How to Adjust to Limit Clinkers?

Which way to adjust to get rid of clinkers if that's possible? I have noticed inconsistencies in my fire and I think it's due to excessive clinkers because my fire will burn back when my clinkers get solid. I believe the clinkers are sticking to the bed and not allowing the coal to feed properly. I really like my fire with the adjustments I have so I am reluctant to start chasing this thing. Is it just the coal or can it change through settings?

I usually only get them when it's burning really hot when it's very cold out.

I;ve mixed Buckwheat (maybe 50/50 mix) with mine at times in my keystoker, still have them at times, but they break up easily. I've had a bridge from the burn plate to the door and it made a big mess.

a lot of good topics on this subject if you search.

here's one from a while ago.

What is a Clinker?

WNY wrote:I usually only get them when it's burning really hot when it's very cold out.

I;ve mixed Buckwheat (maybe 50/50 mix) with mine at times in my keystoker, still have them at times, but they break up easily. I've had a bridge from the burn plate to the door and it made a big mess.

a lot of good topics on this subject if you search.

here's one from a while ago.

What is a Clinker?

Yea I wasn't getting any with buck but now I'm back on rice and you can really see where I switched over where I dump my ash. I still have 3 ton of buck left so I'll see what happens on the next tote. Thanks for the link but all I learned was anthracite is not supposed to clinker!

Clinkers are a sign of too much air for the stoker.

You're burning it too hot. Also there is red ash and white ash coal, the red ash has higher iron content and more likely to clinker.

Clinkers result from coal with a low ash-fusion temperature.Clinkers are when the ash "melts".Some veins will not clinker until close to 3500 degrees.When initial deformation of the ash is around 2500 or less,you will likely have clinkers.So,trying to burn your coal at a lower temp is one thing to do,by cutting back on air as long as you are ok with the heat output.If this doesn't help your situation,you have low fusion coal,and might need to blend a higher fusion coal with it.

All that above, plus since you are using a Power Vent you would also reduce it's draft to match the now reduced combustion air. That way you can keep the settings ratio you say you are happy with.

Thanks for the replies, I will tone it down some more. For those that followed my 80 page saga from last year I have really backed everything off from where I was at then, guess not enough!. Here is a pic from this mornings ash cleaning...those patties are bigger than my hand. I am burning Lehigh and have seen others pics so I should have some really good coal?

Be sure to show us your ash pan again after settled from your adjustments.

With my KAA-4-1 I have backed the pusher plate feed
stroke to fifteen threads out.

The air shutter is exactly where the factory installed the
screw holding it in place on the squirrel cage fan.

I have NO fused clinkers and the ash that falls off the grate
crumbles to dust in my gloved hand.

No matter how low ash the coal is,fusing of ash,or clinkering,wastes coal.You can see unburned coal in your ash being carried out by the clinkers.The clinkers also smother coal from burning.I doubt it is high ash,or slatey,but You probably got some orchard vein coal there,known to have fusion issues.That would have been ok if it was pre-blended ,before cleaning,with their other veins higher in fusion,like mammoth,primrose or Holmes.

lzaharis wrote:With my KAA-4-1 I have backed the pusher plate feed
stroke to fifteen threads out.

The air shutter is exactly where the factory installed the
screw holding it in place on the squirrel cage fan.

I have NO fused clinkers and the ash that falls off the grate
crumbles to dust in my gloved hand.

It is more of a coal thing than a settings thing...different coal, different settings.

Morning guy!!!! Good to hear the only problem is clinkering. I got that when I ran straight rice from one supplier. I called them clinker patties. A little ketchup, onion....no wrong patty. Anyway I mixed it half and half with buck and the problem went away. I switched yards and the problem went away.

If you got a good price on the coal, stick with it and blend it yourself. Try it you'll like it.

I am running lehigh pea in my hand fed boiler with a combustion fan, I am getting "more than normal" clinkers and some bigger than softballs, it's no big deal for me to hook them out with my poker. I chock it up to having the combustion fan and it going from idle to HOT quick, the family is burning the same coal in 3 easy Hannover 1 hand fed stoves and there not clinkering. Still a great clean high heat coal with lower ash amounts.

Doesn't compare to a stoker but wanted to share that with the same coal it's happening to me also.

Great feed back fella's! So far I have to report that I am still getting pretty bad clinkers so I have once again reduced the combustion air. If you can remember me last year I had a huge topic on combustion air and not being able to run my combustion gates to 50%. Well now I have just adjusted to about 5% and have attached a pic. I reset my drafts to factory spec with .02 over fire and .05 at breech since I can adjust the power vent. One thing I have noticed is my boiler is not putting out the heat it has been as my boiler temps were down to 148* this morning when usually it is cycling between 175-185*. I am going to see what happens and burn out the hopper today so I can do a clean out. I have burned 5 ton so far this year so I figure it needs to be done but this will be a good test to see if the clinker problem lessens with new settings. Maybe it is just the coal but the way everyone is bragging this Lehigh up and from the pics I've seen I am confused???