Harry Home owner Bio-Mizer Sawdust Dryer.

[WH_Conley]

Any defunct dairy farms around? One of the old Zero brand bulk tanks, with a little added insulation would be a right smart holding tank with a small footprint.

[Jeff]

Were talking Northern Michigan  where a 13,000 gallon swimming pool can lose 20 degrees in one real cold 24 hour period. It would take a heck of a lot of insulation.

[beenthere]

Heat da pool...

Hmmm?  Da answer to this post came before the post...

[WH_Conley]

The tanks I was thinkin of had alot of insulation to start with. Think $1-1.5k day milk production. Course they were not chincy about heating the building the tanks set in either for that kind of money.

[zopi]

Build a greenhouse around the tank...eat fresh tomatoes all winter...

[John Mc]

Boy wish I had seen this thread earlier.

Jeff, what you are trying to do with your sawdust is very similar to a technique known as a "fluidized bed". We had a heat treating furnace for steel wire that used this technology. It was basically a flat bed similar to yours, filled with "sand". We burned natural gas and "bubbled it up" through the sand, heating the steel wire that passed through the bed. The sand looked almost like a boiling liquid when in operation. A search on fluidized bed might turn up some interesting links.

A lot of little holes for air flow works better than a few big ones. Our furnace had several zones or chambers where we could adjust the fluidizing pressure. The description of the peg board with an air chamber underneath was a good one . If you do end up going with something like this, I would divide the chamber into several segments, with air piped into each one and a valve for regulating the airflow (too much, and you just blow a hole through the sawdust to the surface, and most of the surrounding stuff just sits with no air flow. Too little, and it doesn't "bubble" or "boil".

If you had a 12' x 4' bed, I'd consider dividing it in to chambers cross-ways, so you end up with several 4'x4' or 4'x3' chambers. each one could be adjusted to provide the airflow needed. (Alternatively, a lot of small pipes with small holes rather than the 3 big pipes you have now... but I think the chamber would work better, unless you are prepared to put separate adjustments on each pipe, and still divide the length into zones.)

In our furnace, the wire dragging through tended to pull sand out the exit end, and we had to come up with a system to recirculate the sand back into the inlet end. This got me to thinking... If you tipped your table a bit, you could probably get the sawdust to "walk" it's way down to the low end. If you add the wet sawdust at the high end, and have some method for getting it out the low end, you could have a continuous process, rather than a batch one.

A couple of last thoughts:

In our furnace, having the proper depth to the sand was critical to keeping proper airflow. You may want to play with how much sawdust you put in for one charge.

The air inlet holes in our diffuser bed were covered with what we called "mushroom caps" (I have no idea what the real name was). The idea was to further diffuse the air as it blew out the hole. It would hit the underside of the cap, then flow around it and out the sides of the cap. This helped to prevent the air holes from just blowing themselves a tunnel through the sand (a tunnel would have bypassed the "boiling action" we were looking for. A bottle cap may be too small for this, but that's the general shape.

[Jeff]

Lots of food for thought there John. I can see my dryer is going to be really evolving before next year. This year, winter has set in and I'm limited to what I can do in this sort of weather since I dont have a shop or garage I can work in.  When I get home from the U.P. I will be working on a semi-mechanized delivery system of the sawdust to the Bio-Mizer fuel hopper.

[Jeff]

Tammy stopped by Barnie's and he loaded the only bag he could get to. From outside. It was a frozen shell with some lose sawdust in the center. What a mess. We got it all in the dryer, and the chunks broken up the best we could.  Its obviously wet and I don't see how it can dry in this system, but we'll see.  I've got no other choice until we get to Corleys's this weekend and get his mill cleaned up.   Barnie will be back in sawing mode soon, but right now his commercial wreath operation is still in drive.  I'm going to ride to work with Tammy and go visit to take photos and some video.

[Warbird]

The house has been heated exclusivley with the Biomizer so far this heating season. The colder it gets outside the better the fuel in the dryer bin is burning. Not clear if its because the fuel is getting better or that the biomizer burns it more efficiently when it is having to work a little rather then idle all the time.

I came here to get more info on the Super Sack but found this entire thing very interesting.  Have to head to work now and can't read the entire thread but was interested by what you said about it burning better when it is cold out, therefore running longer.  Did you figure out why yet?  I think it may be as simple as 'the hotter it is, the better it burns'.

I have the same thing with my wood stove and it is simply because it burns wood better when the stove and the wood are already hot.  Take last night, for instance...  It was -24 F when I brought in wood to stoke up the fire for the night.  The cold wood really stifles the fire until it gets warmed up and starts burning better.  I brought in enough wood last night to stoke the fire this morning, so it'd be warmed up already (got to -30 last night.  Brrrr).  Fire took off immediately and burns very well, simply because the stove was already hot and the wood warm.

This whole thing is even more noticeable with wood that is still a bit green or wet.

[Reddog]

So, in the search for dry sawdust for Da boss eh.
It lead us north to da corley5 homestead.
First was some snow removal eh.
 







Then we had to shoe out the hibernating bear. 
Oh, we just put him to work.
 









Da sawdust goes in the da bags. Not on da cloths.






All done.




All in all a fun day eh. Glad ta see you guys today. 
Oh ya eh I really messed with da yooper translater.

[pasbuild]

What did ya do before da boss started burnin saw dust Greg?

[Jeff]

If you add up all the time I've spent in a pit under a saw husk over the last 30 years it probably adds up to one good winter in a bear den.     Problem is if your down there, it aint never for a good thing, and never for a nap.

[WDH]

The price for staying warm .  Looks like a good whack of sawdust.  I have a whack too, but it is in a pile outside and good and wet.  I need to get rid of it somehow. 

Boss, you have some fine friends!!

[Corley5]

I knew if I waited long enough someone would come along and voluntarily clean that out for me    I've got an elevator that fits under there but the last time I used the mill about two years ago the posts for it rotted off and it fell down  .  I sawed the few logs I had to and figured on cleaning it out later.  Later was today and just in time as I've got a sawing job coming up    Thanks Jeff    I hope you can get it to burn.  Always nice to visit with FF friends 

[Jeff]

So far, not so good.  The Bio-Mizer aint liking it. 

[Tom]

There's some sawdust drying info at the end of this video.

[Mooseherder]

You know a cop on the road had to be wonderin' what the heck was in them bags.

[Reddog]

Beans and Peas.

Thats what it said on the bag.