How to Adjust to Limit Clinkers?

As to Lehigh or any other coal YMMV.

Results vary from methods burned, such as by natural draft only or by being fan forced. Then on top of that you have different sizes of coal being used w/ different results. And aswell you have different quanities on grates burning all at one time like some metered thin increments burning, or a deep and wide charged fire-pot ...all this makes for a lot of variability in results before coal propeties enter (fusion/clinker).

Starting w/ good fuel is better than starting w/ not so good fuel, of course.

Stoves are sorta like automobiles... all can get you from A to B...but a lot of differences in rides are out there.

Did you see this fusion w/ your Lehigh buck size also?

If you are having a problem with clinkers from Lehigh call me and ill see what we can do, there are so many variables that can be causing this its not always a coal issue as some might think. Ill try to see if I can help get you get it figured out.. My phone number is 570-621-8871 Matt

McGiever wrote: Did you see this fusion w/ your Lehigh buck size also?

No, I will grab another tote of buck next and see what happens but none of these adjustments have reduced the clinkers, just output.

LehighanthraciteMatt wrote:If you are having a problem with clinkers from Lehigh call me and ill see what we can do, there are so many variables that can be causing this its not always a coal issue as some might think. Ill try to see if I can help get you get it figured out.. My phone number is 570-621-8871 Matt

Thanks Matt, I'll give ya a shout next week

Here is a pic inside my ash bin while still in the boiler. This pic was just taken after running all day at the reduced fan settings. You can see that huge clinker hanging off one of the stoker beds. I can't wait to tear this thing apart tomorrow and see how much flay ash is in there after running 5 ton through it!

Were all the adjustments made to air only, w/ the feed not adjusted?

Since you say only heat output was reduced, you might try only pushing more coal w/o adding anymore air and see what happens to clinkers.
Just make small changes and wait 1/2 an hour till next increase.

McGiever wrote:Since you say only heat output was reduced, you might try only pushing more coal w/o adding anymore air and see what happens to clinkers.
Just make small changes and wait 1/2 an hour till next increase.

Good advice. For some reason, my EFM creates small round clinkers if I run it at a very low feed rate - even with the air properly adjusted. I think it has something to do with the dwell time of the coal on the burn plates. At much higher feed rates, the ashes have zero clinkers - even through the fire is much hotter.

The powervent is also an unknown, at least for me. If it continues drawing a lot of air through the fire after the stoker stops feeding, that may also be contributing to the clinkers. Try increasing the feed rate and see what happens.

I really don't think they look like clinkers in your pictures, the ash does seem to be caking together, but ill bet you can crumble that ash in your hands. A clinker is very hard and solid....

LehighanthraciteMatt wrote:I really don't think they look like clinkers in your pictures, the ash does seem to be caking together, but ill bet you can crumble that ash in your hands. A clinker is very hard and solid....

True Matt, it is just a continuous sheet of trough formed fused ash. But,none the less is not desirable.
It can get long enough that when the weight finally can allow it to snap off, it can bring some active fire parts with it into the ash pan.
Or maybe worse, is doesn't snap off and stops butted up against the door/wall and backs up the feeding of coal or cause it to push coal over the sides...It is best this gets corrected no matter what it might be actually called.

LehighanthraciteMatt wrote:I really don't think they look like clinkers in your pictures, the ash does seem to be caking together, but ill bet you can crumble that ash in your hands. A clinker is very hard and solid....

I know what you mean, I get something similar when my EFM runs for long periods, but it does not cause any issues...Here is a picture of this mornings ash tub (Lehigh rice).
If I had a LL or Keystoker, I would burn buck in it nearly all the time.

I have a efm 520 and while there may be very small clinkers , there are never clinker like I had in a Harman hand fed that I used nut coal. The clinker would develop if I stirred the hot coal for what ever reason , These clinker wouldn't go through the grates when hand shaked and would grow and grow until they took up the entire volume of the fire chamber and had to be removed by hand and was a molten mass of ash and metal crazy stuff. you could barely break it when removed.

McGiever wrote:Were all the adjustments made to air only, w/ the feed not adjusted?

Since you say only heat output was reduced, you might try only pushing more coal w/o adding anymore air and see what happens to clinkers.
Just make small changes and wait 1/2 an hour till next increase.

The burning coal was at the last hole on the stoker bed so couldn't give it anymore without increasing air.

Rob R. wrote:
The powervent is also an unknown, at least for me. If it continues drawing a lot of air through the fire after the stoker stops feeding, that may also be contributing to the clinkers. Try increasing the feed rate and see what happens.

I also reduce the PV when I lower the combustion air or it is as you said

LehighanthraciteMatt wrote:I really don't think they look like clinkers in your pictures, the ash does seem to be caking together, but ill bet you can crumble that ash in your hands. A clinker is very hard and solid....

Matt you would be correct, this is caked together but it does stick to the side and bottom which affects the feed. It doesn't flow smoothly, sticks to the sides and bottom which causes the fire to burn back a bit. I've seen the cake stick off the bed a good 4" and when it breaks off it does take some hots with it.

McGiever wrote: It can get long enough that when the weight finally can allow it to snap off, it can bring some active fire parts with it into the ash pan.
Or maybe worse, is doesn't snap off and stops butted up against the door/wall and backs up the feeding of coal or cause it to push coal over the sides...It is best this gets corrected no matter what it might be actually called.

This is exactly what happens. The ash dump area is very large so there is no way it could stay together till it hits the wall but you are correct that when it breaks off due to the weight it does take some hot coals with it