Amount of Ash on Grates

mattcoalburner wrote:you do not need 1-2" of ash, why burn more coal and have waste if your running at the temperature you want. the recommendation of 1-2" is more so people are not pushing unburnt coal off the edge of the grate.

No disrespect Matt, how do see you'll be burning more coal? Granted coal feed is more which in will create less burn time vs less feed longer burn time.

Wiz wrote:

mattcoalburner wrote:you do not need 1-2" of ash, why burn more coal and have waste if your running at the temperature you want. the recommendation of 1-2" is more so people are not pushing unburnt coal off the edge of the grate.

No disrespect Matt, how do see you'll be burning more coal? Granted coal feed is more which in will create less burn time vs less feed longer burn time.

Your will be 100%sure all coal is burned to the maximum, the slower the feed the less coal being burned per hour

mattcoalburner wrote:

Wiz wrote: No disrespect Matt, how do see you'll be burning more coal? Granted coal feed is more which in will create less burn time vs less feed longer burn time.

Your will be 100%sure all coal is burned to the maximum, the slower the feed the less coal being burned per hour

I agree! Why burn more coal than needed in order to heat any place with hot air. It's just a waste... If it's a boiler, the heat is stored. However, My Kaa-2 can only store so much, due to it's smaller capacity. Too much fire triggers the high limit. Too small of fire has too much lag time. By the time zones are satisfied, I have too much fire, triggering high limit again. I need to find the balance. Or should I say, I have found the balance.

Pacowy wrote:The Keystoker K2/K6 manual says 2" of ash, and says the air inlet must be closed enough to make sure the specified draft can be achieved with the baro closed. I don't see any place where it says the air inlet can't be closed more than that, or that a manometer would be required to do so.

Mike

Iirc, the owner manual states that the installing dealer will use a manometer and set the air adjustment, using the test port on the door.

I looked at the manual before I made that post.

Mike

mattcoalburner wrote:you do not need 1-2" of ash, why burn more coal and have waste if your running at the temperature you want. the recommendation of 1-2" is more so people are not pushing unburnt coal off the edge of the grate.

The recommendation of 1-2" of ash is common across many underfeed and flat/inclined grate stokers and indicates (after a long burn) that you are using efficient proportions of air and coal. If hot coals are going over the edge you're wasting fuel, and if the ash band is wider than that you are blowing air needlessly through dead ash, which has the effect of cooling the combustion area and pushing BTU's up the flue.

Mike

titleist1 wrote:

Pacowy wrote:The Keystoker K2/K6 manual says 2" of ash, and says the air inlet must be closed enough to make sure the specified draft can be achieved with the baro closed. I don't see any place where it says the air inlet can't be closed more than that, or that a manometer would be required to do so.

how do they expect you to know where to set the air inlet to get the specified draft without a manometer? are you able to trust the accuracy of the marks on your baro scale and can you tell exactly where the weight is set with respect to the marks on yours?

As the manual says, the only relationship between the air inlet and the draft arises if the draft is inadequate when the baro is closed. If the draft is adequate with the inlet wide open (or with the inlet closed a certain minimum amount), the baro - not the air inlet - governs the draft, and the user is able to select feed and (lower) air settings that satisfy the load while aiming for the 2" ash band. It is the ash band that tells you whether feed and/or air adjustments are needed to achieve an efficient burn.

Mike

P 4 of the manual - see "after starting fire": http://www.keystoker.com/manuals/2012/K2-K6-6in-Stack.pdf

My printed manual is a few years old, and worded a bit differently, but it states that "there is no substitute for a draft gauge in making these adjustments" I will admit that I frequently dink with the feed, and air, and baro setting. I guess it's a matter of opinion, or technique as far as air adjustment. The only opinion that I've read here more than once and find a bit silly [ok, flat wrong] is that the air " shutter" should NEVER be touched, and remain at the factory starting point of 1/2 open. It's a starting point.

That said, obviously, you don't want to shove still burning coal into the bucket [too little air, or too much feed?]. Someone here recently wrote that the ideal setting is when the coal is completely burned just before it reaches the last air holes on the grate while the unit is running flat out. Then again, if one [or me LOL] blows an excessive amount of air through the grate in the quest for no unburned pieces in the bucket, are they [or I] are blowing heat up the flue and wasting money just to have nicer looking ash in the bucket? Someone else stated that they don't mind some unburned chips in the bucket, and would rather have that than blow more heat up the flue.

Who is right? I wish that I knew.

Dave

p.s. - fwiw, imo, the coal used will effect the best setting of the air shutter. I bet that if one would screen all the fines out of the coal, much less air would be needed. Coal with lots of fines, or typical undersized rice [more like barley] tends to need more air to burn well. At least from what I see.

dave brode wrote:P 4 of the manual. http://www.keystoker.com/manuals/2012/K2-K6-6in-Stack.pdf

Then again, if one [or me LOL] blows an excessive amount of air through the grate in the quest for no unburned pieces in the bucket, are they [or I] are blowing heat up the flue and wasting money just to have nicer looking ash in the bucket? Someone else stated that they don't mind some unburned chips in the bucket, and would rather have that than blow more heat up the flue.

Who is right? I wish that I knew.

Dave

Yes they [or you ] are wasting money to have nicer-looking ash. Many of the old-school stoker manuals were more informative than the new ones regarding the likelihood that some unburned coal would appear in the ash of an efficient fire. It's basically the same as the small amounts of unburned gasoline that go out the tailpipe of your car. If you try to tweak the engine to burn every last molecule, you will lose overall efficiency and performance because you will no longer be at the optimum fuel/air mix.

Mike

Mike,

I'll cut my air back a tad for a few days. Maybe stoich isn't working the best. LOL

Thanks.
Dave

Thanks for all the input. I'm a little thick sometimes, so if I wanted to narrow my ash band a little what adjustment do I make?
Jim

A little more feed or a little less air.

Mike