Further Thoughts on a Self-Contained Chip Burner

[Eric Johnson]

I've been thinking a bit more about this self-contained chip-burning boiler housed in a shipping container that I saw recently at a show in Sweden.

As noted in another post, the back half or third of the container is devoted to chip storage. You load the chips from the top and they are augered into the boiler through a wall built into the container. The and auger mechanism are shown in the pic on the right.

Given the size of this hopper, I'm wondering if it would be practical (or safe) to run a couple of heating coils into the fuel chamber (say halfway down), which would serve to help dry out the fuel, assuming you loaded it with green chips. My questions are as follows:

Would there be a danger of spontaneous combustion if you heated green chips?
Would there be enough "dwell time" for the chips to dry out enough (down to 30% mc) before being augered into the boiler?
Would you lose an unacceptible amount of energy when venting the moist air into the atmosphere?

Assuming these are surmountable problems, seems to me you could have a temperature and/or moisture sensor in the hopper to turn the heating coils on or off. It also seems that you could locate some hot water storage in the fuel hopper, which would also help heat up the chips, depending on how well you insulated it.

As noted in other posts, a big shipping container is a pretty ugly addition to your property, but they can easily be sided and otherwise made to look pretty decent. Add the fact that a shipping box is basically a temporary, portable structure, and it probably doesn't require the same amount of legal permitting and other red tape as a permanent structure would. Heck, you could even integrate a chipper into the hopper, so that all you had to do would be to periodically feed the beast brush and small logs. Not a bad rig for a municipal garage, I'd wager.

 

[deerefanatic]

Eric, are you looking for someone to help convince the wife to let you get one of these?

LOL!

I think you'd lose alot of heat trying to dry those chips out with heating coils... Plus, the problem of the chips getting hung up on them.....

 

[leaddog]

I chipped a gravity box load of chips last year. They were from maple trees cut in late winter and were chipped in late Aug. They were in the sun and were dry, estimated 25% or less. Those chip boilers look like the ticket to me. If only they would export them. Did You see the Refo? That one will modulate 10% to 100%
I'm not sure I would want to confine wet chips but there is ways to sun dry them. Also wet chips will freeze and bridge but bring on those chip boilers. I tried to buy three of those Refo's but the co wouildn't even answer.
The shipping container is a great idea for any boiler room and can be had for about $1500.
I knew you would be impressed when you saw those chip boilers. Just think of all the chips going to waste.
leaddog

 

[leaddog]

Eric, of all the chip boilers you saw which ones impressed you the most and did any of them give a date of exporting them here? If in your talking to manufactorers You run into one that wants to have a test person I'm AVAILABLE.
leaddog

 

[JustWood]

I think some type of hot forced air would be better. I know a guy who is in the mulch business who heats his shop with a giant loop of black plastic pipe that he buries in his mulch pile. The heat is already there ,air flow would be better.