Lignite test in the 520

I'm being sent lignite from the Dakotas and will attempt to burn it in the regular 520 pot. I'll use the short worm and the barrel because it's supposed to be a very fine mix. I'm not sure how it will feed up the worm and how clinkers will affect the pot.

Anybody here burn lignite? Any idea what feed and air ratio to start with? Would it burn faster or slower than anthracite?

Sounds like uncharted territory to me! Sounds like a fun experiment, too!



http://www.answers.com/topic/coal-1

It's only 60-70% carbon. It's going to use a lot of fuel compared to anthracite. It contains more moisture than coal and in storage it can dry out and crumble potentially producing more fines and could pose a conveyance problem in an auger stoker.

Less sulfur therefore considered more "environmentally friendly", whatever that means.

High in volatiles. Fire will be more difficult to control with new fuel introduction.

Those are my best guesses on performance.

i have a friend out there that grew up in a farmhouse heated with local lignite coal.......from what i can gather they had a hand fed stove and he said it was lots of work......he was out here to visit in 2007 and was impressed with my modern coal burning equipment

Speaking of moisture content, the engineer did say it was dried to about 30+%

stoker-man wrote:Speaking of moisture content, the engineer did say it was dried to about 30+%

Anthracite is less then 15% have fun burning make sure you have a poker and a clinker tongs

I thought about that. I don't think I'll let the fire idle too long. With luck, I can reduce the feed/air and run continuously and not have a large clinker develop. I was informed that the place where this is currently burned, the clinkers are the size of a Volkswagon. I'm more concerned about a clinker falling off and pulling hot coals than it getting stuck inside the pot.

Anthracite is less then 15% have fun burning make sure you have a poker and a clinker tongs

I know they dry the coal at Blaschak, but when it finally gets into the bin, it's wet again from being outside in bags or in a pile in a coal yard. How much moisture content it picks up, I don't know.

From my two years experience of working in a deep mine, I know that rocks are a whole lot heavier when they're 100% saturated.

stoker-man wrote:

Anthracite is less then 15% have fun burning make sure you have a poker and a clinker tongs

I know they dry the coal at Blaschak, but when it finally gets into the bin, it's wet again from being outside in bags or in a pile in a coal yard. How much moisture content is picks up, I don't know.

From my two years experience of working in a deep mine, I know that rocks are a whole lot heavier when they're 100% saturated.

Anthracite has less then 15% moisture content in the coal not on the coal and as you know the coal is dry when it goes into the bagging plant the wetness comes from the dealers leaving the bags outside in the weather uncovered not from the bagging plant

coal berner wrote:

stoker-man wrote:Speaking of moisture content, the engineer did say it was dried to about 30+%

Anthracite is less then 15% have fun burning make sure you have a poker and a clinker tongs

reminds me of pappy's old coal cookstove, grampas advice on being prepared for a good fire was to make sure you had all the tools. He would say "check the moisture, then lifter leg and poker."

I got the coal today and started experimenting with it. By the end of the day, the feed rate was 10 and the air about 4. The flyash was kept under control at that air setting, but there is a lot of sparking.

The coal was very difficult to start burning. Anthracite is easy compared to this stuff. It's the consistency of dust with some buck sized pieces along for the ride. I finally got it started by lighting a good supply of anthracite on top of the lignite and then starting the feed. I was really surprised at the low torque required to bring it up the long worm which is almost 11 feet long. It was dry and did not clump. Wet coal like this would never feed.

Once the fire was established, the dust came up into the center of the pot and fell outward to the burning ring where it was consumed almost immediately. There was no clinkering at all, almost no ash and there was no visible smoke inside the boiler or outside at the chimney. I consumed a 5 gallon bucket today and the ash might equal a quart or less and it resembled wood ash. The BTU must be close to that of wood pellets, not enough for our system. Maybe feed and air adjustments will change that.

I shut down the system for 10 minutes, then 20 and finally 30 minutes. The fire instantly came to life, so I assume it will hold a fire until the timer kicks in.

More testing and pictures tomorrow.

I imagine (if the size was right) that the anthracite EFM furnace wouldn't have a problem burning a low coke button eastern KY stoker either.

Send me some and I'll try it.

As I was thinking about this, lignite burn almost exactly like wood pellets and corn mix, the same test I did over the Summer, flame and burning characteristics and heat produced. I think if there was more solid coal and less dust, it would burn better. This stuff is about 80% pure dust.

The dried lignite is rated at 7000 BTU per pound, about the same as the wood pellet/corn mixture used in the Summer. I suspected that it was about the same. After burning for one hour straight, the total ash is less than a quart, burning at 11 teeth feed rate. I'll continue to burn the rest of the coal, about 13 gallons worth and measure the ash. I don't notice any sooting inside the boiler, but I'm sure the flyash is building up. There is no clinkering whatsoever and the ash is a fine white wood-like ash. As shown in the video, the coal pyramids and falls outward to the outer edge where it is almost immediately burned up.

The first video shows the burning fire in the 520 stoker

http://www.youtube.com/watch?v=04jPPuzo4CM

The second video shows that there is very little or no smoke at the chimney

http://www.youtube.com/watch?v=dXSF96_3UVY
This picture shows the flyash produced with the boiler running at full feed capacity, 22# per hour (anthracite weight) and the air setting at 4.



This picture shows the lignite sample sent to us and is barely more than dust. Surprisingly, the dried sample cranks as easily in an 11 foot coal tube as does anthracite.



This picture shows the ash ring after burning all day.



This picture shows the ash. It's as fine as sand.



At the end of the day, with about 120 pounds of lignite burned, the quantity of ash weighed 4 pounds and displaced about a gallon sized container, compared to about 13 gallons of original lignite.

The only comments I would add are that it is not easy to start a lignite fire. Some accelerant, such as kindling or wood pellets are needed and the flue pipes should be able to be easily undone for flyash cleaning. There was no problem with the fire going out with a 30 minute rest, so the timer should take care of that. Even though the lignite easily fed through the 11 foot pipe/auger, a shorter worm will reduce the chances of breaking sheer pins. Dry lignite is a must!

Hello all,

I am the engineer that sent the sample in. When I said we have "clinkers" some the size of small cars, I should have mentioned that our boilers are 21 stories tall and burn 500 tons per hour each. Anyway, great page curious as to conclusions on residential use of our refined lignite product.


Thanks,

Jared pozarnsky
Systems Engineer
Great River Energy

pozarns wrote:Hello all,

I am the engineer that sent the sample in. When I said we have "clinkers" some the size of small cars, I should have mentioned that our boilers are 21 stories tall and burn 500 tons per hour each. Anyway, great page curious as to conclusions on residential use of our refined lignite product.


Thanks,

Jared pozarnsky
Systems Engineer
Great River Energy

Welcome Jared!!! and thank you very much for your help!! Wow sounds like quite the boilers there. How are they fed???