LPG/propane/butane Gas jet sizes

Discussion in 'General Engine Discussion' started by doubletop, Nov 8, 2010.

  1. Nov 8, 2010 #1

    doubletop

    doubletop

    doubletop

    Well-Known Member Project of the Month Winner

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    Tonight I've been researching a new burner for my Rob Roy based on an article "Gas Firing for William" C H Hopkins (Oz) in Model Engineer 18 July 1986 and "Propane Burner" Lindsay McDonnell Modeltec Magazine June 1989. These articles were the basis of successful burners being used on model locos in NZ for some time.

    The idea is to get more gas an air into the system and better combustion. I've just spent a number of hours trying to find out what drill sizes relate to gas jet sizes numbers so I can quantify the #15 jet in my ceramic burner. A bigger number is larger hole but a bigger drill number is a smaller hole, so its not that. I've found a web page that gives the BTU/hr for various hole sizes vs PSI.

    http://www.joppaglass.com/burner/lowp_chrt.html

    http://www.joppaglass.com/burner/highp_chart.html

    Anybody got any clues please?

    While we are on the subject, if you are into this you may find this useful

    www.eclipsenet.com/catalog/contents/Documents/EngGd/efe825tn.pdf

    Pete
     
  2. Nov 8, 2010 #2

    John Rudd

    John Rudd

    John Rudd

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    I found this with hole sizes………..





    Gas Jets, sizes 5 Ref: FTGJ5

    Jet No 5 : 55grm/hr (for butane/propane burners) consumption rate w/valve fully open (figures for guidance only as consumption can vary under different conditions); thread size 1BA, hole size .2 mm;







    Gas Jet, sizes 8 Ref: FTGJ8

    No. 8 gas jet for butane/propane burners; 69grm/hr (for butane/propane burners) consumption rate w/valve fully open (figures for guidance only as consumption can vary under different conditions);
    Gas jet thread 1BA, hole size .25 mm







    Just need the right size of ‘bit’ to make the hole………..
     
  3. Nov 8, 2010 #3

    shred

    shred

    shred

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    Here's one reference for model gas jet sizes: http://www.homemodelenginemachinist.com/index.php?topic=2049.msg39589#msg39589

    There's not really a drill size correlation as most drill sets don't go that small.

    There's also a thread or two on making gas jets, but the search engine here is getting lazy... it took me a while just to find that first link and I knew where it was.
     
  4. Nov 9, 2010 #4

    doubletop

    doubletop

    doubletop

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    John/Shred

    Just what I was looking for thanks

    The Eclipse doc gave me the drill dia for the number codes and the highp_chart from joppaglas the BTU/hr figures for the same drill sizes. With the Calor jet sizes I can relate all the data and get BTU/hr figures for for the calor jets and then establish the relationship between my ceramic burner (with a #15 jet) and the burners in the two articles with jets made with #60 drill and #66 drill.

    I also have the recent article in Model Engineer about the Guilford MES efficiency trials which had 3 Rob Roys competing and provides details of the calorific value and the amount of coal used so I should get some idea of the amount of heat I should need.

    I should then be able to establish if my burner can put out enough heat to keep it running before I head off and make a new burner. Well that's the idea (it could be complete tosh but I've got a lot of data)

    BTW you may find these interesting (the second link has some good docs)

    http://207.200.58.35/Resource%20Library/Forms/AllItems.aspx

    http://207.200.58.35/Resource%20Library/Forms/AllItems.aspx?RootFolder=http%3a%2f%2f207.200.58.35%2fResource%20Library%2fGas%20Check%2fCETP%206.0%202001%20Gas%20Check%20Cross%20References&FolderCTID=0x01200016E31ECAED4C8E4AAEB16325DB5F5979


    Pete
     

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