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Hillbilly Deluxe

Started by mike_belben, November 18, 2017, 09:50:58 PM

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mike_belben

So its my first winter selling firewood in tennessee.  every seasoned piece i had went in a few days after one cold night.  So i need a way to rapidly dry the stuff thats coming off the splitter now.  I had a bunch of nice plywood warping in the shed from a project that didnt happen, and a neighbor gave me a pile of barn board so i started framing this kiln shed. 





Its got a lot of bracing to keep it square in order to hold a full cord.  I will be loading two caged pallets of wood at a time.  The 4 corners are doubled roughcut 2x6 and theres 8 vertical pieces of oak pounded under the joists to prevent sagging under the weight.   Interior dimension is 4x7 with a 5ft doorway height.  The tall front overhang will eventually become one half of an A-frame carport sort of open air work station to keep the splitter under. 



The heat comes from a rocket stove that will burn the scraps off the splitter as well as a bunch of hickory slabwood i get for free, which burns very hot.  The floor is a pallet rack wire grate to allow full airflow. 


This is a test run to burn off the paint and rust before i set the stove in place.  Its just a propane tank cut open and a bunch of 8" stove pipe i had around.  The entire thing was built without a trip to the store actually, just junk i had.






A rocket stove (its just a nickname for any sidedraft stove.. They make a rocket engine sort of noise from the draft suction) is much much easier to light with a tee at the base of the riser.    Load stove, toss in a napkin under the riser, light it to create draft, block or cap the tee and light the fuel chamber.  Itll take right off.   This will get all braced up after i figure out siding, its got some guy wire for now.  The top section is galvy because i ran out out of black pipe.  But its fine.  The stack temp up there hasnt broke 220*f even running the other end orange.  I havent got the money for roofing yet, tarp will have to do for now.




Firepot on the other side.  Stovepipe is held stationary and insulated by a mix of sharp sand and clay.  The pot slips right off to dump the ash, and also that first section is most likely to burn out so its for safety, better to be encased in clay than to let a flame spit out the side.




There is a box fan behind the hickory stack.  The plan was for it to draw warm air away from the firebox, up through the fuel wood and in to the drying chamber.  With the stove doors closed it seems like the fire's CFM demand is too great for this to work right, im still experimenting.






It would be even better if i could get modest airflow without using electric by getting the fire draft to flow across the wood stack.  Only down side is that would be constantly pulling in cool outside air that id have to heat. This might also increase humidity on wet rainy winter days.   Not sure but i'll consider suggestions. 

Thanks

Praise The Lord

barbender

I like it. Necessity is the mother of invention👍🏼
Too many irons in the fire

starmac

Just curious, what moisture content is your goal. We have to be down to 20% to legally burn wood here.
Old LT40HD, old log truck, old MM forklift, and several huskies.

mike_belben

Dry enough to please the customer.  A little sizzle is okay but it cant be bubbling water out the end grain when they toss it in the stove.  At $50 a rick im not gonna go crazy.


Thanks 'bender
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mike_belben

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GeneWengert-WoodDoc

The smaller the pieces, the faster they will dry.  The lighter-weight species also dry faster.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

mike_belben

Thats about what i figured.  I spent a while sealing things up better today and put my first sopping wet batch in.  Already its showing a lot of promise. 
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mike_belben

So i built an intake concentric that brings in combustion air from the outside and scavenges heat off the stack.  Its the rusty tee in this pic.  Not a tremendous flow yet due to leaky structure but the air coming in is hot atleast.   






Im hoping to do without running a fan.  Fresh off the splitter, It takes about 2 days in the kiln to get wood sellable.  The ends start checking and if split open theres no obvious wetness in the center.  Itd probably take 4 days to really get dry.  Im gonna continue insulating and see about a simple coil condensor to speed things up.
Praise The Lord

barbender

I'm inspired, I may have to copy this once you get the bugs worked out of the "hillbilly special"😊👍🏼
Too many irons in the fire

mike_belben

Right off the bat id say make it pole barn style with posts in the dirt, or posts lagged to a micro slab or piers.  Ive nudged it out of position twice in two days! 

V2.0 would incorporate anchored position and a little extra interior width.  I didnt really have any plans, and didnt have enough long boards when i started framing but was eager to just build something.  Pallet racking on slab would make a good skeleton to have started with, then frame a pole barn off of/incorporated into that.  Dry wood in the kiln and store it under the lean-to.

My next gripe would be short duration burn times with that small tank, and struggling to get the tremendous heat in the fire room to travel over into the drying room.  The suction of the fires draft is overwhelming to normal flow of heat rise, unless i use the fan.  Im trying to make money, not spend it. 

Will be experimenting with exterior air intake tubes to the firepot but im not expecting miracles, leaving the firebox doors cracked doesnt seem to do much. Subsequent changes may increase the drying room temp but at what tradeoff in circulation over the wood baskets from the concentric? 

More test and tune as junk/funds allow. 
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mike_belben

Welp, a condensor is gonna have to happen one way or another.  Its a frosty morning and the whole interior is drenched in droplets. 
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thecfarm

You got some good ideas there. Them pallets just about fit.  :o  If I was loading it,I would make it bigger the first time. Meaning I would hit a side and move it.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

starmac

I have seen the little heat powered fans that sit on top of woodstoves and they actually work. Some of the guys on here may have some ideas to use one on a larger scale to have some air flow.
I would almost bet there would be a passive way to take care of the condensation with heat and vents in the right location.
Old LT40HD, old log truck, old MM forklift, and several huskies.

mike_belben

Well somewhere around here i have a ryobi drill i dont use anymore that i intend to strip for the motor and put on a trolling motor battery which would ve easily kept up by a cheap solar panel.   The motor will go on a little plastic chinese drill pump that uses garden hose.  Id adapt that to some baseboard mounted to the wall near ceiling with a piece of sloped gutter underneath to collect drips.  The pump would just circulate bucket water, its plenty cold to condense.  A ground loop buried down a few feet would work for a summer heat exchanger. 

Before i do all that im gonna whip up a 100lb propane tank burner with a top draft line that sucks from the drying chamber only.  My hope is that this alone provides sufficent heat, draft and dehumidification.   In a perfect world the waste heat off the burner body will heat a shop interior space while the draft pipe heats the kiln and maybe a water coil.

Im fixin to scale it up some day.  Cogen baby, 3phase turbine ftw.


Praise The Lord

thechknhwk

I have always been fascinated by these rocket stove things.  I like your project and good luck with it.

mike_belben

They have their strong points.  One of the stoves i built runs on sawdust and waste vegetable oil fed by a variable speed auger from a feed hopper.  It burns orange in the flame chamber and averages 500F on the entire body radiating into the space, but the flue exit temp is around 200F.  Heat whole shop on a 5 gallon bucket of trash.

Conventional stoves waste vastly more BTU up the chimney.  600F on the stove and 500F up the flue is pretty typical.
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mike_belben

Can anyone comment on the nature of suspended airborne water particles?

In the case of my little hodgepodge heater box here without any fans or substantial air flow... is water most likely to be found evenly dispursed, up high or down low? 
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TKehl

The vapor should be somewhat evenly distributed as it sounds like you've hit saturation.  However, the air and vapor low in the chamber should be coolest and most readily condensed.  (I say should as the heat pipe in the bottom could throw this out of whack.

With that said, why not vent off some of the air instead?  The cold air when heated can carry much more moisture.  When it can't carry more (saturation) vent it off.  (Something like a computer cooling fan etc.)  Sounds like you've got plenty of wood to keep it warm. 

Another thought would be to pipe the cold air going to the furnace draft through the drying chamber.  The cold pipe should condense some vapors. 

Last thought would be a hybrid.  Vent off chamber air and let cold air in, but through a baffle system (old tin or duct) such that it would drop out some condensate from the temperature difference.

Nice thing about condensation is it gives up some latent heat from the phase change.  But running with saturated air could be like having the throttle pegged in first gear.  Fresh air in the chamber may be like shifting to 2nd.

Thoughts and theory from a physics geek.   :)  I have not tried this at home... yet.   ;D
In the long run, you make your own luck – good, bad, or indifferent. Loretta Lynn

mike_belben

Well,  venting is low on my list of desires because im hoping to get this thing developed to where it can achieve the legal heat treatment temps for selling state forest bundles.  I think its 140 or 160 for an hour.  Uninsulated and with the tiny burner i was only getting the wood up to 80 and the chamber probably to 100 overall, but definitely hotter down below. 


I insulated much of the interior and built a dramatically different burner that will probably change things enough to throw all my current data out the window.  I will say i burned fresh split wood after 2 days in the prior configuration, so it has some merrit. 

Ideally, i will get this thing dialed into a backyard heat treat oven anyone can build from junk and run on sticks... Then sell plans for a reasonable fee.  My kids are hungry and im getting tired of winters in a camper.
Praise The Lord

TKehl

I can understand that, but a sliding or hinged vent that could be shut when it stops looking like a steam locomotive could be just the ticket.
In the long run, you make your own luck – good, bad, or indifferent. Loretta Lynn

mike_belben

I havent ruled it out.  For now, im working on max temp.  I can always open the door and blast the pile with my leaf blower for 40 seconds to clear out the swampy air.   blows all the dust off and makes for a cleaner pile going into the trailer.  Its pretty windy here throughout winter so baking the cages for a few days then letting them air finish works.  I just need to make more cage bins.
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mike_belben

It dons on me that liability insurance coverage for such a fire hazard would be far more than any profits from trying to sell plans, kit etc.  So i might as well share with you folks. 

I did a very simple burner from a 100lb propane tank (mfg during ww2!) that still uses the rocket style horizontal draft pipe under the wood.. But also has a vertical stack.  This can be intake air or exhaust based on where the fire is.  It can draw from the drying chamber or from the sky.  It can also vent the burning gasses from the fire to the sky or to the box. 

Yes, i realize this has some extreme risks that im working out.  A series of damper baffles and screens for temp control and spark arrest is in order and ill show pics of what i come up with when i get it all worked out.  Basically adjusting baffles and the location of the fire dictates whether its a lower heat from ground level or a very high and fast heat from up high.  Im considering it as drying mode vs heat treat mode.  A mixture of the two is probably going to be most effective. 

Ive also got a pretty clever passive dehumidification in mind from junk. 


I insulated and panelled the walls and have gotten the interior surfaces up to 120f using on the bottom burner with combustion air coming from the drying chamber.  The ceiling cant be insulated until it is roofed and the doors still need some poly iso and weatherstrip.  Id say i can get another 20f from insulation and feel like the 160f target is going to be a reality. 

I still havent made a trip to the store yet.  Everything was on hand. 

Praise The Lord

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