reverse flow design

Discussion in 'Reverse Flow' started by ribrustler67, Apr 21, 2013.

  1. hi all,im starting a new rf smoker,i have a new design for a smoker,just wondering if it will work though,i have a 26'' pipe 6' long,and a fire box from a section of the same pipe 24'' long,my question is, if i mount the firebox center of the cooking chamber on the backside,below the drip pan,and leave both ends open for the heat and smoke,and mount the stack center,behind the doors,right above the firebox,will this work,need some input,im limited on space,reason for this question,easier to ask now than rework later,thanks danny
  2. That design will work fine. There has been at least one build documented here. Do a search in this section for threads started be Dragons Breath. A lot of pics and the same design you are planning.
    The size sounds right. FB is 1/3 of CC volume. Look through as many builds as you have time too. A lot of good info here. You will answer most questions before you even know you had them. But if you do have any, just ask someone will help.
  3. thanks rasimmo,wasnt sure it would draw correctly,one side hotter than the other,was my only concern,thanks again
  4. sgtmonte

    sgtmonte Fire Starter

    Here are a couple pics of mine and it works great.  There is a temp difference of about 15 degrees from center to the edges but otherwise it cooks real nice.

  5. I have always thought about doing the same thing, except using a piece of 8 inch pipe to connect the two. about 6 inches long
  6. thats a mighty fine looking smoker sgtmonte,any chance we could get you to post some pics of the inside,what size hole did you allow from the firebox to cc?
  7. michael ark

    michael ark Master of the Pit

  8. radioguy

    radioguy Smoking Fanatic

    Sgtmonte is your design reverse flow?  If so how is the RF plate stack has me wondering.  RF plate opening at both sides?   
  9. This design will have a temperature differential from side to side including the middle. That being said I smoked 16 turkeys from 11 lbs. to 21 lbs. and by putting smaller birds at cooler areas and larger in the middle they all finished at the same time! Just 1 plus with this style of smoker. I have the reverse flow plate sloping to the left and that's my coolest area. Of course all smokers are individual.

    Post lots of photos while you're building your master piece.

  10. Wow, wht a great idea.  Pretty cool build.
  11. Dave,on my rf plate,i thought about positioning it low in the center and have both ends alittle higher than center,sort of a v type rf,only thing i have to watch is making sure the firebox opening is dead center of the plate,so heat doesnt want to travel to one side more than the other,whats yalls thought on this ,thanks danny
  12. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Danny, morning....  Getting heat/air flow to balance between sides is difficult at best....  If the cook chamber is a little cooler on one side, the air gets heavier and will restrict the flow.... Which ever side the wind hits will be cooler...   I think the SFB Reverse Flow was developed to overcome most of the problems associated with temperature differences.....  It ain't perfect, but getting close...   Temp differences can be a benefit if used to your advantage.... 

    By the way, the Feldon's calculator needs some adjustment if doing a center firebox...   Since the heat/air flow is going in 2 directions, the RF plate spacing, from the bottom of the cook chamber, the square inches of area can be cut in half....or close to it......  You are diverting half the heat/air in 2 directions....  You still use the FB/CC opening X 1.5 divided by 2 for each side....  hope that makes sense...   It's not necessary to do that, but gives more room for food racks....  maybe a couple inches....  

  13. I would think about mounting the firebox towards the back a little bit more, so as it is not directly underneath the cooking chamber. ...or...seperating the firebox from the cooking chamber with a short length of pipe.  Both of these recommendation are due to I feel that you would have a hot spot in the center of the cooking chamber.

    I used to be really stuck on vertical smokers , trying to refine efficiency ( referring to the amount of wood burnt and also sq.ft of footprint the smoker took up )  and on those what I did was allowed the smoke to enter the chamber along the outer walls= heat entered the bottom center of the cooking chamber, then above that was a 1/2 inch plate that diverted it towards a 1 inch gap that ran along the 4 outer walls. Above the 1/2 inch plate was a rack that held full size baking sheet pans that caught the dripping's.  It worked very well , but with out the drip pans, the 1/2 inch plate still got hot enough to burn off the drippings and alter the taste of the food.

    That's why I recommend either of my two recommendations, to give you more of a buffer zone where the heat enters the chamber.  Or think twice about not going with the traditional reverse flow design. I myself took a long time to come back to a off set firebox, mainly because of experience with not so well built units that were very inefficient.
  14. sgtmonte

    sgtmonte Fire Starter

    There's a chamber built into the bottom of the cook chamber.  Heat & smoke enters the chamber through an opening in the back and exits the chamber through 1" holes drilled in the front.

    I don't have pictures of it but here's a sketch I made to show it.  Just imagine this is inside the cook chamber along the bottom.

    Since the heat enters at the center, it is warmer in the middle of the cook chamber.  There's about a 15 degree difference between the center and the sides.

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