Hello all. First post other than introducing myself.
This cooker is 12' long overall. The firebox is 30×30×30 and made of 1/2" steel. The middle is a 30"×7' section of 3/8" steel pipe. The upright box is made of 1/4" steel and is about 36"wide by 30" deep" and 48" tall. My question is t. his. To minimize the amount of work involved, what would yall think of using a pipe about 12" in diameter coming from the firebox, running almost the length of the pit in place of a baffle plate to create the reverse flow effect. I would probably move the upright box to the other end and put it on top of the fire box to serve as a warming box/separate cooker. I would then simply weld up any open spots and move the stack.
Merely my own observation and opinion . It seems as though, despite the incredible weight of the combined unit, that it might be an easier process to install a baffle plate and use a method that has been tried and works almost like a refined mathematical equation then to go thru the same or more work to install the pipe. The baffle can be dropped in with smaller pieces and then seal welded. The pipe has got to be heavy and cumbersome to handle.
Don't forget...this opinion is completely worth the price...zero! What does this unit weigh? I can see why it's a double axle
Make no mistake, there ain't no powder in this Puff ! And... I'm not really a crazy person but I play one in real life
I would go with a plate instead of the pipe. The plate gives off a radiant heat as well as evening out the temps in the cooking chamber. You should run your numbers through the pit calculator and it will get you on the right track, if it's not built pretty close to spec it can be a pain to manage your temps. I agree with moving the vertical box over to the other end. It wouldn't take much work to convert this pit into a nice reverse flow pit. jm2cw.
I think Puff and BigT are correct but there is a way to help decide this. Run this rig through the pit calculator and find out what throat size is called for. Then calculate the diameter of pipe it will take to make the "plennum" you're talking about. Then decide if that size would fit.
I have a feeling that design WOULD work but as was mentioned you might have a "hot stripe" down the middle because the heat transfer surface curves AWAY from the grate on both the front and back - When you are talking about radiant heat - distance is temp. just a hunch…..
And on the eighth day God created barbecue …. because he DOES love us and he wants us to be happy.
Current smokers: Egor (trailered RF) and Easybake (tabletop pellet drive)
Sure looks like a nice cooker just thinking it may be nice to keep it the way it is and build another reverse flow unit then you may have the best of both unless of course you don't like the cooker you have now
Just another view is all
I agree with what Gizmo said. I can see an advantage to having a hotter strip down the middle too. So I wouldn't let that stop me if that was the only con to the process. I think you have a good plan. Main thing is the math, prove it first.
jm2cw
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........
Thanks everybody. I will try the pit calcuator to see if that will work. If it will I'm thinking that the exhaust will probably need to be at grate level to make it work right. If I can't find a way to make this work, then I will probably just leave it alone. I can get pipe cheap or possibly even free. The plate which I'm guessing would probably need to be at least 3/8" thick would be very expensive. As the cooker is right now I can't fully load it due to the 3 feet closest to the fire being much hotter than the rest and I just don't want to have to rotate mid cook. I can deal with the center being a little hotter, but I doubt it will be too much of a difference from side to side. I had a 150 gallon offset with a round fire box that I made tuning plates for. I cut them out of a piece of pipe the same size and I made the width match the opening where the firebox met the cooking chamber. I didn't have any heat variation from front to back with that. I may with this setup since the cooker is wider, but it should be minimal. Also i may be able to get schedule 80 pipe which should help but will add double the weight.
I have seen a couple of them built with a pipe down the middle and another one with a piece of rectangular tubing down the middle and they both worked fine. The main thing is like Gizmo was saying, it will need to be close to the recommended throat size for it to work correctly. If you decide to go with a plate, then 1/4'' will be fine for that.
OK so I checked the calculator and it looks like I need an 18" pipe. This is a little over what I would need, but since I know I won't be able to get a 16" pipe thats my thought process.
Anybody have a thought on running three lengths of 6" pipe? i can get a 19' length of 6" used gas pipe locally for about $7 per foot but I will have to buy the whole thing.
My first reverse flow had a pipe like what you are talking about and it cooked fine. The only problem is cleaning under the pipe. I would recommend a baffle plate simply for that alone, you would have the possibility to eventually getting some nasty stuff under the pipe if unable to get all the drippings out. Rancid grease is not your friend.
