# Advice needed for reverse flow smoker!



## anderjes (Mar 22, 2015)

Hey Everyone Im new to this site. Ive read many different threads on here and got a ton of info from everyone. Im currently on my 2nd smoker build. Im buulding a trailer mounted reverse flow smoker. I have a 320 gallon propane tank. Dimenisons 30in diameter by 10 feet long. Ive done the pit calulator and came up with these numbers.
Cook Chamber Size
24640 cubic inches
Fire Box Size
H-30in W-36in L-24in
Chimney Size
6inx46in
Firebox Air Inlet openings 
6in round and need 3 of them
Fire box to cook chamber opening
Half moon design H-6in L-16in
Same opening for reverse flow plate at oppisite end of cooking chamber 
Height of reverse flow plate 
10in off bottom 
Cooking rack
15in 
Working now on preping trailer so before we start on the tank just want to make sure im on the right track with all my calulations. Any adviced would be apperciated!


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## themule69 (Mar 23, 2015)

I didn't run the numbers but it sounds like your on the right track. I also see this is your first post. So when you get a chance will you drop by roll call so everyone can give you a proper SMF welcome?

Happy smoken.

David


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## anderjes (Mar 23, 2015)

@themule69 did go on over to roll call to do a thread on there. With all of my calulations the only one im kinda confused on is my FF to CC opening. It said i needed 23in of opening, so would my 6x16 opening be enough or is that to big? And then with my reverse flow plate that means i need 23in of opening in that as well correct? Which would roughly put me at 8in from end with 14in across. This one stumps me a,bit,and is probably one of the most important to get spot on.


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## daveomak (Mar 23, 2015)

Follow the step by step in the "circle calculator" portion of the tutorial......  Adjust the "segment height" portion until the "segment area" comes very close to your 23 sq. in. you need....  That segment area opening is the "GREEN" area in the picture....

http://www.smokingmeatforums.com/t/...ak-and-others-ready-to-use-rev-4#post_1264161


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## daveomak (Mar 23, 2015)

anderjes said:


> Hey Everyone Im new to this site. Ive read many different threads on here and got a ton of info from everyone. Im currently on my 2nd smoker build. Im buulding a trailer mounted reverse flow smoker.* I have a 320 gallon propane tank. Dimenisons 30in diameter by 10 feet long.* Ive done the pit calulator and came up with these numbers.
> Cook Chamber Size
> 24640 cubic inches
> Fire Box Size
> ...



The dimensions of that particular tank, may not work for a reverse flow smoker.....  It may be too long and skinny to work properly....


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## inkjunkie (Mar 23, 2015)

DaveOmak said:


> The dimensions of that particular tank, may not work for a reverse flow smoker.....  It may be too long and skinny to work properly....


Even with my extremely limited knowledge of RF's that is what I was thinking.  My little 60 gallon one I am planning is 23" or so in diameter,  with a cc volume of 13860 cubic inches


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## anderjes (Mar 23, 2015)

Thanks for the link share. DaveOmak. I did those calculations and its coming up with 2in segment height. Ive still very confused by it. Math never was my strong suite haha. Im confused on how it wont work as a reverse flow smoker. I know the diameter for that long of a smoker isnt ideal but as long as my openings to FB to CC, RF plate height and opening are correct with the correct stack size and height are right it should work correctly, right? Or is it cause with that being so long,and,skinny its not gonna carry the heat properly? Need help?!


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## daveomak (Mar 23, 2015)

QUOTE:  _ Dimensions 30in diameter by 10 feet long._

30" x 120" length =* 84,823 *cubic inches.....   

FB/CC opening = 339 cu. in.
Under RF plate = 339 cu. in.
etc.....

FB volume = 27,991 cu. in.   30 x  30 x 31

FB air inlets = 85 sq. in.  (80 below the fire grate, 5 or more above)

exh stack   8" ID x 30-36 height... would work....

RF plate height (ED) 14" 

RF plate width 30 "..

The smoke channel below the RF plate takes up 1/2 of the smoker volume.....


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## anderjes (Mar 23, 2015)

[ATTACHMENT=1992]IMG_3183.jpg (635k. jpg file)[/ATTACHMENT]


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## daveomak (Mar 23, 2015)

I would cut the tank down to make a 6' and 4' smokers....


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## anderjes (Mar 23, 2015)

That pit calculator is confusing. I did the tank chamber size so instead of 30x120 it was 320 gallons. with the rounded end i dont which is correct. for my RF plate could i drop the height of it if i had more of a opening at the end? The round end of the tank wont have my cooking  grate over it so that leaves a good amount of room. Just want to see if i can make this a reverse flow or if im,going to,have to cut the dome off the one end. Which would bump it down to 96in


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## anderjes (Mar 23, 2015)

If i cut the domes of the ends of my tank the new dimensions would be 30x88. Would that then work for a reverse flow?


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## daveomak (Mar 23, 2015)

What is it you want, exactly....  The numbers I put in post 8 will work....   The smoker won't work that well....   too much surface area per volume....   too much heat loss...  

One member on here made a tank similar to yours into a "Jambo type smoker" and it worked great...


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## anderjes (Mar 23, 2015)

Jambo type is just a straight stick burning correct? Firebox on one end and exhaust on other? No tuning,plate or anything like that? Thats how my last one was. Had a hot end and a cool end. Which i didnt like. Granted it was only 4 feet long so could fill it up very quickly and always had to rotate. With this tank my cooking area is almost 2x that so it wouldnt be to terrible. FF and FF to CC would be the same as the calculations you did correct?


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## bruno994 (Mar 23, 2015)

Yes, Jambo pits are direct flow, but the FB to CC opening is different than traditional offsets, it is angled upwards so that it actually enters the chamber above the bottom grate.  This also helps create as Jamie Geer likes to put it, his "Texas Microwave", which is the upper grate on the opposite end of the firebox.  Most comp cooks using Jambos will cook their chicken up there.


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## daveomak (Mar 23, 2015)

Jambo Design.jpg



__ daveomak
__ Mar 23, 2015


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## bruno994 (Mar 23, 2015)

Actually coming in to the CC, there is an angled piece, shooting the heat and smoke basically above the lower grate...a couple examples..













jambo1.jpg



__ bruno994
__ Mar 23, 2015


















jambo2.jpeg



__ bruno994
__ Mar 23, 2015


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## bruno994 (Mar 23, 2015)

Here is an internal pic of a new line of pits and smokers being built by Champion Smokers...great looking rigs...













championsmoker.jpg



__ bruno994
__ Mar 23, 2015


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## anderjes (Mar 23, 2015)

[ATTACHMENT=1993]20150323_134445.jpg (2,749k. jpg file)[/ATTACHMENT]


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## bruno994 (Mar 23, 2015)

Would not recommend your FB to CC opening be that high up, all your heat will stay high, unless your exhaust was below the lower grate.  

Thinking about a tank that size, you would probably benefit from building a center fired, reverse flow designed smoker... There have been several documented builds like that on here.  I can't remember who, but if all else fails, do a quick search in the tool bar above for center fired smokers.


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## anderjes (Mar 23, 2015)

with the trailer i have id like to have a side mounted FB. I looked up the center mounted smokers and with the setup i have that not gonna work. Trailer reasons. If i did just a regular stick burning smoker had the FB to CC opening on the bottom and exhaust oppisite side on top. How much do you guys think my temp difference would be from hot side to cool side? I wouldnt some temp change cause it be nice to have a hot side and cool side with smoking different meats. I mean 10' is a long ways i feel. If it was 20 to 30 degrees wouldnt be the worse.


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## bruno994 (Mar 23, 2015)

You are right, as much as I wanted to build my RF to achieve fairly even temps across the grate, there is also something to be said for having cool and hot spots as well.  Chicken likes to be cooked hotter, briskets can be nice when cooked at a lower temp.  I would reckon that you might have a larger margin than 20 to 30 degrees though on that long of a smoker.  Possibly 50 plus...from FB side to exhaust side.  You could go with tuning plates, which will help out quite a bit.  Start with a solid 12-18 inch plate then start opening your gaps all the way down.


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## anderjes (Mar 23, 2015)

So after the first solid piece is in. Just start out after with a 1/2" gap and increase from there? My guess would be with them you wouldnt weld them in place until a couple fires are ran threw and you firgure out the best spacing on them. What kind of height you normally mount them at ? 4 to 6in below grates?


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## bruno994 (Mar 23, 2015)

Yep, 4" below the bottom grate should work just fine.  I wouldn't weld them in, just keep them moveable in case you want to adjust later.


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## anderjes (Mar 23, 2015)

Sounds good. The only thing would be travling with the trailer and finding some way to keep them in place as you go down the road. Thanks for all the info hope to get started on it this weekend


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## daveomak (Mar 23, 2015)

bruno994 said:


> Here is an internal pic of a new line of pits and smokers being built by Champion Smokers...great looking rigs...
> 
> 
> 
> ...



Nice smoker....   one more design to think about....   I think they all work...  just taking the time to figure them out so you get good Q is what it's all about....


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