100# Propane Cylinder Reverse Flow Build Assistance

[fishgod]

I picked up 2 old 100# propane cylinders for $20.  I got two thinking I could use one as the cook chamber and cut the other one up for the firebox. One cylinder is 47in and the other 46.5in circumference by 40 inches tall. I'm wondering if by the time I have to compensate for the wall thickness (which I don't know yet) the cook chamber wont be very big and the baffle plate might be to close to grill grate on a reverse flow.  I have calculated the numbers, see below. Is there enough space to make a decent cooker? I will adjust the numbers when I get exact measurements. This is kind of a practice build since I have very limited welding skills(maybe an hour total).  I would like a bigger cooker at some time but don't want to practice on expensive paid for pipe.


14.59 x 14.59 x .7854 x 39.5 = 6603.87 / 231 = 28.59 Gallons

6603.87 x .004 = 26.42 x 1.25 = 33.03 FB/CC opening in square inches(Increased by 25% because of the small cooker size)

6603.87 x .004 = 26.42 x 1.25 = 33.03 = 32.60 Area under the RF plate in square inches(Increased by 25% because of the small cooker size)

6603.87 x .004 = 26.42 x 1.25 = 33.03 Area required at the end of the RF plate in square inches(Increased by 25% because of the small cooker size)

6603.87 x .33 = 2179.28 minimum volume of the Fire Box

6603.87 X 0.001 = 6.6 FB air inlets in square inches

6603.87 x .022 = 145.29 Exhaust Stack Volume in cubic inches


FB to CC Opening:

Radius
7.295
Segment Height ED
3.5
Chord AB
12.46

Fire Box
Height 15 inches
Width 13 inches
Length 14 inches

Exhaust Stack 3in Pipe 20.55 inches

Air Inlet
Lower: 1.25 x 4.25
Upper: 1.25 x 1.25

 

[fishgod]

Well, I couldn't seem to get any help so I pressed on. Did my first burn in on my smoker. Still needs to be cleaned up and painted but boy did it work great. It was easy to bring up to temp and get TBS. Below are a series of pics during the build.

 

[fishgod]

I have the build details for the smoker if anyone would like them.

 

[Dutch_Erik]

Looks good :) how does it run?

 

[meatsweats86]

Great looking build. If you could PM the details that would be awesome. I just bought a welder and able to get my hands on some tanks. I just wish those tank were a little wider and they would be perfect!

 

[fishgod]

Looks good :) how does it run?

The burn in/clean out went well. I stoked the fire and ran the unit at 450 degrees F for an hour. Then let it cool down. To night I am going to run a practice burn/season it. In prep for the morning. I have added a shelf and painted it since the last picture. Below is the finished smoker.

Great looking build. If you could PM the details that would be awesome. I just bought a welder and able to get my hands on some tanks. I just wish those tank were a little wider and they would be perfect!

I agree meatsweats86. However using a rib rack I can get 5-6 racks of ribs, or 2 boston butts, or 1 brisket. So not to bad. I did find an old 100# cylinder so it was shorter and fatter than the newer cylinders. I will post a copy of the build calcs for you.
This smoker was for teaching myself to weld and learn how to do it. My eventual goal is to pick up a piece of 24 or 26 inch pipe and make a forever smoker.

 

[Fade2Blacc]

fishgod your smoker came out amazing. For not getting any assistance (what i see) when you asked you did a great job. Love to see some smoking pics going on. Points for days