Hi guys, like all you DIY I like building things, not always cheaper but I
always learn a lot.
Has anybody build their own corn burning furnace or has some of the details,
like size of fire pot, air holes size and placement. I am interested in an
under fed system. Any other details that I have not listed would be
I have been playing with this idea for awhile as well. Having a
virtually unlimited supply of corn, and the ever increasing cost of
fuel, I have been thinking about it a lot.
What I have done so far is look at all of the display models to get an
idea of layout and design.
The cost for the fuel value of corn is less than the equivilent cost for
fuel oil or propane. In the rural farming communities of the Midwest,
corn is abundent and very cheap. You can also pick up some that may be
contaiminated so it cannot be used for animal feed even cheaper than
In a stove it burns cleanly, easy to make an automatic feeder.
Gary Brady wrote:
Yrs. back I saw a guy heat his shop with a corn cob furnace. It worked
very good. He used broken cobs without kernels & made an autofeed auger
from his gravity box. Could almost get the furnace red hot.
Larry Jaques wrote:
A number of folks in my area have copied the design of corn stoves for sale.
I seen a really nice one at the MN state fair last summer. Three problems
have cropped up with the stoves I'm aware of:
1. Heat cracks and bends the agitator fingers. This could be solved by using
only 304 SS for this component.
2. Ash buildup is a serious problem. Daily cleaning is required with some
lots of corn. Combustion efficiency goes to heck when the air holes are
plugged. Oyster shells have helped, but not enough.
3. Most units only produce 50,000 BTU on a good day, too small a heat
source. You'll still need a backup.
I was talking this over with a friend last fall. Someone should look into
building a unit that works like a coal boiler: Grind the corn up, feed into
a firebox with a strong air flow from below. This is called a fluidized bed.
The ash goes out the stack. Making a working design small enough would be
the biggest challenge here, most commercial coal unit are for 1,000,000s of
When I was working, I was involved in wood chip burning and I remember one
company was working on a small fluidized bed but I do not know if they ever
finished the project. The problems that you mentioned seem to be common to
the stoves. I am looking for a furnace, a corn burner or stoker in a
boiler. The underfed system seems like the best design to me. The corn
comes in from the bottom pushing everything up and the clinkers are pushed
out of the pot. I know in the wood chip burners, the underfed was one of
the best design and less trouble. There is no dealers around here so I am
limited to looking on the web. Some pots seem to have the air holes around
the top of the pot and other seem to have them part ways down the pot. It
is something that I will have to experiment with so the prototype will
probably be fairly light steel, as long as it would last a few weeks. Once
I would have a good design, I would probably get a pot casted in cast iron.
It is hard to see the details from small pictures on the web.
Thanks guys for the input and I would appreciate any other information.
"Karl Townsend" wrote
in message news:pM0Sd.1422$ firstname.lastname@example.org...
Dave Hinz wrote in
And I thought I'd read in this thread somewhere towards the beginning tha
the corn should be completely dry.
I'm wondering if it isn't more like I had heard when the corn furnace came
out here in northern wisconsin the a higher moisture corn would give a
higher temp (steam?)..hmm makes sense to me unless I'm missing something.
Well, I suppose that would affect how it "flows" in the hopper, and how
hot and completely it will burn.
I think if you're heating up water to boil it off before you can burn
the kernel, you're wasting energy. Drier corn would seem to be the
best fuel. This is all spitballing, I haven't read about moisture levels
and how they change heat output per bushel, but I'd think it's like
firewood - the drier, the better.
Nice thing is, if you get a dual-fuel furnace, you can burn wood _or_
corn. I've got a forced air setup that I'd love to put into use;
it's rated for coal as well, but that's unlikely in my area than corn
is (south-central Wisconsin).
Eric I have burned corn in my home in commercial units for the last
6 years or so & have also modified a monarch wood stove to accept corn
for heating my shop. Im not sure what the under fed system is but I
just ran an old coal auger thru the side of the wood stove & built my
own firepot. If you need more details, email me at email@example.com.
Hi Dave if you build this unit I would like to know more about it. What I
am mostly looking for is the size of the pot for a 100,000 furnace, where to
place the air hole for combustion air. Searching the web, most are using a
60 cfm fan for combustion air. They are using a 2" auger. Somebody ask
about the underfed system. It has the auger in the bottom of the pot
pushing fresh fuel into the fire from the bottom, thus pushing out of the
pot ashes and clinkers. These system do not require the daily cleanup that
some of them need. I would appreciate any information.