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too much unburned ashes, what should I adjust on my Eko 40

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by leatherguy, Dec 14, 2012.

  1. leatherguy

    leatherguy Member

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    I'm into my 3rd year (year round burning) and lately I've had a tremendous amount of unburned coals and ashes going thru the nozzle, I checked my nozzle- some erosion, checked my air settings 3/8" and 3.5 turns fan 50% shutters full open. wood is 2 yr old ash and yellow birch, I've had these settings work for me since I first set up my boiler. I made a screen to sit on nozzle opening now the charcoal sits in burn chamber plugs nozzle flow and no gasification. I'm going to modify my screen openings a little. So what is causing the wood to break up so much into charcoal.

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  2. Fred61

    Fred61 Minister of Fire

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    Erosion of the nozzle would be the primary culpret followed by nice dry 2 year old wood that breaks down into charcoal chunks sooner than moist wood. I built an overlay from a half brick to protect the nozzle from further wear which stops most coals but I have several unburned coals drop through because I stir the the gray ash out of the coals allowing them to drop through the nozzle every day when I start a new fire and many unburned chunks drop through along with the gray ash. I have a hoe specifically shaped to the U bricks and drag it all out into a 1/8" hardware cloth mesh which allows the gray ash to drop through into a brownie pan and the charcoal gets tossed back on to the prepared fire before lighting.
  3. leatherguy

    leatherguy Member

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  4. leatherguy

    leatherguy Member

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    I modified my screen that lays over the nozzle 1/2" slotted stainless steel mesh. I've got great gasification going now. lets see what happens, I'll check it @ 6pm tonight and fill the boiler for the night. I'll order a new nozzle but it seems a nozzle ought to last a lit.tle longer
  5. mr.fixit

    mr.fixit Member

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    Let us know what you find out on the replacement nozzle.(cost-availability)

    This is a thread on what I did to extend the life of the nozzle http://www.hearth.com/talk/threads/oak-nozzle-erosion-on-eko-40.72151/

    Someone on another thread commented that it was a "cobble job",but you know what, it was a easy fix and works great IMO. When the nozzle is the correct width it prevents larger coals from falling through.

    I always thought a thick piece of stainless steel with the slot cut in it would work too.

    I think the nozzle is going to be a wear item for us users that go thru alot of wood. Anything a person can do to extend its life is worth the effort.
  6. hartkem

    hartkem Member

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    I used mr. fixits idea and put the firebrick overlay on my EKO before the first fire. Its worked perfectly. I will inspect the condition of the bricks/nozzle this spring.
  7. henfruit

    henfruit Minister of Fire

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    I am useing a cast iron nozzle.So far so good.
  8. Fred61

    Fred61 Minister of Fire

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    Last year I just laid the brick over the nozzle. This fall I blocked in the spaces fore and aft of my home made nozzle brick in case it accidentally slid.
    resized brick 2.jpg
    View attachment 85066
  9. Fred61

    Fred61 Minister of Fire

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    resized brick 1.jpg
  10. mr.fixit

    mr.fixit Member

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    They should be made with an easily replaceable nozzle insert just like you made there Fred.
    That looks like a larger size firebrick than I've seen at the homecenters.Was it from a brick and block supplier?
  11. Fred61

    Fred61 Minister of Fire

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    Gee Fix, I don't know. I stole it out of the back of my brother-in-law's truck. He's a mason. I do think it's bigger than a standard fireplace firebrick. I'll measure the other one I stole tomorrow and let you know.
  12. leatherguy

    leatherguy Member

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    I am happy to report that I had a complete burn last night, no unburned charcoal. So my stainless grate with 1/2" slots is going to work. I'll try to find some fire brick similar to freds. I think that will last longer. I like the Idea of a cast iron nozzle, anybody make them for an Eko?
  13. stee6043

    stee6043 Minister of Fire

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    In addition to the nozzle discussion I'd offer that I only run my fan shutter full-open during startup. Once I have a good burn established I'll take my fan speed down to 50% and close up my shutters sometimes more than 50% closed. I use my stack temps as my guide.

    Have you read the "fine tuning EKO" thread? Might help you maximize your burns. Won't do much for your nozzle though...
  14. Fred61

    Fred61 Minister of Fire

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    The actual dimensions of the brick are: 8-15/16 X 4-3/8 X 1-3/16. I am assuming it is from the block plant. Masons don't usually shop at HD.
  15. maple1

    maple1 Minister of Fire

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    What did you cut the firebrick notch out with?

    Also curious about the stainless slotted grate mentioned above - can you post a pic?

    I put a fireplace grate in the bottom of my wood chamber (with the legs cut off) - the 'nozzle' in a Varm is actually a great big round hole, and I thought doing something to help keep the coals in the wood chamber as long as possible would be a benefit. After using the fireplace grate for over a month, I think it is a big help - but the grate is now almost toast. So I'm looking for something else cheap & easy. I was thinking of just finding some stretch metal scraps and simply replacing as they wear away - likely can't get much cheaper & easier. But I'm still looking for other ideas. I'll be keeping my eyes open for different sized fire brick I might be able to notch/cut to fit - along with some stretch metal scraps. I have no idea where to find some cheap stainless stuff.
  16. Fred61

    Fred61 Minister of Fire

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    Penciled on the outline, clamped it, and plunge cut it three or four times with my Makita circular saw with a dry cut diamond blade. Flipped it over finished the cuts , broke out the center and Polish planed the ends. Total time, 7 minutes.
  17. leatherguy

    leatherguy Member

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    The stainless grate is made from a 1/4 slotted aggregate screen the wires are about 1/16 " thick and I took out every other one in the lengthwise direction so i have an effective slot width of 1/2" The piece of screen 4" x 12" fitts nicely on top of the nozzle and stays put I don't usually rake ashes in the upper chamber i just leave it alone for the season but i did a lot of raking when i tried using 1/4" slots and the screen never moved . Now we just have to see how long this screen lasts. If it lasts the season maybe I will market them. I'm not much good with pics, but when I look in my upper chamber after a complete burn I just see a wire centered over the nozzle slot and the rest of the screen is buried in ashes.
  18. mr.fixit

    mr.fixit Member

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    Polish planed?
    That firebrick is the same size as the std. ones that the home center carries.Just looked smaller in the pic.
    The 25 must have a slightly smaller nozzle size than the 40 unless you made it smaller on purpose.
    The length on the 40 is pretty close to the length of the std. firebrick.
  19. Fred61

    Fred61 Minister of Fire

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    Polish plane: When a citizen of Poland revs up his circular saw and works it back an forth across a surface to remove material and even it out. It's also the way I do it and I'm from Western European descent.

    Yes my nozzle is the same size as on the 40 but I wanted the brick to hold together so I left little real estate on each end. Didn"t appear to have any detremental effect on the preformance. I also experimented with a narrow slot (about 3/4 inch) but it had noticeably poorer performance.
  20. Medman

    Medman Feeling the Heat

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    I'm glad to see this discussion. I opted for the cast in place repair option for the nozzle on my EKO25. I used the recommended refractory cement and built a form to shape a new nozzle. It looked great and worked well at first, but disintegrated after just about a month of burning.
    I have now switched to the cut firebrick nozzle and my boiler is working better that it did when new. I cant believe the difference the size of the nozzle opening makes on performance - in this case, 1" wide by 6" long is about perfect. I now get about a quarter of the ash and coals I used to get, and burn time is way longer.
    I also sift the ash from the coals and recycle them into the upper chamber, but I wait until the coals are cold and outside to control ash and dust in the shop.
  21. maple1

    maple1 Minister of Fire

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    What is the size of the factory nozzle opening - I assume it's bigger?
  22. mr.fixit

    mr.fixit Member

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    I see New Horizon carries new nozzles for the EKOs now. http://www.newhorizonstore.com/Products/282-nozzle-for-eko-models.aspx

    This is the first time that I have seen them listed. Not to sure on how hard it is to replace but it looks like a job and a half.

    The fire brick overlay is easy to do and a person can tinker with the opening size.I suppose that has a direct effect on boiler btu output.

    I know that with the correct size nozzle or even slightly smaller,I can maintain nice gasification at slower fan speeds.
  23. leatherguy

    leatherguy Member

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    Just an update. I got abouts 13 days buring at full gasification, I pulled the screen and the wire was broken and very thin. so i got 2 fire brick 9 x 4.5 x 1.25 cut one in half and cut a 3/4 x 7 slot in the other like Fred did and laid them on top of my old nozzle the 1/2 bricks in front and in back of the new nozzle piece. $2.30 for 2 bricks I think I'll wait to order a new nozzle. I'm getting good gasification a little longer burn with narrow slot and best of all a complete burn with no charcoal at all in the lower chamber. Thanks for your help and feedback, and have a great holiday season.
  24. easternbob

    easternbob Member

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    I just tried Fred61 idea of the firebrick. Put it in yesterday afternoon. Wow it is working great. This morning I had almost no ash or coals down in the bottom as opposed to what I've been finding every morning for a year or so. Gasification looked great. I will forsure keep a few firebricks around, great simple fix.
    How long have people been getting out of the firebrick fix?
  25. mr.fixit

    mr.fixit Member

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    I did my overlay over 1 year ago and still using it. I overlayed the whole upper chamber bottom to protect the rest of it. See my posting at the beginning of this thread. This has been the best improvement that I have made to the boiler.
    I also did it this way so I could experiment with different lengths of slots to vary output.Easily done as the thickness of the 2 cut firebrick that form the for and aft of the nozzle opening can be moved to shorten or lengthen the nozzle.

    Today the turbulators are coming out to clean the tubes.I think I will replace them with chains since weiland13 had such good results doing that.If anything they will be alot easier to remove for cleaning vs. the original turbs.

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