Information on Wood Gun Autofeed mechanism

[emesine]

I am getting ready to build a home on a forested site in Indiana. I would like to heat with wood as my only energy source. I am planning on designing in an extra car space in my garage to serve as a large bin for wood chips. To fill the bin, I will simply park a chipper in front of the garage and start throwing in logs. I'd like to use the wood gun autofeed machine to get the chips into the wood gun. I figure it will pay for itself in a matter of just a few years given Indiana winters.

Does anyone have any input on how well the wood gun autofeed mechansim works? I'd like to be able to pile a bunch of chips against the auto-feed auger and not have to mess with it for a week or so.

As this is looking pretty costly, I am also thinking of a log based burner. On the other hand, if I can work out a reliable wood chip boiler I won't have to buy a gas or electric heater at all.

Andrew

 

[flyingcow]

Just a thought. I live in northern maine, and thought briefly about finding a residential chip burning set up. Figuring that there is a lot of commercial chip burning plants around me. Makes sense, if they can, why can't I on a smaller scale. Hit a few walls along the way. Many of which you will find on your journey, maybe not, who knows.

The math I also did......I burned about 800 gals of oil a year, pretty good for what I've got. Using a wood burning gassifier boiler, figure 1 cord of wood(hardwood approx 5,000lbs) = 150 gals of oil. That's about 5.3 cord a year. I would guess the chip burner would burn more.

I also haul a open top, 48ft, chip trailer. I have hauled "green" or "dry" (clean) hard wood chips. About 140+/- cubit yards of room in my trailer. Fill it and figure about 35 ton or 14ish cord. It's a big area. Figure half of that, that's a lot of area. Wood chips will not do well in long storage unless, dried well. Chipping as you go, they are very wet.

Also figure on heated storage, not too warm, but well above freezing. The wood chips freeze likes there is no tomorrow. Even the dry ones.

Good luck, I came across a few burners, but they were in the U.K. Not for sale over here at that time.

 

[emesine]

Thanks for the information! I never considered that the chips might freeze.

I am thinking a chip bin 12 X 24 feet (288 sq feet) filled about 5 feet deep- about 55 cubic yards. By your calculations that will be about 13 tons of chips. That should (hopefully) be enough for a season of heating.

I'm thinking of gathering wood over the spring and summer in the form of poles, logs, etc., then chipping all at once in August or September. That should help somewhat with moisture content. I am also considering running hot water through the cement floor of the bin. With heating below and a fan blowing over the top of the pile I might be able to dry 5 feet of chips over a week or so (OF course that would burn a few wood chips....)

Is there a better way to dry chips? A rotting pile of wood chips does not sound pleasant!

Andrew

 

[tom in maine]

I used to burn chips, years ago. There was a lot of work done at the University of Maine related to chip burning.
I used to get tons delivered into my basement. They were green paper grade chips and would get "ripe" by the time
I would get around to burning them. They were certainly drier, but got quite moldy. Obviously, they need a separate bin.

The beauty of chips, being small bits of wood that are easy to mix with air, is also a feature that allows them to pickup a lot of water much more quickly than stickwood when left outdoors.

A friend recently built a chip unit that worked well with wet chips, but paid the same penalty we pay when trying to burn green wood.
He is going back to stick wood after using chips for a couple years and then using pellets last year. 20 acres of wood lot and wet chips will do that.

 

[Fred61]

I e-mailed these guys last year.
http://www.moderator.com.pl/en/?link:index
They do not have dealers or distributors in the US but indicated they would ship to US. Big language barrier!
Click the "How does it work" arrow to see an animated description. It should be fairly efficient since you can get it with a ceramic fire box to help keep the fire hot.

 

[Fred61]

Thanks for the information! I never considered that the chips might freeze.

I am thinking a chip bin 12 X 24 feet (288 sq feet) filled about 5 feet deep- about 55 cubic yards. By your calculations that will be about 13 tons of chips. That should (hopefully) be enough for a season of heating.

I'm thinking of gathering wood over the spring and summer in the form of poles, logs, etc., then chipping all at once in August or September. That should help somewhat with moisture content. I am also considering running hot water through the cement floor of the bin. With heating below and a fan blowing over the top of the pile I might be able to dry 5 feet of chips over a week or so (OF course that would burn a few wood chips....)

Is there a better way to dry chips? A rotting pile of wood chips does not sound pleasant!

Andrew

If I were going to burn chips, I would purchase an old galvanized silo and mount it horizontally on a bed made from automobile tires and wheels like those drum type compost tumblers. Perforate it with several (hundred) holes, Drive it with a gear motor so that it made about 1 rev. per day. Of course, it would need a canopy.

 

[emesine]

Thanks for the information on "Moderator" in Poland. 'Can't wait till I call for Tech support. Their system is certainly a lot simplier than the wood gun autofeeder.

It sounds like woodchips are doable, but it is critical that they be dry for the simple reason that I don't want a pile of 13 tons of rotting wood chips in my garage. Here is a system:

1. Lay out an array of 3-4" perforated pvc pipes along the floor of the chip bin, connected to a blower fan.
2. Lay down some pex tubing in the cement of the floor of the bin (connected to the boiler).

Chip wood into the bin to cover the pipes to a depth of 5-6 feet (around 13 tons of chips). Immediately after chipping fire up the boiler (burning the same green chips, or dry wood if green chips won't burn well) and run hot water to heat the cement floor of the chip bin. Turn on the blower fan to move air through the pile and help dry the chips. Leave all of this running for a good week to fully dry a season's worth of wood chips (This might take a significant amount of wood fuel, but it is worth it to have a dry chip pile.) The pile will be stored in a closed bin, so once dry it should stay dry. If we get some particularly cold weather it would be easy for me to keep the pile from freezing by turning on the floor heater again.

The cost of all this comes down to pex tubing through the cement in the floor, some PVC pipe, and a blower fan. Pretty reasonable. The only problem I see here is that I will be obligated to move my chip pile by hand- you can't run heavy equipment over PVC pipe. My wife also might not appreciate my firing up a boiler in August in her basement, but we'll see

Thanks again for all your assistance. My architect (who happens to be my father-in-law) is going to think I am nuts to design my house around my heating system.

Andrew

 

[sdrobertson]

One word of caution...piling all of those green chips will create allot of heat in the middle as they set and start to dry. Allot of barns have burnt down when the hay was really packed in while it still had some moisture in the bales and they were packed in tight. I've seen piles of "mulch" at saw mills that when you get to the middle it was steaming from the heat.

 

[flyingcow]

You have to wonder....is it more/less expense to cut, split, and pile firewood. Or is it more/less expense to chip and dry wood chips, given the cost of heated floors or motor driven dryers, etc, etc.

You are figuring "wood chips", what you will be working with is wood chips/bark etc. Now you're dealing with is called "whole tree chips". Extremely high moisture wood chips and green bark. Has the potential to be a PITA. Especially, the smaller diameter the tree, higher ratio of bark versus good chips. Wish you the best of luck.

 

[Como]

I looked into it but decided that pellets would be a better option than chips. For the reasons mentioned, assuming we stored in wood rather than water.

We were in the UK recently, many of the National Trust properties we visited are switching to biomass and chips.

 

[slowzuki]

I have visited a residential chip burner. He burns year round with softwood chips. He chips once a year after leaving the wood to dry a year so they aren't completely wet. The unit works well but is big. He is planning to convert but more due to promotion reasons for a wood pellet association.

 

[pybyr]

Seems like it could be done, but that one might have to plan and monitor storage of chips carefully. In wet locations/ spells, I've seen open piles of chips develop some incredible internal decomposition.

 

[flyingcow]

Also, if you don't have heated storage, green chips/chips with bark in them will freeze up hard! Trust me, I have hauled this stuff. Not a pretty sight.