"Mini Smokehouse" (gathering parts)

Discussion in 'Smoke Houses' started by jckdanls 07, Apr 14, 2013.

  1. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    so in searching for a new orifice... as numbers get smaller does that mean the hole is smaller ? thinking if I get a smaller orifice then my air vent holes wont have to be bigger... or just go with the same orifice and make air holes bigger... this is the one I currently used...

    http://www.bayouclassicdepot.com/5235_propane_burner_part.htm


    but also shuffling around the idea of using 1/4" plate for the cap and weld it on to the pipe and make my venturi with that... that way I can make an adjustable air shutter as well... make my air vents bigger and use the adjustable air shutter to control the air...
     
    Last edited: Apr 28, 2013
  2. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Keith, morning..... the numbers below were taken from the chart I linked to in post # 14....   The values are in 10,000's of an inch....  Bigger number, smaller hole.....  If you look at the chart, BTU values are given for orifice size and pressures....   Dave

    1/32 .0313 

    67 .0320 

    66 .0330 

    65 .0350 

    64 .0360 

    63 .0370 

    62 .0380 

    61 .0390 

    60 .0400 

    59 .0410 

    58 .0420 

    57 .0430 

    56 .0465 

    3/64 .0469 

    55 .0520 

    54 .0550 

    53 .0595 

    1/16 .0625 
     
  3. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member


    where dahell did my link go ? coulda swore I put one in the post for the one I picked up at Lowes.. but anyways... come to find out.. the orifice is to big...
     
  4. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Jack, evening..... What size threads does the new orifice have ?? 1/4" NPT ??  If the pipe cap is too small, get a pipe bushing reducer...  If you need a 1 1/4" cap to fit the orifice, get a Bushing Reducer from 1 1/4 to 1" pipe.... the orifice should go in the center of the cap and 4 holes around the outside for proper gas/air mixing...  drill and tap for the orifice.... drill 4 air inlet holes and try it out... drill out the air inlets as needed for a good fuel/air mix....    If the orifice is still too big and the mixture is too rich, I have used a small ball pein hammer and tapped all around the orifice to close it in by working the brass....  then using a number drill, redrill the orifice to the correct size.....  I think Joe used a contactor tip for a MIG gun for his orifice....  .030 or .035..... they are threaded and just screw in so they are easy to change....   I think I read that in his thread about making ribbon burners....

    http://www.grainger.com/Grainger/Hex-Bushing-5P521?Pid=search

    [​IMG]

    http://www.grainger.com/Grainger/LINCOLN-ELECTRIC-Contact-Tip-6JDW9?Pid=search

    [​IMG]
     
    Last edited: Apr 28, 2013
  5. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    Thanks Dave... Those are both good ideas.. will keep them in mind... I talked to Joe and he is gonna stop by HD and look at the one they have and see if the orifice is of the right size... unfortunately they don't give the orifice size in the description

    http://www.homedepot.com/p/King-Koo...read-and-Orifice-04503/203009030#.UX3CurUsnIF


    looking at your chart and comparing notes.. the .035 contactor tip would be a #65... far smaller than the #57 I currently have
     
    Last edited: Apr 28, 2013
  6. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Looking at King Kookers on that site, anywhere from 12,000 to 90,000 BTU units....  hard to tell which unit your hose is made for..  the size of the orifice will tell the tale...   
     
  7. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    and looking at your chart (link).. if I'm reading it right.. the 12,000 btu is a #57... same as I have now... and that sounds about right as they are both (HD and Lowes) for the big deep fryers...
     
  8. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    I just looked up "Gas Oven BTU Range" and it appears 15,000 to 18,000 are the range of gas ovens....   That gets the ovens up to 6-700 degrees for self cleaning....  take a guess from there what your needs will be.... and those ovens turn on/ff and are probably on 25% of the time...  (that is a guess).... 
     
  9. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    ok.. so I made a new end cap with bigger air holes... MUCH BETTER.... will get pics when it gets dark.... my question now is.... what happens when your air vents are to big.... what does the flame do then... thinking about drilling some smaller holes in between the 4 main holes....
     
  10. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Too much air and the flame will be lean....  You would then have to add a bigger gas jet orifice...  It needs to be balanced... air/gas for a good burn....  Dave
     
  11. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    yea Dave.. I know it will be lean... but what will the flame look like ? when it's fat (rich) it's a yellow flame... so what's lean look like ?
     
  12. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    ok.. so here's the burner with the new end cap... results are much better

    this is on low with the slits facing up


    this is on med- high


    now I turned the burner over with slits on the bottom...

    Low


    med- high


    the last pic shows a hint of yellow... that's why I'm thinking maybe another smaller air hole or two in between the main air holes...
     
  13. s2k9k

    s2k9k AMNPS Test Group

    I don't know Keith, that's a pretty sweet looking flame you got!!!
    I'm thinking with the small box you are building you probably won't need to go much above low.

    One thing that has been concerning me as I am still designing mine is running the pipe through the wooden side of the smokehouse. I'm concerned of the pipe getting hot and resting up against wood, heating the wood and we know what can happen then!
     
  14. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Lean flame is usually noisy from too much air flow and not enough gas... (usually caused by too high a gas pressure through too small an orifice)  Ideal is where you can adjust the flame from small to large and the color, symmetry of the flame is the same.... like the burner on a propane stove....  

    Everything has to work together.....   pipe diameter for flow, slot/hole size in pipe for the gas mixture to flow through, gas orifice for BTU output and air holes in the cap for proper air/gas mix in the venturi....   Then comes the proper gas pressure.... The gas flow, from the orifice, sucks air in the holes in the cap... it does it because of the venturi effect at the orifice area..... http://en.wikipedia.org/wiki/Vena_contracta  ....Proper gas pressure is required for the speed of the gas coming out of the orifice to perform the mixing, sucking and velocity of the gas to travel down the pipe to the slots and proper gas/air mix ratios...   

    Look at your gas stove for an example.... pressure and orifice etc. are designed as a unit for proper combustion....   coleman stove will work... side burner on the BBQ....    Seeing is the best teacher....    

    Dave 
     
  15. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Dave, the pipe should not get hot if the flame is up...  put a shield over the pipe to keep stuff out of it.... 

    Keith.... That looks good.....  Maybe the yellow part is because one or two slits have crap in them....  Run a brush down the burner tube and through the slots....   Try drilling ONE of the holes in the cap out 1/64"....   Clean all the burrs from the building process.......
     
  16. bamafan

    bamafan Smoking Fanatic OTBS Member

  17. s2k9k

    s2k9k AMNPS Test Group

    I just remember the one they built for Jerry and Joe put the pipe in with the slits facing down, like Keiths 2 bottom pics above. I didn't know if they had to be facing down for it to work right.
     
  18. s2k9k

    s2k9k AMNPS Test Group

    I was looking at burners like that too but am concerned that the fresh air intake for the burner would be inside the house and there might not be enough O2 after awhile.
     
  19. jckdanls 07

    jckdanls 07 Master of the Pit Group Lead OTBS Member

    good deal Tim.. just make sure you get the regulator WITH a needle valve so you can adjust the heat.... thinking you will need a deflector over the top of the burner as well..


    Dave... the pipe burner is turned upside down to prevent any drippings from going in the slots....
     
  20. s2k9k

    s2k9k AMNPS Test Group

    OK that makes sense Keith. I'm thinking of putting a thermal mass over top of my burner to help evenly distribute the heat.
     

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