+ Reply to Thread
Results 1 to 8 of 8

Thread: Preheating AUF/AOF

  1. #1
    Join Date
    Jan 2010
    Location
    Corinth, New York, United States
    Posts
    480

    Default Preheating AUF/AOF

    Has anyone tried preheating there AOF/AUF by putting a larger diameter pipe around their smoke stack. So for example i run an 8 inch stack, i was thinking of trying 10 inch pipe around it with a Tee at the bottom that could be reduced down to hook to my blowers. I run 800 degree stack temps but at the rate of flow my blowers use im not sure if it would get too hot. I also thought if not go all the way through the roof with the outer pipe i could add or subtract pipe lengths to adjust the temp. I wouldnt think i would want to run temps of more that 150 degrees but i think any would help. Thanks Jeff
    2017 190Taps on vacuum
    44 on 3/16 natural vacuum
    10 buckets
    20 taps on bags
    Brand new Smokylake 2X6 pan set with auto draw
    Revamped sugar house
    Homebuilt 2 4x40 membrane RO
    Homebuilt filter press
    Rebuilt arch with under and over the fire air we have named V 2.0
    New Smokylake steam bottler

  2. #2
    Join Date
    Jan 2011
    Location
    Poultney VT
    Posts
    2,392

    Default

    Quote Originally Posted by Wanabe1972 View Post
    Has anyone tried preheating there AOF/AUF by putting a larger diameter pipe around their smoke stack. So for example i run an 8 inch stack, i was thinking of trying 10 inch pipe around it with a Tee at the bottom that could be reduced down to hook to my blowers. I run 800 degree stack temps but at the rate of flow my blowers use im not sure if it would get too hot. I also thought if not go all the way through the roof with the outer pipe i could add or subtract pipe lengths to adjust the temp. I wouldnt think i would want to run temps of more that 150 degrees but i think any would help. Thanks Jeff
    go find my pictures and take a look
    Business Name
    Flat Lander Sugaring (who would think a guy from Az be making syrup)
    125 on Sap Suckers
    Close to 475 High Vac
    400 gravity adding more
    leader 2x6
    home made preheater
    hoods
    1 7D749 for AOF
    New FLS Tsunami Arch
    4 membrane TR Industries RO 2HP 3 phase 601GPH 250 PSI
    PID Display for Arch Temp.
    Chumlee of the trader

  3. #3
    Join Date
    Jan 2010
    Location
    Corinth, New York, United States
    Posts
    480

    Default

    It looks like your pulling from the piggyback or steam away is that what you do or is this the wrong picture?
    2017 190Taps on vacuum
    44 on 3/16 natural vacuum
    10 buckets
    20 taps on bags
    Brand new Smokylake 2X6 pan set with auto draw
    Revamped sugar house
    Homebuilt 2 4x40 membrane RO
    Homebuilt filter press
    Rebuilt arch with under and over the fire air we have named V 2.0
    New Smokylake steam bottler

  4. #4
    Join Date
    May 2011
    Location
    Chatham NH
    Posts
    809

    Default

    I have seen where some people have run steel pipe under the flue pan or in the transition area from the flue pan to the stack, basically making use of the hot air that is going up the stack. I think the idea is to have your blower pushing the hot air through the system from the start rather than having the blower handling the hot/super heated air.
    Last edited by n8hutch; 10-06-2017 at 08:37 AM.
    Nate Hutchins
    Nate & Kate's Maple
    2018 1000 taps?
    20x36 sugarhouse
    CDL 600gph RO
    Franken evaporator, lapierre arch, smokylake pans and a leader hood with pre-heater.
    A wife and 2 kids.

  5. #5
    Join Date
    Dec 2011
    Location
    Amherst, Wi
    Posts
    18

    Default

    Yes sir, I have a 2 x 6 with a 10 inch over an 8 inch stack. AOF & AUF. I think it works great! Truly believe it saves me fire wood. Would do it again.
    Treemonkey
    2014 180 taps Half on vac
    2015 330 taps 230 on vac
    2X6 wi Smokey Lake pans
    Home made RO one 4" membrane
    Arch wi AOF, AUF, and heat recovery.

  6. #6
    Join Date
    Mar 2006
    Location
    Lanark, ON
    Posts
    2,001

    Default

    It would definitely help but I'd have the blowers draw in cold air, push it through the space between the 8" and the 10" stack pipes (I'd go bigger to say 12" for the outer) and to the AOF/AUF nozzles.

    The commercial high efficiency wood units (like our Force 5) draw in cold air and pipe it around the fire box to the nozzles but your idea is definitely something worth trying!
    4,600 Taps on vacuum - More to come when Time & Energy Permit
    9,400 gallons storage in Zero and Open Top Tanks
    600 GPH CDL RO - NEW for 2015 a 2nd 600 GPH tower!!!
    3.5'x14' Lapierre Force 5
    http://s246.photobucket.com/albums/gg98/ennismaple/
    www.ennismaple.com

  7. #7
    Join Date
    Jan 2010
    Location
    Corinth, New York, United States
    Posts
    480

    Default

    I'm going to try something but I'm not sure what yet. I think pushing the air is the proper way to do it but I have pulled hot air 160 to 180 degree through a squirrel cage blower for years without an issue.
    2017 190Taps on vacuum
    44 on 3/16 natural vacuum
    10 buckets
    20 taps on bags
    Brand new Smokylake 2X6 pan set with auto draw
    Revamped sugar house
    Homebuilt 2 4x40 membrane RO
    Homebuilt filter press
    Rebuilt arch with under and over the fire air we have named V 2.0
    New Smokylake steam bottler

  8. #8
    Join Date
    Mar 2013
    Location
    Hoosick Falls
    Posts
    1,975

    Default

    Preheating will make a huge difference in fuel consumption. Increased our charge duration on the outside wood heater by feeding the blowers hot air from a 10" around an 8" well casing. Nearly a 40% increase in efficiency.

    I have sketched out running a tube inside the chimney and into an AOF and AUF.

    This was before I put an exhaust fan for a garage to remove the truck exhaust onto my air under fire. The pressure is so high I don't need any AOF to maximize the burn wood lasts longer next to no ash and stack color is clear 30-50 seconds after a charge of wood.

    Pulling in ambient air will make the fans last longer. My motors need lubrication every 4 months when in hot air. annually for the one in the warm room air.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts