rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 17:01:49 GMT -5
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Post by racket on Nov 14, 2018 17:25:45 GMT -5
Hi Rick
That FT looks OK .
What radial gap between flametube and outer can wall??
What size are your injection holes ??
You mention that your injection holes squirt out above the Primary holes , they need to squirt at the holes so theres a collision between air and fuel to get good mixing .
When you say its got a fluttering combustion , that can be "normal??" depending on severity , the combustion is pretty intense and can be "noisy" .
Cheers
John
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Post by azwood on Nov 14, 2018 17:53:25 GMT -5
Hi Rick That FT looks OK . What radial gap between flametube and outer can wall?? What size are your injection holes ?? You mention that your injection holes squirt out above the Primary holes , they need to squirt at the holes so theres a collision between air and fuel to get good mixing . When you say its got a fluttering combustion , that can be "normal??" depending on severity , the combustion is pretty intense and can be "noisy" . Cheers John I've found at low air speeds propane gets real hot.are you sure you don't have any leaks in your outer can or pipework that seems to upset things.you can also angle the secondary holes upwards with a steel rod try that.but listen to rackets advice he taught me lots got mine sorted it runs great now. |
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 17:58:31 GMT -5
1 inch,5 inch F/T and 7 inch outer. I'm going to line up the injector to the primary holes. the holes on the injector are .080 inch and there is 8 of them.
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 18:01:16 GMT -5
Is there any benefit in adding some tertiary holes as far as cooling effect.
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Post by azwood on Nov 14, 2018 18:08:23 GMT -5
Is there any benefit in adding some tertiary holes as far as cooling effect. After looking at the pics I don't think a air division would help but bending the holes so there fluted towards the airflow never hurts. |
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 18:14:37 GMT -5
Ill give it a shot
Thanks
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Post by racket on Nov 14, 2018 18:18:04 GMT -5
Hi Rick
Yes, line them up first and try .
Plenty of gap .
If you still have problems maybe make the injection holes smaller so as to increase the fuel jet velocity , 0.080" is kinda big , they probably need to be <0.060" especially with 8 of them , you need to get the fuel jets out to the air jets coming through the FT wall .
DO NOT change Tertiary holes at this stage .
Do you have a pic of the flametube since its been running so as to check the colour pattern along the tube to verify where combustion is occuring .
Cheers
John
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 18:42:57 GMT -5
In the pic you can see the hot area on the outer shell. I'll run it in a couple of hours and give a report on where we're at.
Thanks for all the input.
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Post by racket on Nov 14, 2018 19:02:40 GMT -5
OH !!!
The outer can shouldn't get coloured..............and especially down at the Secondary Zone holes.
I'll wait for your next run report .
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 21:08:02 GMT -5
It runs great now. EGT is lower and it runs smooth as silk. I moved the injector into the primary holes and angled the secondary and tertiary holes towards the end cap. I already angled the holes before I read your advice Racket.I just went for it and fortuneatly it seems to work. I agree Racket that propane only produces so much RPM. Maybe a second tank.
Thanks again gentlemen
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 14, 2018 21:09:41 GMT -5
the outer can is only .063 thick so that might be why it shows discoloration.
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Post by azwood on Nov 14, 2018 23:46:45 GMT -5
It runs great now. EGT is lower and it runs smooth as silk. I moved the injector into the primary holes and angled the secondary and tertiary holes towards the end cap. I already angled the holes before I read your advice Racket.I just went for it and fortuneatly it seems to work. I agree Racket that propane only produces so much RPM. Maybe a second tank. Thanks again gentlemen Lol awesome another running jet to upset some people with some sweet noise. |
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Post by racket on Nov 15, 2018 0:41:43 GMT -5
Congratulations :-)
You could try sitting the propane cylinder in a tub of warm water ( body temperature) to prolong the vapour pressure , the "boiling" propane will take heat from the warm water rather than itself .
A thin outer can still isn't a reason for that heat colouration , I've used 0.040" WT without colouring ,
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rickw
Junior Member
Joined: November 2018
Posts: 73
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Post by rickw on Nov 15, 2018 1:22:42 GMT -5
thin outer can still isn't a reason for that heat colouration , I've used 0.040" WT without colouring ,
Its good to know that I’m not to thin with the combuster wall thickness. It’s what I had on the shelf.
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