Divider Plate

Discussion in 'Reverse Flow' started by 68formalgt, Jun 20, 2011.

  1. Would 1/8" plate be thick enough for the divider plate on a 16"x 42" horizontal patio smoker? Also how high off the bottom of the tank should the divider be, I didn't see this on the calculator?
     
  2. 2bears

    2bears Smoke Blower

    Are you refering to the reverse flow plate?

    If so I would do at a minimum 3/16" as it doesn't take long to heat 1/8" metal up.

    Make sure you leave enough room between the RF plate and the fire box opening so any flames do not come in contact with the RF plate as this will give you a hotter temp on the fire box side. Some actually put a plate at the top of the fire box opening, extend it in the chamber and angle it down a little to keep flames from hitting the RF plate. I did this on my 30" x 45" cart model.
     
  3. So make the opening larger then needed so some of the flow will be blocked off by the angled plate?
     
  4. 2bears

    2bears Smoke Blower

    No, it won't interfear with the air flow. The plate can be the width of the top opening and maybe 10" deep. Weld it in at a small angle down going into the chamber. You may need a support to hold the end that is inside the chamber in its place.

    On my cart model I made a steel box that goes into the chamber that is about 14"x12x5 and has no ends that is welded in the chamber opening so it directs the heat straight into the chamber so it does not go in the chamber and up on the RF plate.
     
  5. sqwib

    sqwib Smoking Guru OTBS Member


    Exactly what I had to do
     
  6. Ok that sounds like a good idea. I'm starting to get my steel together so I'll add a little plate to make a diverter box.
     
  7. sqwib

    sqwib Smoking Guru OTBS Member

    Here's what I did.

    Update 9/01/10.

    I was a bit unhappy with my last cook, I was getting an average of 70 degree difference from left to right, sometimes peaking to a 90 degree difference, this was unacceptable. I did not realize the difference was so great until my cook last weekend.
    I tried Fire management and that had no effect.


    The top of the firebox was getting hammered with heat and 6" of the firebox is inside the smoke chamber.
    There is definitely a lot of convection going on.


    Here is how I fixed the problem.

    The Green represents the top of the firebox that is inside the smoke chamber, the Blue represents the reverse flow plate and the Red represents the baffle plates installed to reduce the heat from hammering the top of the firebox, causing excessive radiant heat.

    [​IMG]CLICK ON THE ABOVE DRAWING FOR THE TEMPERATURE TEST RESULTS

    Now I am getting an average 23 degree difference. I most likely could get it closer.

    I did another temperature test on my most recent cook, the temps were even better, averaging about a 15 degree temperature variance, click chart below.

    click here forTemp Test 2, 15 degree variance.


    At this point my testing is done, I am pretty comfortable with the even temps of the smoker.
    The smoker is maintaining 15 degrees or less variance at the 225-275 range and with that said, I will focus on making some awesome "Q".
     
    Last edited: Jun 27, 2011
  8. My father and I are getting everything together to start our first RF smoker.  The calculators have been a huge help in figuring out dimensions.  One thing I haven't been able to figure out is how much room to you leave between the end of the plate and the end of the tank. 
    Thanks in advance!
     
  9. sunman76

    sunman76 Master of the Pit

    not sure what kind of tank you got but I just left they dome end open on mine...I think it was about 7 or 8" or so.

    but this was my first build and it works great, but someone should be along to give some solid advise.

    good luck and post up some pics.

     [​IMG]

    dont have a good pic but the RF plate stops about 2" after my door where that weld seam is.
     
  10. sunman,

    what size tank is that?  I'm trying to figure what a good size tank would be to use.  I would like to be able to cook for a large group but I also dont want one that is to big where it would be difficult to just cook for the family.
     
  11. Thanks SQUIB I was thinking the plate would run the other way. Say from the top center of the fire box sloping down extending into the smoke chamber and extending a couple of inches below the reverse flow plate.
     
  12. 2bears

    2bears Smoke Blower

    Thats a lot of data, thanks for taking the time and posting the results
     
  13. sunman76

    sunman76 Master of the Pit

    I think just from looking at other it ia so where around the 200 mark.  It was a old airtank we repalced at work.
     
  14. What about adding a small dam on the open end of the divider plate so it will hold water? Is this a good thing to do? Does it help with evening out temps? I've seen a few builds with this mod just wondering about results.
     
  15. 2bears

    2bears Smoke Blower

    I did this to both of my builds ( 500 gallon and a 120 gallon smoker) and think it will work for that but the RF plate is sloped down so it would take a lot of fluid to get enough fluid to make even heat. Mine do slope quite a bit and I have not tried to add any fluids yet. The thought was to add apple juice or other flavored juice to  try and help with flavor.

    The damn at the end also provides value when cleaning the unit out as you can use water inside and capture all or most of the dirty water and drain it out the bottom ( you must add a drain to the RF plate).
     
  16. Thanks for all the info everyone. I'm excited to get started on this build, I'm just hoping it turns out as well as some of your builds.
     

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