Please define "reverse flow"

Discussion in 'Reverse Flow' started by smokinfireman, May 12, 2011.

  1. [​IMG][​IMG][​IMG][​IMG]I am relatively new to the smoker clan, having only been at it for about 5 years now. I bought a CharGriller Pro back then, and have progressed to having built my own.

    What I built was a 250 gal fuel oil tank, vertical stance. At the time, I had a "bright idea" to put a 1/4 inch thick plate just above the fire area in order to avoid flare up onto the meat. (My fire is directly inside the tank, not an external firebox.) It is mounted tight against the end wall over the fire, and runs to within 6 inches of the other end, with approx 4 inches of space between the plate and sides of the tank. It also doubles as a charcoal tray for regular bbq such as burgers or sausage patties. The smoke stack is on the opposite end of the fire access door. The red box is a great storage area to carry all my wood and tools.

    What I did not realize at the time was how well the plate evenly dispersed the heat and smoke, and the recovery time when I open the lid. 

    So what exactly is reverse flow? And could someone post pics here of the inside area showing this? Thanks in advance for your info.
    Last edited: May 12, 2011
  2. fpnmf

    fpnmf Smoking Guru OTBS Member


    This site has tons of info.

    I would suggest you spend some time reading all the different forums and the WIKIs.

    Then use the handy dandy search tool for specific interests!!

    Have a great day!!!

  3. smokinal

    smokinal Smoking Guru Staff Member Moderator OTBS Member ★ Lifetime Premier ★

    On a reverse flow the stack & the firebox are on the same end. It sounds like the plate you installed is the same as you would find in a RF, only the exhaust is on the other end. 
  4. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    Not sure I understand completely what you are describing but you said it was vertical so I assume the diameter of the smoke chamber is between 24 and 36 inches but the cooker stands maybe 5 ft tall?  The plate is acting more as a diversion plate and prevents as you said grease from dripping directly on the fire.   If you have a temperature problem it is more pronounced the higher you go in the chamber.

    In most offsets the temperature difference is most pronounced the closer you are to the firebox.  Heat enters at the fire box, rises to the top of the cook chamber and travels horizontally to the exit stack. 

    In a reverse flow cooker the heat enters beneath a heavy metal plate installed horizontally.  The heat and smoke are trapped under this plate until it reaches the far end of the cooker where it then rises and travels back down toward the firebox end and exits the chamber.  It makes the horizontal trip twice.

    As the heat travels under this plate the plate heats and redistributes the heat more evenly throughout the smoker.  The smoke travels the length of the food on its way back to the exit stack.

    Another advantage to a well built reverse flow is all the additional steel acts as heat sink, helping with recovery times and reducing temperature spikes.   

    Welcome to the forum,  don't forget to tell us a bit more about yourself and keep us posted with your cooking by posting lots of Qview

  5. Thanks, Al. Question: Would my plate need to be touching the sides of the tank for it to be a true reverse flow? I did upload some pics of it.
  6. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    Yea,  just saw the pics.  In a reverse flow the plate is welded on three of the four ends and the firebox is outside the smoker
  7. 2bears

    2bears Smoke Blower

    Yes the plate needs to touch the sides and most weld it in solid so no heat gets through until it reaches the end where you are 6" from the end of the cooker.
  8. Thank you, Gentlemen for that info. I am considering building a new one some time this year, but for now, this one works very well. I have not had any complaints as of yet about anything I have cooked on it.

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