That fire Oxygen triangle does not apply to certain compounds like Acetylene.
If you used Acetylene it would turn into a hand grenade.
The pressure jets use a spiral SS tubing in the CC itself, to bring the propane temperature up really high before entering the intake.
Good luck and lets see some videos!
Jims Little 3 Lb Thermojet
Moderator: Mike Everman
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GRIM
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Heres some videos (sorry about the quality) also i seem to have to post them seperately , bear with me , i dont have much experience with these video things
none of these runs have the gas connected you can see the regulator thing on the grass however all were started on gas
the first is running on kerosene
none of these runs have the gas connected you can see the regulator thing on the grass however all were started on gas
the first is running on kerosene
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GRIM
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This one is running on sunflower oil , (from the kitchen, my wife hasnt missed it yet)
any way in this video i have the fuel line disconnected and the gas disconnected , it is just running on the residual liquid/vapor trapped in the jacket by the check valve
in all cases the throttle response is very slow , especially the "run down" but i seem to be able to get a much lower idle than on propane , however this more than likely is due to the injector position
i can actually shut the fuel off and diconnect the fuel line and it will keep running for various seconds , this may have advantages , but i see big disadvantages
I have never seen very good thrust with this engine , on propane or any of these liquids i assume it to be close to erics 10Lb design , but have never seen more than about 2kg , thats about 4.5 lb in real money
i may have screwed up with the scaling of erics design , i just used the "align" command and scaled everything up to suit my 2" tailpipe
anyway its all good fun
and if anyone has any ideas how i can increase thrust please let me know
any way in this video i have the fuel line disconnected and the gas disconnected , it is just running on the residual liquid/vapor trapped in the jacket by the check valve
in all cases the throttle response is very slow , especially the "run down" but i seem to be able to get a much lower idle than on propane , however this more than likely is due to the injector position
i can actually shut the fuel off and diconnect the fuel line and it will keep running for various seconds , this may have advantages , but i see big disadvantages
I have never seen very good thrust with this engine , on propane or any of these liquids i assume it to be close to erics 10Lb design , but have never seen more than about 2kg , thats about 4.5 lb in real money
i may have screwed up with the scaling of erics design , i just used the "align" command and scaled everything up to suit my 2" tailpipe
anyway its all good fun
and if anyone has any ideas how i can increase thrust please let me know
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Eric
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Yea all those videos seem to be running really really low throttle. Are you able to flame it out on propane? How far in do you have the propane injectors?
Did you have the intakes stick into the combustion chamber or go flat against the cone section like the 3lb design?
Small engines benifit from having the intakes flush with the wall, it helps gas flow in and out at higher frequencies, the bigger engines can have the intakes sticking in, and depending on the length of your intakes, it may need it.
Any plans to try some water injection? Seems like your setup is perfect for it.
Eric
Did you have the intakes stick into the combustion chamber or go flat against the cone section like the 3lb design?
Small engines benifit from having the intakes flush with the wall, it helps gas flow in and out at higher frequencies, the bigger engines can have the intakes sticking in, and depending on the length of your intakes, it may need it.
Any plans to try some water injection? Seems like your setup is perfect for it.
Eric
Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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GRIM
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Hi Eric
Thanks for replying
To answer your question on propane i will have to elaborate a little
I am in Chile (British origin) been here about 7 years,
the gas they sell here comes in cylinders of 5, 12, 15, and 45 kg
the only ones that have a proper valve are the 45 kg and they are way too heavy and bulky to cart off to the test site
all the other cylinders come with the QD type of valve so i am forced to use a regulator , well i came accross a regulator that is really noting more than a valve , no diaphragm etc it just pushes down on the pin in the valve cylinder and releases cylinder pressure , i drilled the passage out as large as possible (approx 5mm dia)
there are two types of gas , standard and catalitic ,
connecting a pressure gauge to the end of the hose and opening the valve i measure max 15 psi @ 10 deg c with the standard and max 45 psi with the catalitic
i have been using the catalitic type
i remember in the uk propane cylinders were orange and butane were blue , i do not remember the static pressures
so to answer your question NO i havent been able to get it to flame out on what i believe to be propane, hence my desire to use liquid fuel
the intakes are flush with the cone as in your 3 lb design
the (vaporized liquid) injectors (1/4" dia figure eight at the pointy end ) are about 1" into the intakes measured from the tip of the flare
the gas start injectors, (3/16 tube cut off square) are positioned about 3/8" away from the flare , it starts first time every time by just opening the gas up with them in this position
will have to look into the water injection , hadnt considered it
i can post a pdf of the engine dimensions if it would help , but only with your permision , its your original design, just scaled up
Thanks for replying
To answer your question on propane i will have to elaborate a little
I am in Chile (British origin) been here about 7 years,
the gas they sell here comes in cylinders of 5, 12, 15, and 45 kg
the only ones that have a proper valve are the 45 kg and they are way too heavy and bulky to cart off to the test site
all the other cylinders come with the QD type of valve so i am forced to use a regulator , well i came accross a regulator that is really noting more than a valve , no diaphragm etc it just pushes down on the pin in the valve cylinder and releases cylinder pressure , i drilled the passage out as large as possible (approx 5mm dia)
there are two types of gas , standard and catalitic ,
connecting a pressure gauge to the end of the hose and opening the valve i measure max 15 psi @ 10 deg c with the standard and max 45 psi with the catalitic
i have been using the catalitic type
i remember in the uk propane cylinders were orange and butane were blue , i do not remember the static pressures
so to answer your question NO i havent been able to get it to flame out on what i believe to be propane, hence my desire to use liquid fuel
the intakes are flush with the cone as in your 3 lb design
the (vaporized liquid) injectors (1/4" dia figure eight at the pointy end ) are about 1" into the intakes measured from the tip of the flare
the gas start injectors, (3/16 tube cut off square) are positioned about 3/8" away from the flare , it starts first time every time by just opening the gas up with them in this position
will have to look into the water injection , hadnt considered it
i can post a pdf of the engine dimensions if it would help , but only with your permision , its your original design, just scaled up
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Eric
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The 10 lb thermojets can handle the fuel delivered much farther in, self starting with propane needs the injector near the flare, but liquid fuel you should be able to inject almost in the combustion chamber even with a really basic nozzle, actual spray nozzles can even be up to a few inches into the combustion chamber.
Thats too bad about the gas cylinders.
I doubt the dimensions are the problem, seems like it needs to get more fuel, and maybe deeper injection.
If the liquid isnt injected far enough you can see the excess fuel being blown off as fog instead of being burnt to produce power, with deeper injection you wont get as much blow back and you should see a big gain in power.
Eric
Thats too bad about the gas cylinders.
I doubt the dimensions are the problem, seems like it needs to get more fuel, and maybe deeper injection.
If the liquid isnt injected far enough you can see the excess fuel being blown off as fog instead of being burnt to produce power, with deeper injection you wont get as much blow back and you should see a big gain in power.
Eric
Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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Eric
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Here is a picture and video of the new line of engines, the "3" lb thermojet. It can self start on propane like the larger 10 lber, and really screams.
Low throttle it really isnt too loud at all, high throttle on the other hand is very very loud.
Jims little engine was based off the 3lb thermojet plans I made, with smaller diameter intakes since I didnt have the proper tubing at the time.
This new version has slight dimensional tweaks compared to the original plans.
This new engine has a intake ID of .55 compared to .44 for his engine and .50 specified on the plans. The combustor can handle more air, so I figured why not give it to em.
Also the intake flares are quite subtantial flared from .55" to a hair under .90" instead of .65" . This gives it about 60% more cross section than Jims model, and pulls in a lot of air with the big flare.
More testing tomorrow, with a bit of playing around with injector placement I am hoping for 4.5 lbs out of this little monster. Augmentation should work quite well, there is definately a lot of heat for it to harness on max throttle.... 8" flame = plenty of heat
http://www.youtube.com/watch?v=jxq0tXH-JhI
Eric
Low throttle it really isnt too loud at all, high throttle on the other hand is very very loud.
Jims little engine was based off the 3lb thermojet plans I made, with smaller diameter intakes since I didnt have the proper tubing at the time.
This new version has slight dimensional tweaks compared to the original plans.
This new engine has a intake ID of .55 compared to .44 for his engine and .50 specified on the plans. The combustor can handle more air, so I figured why not give it to em.
Also the intake flares are quite subtantial flared from .55" to a hair under .90" instead of .65" . This gives it about 60% more cross section than Jims model, and pulls in a lot of air with the big flare.
More testing tomorrow, with a bit of playing around with injector placement I am hoping for 4.5 lbs out of this little monster. Augmentation should work quite well, there is definately a lot of heat for it to harness on max throttle.... 8" flame = plenty of heat
http://www.youtube.com/watch?v=jxq0tXH-JhI
Eric
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Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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GRIM
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Eric , very impressive
your comments on flares called attention to me , my TJ inlets are made from hydraulic tube with the JIC type conical end, 37 degrees i believe just a flat cone not at all rounded
Could be i have some grinding to do ! thanks for the hint
But what really provoked me to reply was the OTHER PULSEJET you cunningly let slip into the video , looks huge , are we going to see video ?
thanks anyway
your comments on flares called attention to me , my TJ inlets are made from hydraulic tube with the JIC type conical end, 37 degrees i believe just a flat cone not at all rounded
Could be i have some grinding to do ! thanks for the hint
But what really provoked me to reply was the OTHER PULSEJET you cunningly let slip into the video , looks huge , are we going to see video ?
thanks anyway
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Eric
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Haha notice that did you? I actually was just keeping it out there because it takes up a lot of room. When we get some wet weather and I get brave I will give it another run and have the camera set up on tripod.
Eric
Eric
Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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Eric
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Here is a closeup of the flame, though it looked interesting, compared to the flame produced by Jim's engine.
Eric
Eric
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Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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Jim Berquist
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Another Fine Machine by Eric!
Eric: the Tear Drop Flame on mine, seems to elongate with other fuels.
I wont get into everything I have tried! The little Beast will consume almost every thing I feed it. Best performance was a gasoline/Paraffin mix. Bumped it up from say 2.5 to over 3.0...and some. Just checked on a sorry old fish scale.
Flame elongated some what like that and sound was deeper and much louder. Freq seemed to stay about the same as expected.
On this engine, you can tell the trust has moved from a comination of intake/ tail to the tail end..
Good stuff!
It seems you have found the ballance!
As Jim little thermojet is a diviant from your original engine this is a good experament! Is this one based one your original desien or the little Beast?
As I Understand it , Mine is a bit shorter and the intakes a bit less volume!
Mine Rockes!!!!!!!!!!
When I have the money, WILL put it on a 2 meter glider and fly it!
Eric: the Tear Drop Flame on mine, seems to elongate with other fuels.
I wont get into everything I have tried! The little Beast will consume almost every thing I feed it. Best performance was a gasoline/Paraffin mix. Bumped it up from say 2.5 to over 3.0...and some. Just checked on a sorry old fish scale.
Flame elongated some what like that and sound was deeper and much louder. Freq seemed to stay about the same as expected.
On this engine, you can tell the trust has moved from a comination of intake/ tail to the tail end..
Good stuff!
It seems you have found the ballance!
As Jim little thermojet is a diviant from your original engine this is a good experament! Is this one based one your original desien or the little Beast?
As I Understand it , Mine is a bit shorter and the intakes a bit less volume!
Mine Rockes!!!!!!!!!!
When I have the money, WILL put it on a 2 meter glider and fly it!
WHAT TO FRAP, IT WORKED![url=callto://james.a.berquist]
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Jim Berquist
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GRIM
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Just a couple of photos
unfortunately still cant get any serious thrust out of this motor
tried rosco jectors , double d , and straight pipes , there is indeed a sweet spot about 1 1/2 inchs into the inlets
running liquid propane into the jacket i can get about 3 lbs of thrust opening the flow control up more , the sound starts to loose its resonance and thrust decreases slightly, and more fuel causes a flame out,
i am sure the problem is not a lack of fuel now,
i am also happy that the jacket works well and i can pump liquid propane or kerosene and get similar results,
just a bit stumped as to why im so down on power
anyway maybe the faceted thing will make the grade
unfortunately still cant get any serious thrust out of this motor
tried rosco jectors , double d , and straight pipes , there is indeed a sweet spot about 1 1/2 inchs into the inlets
running liquid propane into the jacket i can get about 3 lbs of thrust opening the flow control up more , the sound starts to loose its resonance and thrust decreases slightly, and more fuel causes a flame out,
i am sure the problem is not a lack of fuel now,
i am also happy that the jacket works well and i can pump liquid propane or kerosene and get similar results,
just a bit stumped as to why im so down on power
anyway maybe the faceted thing will make the grade
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Irvine.J
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Grimmage
yo man, I had the exact same power issue you describe early on with a large engine. What it turned out to be was simply an intake tuning issue. I brought it in a bit with a sliding intake, all of a sudden it just went crazy! Maybe make some very thin sliding intakes for yours too? I'd also mention you will almost definitely not need run liquid propane. An engine that size should have no problems running crazy hard on an unrestricted 20lb tank.
Don't give up yet man, its a cracker!
Stick with the rossco's till it starts operating properly, then go onto the double d's. If it wont run on a rossco its unlike to run on anything else. It seems pretty much a misconception that a big engine wont run on vapour, the Hpx-30 can start very easily on a relatively strongly pinched rossco.
Best of luck again.
Don't give up yet man, its a cracker!
Stick with the rossco's till it starts operating properly, then go onto the double d's. If it wont run on a rossco its unlike to run on anything else. It seems pretty much a misconception that a big engine wont run on vapour, the Hpx-30 can start very easily on a relatively strongly pinched rossco.
Best of luck again.
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