New reverse flow build for the deck!

Discussion in 'Reverse Flow' started by bbally, Jan 16, 2010.

  1. bbally

    bbally Master of the Pit OTBS Member

    Had some metal sitting around and decided to design out another reverse flow. Unlike my trailer mounted rig I scaled this one way down for everyday use.


    The inside of the roll back plate is the important part to me. It must go past any door or hatch opening to remove the infrared energy correctly. This plate sets the difference between even heat and hot spots.


    The angle iron sitting inside will be the shelf once the expanded metal is tacked onto it.


    The firebox can be loaded from the top or the side, the side is set up with a flip panel haved to remove ashes easily. The shovel is shaped to the radius of the firebox for a one pul removal of debris.


    She is starting to look like a cooker. Just using weld chipping hammer handles. They are so cheap to purchase as harbor freight that making you own is a waste of time.


    The large rectangular stack does several functions, being the exhaust stack is its main job, but on the back it has a door and there are three dowel hangers in it so I have hang come bacon, rounds or links in there for a family size cold smoke of some cured meats.

    This is one of four being built. Then I will take them down to powder coat. My boss and a couple employees are each getting one of the units along with mine. All the pipe is scrap from the pipeline work we do during the spring, summer, and fall. Winter we do get to play a little.

    I will add more pictures as it gets better looking.
  2. gene111

    gene111 Smoking Fanatic

    very nice look forward to seeing it finished & if you have to much metal sitting around just send it my way!![​IMG]
  3. silverwolf636

    silverwolf636 Smoking Fanatic OTBS Member

    That is one nice lookin rig there. I like the thickness of the pipe too. That chipin hammer idea is fine too. I have like five of them and don't know how I accumilated so many. Can't wait to see the finish.
  4. jak757

    jak757 Smoking Fanatic Group Lead

    Wow -- that's impressive. Mad skills there! That looks like it's going to be one heck of a smoker!
  5. cajunsmoke13

    cajunsmoke13 Master of the Pit OTBS Member

    Nice looking reverse flow.
  6. solaryellow

    solaryellow Limited Mod Group Lead

    Very nice. [​IMG]
  7. pineywoods

    pineywoods Smoking Guru Staff Member Administrator Group Lead SMF Premier Member

    Looks like a great start I'll be looking forward to more of your build
  8. div

    div Smoking Fanatic

    Yeah looks real sturdy ... wish I had some spair brains lying around to be able to do something like that [​IMG]
  9. morkdach

    morkdach Master of the Pit OTBS Member

    way to go bbally thanks for the idear on smoke stack & [​IMG] for it
  10. shooterrick

    shooterrick Master of the Pit Group Lead OTBS Member SMF Premier Member

    Great lookin smoker. I love the reverse flow design. Congrats![​IMG]
  11. capt dan

    capt dan Master of the Pit OTBS Member

    Nice build Bob! I bet it will do a great job![​IMG]
  12. treegje

    treegje Master of the Pit

    a thing of beauty,good job [​IMG]
  13. graybeard

    graybeard Smoking Fanatic OTBS Member

    IMPRESSIVE! I'm anxious to see the finished product. [​IMG]

  14. mulepackin

    mulepackin Master of the Pit OTBS Member SMF Premier Member

    Very nice work. You must be one busy guy. I'm trying to wrap my head around your roll back plate and infrared energy management.
  15. bbally

    bbally Master of the Pit OTBS Member

    Three things come together on the reverse flow plate. Actually four, but three main things.

    The firebox size combine with the plate and cook chamber length and the flue size. These decide when complete combustion is created. How much of the combustion energy will be absorbed into the material and how hot the exhaust will be when it comes around the plate to start its path back to the flu stack.

    There is also an effect from the guage of the cooking chambers material.

    Material guage is a trade off. Thinner means quicker heat up and faster response to temperature changes in the firebox. Thicker means slower warm up, but offers excellent dampening to variations in the firebox temperature.

    I like to see 30 minute warm ups, and 1 minute response times to temp changes in the firebox. So I specify highly Infrared active materials and choose the guage based on wattage received verses wattage emitted.

    All temps in a cooker are determined by Infrared energy. No other wavelengths of light contribute to heat.

    When looking up materials I look at their blackbody functions. I use an atomic spectrograph to look at it when engineering a unit.

    I want to choose materials that relieve 75 percent of the energy before the roll back. So a firebox burning with a 1000 F temp will always roll at a 250 F temp toward the flu.

    Then I go back and engineer the combustion chamber draft so the air ratio will eventually cause a firebox box temp of 325 F on its choked condition. This is required because as the material heats up it will absorb less and less infrared energy. So the only loss at that point becomes the cooker walls to the outside temperature. Guage of the cooker walls let you control BTU losses which can be calculated to watts and then to horsepower. This allows me to add that loss into the firebox condition for "range of horsepower operation" which means I can cook in the cold of winter without worrying about blankets and such. This all comes together to create a system that when balanced will have an Infrared source, loss, and retainment that maintains 225 F to 375 F in all operational conditions and modes.

    Which is why when I dump a cooker because I am building a new one, there is usually a line for the old one.
  16. smokemifugotem

    smokemifugotem Meat Mopper SMF Premier Member

    You are one smart son of a gun!!! I wish i had access to the knowledge you have to help me in designing my build. I kind of go for the shoot first and hope it works method. Works so far... but i know there is room for improvement.
  17. bbally

    bbally Master of the Pit OTBS Member

    Design online is to involved to do that for you. But if you got questions I will answer them with what I know. And what I know is always changing with every build.
  18. bbally

    bbally Master of the Pit OTBS Member

    The little patio units are coming along well.

  19. dirt guy

    dirt guy Smoking Fanatic

    Very nice build, Bob. Kudos.
  20. bbally

    bbally Master of the Pit OTBS Member

    Decided to build a couple as a few wanted the design.

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