Berlin wrote:I don't like an MPD for that reason and I have probably mentioned this in other posts - it is a very effective soot catcher with bit coal. Some guys have luck with a baro damper, which is much better, but still not a huge fan. When the volitiles are burning off bit coal, it is not always a smooth process - if you've ever watched a wood fired in a modern stove with secondary burn turned down low, you'll know what I mean - the gasses ignite on one side then the flame slowly fills the stove, then the flame becomes smaller, then it catches up to the volatiles being released and repeats. A mpd will create pressure inside the stove every time the flame gets bigger and you end up with some puffing - this happens on wood stoves w/ and mpd also under certain conditions. You have to be able to control the air on a bit fired appliance BEFORE it gets into the stove - mpd's do this by preventing air from leaving the stove and that doesn't work well on evey stove with every bit coal - you may have the problems you're having. If the stove isn't sealed tight, you won't be able to control the fire w/out a mpd, this isn't the fault of the coal, it's the lack of a properly sealed appliance that caused this problem.
There's no need to "babysit" a bit coal fire or keep adjusting the air throughout the burn - set it and forget it (but you have to get the setting right) You control the heat with the underfire air, the overfire air adjustment doesn't move, but is adjusted to get a partial burn of the volitiles (don't waste your time trying to burn off all the volatiles, it wont' happen and the attempt will cause you problems). If you have air leaks then all this is irrelevant. stop waiting for it to burn off the volatiles, do you sit around a wood fire waiting for the volaitiles to burn off? then don't do it with bit coal.
I've used bit coal for years in a hand-fired stove, and I've taught others (in person) how to successfully fire it as well. I know many who've switched to bit lump coal FROM anthracite because it's easier to use. It's not as complicated or scary as many make it seem to be. I haven't had a backpuff from my hand-fired stove in years and I have NO smoke, smell, or mess in my house burning bit coal, hand-fired. There's no need for anyone else to either.
The size of a brick is about the minimum size of good bit lump coal. If your fire is that hot, the problem isn't sealing the top, it's that your underfire air is not controlled or excessive. You will have smoke, a proper hand fired setup will always have some smoke, some coals and sizes more than others - do NOT adjust your fire controls from what smokes or doesn't smoke.
Good information Berlin. I remember reading post about bit that you have written before and I am glad you chimed in. The advantages to burning this bit is that it burns to a really fine ash like wood and I still have had no clinkers. The anthracite will clog my stove up with shale like ash after a week of burning and usually need to dump it and start all over but anthracite is so stable and keeps good high temps for a long time. I can't get as long of burns with this bit.
The door is leaking from the WM tabs I just bought another WM to use the top and door from that because it is sealed well. The rest of this stove is sealed 100% . Tomorrow I will swap the tops and door and try again. Are there any good bit burning YouTube videos you would recommend ?
Btw if anyone missed where I posted the size of bit I'm burning . It is anywhere from bricks to nut but it is mainly the larger stuff and I was say and avg of stove coal or slightly larger.
Now with a wood ire burning hockey split logs I trust it as much as my ant. I can get it going , close te mpd and it will burns a long time with no smoke and no I don't sit and watch it. But burning this bit is a lot different than my hickory which leaves me a little more confused.
By the way, if you are familiar with the WM 414a should I not bank it to the too of the fire brick? Until a lot later?
I just filled it up half way with bit tonight and it's doing well I also haven't closed the mpd at all and it is a good stove temp now and fairly low flue temp. I'm going to slow fill it to the top and see how she does tonight.