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Pellet mill.....anyone here have experience with them?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Spartan, Jan 3, 2011.

  1. bugzme

    bugzme New Member

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    here are the pictures of the feeder tube: assembled: auger internal: auger length: disassembled:
    I used 105mm (external diameter)pvc and 110mm T pieces as this is still just a test unit but if it handles the heat off the pellet press will remain as it is
    cost to build $24 in pvc parts, 100mm Auger spare from posthole digger.
    In the assembled pic you cannot see the bolt sticking out which attaches to the motor as it is rather short for now
    I will be welding a longer bolt to it once motor is ready and i know what its shaft size will be.
    on the opposite end there is a lug which the auger end sits over to keep it centered inside the pipe.
    it works well turning free hand so shouldn't have any probs with motor.

    Attached Files:

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  2. bugzme

    bugzme New Member

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    also the pvc used is 3mm thick with heat rating of 70*C
  3. BobMac

    BobMac Member

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    Spartan,
    Why mess with augers??Its just saw dust, setup a vacume system.
    Thats how I move corn and bulk pellets.

    http://cornvac.com/mobile.html

    Just a thought :)

    Good Luck BobMac
  4. bugzme

    bugzme New Member

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    you felt how much pressure comes out of an industrial extractor? would blow the sawdust through the machine and also over feed it
  5. tjnamtiw

    tjnamtiw Minister of Fire

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    I think you are right on using an auger feeder to feed the mill. It's a good steady feed and no worries about blowing dust everywhere or needing filter bags. I might suggest searching the internet for sales of plastic processing businesses near you. Many, many are going out of business as the Chinese steal more jobs. I've been to several and was amazed at the prices being paid for equipment. You can literally buy things at a couple of cents on the dollar. I spent my time shaking my head in disbelief after having spent my career buying new equipment and knowing what it cost me. Even using a small hopper loader might work to give you drops of a few pounds at a time. I saw them being sold for $10 each!

    http://www.meadoworksinc.com/ is just an example. Search for plastic processing plant auctions. You could come home with a Bridgeport mill for $500. :)
  6. Spartan

    Spartan Member

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    That design wont work. Sawdust binds very easily and there is no way in hell you are going to get saw dust to flow into a tube and onto the augur. You need to open one end and expose the augur well into the material in order to break it up. Believe it or not, I have a dump bin which drop the dust from the bottom. I have seen it bind across THREE FEET and the lift truck has to give it a nasty shake to break it,.

    The best way to do this is to have a small motor with a quarter inch spring steel bar rotating horizontally and then the augur transfers it vertically. I spent about half an hour trying to find a video on youtube that shows an integrated bin and pellet mill. I couldn't find it and I will try again. What they do is rotate a bar on the bottom and as it rotates, it refills a small box on the bottom. From there, the augur picks it up and dumps it into the mill. It's not really as hard as it sounds if you are going to do a "pro" system. And it's not expensive either. Any sheet metal shop can make it for you for a few to maybe several hundred dollars.

    My "barrel" design was going to have the augur exposed on the bottom, about a foot long. Basically, several shovel full to fill the barrel and when it gets down to half way, fill again. If I bring it to the next level, I would make the system that I described above. Then the issue is that I now have to move a 300kg press off the trailer AND a 100kg bin feeder. Doable....but my back is going to scream for disability pension. Worse still, this is suppose to be something that I can do ten years into my retirement. I need to give it a bit more thought as to "portability".

    FOUND IT!

    http://www.youtube.com/watch?v=x_H2hR_lJIo

    Notice the undulating saw dust. That is simply a small bar rotating and pushing more material into the augur hole. Neat and smart design. Now I got to figure how to make it portable.
  7. Spartan

    Spartan Member

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    That is a VERY GOOD idea BUT.....you can control the rotation to control the feeding rate but how do you control how much material is on the top, before the rotating vane? You have to set up a proximity switch and then start the vacuum on and off. In the end, you will burn out the vacuum motor. Augurs are mechanically stupid things that for the right application are unbeatable.

    BTW...that rotating vane is common in the wood industry. It's on the bottom on most of those massive industrial dust collectors. Basically, you can transfer the dust out of the silo even if it is under pressure. Needless to say, they are much bigger and made of heavy sheet metal.
  8. Spartan

    Spartan Member

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    Actually, it's perfect design for "pressure" systems. As the vanes rotate, they seal off the pressure and the entire system is balanced because at no point the system open to free air. Look at it closely. As it rotates, it exposes no more then two vanes which balance each other out. That is the system that almost all industrial dust collection systems use.
  9. tjnamtiw

    tjnamtiw Minister of Fire

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    If you are going to be loading the hopper by hand, then give the bottom of the hopper very steep sides so that the sawdust doesn't BRIDGE OVER (the technical term for what Spartan was calling 'binding'). The angle is different for each type of material and is called the 'angle of repose'. If it's steep enough, the dust should slide down into your screw, BUT Spartan is right in saying if you had a section of half pipe that the dust could fall into the screw more easily, it would make life better. Same thing as our pellet auger systems.


    http://en.wikipedia.org/wiki/Angle_of_repose

    http://www.civl.port.ac.uk/britishsteel/media/BSCM HTML Docs/Angle of repose.html (don't know why it won't put the on each side of HTML)
  10. bugzme

    bugzme New Member

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    I see what you mean about having to agitate the sawdust in the silo, i had considered this before making the silo but thought if it becomes necessary i can add it on after. my silo "cone" has dimensions of 680mm diameter at top with a depth of 300mm ending in a 105mm flange. also my silo will be under pressure as i am using the dust extractor to fill the silo which will give it the cyclone effect and wont actually be filling the silo before commencing the pellet process. I intend to run the pellet mill and auger feed prior to relocating the prepared sawdust into the silo "IF" the sawdust does compress in the silo i will add an agitator which can easily be done with an old washing machine motor and the other leftover auger from my posthole digger (it came with 3 of them). when the silo is finished i will also take some pic's for you so you can see how i added the extractor parts into the drum design.
  11. Spartan

    Spartan Member

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    I'm not clear on how you are designing it. From what I gather from your dimensions (and I can be wrong), you are going to have a fairly small silo. Also, if you are going to put the system under pressure, you will have sawdust blowing out.

    Make it, try it and make a video. If it works, great, if not, at the very worst, all you lost is a bit of time a little bit of money.

    Do you have access to a plastic 200 liter drum? Or a regular steel drum? If your's fails, then try my idea. Even if you use two thirds of a barrel while the other remains as a "filler" you will still have about 20 pounds going through before it needs refill. Which at 200 pounds per hour, would give you about 6 minute refill cycle. Of course you can cheat and weld another half barrel on top but be aware, for every ton you make, you will be shoveling a ton.....and feel every damn inch of it if you go higher. *ouch*

    BTW.....if you don't have one, find and buy a large aluminum grain or snow shovel. Regular shovels are too small and you spend more energy lifting it's mass then dust.
  12. bugzme

    bugzme New Member

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    He he I see I have confused you by not fully describing the silo. I got a 44 gallon steel drum and an industrial extractor (the type with a metal band in the middle and a bag above and below that). I then disassembled the extractor and have welded the metal center band to the lid of the drum (this piece creates the cyclone effect) one of the bags will remain attached to the top of the metal band to allow the pressure to escape there (the bag is held vertical by a rod). I then will remove the base of the drum and weld the cone there. cone dimensions are 680mm at widest point narrowing down to 105mm covering a total distance of 300mm. the motor/blower part of the extractor will be used to extract the dust from a second 44 gallon drum that will have a posthole digger mixing the sawdust with water and any binder (if required). the motor/blower then blows the prepared mixture into the metal band welded to the silo. I will post some pics once I have this complete.
  13. bugzme

    bugzme New Member

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    Ok my silo is complete, I tested the extractor/ blower today and it can easily blow wet sawdust up to 5m vertical so it will have no trouble entering the silo. I did install the feeder tube but encountered a problem, the motor was not reversed polarity and caused to feed in the wrong direction and jammed the unit. i disassembled it and cleaned it out which was when I realised it was spinning clockwise, When the feeder tube became blocked the silo did bridge up. I will change the motor polarity and retest next weekend, Hopefully with the silo being under pressure and constant vibration from feeder tube will stop the bridging otherwise an agitator will be installed. My pellet mill is arriving this week hope customs goes smoothly and will have the unit before the weeks end. Will keep you updated. In the pic of the silo I have not put on the top bag as of yet, you can see the blue section at top, that is the section off the extractor which creates the cyclone effect. It is welded to the 44 gallon drum lid and the cone is welded to the bottom.

    Attached Files:

  14. tjnamtiw

    tjnamtiw Minister of Fire

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    On the hoppers where I worked, we installed small tubing at the base of the cone through which we could blow shots of compressed air to break up bridging, if it occurred. Something to consider.
  15. bugzme

    bugzme New Member

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    Will try that, it sounds alot easier to install than an agitator system
  16. tjnamtiw

    tjnamtiw Minister of Fire

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    It worked well for us to dislodge plastic regrind flakes, which are a real SOB.
  17. Bill Bennion

    Bill Bennion Member

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    Try mounting a massage chair vibrator to the outside of the cone.
  18. tjnamtiw

    tjnamtiw Minister of Fire

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    Wow, you just gave me an idea for my inserts since they always have a hard time feeding the entire hopper load no matter how much polishing, waxing, spraying, or praying. it's the nature of the beast for inserts. Rig that sucker up to vibrate when the auger gets power. Hmmmmmmmmmmmm. Or I could use my wif............ oh, never mind..................................
  19. bugzme

    bugzme New Member

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    I don't have a massage chair so i will try the compressed air trick. I'm thinking... instead of adding tubing it would be easier to just drill a 6mm hole and make a collar to cover the hole (like the pellet fine filtration set up some of you have made) then just uncover the hole when it bridges and insert an air gun nozzle into the cone that will allow directional discharge of compressed air.
  20. tjnamtiw

    tjnamtiw Minister of Fire

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    That should work and it will allow you to 'sweep' the area of the bridge.

    We had ours set up on a timer and it would swirl air around in a circle but compressed air is very expensive (really) so your idea is a good one.
  21. Countryboy1966

    Countryboy1966 Member

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    Curious on where these systems are now? Did they become sucessful?
  22. jdempsey

    jdempsey Feeling the Heat

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    And what happens when one should purchase one of these pellet mills and the pellets that are produced are the quality of natures heat or infernos.

    Theres a reason you dont see leaf or grass pellets sold commercially more than likely, low BTU and extremely high as content.
  23. Spartan

    Spartan Member

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    Any updates?

    Bugzme?

    As for me, I went to see a small working pellet mill. The small ones are an absolute waste of time. One is better off to het a job as a Walmart greeter and then buy the pellets.
  24. tjnamtiw

    tjnamtiw Minister of Fire

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    I tried to get a job as a WalMart greeter but I couldn't say 'Welcome to WalMart in Spanish and Farsi!!!!!!!! :-S

    Higher ash content with these pellets is a given so one must be ready to deal with more frequent cleanings as part of the commitment. I agree it is a labor of love or a challenge to do the impossible! A lot of work UNLESS you can pool resources with a group of pellet users. That's the ONLY way it makes economic and energy usage sense.
  25. Spartan

    Spartan Member

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    Or buy a HUGE house that uses a lot of energy! Al Gore, are you listening?

    I found 3 small pellet mills for sale. All of them were for sale with "time" related excuses. Making a bag every hour or so is pathetic use of time. The upside is that two of them made some pretty good pellets.

    Although I like the idea of "endless free heat".....unless one invests at least several thousand for an electric 25 hp mill, it doesn't make "cost of time" sense. Even with free material and adding some basic value for labor, I have to consume at least 8 tons a season to make sense.

    BTW...what's wrong with a Walmart greeters? How else can I find a 80 year old girlfriend?

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