big old combustioneer running again!

Finally got the big combustioneer up and running. Will post some pics soon. Need to run some more pipe to existing duct work but have a couple 8 in tied in and it is pumping heat into the house. Does anyone have a good way to tweak the feed and air ratios?

Still have some details to finish.

Goodness Gracious...that things a "beast"

What model is that?
How many btu/hr?

Combustioneer model 24 FA. 156,000 btu according to the spec sheet but that was 20 lb/ hour with 12,000 btu coal. I'm burning 13,500 coal so I'm sure I could get a little more out of her. Have my thermostat on 77 now, partly because I can but mostly out of spite to my wife who is always complaining it is cold!

Now that's a coal furnace
Did you paint those red parts? I don't remember them being that color.
I need to find photos of the big stokermatic furnaces and post them. They are red with black firebox door and look really cool.

As far as air and feed, it depends on the coal and chimney draft so adjustments will need to be made over a day or two.
I would recommend settings that keep a bed of coals heaped up to about 5 inches above the top of the tuyers and not producing smoke when the stoker is running. A coal bed more than about five inches with smoky fire would mean too little air or too much coal and a shallow coal bed burning very bright with lots of sparks indicates too much air or not enough coal.....but again it depends on the characteristics of the coal.
Clinkers should develop around the outside edges of the burning coal.

I'm sure Berlin will have some more pointers for you.

One of the biggest issues with these furnaces (and unfortunately common to combustioneer stoves as well) is cracking of the heat exchanger, once these cracks develop, it's very hard to keep them closed even after properly welding them or welding a plate over them because of where the stresses have been concentrated in the steel. I'm mentioning this first because they are preventable - if you don't have any, you'll want to make sure it stays that way. First the fan/limit control: set the limit at 160, close @ 110 and open @ 90. Next, you need more airflow! if it keeps hitting the limit either the blower is running too slow (larger pully needed on motor) or your ducts are way too small. Running two or even four eight inch ducts isn't adequate.

As far as adjusting the fire, you want to make sure of a few things: the clinker forms outside the firepot. the fire should be bright and NOT produce any smoke while running. as rockwood said, you want the fuel bed to be burning a bit above the tuyeres (extended idle times will reduce it's depth, but that's ok). You will achieve this by allowing loose ash to accumulate and by adjusting the air so that the fuel bed reaches an equilibrium (where fuel burned matches fuel introduced) at around 3-8" above the tuyeres (once again, the higher the coking tendency, the deeper the bed will need to be and the deeper the loose ash will neeed to be). You need to set your baro to between -.03 or -.04. you must have a baro (if you don't it will burn back into the worm and ruin it and the tuyeres). excessive air will also ruin the worm and the tuyeres quickly. If the clinker is forming as chunks in the firebox or as a ring outside the tuyeres, you are ok, if the clinker is forming in the tuyeres and you have a narrow column of flame shooting out of the center of the tuyeres (think raiders of the lost ark) you have too much air and the fire is burning down into the tuyeres. Some sparks are inevitable, but if it looks like a firework, you need to either increase the feed or (because these furnaces/stokers are underrated) more likely simply reduce the air. It takes some time for the stoker to visibly respond to changes either in feed or air; it may take a couple of hours or a day depending on load/runtime. The stoker will NOT behave predictably until the NECESSARY amount of loose ash has accumulated in the firebox - depending on the coking tendency of the coal it could be from 3 - 8" before the fire behaves consistently. Only remove the clinker ! Do not remove loose ash unless it becomes excessive or the weather is so mild that the stoker doesn't run long enough to produce a clinker - and then only take out what's necessary.

I'm sure there's a lot more but it's been a long day. Once you get it where you think you need it post some pics and we can critique your stoker fire

Finally have some clinkers, nice large ones forming in a ring around the tuyeres. My only concern is I am getting some coke trees, not huge ones but they are there. I don't have a manometer but set the air according to stoker instructions. I'm sure there still is some tweeking to be done. Need to find a new micro switch for my holdfire timer as it doesn't always come on during the holdfire cycle. So far so good though, sure beats hand firing anyday of the week.

Willis,

Is that a Wil-Burt Timer?
If you could post a picture of that micro switch for the hold fire timer, I just may have something that could work.

McGiever

Here it is, unimax 2tmt52-4.

Willis wrote:Finally have some clinkers, nice large ones forming in a ring around the tuyeres. My only concern is I am getting some coke trees, not huge ones but they are there. I don't have a manometer but set the air according to stoker instructions. I'm sure there still is some tweeking to be done. Need to find a new micro switch for my holdfire timer as it doesn't always come on during the holdfire cycle. So far so good though, sure beats hand firing anyday of the week.

Sounds like you're getting it dialed in.
The coal out here doesn't make coke trees so I don't have any experience with those but If they're not getting big enough to fall outside the fire where they won't burn then I wouldn't worry about it.
A manometer would be for setting the baro damper not for stoker settings and I agree with Berlin that a baro damper should be used.
A switch should be easy to find and I don't think you'll lose the fire this time of year anyway unless there's no call for heat for an extended period of time.

Willis wrote:Here it is, unimax 2tmt52-4.

Think you could make this work?



This looks exact for mounting.




Willis, Let me know if you want either or both...I'll drop in the mail to you if you want.
The first pictured one is new, second is a used one scavenged from something.

Thanks, but I called Willburt today and ordered the right one , I'm tired or rigging things up after installing the furnace, only 12 dollars. Still getting coke trees though and have adjusted the air every which way. Not a huge deal just hit them with poker when I check fire.