Wood Chip Boiler

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jebatty

Minister of Fire
Jan 1, 2008
5,796
Northern MN
Does anyone use a wood chip boiler, either dry chip or green chip, in a large residential to small/medium commercial application? If so, how has it worked? What's really good? What's not what was expected? etc.? A local school has an interest in taking a look at this because it has a local source of chips, both dry and green. Thanks.
 
I built a chip boiler back in the '80's. Norm Smith, an Ag Engineering professor and friend of Dick Hill's told me not to try to build one because "You will burn your house down".
Well, that was enough for me. He had published a lot about chip boilers, so I built one and it worked fairly well.
I used green paper chips that were delivered into my basement. They molded as they dried in the warm basement.
Drying chips can be laborious and/or expensive.
 
Probably in the range of 350,000 to 700,000 btuh
 
Talk to Marc at BioWin, he advertises on her. he has a real good one. Foamit UP
 
I've got BioWin on my list and will make a contact as soon as I gather more info.
 
The Froling chip units in that range look amazing. I'm not sure what they cost though for a full running unit.

There are many choices. Ram feed, underfeed stoker, pneumatic spreader stoker, chain stokers. They are a bit more maintenance intensive than a pellet unit. I have recently been working on a project for work for the same size system as the school. Undersizing would be best if turn down ratio is needed. Multiple units is the easiest way to do that.
 
Heizomat. Imported and distributed by Marc, I'm the Upper Midwest contact.
Fully modulating, and the price is more reasonable the larger you go, so slight oversizing is actually more desirable, especially if you want the flexibility to burn greenish chips.

Emailing off list.
 
I looked at the lopper/drummer website, asked for information on one of their chip burners (the smallest one) (and one or two of their stickwood boilers as well), and my mailbox has been sadly lacking any information. Must have been a couple of weeks now. No prices and not much detail on the website, won't send info when asked, looks like one more crummy heating distributor that doesn't actually want to sell product. Oh, Well...

Re: the heizomat - this from a year ago here:
https://www.hearth.com/talk/threads/heizomat-wood-chip-boiler-videos.108849/
 
I know of one school up here has one running for a few years. The shoulder season, they do not run it. It needs the bigger heat load to be effective. Thats why we're looking at pellets with a cascading type of system, for our school. But we're very early on in doing this.

I'm on a school board in that region and see if i can get a contact number of who oversees this biomass unit.

Just my 2 cents.
 
Really appreciate the info. This "project" is in the pre-feasibility stage, really early in the process, and I am collecting info for purposes of preliminary evaluation of roundwood/cordwood, pellet and chip boilers systems.

Initially I am not overly attracted to chip boilers due to issues relating to variable chip size and moisture content, and my attraction is even less for hogwood boilers in the size range of interest. Cascaded pellet boilers are of initial interest, as are larger cordwood boilers with storage. The school currently is served by two 500MBtu propane boilers, with one normally sufficient to meet all demands, and the second for peak needs and backup. But the discussion also includes possible expansion of the system to serve an adjacent building. At least one, if not both, propane boilers would be retained as backup.

I will continue to collect info.
 
Several schools in Vermont heat with wood chip boilers but I don't know if there is any central source for information on the projects or if they are engineered separately. Some have been in place for several years so I believe they are past their experimental stage. I had heard rumors that they needed "graded" chips but I'm not sure about that. I keep my ears open for any information I can obtain.
 
The Fröling TX150 is a 500,000 btu/hr ASME boiler that can burn pellets or semi-dry (<30%) wood chips. Like the P4 it can be cascaded up to four boilers, but it sounds like replacing one LP boiler with a single chip boiler and using the other LP boiler for peaking and back-up is a great plan. Most are being used with pellets because the semi-dry chip is not yet widely available, but it sounds like this project might have access to them. Chips must meet the G30/W30 spec. See details about the boiler on our web site here: http://www.woodboilers.com/products/wood-chip-boilers/froeling-tx-150.html and a posting about a really cool four-boiler install on our blog here: http://blog.woodboilers.com/2014/03/featured-installation-four-froling-tx.html Yes, that is a six foot and an eight foot step ladder next to the buffer tank (3000 gallons!).
 
Several schools in Vermont heat with wood chip boilers but I don't know if there is any central source for information on the projects or if they are engineered separately. Some have been in place for several years so I believe they are past their experimental stage. I had heard rumors that they needed "graded" chips but I'm not sure about that. I keep my ears open for any information I can obtain.

It is my understanding the VT has more schools heated with wood chips than any state in the country. Also that most are larger installations burning green chips.
 
I do not have a lot of information. But the hospital near buy just got there new chip boiler comissioned. There is a big bio tomatoes green house around here heating with chip boiler as well. And it was on the news lately that many schoold and public building in the matapedia valley are in the pre fesability stage as well.
 
It is my understanding the VT has more schools heated with wood chips than any state in the country. Also that most are larger installations burning green chips.
Wow. that's pretty. nice work.

karl
 
Might there be a rule of thumb as to Btuh output when a green chip boiler, vs dry chip or pellet, becomes practicable?
 
Might there be a rule of thumb as to Btuh output when a green chip boiler, vs dry chip or pellet, becomes practicable?
Comparison probably exists but I hope that they take into consideration that these chips will not dry themselves and resources must be added to reduce the moisture in a large scale operation. The extra BTUs might not warrant the cost.

Brought to you by someone who doesn't know squat about the process:p
 
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I drive tractor trailer. I've hauled clean wood chips, hog fuel, straight bark, sawdust,shavings, etc. This was in a 150 cu/yd open top trailer. 7 or 8 months a year it's alright. But the other 3 to 4months of the year(winter). It can be a big pain in the azz. Wait until you have to shovel a load off(by hand) because the walls/floor of the trailer weren't pretreated( with either diesel or antifreeze) enough to prohibit freezing in a big solid chunk. It freezes to the walls like JB weld. I've seen loads sit in a heated garage for days before they loosen up.

To me, the extra cost to handle hog fuel, or even chips, just seems to be an added cost that you wouldn't see with pellets. Yes, you can park a live floor trailer inside a building and plumb it to unload as needed. But one way or another, you're going to pay $80k to$100k for that trailer.Plus have a heated facility to park that trailer in.

But as fred says----Brought to you by someone who doesn't know squat about the process:p
 
Below some pictures from the Heizomat container discharge system.
There are for sure more things to think about it with wood chips then with pellets.
The handling of wood chips is much more complex, but for anything over 200 kW it is a no brainer in my opinion.


aufstell3_2.jpg
aufstell1.jpg

aufstell2.jpg
 
Where are these pics from? My concern/ with cost is I would think the fuel would freeze on the walls etc.?

These are from Heizomat installs in Germany/Austria. I did see some installs 3 weeks ago.
The containers can receive some form of heating in the bottom. Heat rises.
The floor is a movable floor, it "walks" the wood chips to the front where a solid auger discharges them.
So, again as with wood pellets the Germans/Austrians are 10/15 years ahead of us for what concerns medium scale wood chips boilers.
All is mechanically sound and most of the issues we can/will think off are addressed.
There are between 15 and 20 top notch "biomass" manufacturers in Austria/Germany alone.
Each of them sells at least 500 to 1000 medium scale systems per year.
It's impressive and scary at the same time.
For us here in North America to catch up it's a matter of opening up to the technology that is available right there and get it over here, rather then trying to reinvent the wheel (pellet boiler)
 
These are from Heizomat installs in Germany/Austria. I did see some installs 3 weeks ago.
The containers can receive some form of heating in the bottom. Heat rises.
The floor is a movable floor, it "walks" the wood chips to the front where a solid auger discharges them.
So, again as with wood pellets the Germans/Austrians are 10/15 years ahead of us for what concerns medium scale wood chips boilers.
All is mechanically sound and most of the issues we can/will think off are addressed.
There are between 15 and 20 top notch "biomass" manufacturers in Austria/Germany alone.
Each of them sells at least 500 to 1000 medium scale systems per year.
It's impressive and scary at the same time.
For us here in North America to catch up it's a matter of opening up to the technology that is available right there and get it over here, rather then trying to reinvent the wheel (pellet boiler)


The sad thing is that the code and rating agencies will never allow that to happen without collecting their "tariff" and making the Euro's redesign and reengineer an already superior product.
Just. Sad.
 
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