140 gallon reverse flow insulated firebox build.

Discussion in 'Reverse Flow' started by adam a, Apr 28, 2016.

  1. adam a

    adam a Newbie

    Hi all,

       I have got my hands on a 140 gallon air receiver tank that I plan to turn into a reverse flow off set. I've used Dave's calculator that was converted to excel so would someone be kind enough to check the results for me. They look pretty good but a second opinion will allow me to cut up the cylinder with some confidence that I'm doing the right thing.

       I also plan to insulate the firebox with some 1200 degree kiln insulation I have and use a glass door off a combustion heater so I can see what's going on with the fire. Thanks in advance.

    Last edited: Apr 30, 2016
  2. adam a

    adam a Newbie

    martyinco likes this.
  3. adam a

    adam a Newbie

    bdskelly likes this.
  4. They are correct, I see you are using Dave's calculations.

    Be a fun build to watch

  5. adam a

    adam a Newbie

    Someone was kind enough to convert it to Excel which made it very easy to use. 
    Last edited: Apr 30, 2016
    martyinco likes this.
  6. Love Excel ------------

    martyinco likes this.
  7. adam a

    adam a Newbie

    So do I. :) Thanks for checking the maths.

         My next step is to clean up the corrosion, cut off the motor mounts and get a coat of primer on it. I'm going to measure out the door and cut it and the fire box openings out. I'm also going to put a concealed door seal on the CC opening so that's going to take a bit of work to do the curved sections but it will be worth it. I got the idea for the combustion stove door after thinking of a way to use the vents out of one so I didn't have to make them and it made sense because of the integrated seal built into the door.   

  8. bdskelly

    bdskelly Master of the Pit OTBS Member SMF Premier Member

    Looks like a GREAT start. Glass door... Fancy! I usually just leave my door open.

    Watching this build closely. Point! 

  9. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Afternoon Adam......   For the door seals, it's perfectly OK to use thin metal...  1/16" X 1 1/4" works well...   or what ever is handy...
    adam a likes this.
  10. adam a

    adam a Newbie

    I'm going to fold up the straight sides and weld up the curved sides from 3 pieces. It will be a little fiddly but will work well. I'm planning a covered area so I hope this lasts a long time.

    I'm in the process of finding an old combustion heater that I can cut up so I'm building the CC first and I have access to a laser cutter so I'm making the hinges, counter weight and handles out of 2 pieces. One per side and weld them to the door. I'll take a picture of the mock up when i make it out of ply.

  11. adam a

    adam a Newbie

    Would putting the fire box door on the front cause any issues. I'm thinking of putting the doors on the front and the vents on the side to keep the airflow clean bu

    t make it easier to load wood and see the fire through the glass door.

  12. martyinco

    martyinco Newbie

    I cant wait to see the build come together [​IMG]

    Even more excited that someone is using the Excel spreadsheet I made [​IMG]
  13. adam a

    adam a Newbie

    Thanks for making it super easy. :)
  14. adam a

    adam a Newbie

    I've decided to build the fire box 24" x 22" x 21" to give me a slightly bigger fire box which will allow me to put the double cast iron combustion stove doors I scored on the front and to allow for the 1 inch of insulation so the FB isn't wider than the CC. 


    I've also done the calculation for the RF area so I can start cutting .

    Last edited: May 10, 2016
  15. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Why did you use the 2 knowns above.... 

    How did you know what the segment height was supposed to be ?? 

    These are the variables I used to get the correct segment height.....

    Click on the 2 variables you know

    ......Radius and Central Angle...........................Radius & Chord AB
    [X] Radius & Segment Height ED.....................Radius & Apothem OE
    ......................................................Radius & Arc AB
    ......Chord AB & Segment Height ED................Chord AB & Apothem OE
    ......Segment Height ED & Apothem OE...........Chord AB & Arc AB


    Last edited: May 17, 2016
  16. adam a

    adam a Newbie

    I started at 6 and 6 and then adjusted from there. Only took a couple of adjustments to get the right area.

Share This Page