Results 1 to 5 of 5

Thread: Oil Drip Burner Sizing?

  1. #1

    Oil Drip Burner Sizing?

    I'm a long time lurker, first time poster, and I'm having a bit of trouble with my waste oil burner. It is a Brute/Hot Shot based drip design heating my forge. I wasn't getting quite as much heat as I wanted off of a 1" air tube, but the 1/8 sch. 80 pipe that I'm using would deliver more oil than I could burn. So... more air + more fuel = bigger fire = more heat? But I'm afraid that in my greed for more heat, I may have made my burner too big for my forge. I stepped it up to a 2" air flow, and I'm getting a oxidizing flame in the forge, but lots of fire and a heavily carburizing flame at the forge door. The only thing I can figure is that I'm using too much of my forge volume to vaporize the oil/ heat the air to combustion temps, and it's reaching that temp about the time it hits the door. My forge is roughly 6" diameter x 22" long. If I'm doing my math correctly, that comes out to about 620 cubic inches. Am I on the right track? Are there any rules of thumb for sizing burners to volume of combustion chamber? I'm thinking of going back down to 1.25" or 1.5" pipe. Do any of you oil drip gurus have advice for me?

  2. #2
    Senior Member
    Join Date
    Dec 2010
    Location
    Vienna, Austria
    Posts
    758
    Blog Entries
    4
    What blower are you using?

  3. #3
    Quote Originally Posted by rotarysmp View Post
    What blower are you using?
    Just a squirrelcage blower off of a Becket oil gun. I have a sliding gate damper to help control air volume, but it seems as though I need a certain minimum velocity for it to work right.

  4. #4
    Administrator Site Admin
    Join Date
    Dec 2005
    Location
    Huatulco, Mexico
    Posts
    3,192
    My Hot Shot would melt my furnace if I really poured the air and oil to it.



    I suspect that your lack of heat with the one inch tube was not due to the size of the tube but to other factors.


    1. not enough blower pressure. I use a five gallon shop vac for my Hot Shot and my Brute, and it is not quite as strong as I would like for the Brute.
    2. not enough of a hot surface near the end of the burner tube to vaporize the oil. In a melting furnace, the furnace wall and the crucible are red hot (and hotter).


    Here is a centrifugal blower I made that is not enough for either burner. I am sure that this blower puts out more air pressure than a squirrel cage blower. You need pressure as well as volume to get the air through the tube fast.



    Richard
    When I die, Heaven can wait—I want to go to McMaster-Carr.

  5. #5
    Quote Originally Posted by Rasper View Post
    My Hot Shot would melt my furnace if I really poured the air and oil to it.



    I suspect that your lack of heat with the one inch tube was not due to the size of the tube but to other factors.


    1. not enough blower pressure. I use a five gallon shop vac for my Hot Shot and my Brute, and it is not quite as strong as I would like for the Brute.
    2. not enough of a hot surface near the end of the burner tube to vaporize the oil. In a melting furnace, the furnace wall and the crucible are red hot (and hotter).


    Here is a centrifugal blower I made that is not enough for either burner. I am sure that this blower puts out more air pressure than a squirrel cage blower. You need pressure as well as volume to get the air through the tube fast.



    Richard
    I'm quite certain that if I could have shoved more air down the 1", I could have gotten it hotter, but to compensate for the lack of air, I put in a bigger pipe. Bigger pipe = more air, but at a slower velocity for a given volume. I think I should have gone to 1 1/4" pipe instead - more air but minimal velocity change. I used fire clay to make a slight choke almost at the end of the burner, just before the end of the oil drip, and it seemed to work much better. I might have had a bit much on the flame.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •