Yes, the feed does have to be constrained to the same flow area as the horizontal tunnel. Air being forced down past the sticks is the only thing that forces the smoke / wood gas to flow down into the firebox instead of up. If the stick protrude above the feed lip, or if the feed is too large, or even if you get one big flat chunk acting like a damper up by the burn tunnel end and a gap behind it, there's an increased risk of smoke wicking back up the sticks without enough air drafting downward to suck it back down.
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17 years in a straw bale house.
Dale Hodgins wrote:
The plan is to build a U-shaped sheet metal slide which is set about 10° from vertical so that long lengths of firewood will lay straight and automatically feed into the rocket stove.
jacob green wrote:
Dale Hodgins wrote:
The plan is to build a U-shaped sheet metal slide which is set about 10° from vertical so that long lengths of firewood will lay straight and automatically feed into the rocket stove.
Hello Dale.
Did you ever try this?
What kinds of variables did you encounter?
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Roy Hinkley wrote:
For automated feed I decided to go with some kind of gravity driven system for simplicity.
I tried various configurations before that always resulted in some smoke up the feed tube or tray and after a few failed tries I made a chute that was canted at about 50-55deg, that results in a 4 x 5.5 inch tube about 6" long with a tray that extends another 8-10 inches that the wood sits on. I left the wood chute at 4 x 4 with the other section below as an air feed just like the shelf in a typical rocket stove. Instead of sucking all the air past the wood I think the air flow underneath creates a sort of venturi effect and a constant low pressure at the base of the wood feed chute.
Strangely, when the air tube was not parallel with the feed chute it didn't work nearly as well. I'm experimenting with tapering the air tube to increase the velocity but the cold weather has me hibernating just now.
The pics are poor and as soon as it warms up a bit I'll test some more to get the best configuration I can and weld it up and the clamps won't be in the way. I also made the whole feed tube hinged to make cleaning and initial lighting up easier.
More stove pics in that album if you want a better picture of the whole thing.
http://i828.photobucket.com/albums/zz206/Indyyeti/energy/rocketstove4_zpsa964f6e9.jpg
http://i828.photobucket.com/albums/zz206/Indyyeti/energy/GEDC1386_zpsf10708c9.jpg
Functionally, the conveyor belt would be an excellent idea, the only problem is the width. Now if you want a real serious furnace going, that wide a conveyer belt will stoke enough to heat a large building!
Like you may have had in mind, something on a much smaller scale, improvised would be good. One other likely hazard to deal with is the fact that in prolonged use of such a system, the works would almost certainly get jammed up with debris and dirt from the wood being handled. The idea is sound, it is how to put together something that will work like that without needing much maintenance. Your rollers/wheels/bearings would have to be both as out-of-the-way (under?) as possible, and also as generally covered and protected as well - that's the trick.
Skateboard Trucks/Wheels !!!
I have considered the wheels and trucks from skateboards. Lay a skateboard down upside down, and you will see that most size logs would rest well on them, generally speaking.
Skateboard trucks/wheels are built to hold weight, obviously must not have too much of a problem with dirt and debris, and are easy and cheap to find, especially if you check out thrift stores, yard salkes, Ebay, etc.
They would also easily handle the somewhat more or less irregular shape of various logs with thier inherent pseudo-suspension? (?)
In this case, I would think to use skateboard trucks/wheels in pairs, opposed and at 45 degrees to each other, essentially holding the log slightly above and slightly between them, to hold the log securely as it passes.
They would be easy and cheap to service or replace if/when necessary.
John Abacene wrote:
Ok, I wrote a small novel here.... Do I get a gold star??? lol...
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kent smith wrote:Dale, glad to hear about the maples. Most of our wood lot is covered with maples and I need to thin some out. The crowns are so thick that on a sunny day it is dark and damp while walking around. Maples are the predomenent new growth on our place in the woods, but out in the pasture it is black locus and sumacs.
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John Abacene wrote:...
Brancjing up from that, there might be potential for central home vacuum - start the fire raging, vaccum the floors, the dirt is instantly removed and incinerated. - No bags or filters to change!
l...
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