Chronicles of the Clayton

New record for most coal added at one tending. 71 pounds.

Ashley is still chugging along nicely with the once per day tending. It seems like she's been baking us out of the house a little more than she used to. I really think that exhaust diverter has been quite a game changer..

Ash/coal percentage over the last 10 days 12.6%

I'm off for the next 12 days so I may pursue another modification to the furnace. I've been shaking down with the load door open to slow down air flow thru the coal bed in an attempt to keep fly ash to a minimum. To gain access to the shaker nub I have to open the ash pan door. I would really like to be able to shake with it closed. I'll need to make a hole in the ash pan door that my shaker handle will fit thru. I can furnish the hole with a swinging type door with a bolt and compressed spring just like my primary air control. The hole would be right between the spinner and the auxiliary primary air control that is currently on the ash door now.

It would be a simple project but there is one hang up. The grate frames float on top of a ledge that they sit on. The frames tend to creep around a small amount, about an inch total from one side to the other, slowly over the period of a month or so. For the hole to line up with the shaker nub, the grate frame will need to be confined somehow. I'm thinking I'll drill a hole in each frame corner along with a hole in the ledge that it rests on and just drop a bolt thru each to prevent any lateral movement of the frames. It would mean a total shut down and clean out which really makes it a big job.

I've brought this up before and it was suggested to make a "sub" door with a hole for the shaker handle that I could cover the ash pan door opening with. It's a great idea too but still doesn't fix the floating grate issue.

Lightning wrote:............ The grate frames float on top of a ledge that they sit on. The frames tend to creep around a small amount, about an inch total from one side to the other, slowly over the period of a month or so. For the hole to line up with the shaker nub, the grate frame will need to be confined somehow. I'm thinking I'll drill a hole in each frame corner along with a hole in the ledge that it rests on and just drop a bolt thru each to prevent any lateral movement of the frames................

Something to ponder, I feel the tolerance and movement may be to relieve stress from the grate itself when shaking, allowing movement takes pressure of the grates and connections there of. My box stove has 2 beefy grates and they sit in a floating frame as well, when ever there was a jam I could feel and see everything move a bit and I would investigate. Maybe a larger opening, (left and right), and door will minimize your work load? just my 2 cents.

michaelanthony wrote:I feel the tolerance and movement may be to relieve stress from the grate itself when shaking, allowing movement takes pressure of the grates and connections there of. My box stove has 2 beefy grates and they sit in a floating frame as well, when ever there was a jam I could feel and see everything move a bit and I would investigate.

Good points and probably good reason to leave well enough alone..
I'll put some more thought into it...

Lightning wrote:

michaelanthony wrote:I feel the tolerance and movement may be to relieve stress from the grate itself when shaking, allowing movement takes pressure of the grates and connections there of. My box stove has 2 beefy grates and they sit in a floating frame as well, when ever there was a jam I could feel and see everything move a bit and I would investigate.

Good points and probably good reason to leave well enough alone..
I'll put some more thought into it...

Well I like the idea of the bolts along the lip of the furnace holding the grate frame in place because you can remove them if things don't work out

Another 12 days have passed since my last ash weigh in. Somehow I ran a 17.5% coal/ash ratio this time. Not sure why lol.. Oh well, we'll see how the next one looks. Maybe I counted something twice.

Didn't get to the mod I mentioned earlier, was just too much going on with the holidays. We also had my step daughter and her guy stay with us for the week.

Still running the 24 hour tending cycles. I did come up with something interesting though. At a ball park of up to ~60 pounds per day I can run a fire that leaves a reasonable amount of burning coal left at shake time. This is an output value of ~25,000 BTUs per hour. I call it one of my very own "fun facts".. The max BTU output rate for a 24 hour burn cycle is roughly 25,000 BTUs per hour. I wonder if that little factoid would be handy in sizing a heating appliance.

Next week will be the end of the 24 hour burn cycles though. High of 52 tomorrow, then plunging to a high of 18 on Monday and some below zero nighttime lows later in the week. Yay!

I must have gotten a little too excited about the upcoming chill down.. 73 pounds all at once, out of a heaping 6 gallon and half gallon bucket..

73lbs? In one scuttle bucket? I guess it's keeping your strength up Lee. Better have that thing magnafluxed, and make sure that handle doesn't give way. Sounds like lots of good data on this thread. I can't believe you guys are still almost 60*. What a crazy winter. Guess you'll be stretching the legs on that Clayton next week. Have fun!
P.S. Are you inside that furnace, when taking pictures? Looks pretty cramped in there.

A hole in ash pan door = primary air and a blaze on your hands are you up for that?

ddahlgren wrote:A hole in ash pan door = primary air and a blaze on your hands are you up for that?

Funny you mention that.. I actually put a brick up against the ash pan door so my big black cat can't bump the lever and open it.

This is a clip from an earlier post I'd like to elaborate on...

When I cut back secondary air, I also see my flue pipe temp fall.. does it fall because the flue gas there is cooler? Or I have a better explanation.. it falls there because there is less mass moving thru the pipe at the same temperature. And since there is less air mass, the pipe can loose it to the room easier. Kind of like wind chill effect in reverse.

The furnace was run a little harder than usual today due to the cold blast we're getting. Pushing 120 degrees thru the warm air supply coming off the furnace. I thought I would pursue a little experiment. I came home from work, the furnace was about 12 hours into it's burn cycle at a heftier burn rate than usual.

Below is a collage. The top row of pics is the warm air duct temp as seen with a meat thermometer with it's probe inserted into the center of the stream about 2 feet from the furnace. The pic under each is the "over the load door" temp (top) and the flue pipe temp (bottom).

The first pic shows the temps with a sliver of secondary air (372/273)
The second pic is after 30 minutes with a fair amount of secondary air (370/284)
The third pic is after an hour of returning to a sliver of secondary air (374/275)

Isn't it interesting that even though the flue pipe increased by 11 degrees there is NO change in the heat output of the furnace? Wouldn't it stand to reason that if there is an increase in flue pipe temp then I should see a drop in the warm air duct temp? Isn't it constantly preached that higher flue temp means lost heat out the chimney? Why didn't heat output of the furnace fall?? Still 120 degrees thru the entire duration of the experiment..

Every time I look for an answer I find more questions..

Stack temp went up 11 degrees so you would expect a drop in output. That did not happen so something compensated for the rise in stack temp. That something might very well be an increase in combustion efficiency, specifically burning more CO with the increased over fire air. Losing more heat up stack, but producing more heat in fire box.

I don't know Lee, they all look fairly consistent to me. Maybe the minor difference in stack temp is influenced by something other than increased primary air. Lots of variables, including even just the time element. And as you know, these things burning coal are kinda slow to react. But I give you credit for collecting data. One day, you'll be sipping on your "hot beverage" and it'll all click, and you'll say "Hey, Now I've got it!" And when you do, please share, cause I haven't got a clue.

franco b wrote:Stack temp went up 11 degrees so you would expect a drop in output. That did not happen so something compensated for the rise in stack temp. That something might very well be an increase in combustion efficiency, specifically burning more CO with the increased over fire air. Losing more heat up stack, but producing more heat in fire box.

I like that answer, it makes good sense. It may also explain why many manufactures decide just to use a fixed secondary air for a dedicated coal burning hand fed stove. The next time I run the experiment I'll try it with even more secondary air to see if how it influences things.

joeq wrote:I don't know Lee, they all look fairly consistent to me. Maybe the minor difference in stack temp is influenced by something other than increased primary air. Lots of variables, including even just the time element. And as you know, these things burning coal are kinda slow to react.

I only have small windows of time during a burn cycle to make changes to one thing while all other variables are holding steady to see it's influence. When splitting hairs, one must hold their head very very still...

Edit - Its possible too that 11 degrees on the pipe just isn't significant enough to influence heat output.. But was hoping I'd see something lol

I would try a 7 day test of the secondary air wide open, see what it does, hopefully the OAT are the same roughly