide valve presses down on a pushrod under the engine to close a momentary switch and energize the buzz coil.  The valve then returns to center where the exhaust is opened.
Craig

Offline Roger B

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Re: Three Otto & Langen models
« Reply #8 on: November 07, 2020, 08:04:16 PM »
Excellent  :praise2: :praise2: and yet more to learn about combustion  ::)  :headscratch:  :wine1:
Best regards

Roger

Offline Craig DeShong

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Re: Three Otto & Langen models
« Reply #9 on: November 08, 2020, 02:17:44 AM »
I use spark ignition because Iíve been told that the stoichiometry at the size of these models will not support a carrier flame.  Iíve done a little testing, enough to convince me that a carrier flame canít be confined in as small a space that would be required for a scale size slide valve.

An option has been suggested to me that I havenít tried, but might have merit.  Iíll describe this in case someone wants to investigate this further.

The plan would be to have the same external flame at the valve used in the full size.  Rather than attempt a carrier flame in the valve, a filament would be installed that would be heated red hot by the external flame (as opposed to lighting the carrier). The valve motion would then transport this glowing filament inside the valve (as the full size does a carrier flame) and expose it to the cylinder where the glowing filament would ignite the charge in the cylinder.  This would very closely mimic a flame ignition engine.
Craig

Offline Alyn Foundry

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Re: Three Otto & Langen models
« Reply #10 on: November 08, 2020, 11:56:33 AM »
That's an interesting proposition Craig.

Being in my mid 60's I grew up in a town that had Gas piped to many residents. Strangely my father had a dislike of the stuff and carried on using solid fuel for heating and cooking. The AGA was a wonderful friend particularly during the winter of 62/3.

At school I chose Physics as one of my educational goals, I still remember the experiment. Eddie, our master set up two long glass tubes horizontally and filled one with Town gas and the other with bottled gas, probably Propane. We all gathered round to watch the race. We watched in amazement at the flame fronts as they burned along the inside of the tubes. It was like the Tortoise and the Hare! The Town gas actually gave a whoop as it burned whilst the Propane just plodded along. For an encore Eddie proceeded to blow up a tin can by filling it with Town gas and lighting a flame from a small hole at the top. As the gas burned it reached its correct ratio and " bang " blowing out the press fitted lid. Several lessons were learned that day and thanks to the way they were presented have never been forgotten.

On the full size Otto's it's been well proven that Propane can be used for the main fuel but in the carrier its slow rate of propagation just won't work. That's the problem with scale modelling, been there and got several shirts.

Cheers Graham.

As a Post Script, here's my little Leek atmospheric gas engine running on HHO, the gas generated from the Electrolysis of water.

« Last Edit: November 08, 2020, 12:02:56 PM by Alyn Foundry »