Corn burner/water heater

Alternative Energy Source replacing propane/natural gas/fuel oil. Year # 2
On Oct 6, 2008 I began a 2nd year burning mostly corn on the home farm. I installed a larger corn burning hot water heating outdoor furnace to heat the house. The furnace is a commercially manufactured corn burning water heater. It has the following specs:

Corn capacity: 8 bushels There's a lot of difference in corn types. Some burns clean with little ash, some burns poorly with lots of ash. I'm still sorting out which corns burn best and why.
Water capacity: 46 gallons ( I am using soft water that is softened using a household water softener). Using no antifreeze or rust inhibitor. This stove has a water reservoir surrounding the firebox.
Electric: 110 volt. I used 3/12 with ground. I have two possible hot wires and one common ground plus a neutral.
Distance from house: approx 70ft....mounted alongside the driveway. All outside pipes and electric wires are buried underground.
Water Pipe used: Pex tubing....1¼ in diameter or 1in diameter cpvc (in the house only). The undergound 2 pex lines (inlet & outlet) were wrapped with fiberglass insulation and inserted into a 6 in black plastic non perforated field drain tile and buried about 3 ft deep.
Fittings: Watts 'o' ring connector fittings, elbows, tees, etc., or standard plumbing cpvc fittings. I love the Watts fittings and the cpvc is easy to work with too.
Valves: Mostly cpvc ball valves. Some brass or stainless ball valves with 1in pipe threads on either side of the pump.
Pump: 42 gpm pump 110Volt 1 inch inlet and outlet. Its mounted at a lowest point in the basement about 80 ft from the tank and sucks hot water from the tank then goes to 2 heat exchangers installed in the 2 furnace plenum. The original furnace blower runs continuously 24 hrs. per day and extracts the heat from the water. The slightly cooled water is returned to the tank. The distance the hot water travels from the pump, through the house, and back to the tank is approx. 200 ft. It looses about 10 degrees F. from hot outlet to cooler inlet at the tank. This is a non pressurized water system. The whole water system can be drained in the basement near the pump. One pump is very adequate.
Capacity: Manufacturer claims 250,000 btu burner output. There is some heat loss mostly at the burner door and flu pipe (8 in dia).
Quantity corn used at full output.   300 lbs. per day approx.
Cost comparison to propane. 91000 btus/gallon propane, 9000 btu's per lb. of corn   (takes 10.1 lbs corn to = 1 gallon propane for btu's ). Propane price is $2.00 per gallon and corn is approx. 6cents / lb. Therefore burning corn is equivalent to burning 60 cent propane or less than one third the cost of burning propane. Corn at $6.10 per bu and Propane at $2.00 per gallon would be approx. equal in cost/btu output in this situation.
Management: Burning corn outside takes some management. You have to 'poke' the ashes/clinkers loose from the burning pot 2 or 3 times per day. You have to empty the ashes/clinker box once per day or two.   You have to 'scrape' the soot down from the water tank above the fire pot 2 or more times per day. The soot prevents a good heat transfer to the water and acts like an insulation barrier. You may have to add water every couple of weeks. I left mine unattended for about a 36 hour period and it was heating at at less output with the ashes coving the burner pot totally and needed to be emptied to bring it back up to full output. My house is actually two houses connected by a great room with two furnaces. This year the burner has run at the max for most of the time since November. Heat controls in the house is not needed.   My wife loves the heat, it's continuous and the air is always slightly warm coming from the vents and the floors.
Comment: I like the outside burner....the fire is away from the house...less fire hazard, the mess is also outside the house, the ashes are outside the house and if mounted near the driveway is easily accessible by vehicle for refilling with corn. I bag my own corn and put it on pallets and bring a pallet when needed and fill the bin once per day. I have a skid steer with forks and place the pallet next to the corn burner and it's quite easy. I cover the pallet with a small tarp to keep the bags dry. I recently made a bulk bag stand and I fill bulk bags (totes) about 1500 lbs per and put them on the stand and gravity feed the corn to the burner hooper. It works great but you have to get your machinery started in the cold weather to get the bag up on the stand.

Another thing I've done....purchased wireless thermometers and installed them at the burner, the pump, the heat exchangers, and in certain rooms in the house. This gives me insight into what's happening in the system and I can always tell when something has changed... and might lead to a problem.

I modified the internal parts of the firebox. The original stir rod was "L" shaped off the end of the auger....it stirred things up to much....I made one out of 1/2 inch rod straight off the auger and welded 2 small cross pieces in a couple places. I also put in more baffles in the firebox to keep the heat and fire in the box longer.

My next couple of changes I'd like to make....to gasifiy the ash and clinkers, and to capture more heat off the flue. I'd like to burn some DDG pellets if I could find some. I've burned wood pellets...and they work great but are more expensive than corn. If I could chip wood in small enough and uniform enough pieces I'd be able to burn a lot of wood that I have around the farms. It would have to go through a 2 1/2 half in dia. auger.

Carbon neutral....the idea is to approach carbon neutrality when heating, driving, farming, etc..   Carbon that is sequestered in the top portion of the soil that can be used to produce renewable fuels is considered carbon that is neutral.    Carbon being brought up to the surface put into service as is carbon from fossil fuels that were deposited millions of years ago and now being used is not carbon neutral.

Cornburner in winter

Alternative Energy Source replacing propane/natural gas/fuel oil.
On Dec. 3, 2007 I began a new experiment on the home farm. I installed a corn burning hot water heating outdoor furnace to heat the house. The furnace is a commercially manufactured corn burning water heater. It has the following specs:

Corn capacity: 8 bushels There's a lot of difference in corn types. Some burns clean with little ash, some burns poorly with lots of ash. I'm still sorting out which corns burn best and why.
Water capacity: 27 gallons ( I am using soft water that is softened using a household water softener). Using no antifreeze or rust inhibitor.
Electric: 110 volt. I used 3/12 with ground. I have two possible hot wires and one common ground plus a neutral.
Distance from house: approx 70ft....mounted alongside the driveway. All outside pipes and electric wires are buried underground.
Water Pipe used: Pex tubing....1¼ in diameter or 1in diameter cpvc (in the house only). The undergound 2 pex lines (inlet & outlet) were wrapped with fiberglass insulation and inserted into a 6 in black plastic non perforated field drain tile and buried about 3 ft deep.
Fittings: Watts 'o' ring connector fittings, elbows, tees, etc., or standard plumbing cpvc fittings. I love the Watts fittings and the cpvc is easy to work with too.
Valves: Mostly cpvc ball valves. Some brass or stainless ball valves with 1in pipe threads on either side of the pump.
Pump: 42 gpm pump 110Volt 1 inch inlet and outlet. Its mounted at a lowest point in the basement about 80 ft from the tank and sucks hot water from the tank then goes to 2 heat exchangers installed in the 2 furnace plenum. The original furnace blower runs continuously 24 hrs. per day and extracts the heat from the water. The slightly cooled water is returned to the tank. The distance the hot water travels from the pump, through the house, and back to the tank is approx. 200 ft. It looses about 10 degrees F. from hot outlet to cooler inlet at the tank. This is a non pressurized water system. The whole water system can be drained in the basement near the pump. One pump is very adequate.
Capacity: Manufacturer claims 200,000 btu burner output. There is some heat loss mostly at the burner door and flu pipe (6 in dia).
Quantity corn used at full output.   250 lbs. per day approx.
Cost comparison to propane. 91000 btus/gallon propane, 9000 btu's per lb. of corn   (takes 10.1 lbs corn to = 1 gallon propane for btu's ). Propane price is $2.00 per gallon and corn is approx. 9 cents / lb. Therefore burning corn is equivalent to burning 90.9 cent propane or less than half the cost of burning propane. Corn at $10.00 per bu and Propane at $2.00 per gallon would be approx. equal in cost/btu output in this situation.
Management: Burning corn outside takes some management. You have to 'poke' the ashes/clinkers loose from the burning pot 3 or 4 times per day. You have to empty the ashes/clinker box once per day or two.   You have to 'scrape' the soot down from the water tank above the fire pot 2 or more times per day. The soot prevents a good heat transfer to the water and acts like an insulation barrier. You may have to add water every couple of weeks. I left mine unattended for about a 36 hour period and it was heating at at less output with the ashes coving the burner pot totally and needed to be emptied to bring it back up to full output. My house is actually two houses connected by a great room with two furnaces. This year the burner has run at the max for most of the time since I started it. Heat controls in the house is not needed.   My wife loves the heat, it's continuous and the air is always slightly warm coming from the vents.
Comment: I like the outside burner....the fire is away from the house...less fire hazard, the mess is also outside the house, the ashes are outside the house and if mounted near the driveway is easily accessible by vehicle for refilling with corn. I bag my own corn and put it on pallets and bring a pallet when needed and fill the bin once per day. I have a skid steer with forks and place the pallet next to the corn burner and it's quite easy. I cover the pallet with a small tarp to keep the bags dry. My next project is to put up a bulk bin with gravity feed to the corn burner. One 125 bu bin of corn should last a month or more. I'll have to fill it with an farm auger and haul it in bulk with a truck.

Another thing I've done....purchased wireless thermometers and installed them at the burner, the pump, the heat exchangers, and in certain rooms in the house. This gives me insight into what's happening in the system and I can always tell when something has changed... and might lead to a problem.

I made a expanded metal base and mounted above the fire pot and put in wood to see what happens. Guess what, the burning of the wood and corn together, actually takes some of the heat away and cools the output water a few degrees. There is not enough Oxygen to support corn and wood burning together. I believe the combustion fan is rated at 68 cfm.

Carbon neutral....the idea is to approach carbon neutrality when heating, driving, farming, etc..   Carbon that is sequestered in the top portion of the soil that can be used to produce renewable fuels is considered carbon that is neutral.    Carbon being brought up to the surface put into service as is carbon from fossil fuels that were deposited millions of years ago and now being used is not carbon neutral.