Axeman Anderson 1959 130M

We shot a couple videos of the new "Super Slow" coal burning method.

I came home to find a strange occurrence today, the fire door stuck open! I had installed a spring to be sure the fire door opens at the end of a heat call. The spring worked it's way into the door hanger keeping the door from closing. I removed the spring, all is well.

I checked the fire with the Dip-Stick and it had shrunk considerably, 7" from the grate to 10". That is a very high, thin fire. I'm not sure if this was due to the fire door problem. I think it might be that we are not feeding it enough coal now. I did some manual ashing and increased the ashing from 2 to 3 teeth. If the fire is still too high tomorrow, we will increase the auger speed.

Current settings,

Anthrastat = 135
Fan RPM = 1725 (Stock is 2875 RPM)
Ashing = 3 Teeth
Auger speed = 2.07 RPM (Stock is 8.05 RPM)
Aquastat = 170
It ran for 9.5 hours over the past day.

-Don

For sure, not having the fire door closing by fan cycle as designed would not give normal results.

OK, we found out how low we can go! The fire continued to shrink today. It's been a lot colder for the past two days than it has been. I put a 2" pulley on the auger drive motor to increase the feed rate some. 5 days worth of ash. Still looks pretty good. Current settings,

Anthrastat = 135
Fan RPM = 1725 (Stock is 2875 RPM)
Ashing = 3 Teeth
Auger speed = 2.67 RPM (Stock is 8.05 RPM)
Aquastat = 170

I made some feed rate calculations based on the rated 130,000 BTUH net output of this boiler. We are assuming, 12,250 BTU per pound coal, 10% crap in the coal and 80% boiler efficiency.

Basically using the 1725 RPM motor and calculating all the drive ratios we arrived at 0.5 pounds of coal for every complete forward/backward cycle of the ash grate. The auger speed directly effects how many ash grate cycles happen per hour so this gets calculated in too.

With the 2" Auger drive pulley the auger spins 2.67 RPM. At 1 tooth, the ashing grate will make 3.2 complete cycles per hour. This comes out to 1.602 pounds per hour, 2 teeth is 3.204 pounds per hour and 3 teeth is 4.806 pounds per hour.

So that means, if this is correct, we are currently running 4.806 pounds per hour. At least now we know why the fire is shrinking in this cold weather. We were running at about 2 pounds per hour with the 1.5" pulley and 2 teeth.

I will check the math again and continue to Dip-Stick the fire to see where we are.

-Don

I back checked the math and it still looks good.

With the original 130M pulleys, 1 tooth on the ratchet wheel is 4.686 pounds per hour. 2 teeth is 9.372 pounds per hour and 3 teeth is 14.058 pounds per hour.

That is something I never realized before, 1 tooth makes a HUGE difference in feed rate.

-Don

Today we cleaned out the stove pipe using a 4" brush. And we wired the clock to the auger motor. Now we can actually measure how much coal we use. When I Dip-Sticked it this morning the fire was down on the grate and to top was 7" above the grate. That was not good so I changed the feed to 2 teeth from 3. Now we are 2" to 7.5", just about perfect. Current settings,

Anthrastat = 135
Fan RPM = 1725 (Stock is 2875 RPM)
Ashing = 2 Teeth
Auger speed = 2.67 RPM (Stock is 8.05 RPM)
6.4 grate cycles per hour, 3.204 pounds per hour
Aquastat = 170

-Don

Don

How do you come up with the coal consumption per hour?

lprince wrote: ↑

Tue. Jan. 15, 2019 4:42 am

Don

How do you come up with the coal consumption per hour?

Keep in mind, this is a mathematical estimate and its for a 130M. Also my feed rate is currently reduced from stock by pulley reduction.

StokerDon wrote: ↑

Fri. Jan. 11, 2019 7:24 pm

I made some feed rate calculations based on the rated 130,000 BTUH net output of this boiler. We are assuming, 12,250 BTU per pound coal, 10% crap in the coal and 80% boiler efficiency.

Basically using the 1725 RPM motor and calculating all the drive ratios we arrived at 0.5 pounds of coal for every complete forward/backward cycle of the ash grate.

You could do the same for the 260M. You would have to know all the pulley, sprocket and ash gear sizes/teeth.

-Don

How do you account for the coal falling back down the center of the auger?

hotblast1357 wrote: ↑

Tue. Jan. 15, 2019 6:24 pm

How do you account for the coal falling back down the center of the auger?

????? That's what it's supposed to do. Once the transfer head is full, the incoming coal just rolls back down.

For the feed rate...
Because although the clock is running...
Coal is returning to the bin...

hotblast1357 wrote: ↑

Tue. Jan. 15, 2019 6:24 pm

How do you account for the coal falling back down the center of the auger?

You don't need to. The only thing the auger has to do with this is it pushes the ashing lever once per rotation. And it has to keep the coal tube full.

The thing we are trying to do here is equate feed rate to ash grate cycles. On an Axeman,you need to know the auger RPM for that.

-Don

I tried this with ash grate motor run time last year.. it’s all in my thread.. turned out to be kinda sorta reliable.. but it changed with outside temperature, boiler demand. Larry worked with it on me, wasn’t that reliable, also tried it with fan motor run time, same difference.

hotblast1357 wrote: ↑

Tue. Jan. 15, 2019 6:52 pm

I tried this with ash grate motor run time last year.. it’s all in my thread.. turned out to be kinda sorta reliable.. but it changed with outside temperature, boiler demand. Larry worked with it on me, wasn’t that reliable, also tried it with fan motor run time, same difference.

Yes, I remember. When I get a chance I'm going to read back through that. After making some ash weight measurements, I think my 3.2 pound per hour mathematical estimate could be as much as 50% off the mark.

The way mine is set up now, we really have nothing to go by to figure feed rate. One thing is for sure though, it is burning a lot less coal than it was. OR more accurately, it is burning the coal way more completely than it was.

-Don

Thanks for all the great information Stoker Don. This will be quite helpful when I get my boiler up and running one day.

No problem Zig, I'm glad this was helpful.

Over the past 4 days the auger motor has run for 31.4 hours, 7.85 hours per day. The ash is looking really good. Powdery ash and some good clinkers. The ash pan and chain weigh 9.5 pounds. 27.5 pounds of ash in 4 days. The Dip-Stick is showing some heat down on the grate again. The top of the fire is about 7.5" above the grate. Current settings,

Anthrastat = 135
Fan RPM = 1725 (Stock is 2875 RPM)
Ashing = 2 Teeth
Auger speed = 2.67 RPM (Stock is 8.05 RPM)
6.4 grate cycles per hour, 3.2 pounds per hour
Aquastat = 170

A little analysis.
3.2 pounds per hour for 31.4 hours is 100.4, 25.12 pounds per day.
27.5 pounds of ash from 100.4 pounds of coal is 27.4%.

I think this pretty much proves that the 3.2 pound per hour calculated feed rate for this setup is a bit off. It is a starting point though. I also don't believe this is 27.4% ash. It's more like 15% to 18%.

27.5 pounds of ash at 15% is 183.33. 5.84 Pounds per hour.
27.5 pounds of ash at 18% is 152.78. 4.85 Pounds per hour.
27.5 pounds of ash at 20% is 137.5. 4.38 Pounds per hour.

This is not perfect but we do seem to be running between 4.38 and 5.84 pounds per hour based on the ash weight. We will see if this theory holds up over the coming days and weeks.

-Don