Central Boiler FORGE 3500 Outdoor Coal Boiler

 
User avatar
Lightning
Site Moderator
Posts: 14659
Joined: Wed. Nov. 16, 2011 9:51 am
Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Sun. Dec. 02, 2018 7:50 pm

I will try to get some numbers soon. In the meantime, I'd like to let y'all know that he's been able to keep a coal fire for nearly a week now. Here's a stat graph for the last 24 hours. He's got a nice thick bed in there now that's burning efficiently. The boiler is occasionally over shooting and goes into high limit mode which seals the combustion air completely. It regains control of the water temp and automatically falls back into standard run mode. During standard run mode, it automatically regulates the water temp by adding combustion air. Between cycles of maintaining water temp it goes into idle mode. During idle mode it reduces combustion air to 10% driving by natural draft only. Also during this mode it's set to pulse the fire every 18 minutes for a 3 minute duration. I'm thinking we need to reduce the pulse settings to prevent the over shoots now. Any advice or comments about that?

Attachments

Screenshot_20181202-194027.jpg
.JPG | 175.2KB | Screenshot_20181202-194027.jpg


 
CapeCoaler
Member
Posts: 6515
Joined: Sun. Feb. 10, 2008 3:48 pm
Location: Cape Cod, MA
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Post by CapeCoaler » Sun. Dec. 02, 2018 8:52 pm

Looks like it might overshoot during low use periods...
So yes reduce pulse...
Maybe every 27 min for 3 min...

 
KLook
Member
Posts: 5791
Joined: Sun. Feb. 17, 2008 1:08 pm
Location: Harrison, Tenn
Other Heating: Wishing it was cold enough for coal here....not really

Post by KLook » Sun. Dec. 02, 2018 9:13 pm

I hope his coal cost is very low.....

Kevin

 
User avatar
Lightning
Site Moderator
Posts: 14659
Joined: Wed. Nov. 16, 2011 9:51 am
Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Sun. Dec. 02, 2018 9:41 pm

CapeCoaler wrote:
Sun. Dec. 02, 2018 8:52 pm
Looks like it might overshoot during low use periods...
So yes reduce pulse...
Maybe every 27 min for 3 min...
Here's the thing though, the way it's set up currently there is no such thing as a low use period. It's constant circulation straight out of the boiler, thru the house loop, and back into the boiler. The heat demand doesn't change at all. I told him to make sure that circulator never stops pumping, it's the only thing that's taking heat away from the boiler.

The variable is the health of the fire, and it seems to be becoming very healthy. It's responding more actively to the pulses than it was before. I think for the first few days, only part of the fuel bed was actually ignited. The size of this fuel bed boggles me. I bet you could heap 500 pounds into this thing and just let it coast for 4-5 days lol.

He's been tending every 12 hours and I advised him to slow down on the loading because fuel bed is getting thick. The first few days he was putting in 4-5 buckets per day. He's putting in one bucket every 12 hours at the moment.

I've even thought about reducing the grate area by plating off half of it. He mentioned that the dealer said he would need this big of a boiler. Who in their right mind sells a boiler capable of 350,000 BTUs to a guy with a single level 2500 sq ft house?

 
CapeCoaler
Member
Posts: 6515
Joined: Sun. Feb. 10, 2008 3:48 pm
Location: Cape Cod, MA
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Post by CapeCoaler » Sun. Dec. 02, 2018 9:50 pm

But look when it shut down the air...
10 am and 10 pm...
Showered and off to work by 10 am...
Tucked in for night by 10 pm...
Sure it circulates...
But the actual load...
DHW or heating the house...
Nothing to draw off the heat building with the pulse...

 
User avatar
lsayre
Member
Posts: 21781
Joined: Wed. Nov. 23, 2005 9:17 pm
Location: Ohio
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Lehigh Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75

Post by lsayre » Mon. Dec. 03, 2018 4:54 am

Lightning wrote:
Sun. Dec. 02, 2018 9:41 pm
I've even thought about reducing the grate area by plating off half of it. He mentioned that the dealer said he would need this big of a boiler. Who in their right mind sells a boiler capable of 350,000 BTUs to a guy with a single level 2500 sq ft house?
Someone who has no clue with regard to what they are doing. Only a heat loss calculation can determine his BTUH need, but I'm fairly certain that it will not be appreciably more than 70,000 BTUH. The main problem with all of these outdoor units appears to be an inability to move the BTU's from the boiler to the home and back via seriously undersized piping combined with an undersized circulator. So rather than fix the real problem, they make the boiler larger.

 
User avatar
Lightning
Site Moderator
Posts: 14659
Joined: Wed. Nov. 16, 2011 9:51 am
Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Wed. Dec. 05, 2018 9:12 am

CapeCoaler wrote:
Sun. Dec. 02, 2018 9:50 pm
Sure it circulates...
But the actual load...
DHW or heating the house...
Nothing to draw off the heat building with the pulse...
What I mean is the BTU draw doesn't change. The pump is always on, pushing water from the boiler, thru the rads and back. You can see the steady draw between the blue lines I put on this graph below.

He came over yesterday, I did a shake and load on my furnace with him to further his education with using anthracite. He also brought me two cases of beer and a gift card for my wife to show his appreciation, I was very grateful :)

His boiler is running fabulous, we turned down the pulse frequency to 30 minutes now that his fire bed is healthy. I think the over shoots were due to the fire getting a little too frisky during demand calls then egged on by the frequent pulses afterwards. I'm gonna help guide him thru a 24 hour burn here in the next couple days. Should be a piece of cake for that boiler.

I sent him home with my IR gun to get some measurements on the radiation loop.

Attachments

20181205_085905.jpg
.JPG | 170.6KB | 20181205_085905.jpg


 
Qtown1835
Member
Posts: 705
Joined: Sat. Nov. 08, 2014 11:47 am
Location: Quakertown, PA
Stoker Coal Boiler: Keystoker '81 KA4 (online 1/16/17)
Coal Size/Type: WAS Lehigh Rice (TBD)
Other Heating: EFM SPK600

Post by Qtown1835 » Wed. Dec. 05, 2018 9:35 am

Thats a cool setup. It would be sweet to be able to just throw entire bags of nut into the fire box. :) The GUI controls aspect is also neat to see. Should make for a great system tune anticipating additional heat load with outdoor thermometer and scheduled rampup periods to DHW usage.

 
User avatar
lsayre
Member
Posts: 21781
Joined: Wed. Nov. 23, 2005 9:17 pm
Location: Ohio
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Lehigh Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75

Post by lsayre » Wed. Dec. 05, 2018 10:57 am

If I had an outdoor boiler I would connect it to a Taco Viridian VT2218 variable speed and Delta-T driven ECM circulator, and (initially at least) set the desired Delta-T to 20 degrees F.

This circulator will deliver up to 7 GPM at a friction head of 13.5 ft. in its attempt to maintain a 20 degree Delta-T.

7 GPM (if it can be achieved) will deliver 70,000 BTUH with a Delta-T of 20 degrees for initially 180 degree F. water. And since the VT2218 is variable speed, when the home only needs 20,000 BTUH, it will slow itself down to 2 GPM. And it will likewise cover every demand inbetween.

 
User avatar
Lightning
Site Moderator
Posts: 14659
Joined: Wed. Nov. 16, 2011 9:51 am
Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Wed. Dec. 05, 2018 1:02 pm

That's awesome advice. I'll have him snap a picture of his current circulator when he gets home. I also encouraged him to register here so that he can get good advice directly from you guys.

 
Olllotj
Member
Posts: 558
Joined: Thu. Sep. 04, 2014 10:01 am
Location: Western NY 14141
Stoker Coal Boiler: Keystoker KB-8
Coal Size/Type: Buckwheat
Other Heating: Utica Propane Hot Water

Post by Olllotj » Wed. Dec. 05, 2018 1:17 pm

Did you ever get more info about the pex size or users on the loops?

 
CapeCoaler
Member
Posts: 6515
Joined: Sun. Feb. 10, 2008 3:48 pm
Location: Cape Cod, MA
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Post by CapeCoaler » Wed. Dec. 05, 2018 1:19 pm

What I mean is the BTU draw doesn't change. The pump is always on, pushing water from the boiler, thru the rads and back. You can see the steady draw between the blue lines I put on this graph below.
So primary loop is thru radiators...
No secondary circulators...
No solenoids...
How do you control the heat...

 
User avatar
McGiever
Member
Posts: 10130
Joined: Sun. May. 02, 2010 11:26 pm
Location: Junction of PA-OH-WV
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hand Fed Coal Boiler: BUCKET A DAY water heater
Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Wed. Dec. 05, 2018 1:37 pm

lsayre wrote:
Wed. Dec. 05, 2018 10:57 am
If I had an outdoor boiler I would connect it to a Taco Viridian VT2218 variable speed and Delta-T driven ECM circulator, and (initially at least) set the desired Delta-T to 20 degrees F.

This circulator will deliver up to 7 GPM at a friction head of 13.5 ft. in its attempt to maintain a 20 degree Delta-T.

7 GPM (if it can be achieved) will deliver 70,000 BTUH with a Delta-T of 20 degrees for initially 180 degree F. water. And since the VT2218 is variable speed, when the home only needs 20,000 BTUH, it will slow itself down to 2 GPM. And it will likewise cover every demand inbetween.
Nice, no doubt, but with a one loop or zone there may be less expensive ways to do the same thing...like adding an outdoor reset aquastat. Keeping the existing pump would still have the penalty of higher cost to operate, but the savings over the ECM pump motor would or will have taken a long time to recoup.

https://www.pmmag.com/articles/98055-outdoor-rese ... art-choice

SWITCHING-RELAY-WITH-OUTDOOR-RESET-CONTROL

 
User avatar
Lightning
Site Moderator
Posts: 14659
Joined: Wed. Nov. 16, 2011 9:51 am
Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Wed. Dec. 05, 2018 1:39 pm

Olllotj wrote:
Wed. Dec. 05, 2018 1:17 pm
Did you ever get more info about the pex size or users on the loops?
That will be soon, I may go over to his house later this afternoon.
CapeCoaler wrote:
Wed. Dec. 05, 2018 1:19 pm


So primary loop is thru radiators...
No secondary circulators...
No solenoids...
How do you control the heat...
That is correct. There is currently no control of the heat. His home thermostat is wired directly to the pump which is set at 90 to prevent the pump from shutting off. His circulation and radiation system needs our help.

 
CapeCoaler
Member
Posts: 6515
Joined: Sun. Feb. 10, 2008 3:48 pm
Location: Cape Cod, MA
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Post by CapeCoaler » Wed. Dec. 05, 2018 4:16 pm

Aye Captin' windowstats...
Are the radiators separated in any way...
or just run as a loop to circumvent the failing in slab piping...
Slab on grade...


Post Reply

Return to “Hand Fired Coal Boilers Using Anthracite”