Why can’t I get a complete burn with this coal?

 
lzaharis
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Post by lzaharis » Tue. Dec. 04, 2018 4:25 pm

Can you buy stove coal locally ? I always used a mix of nut and stove when the weather really got nasty and I used rice coal on top to overnight the fire some nights.

 
milw boiler
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Post by milw boiler » Wed. Dec. 05, 2018 12:11 am

Royall went to a straight sided chamber because they couldn't get coal to burn in their V grate either. The OP used a lot of coal & it appeared to be mostly burnt. The heat did not go into the boiler water. All the Royall's that I know of used a horseshoe water tank over the top of the boiler. There is no water any where near the coal. The OP has a wood boiler & one that is 50 percent efficient at that. The ones that have said there are wood boilers & coal boilers are right, in my opinion. The V grate Royall is not a coal boiler...again...the factory had to redesign it. Buy a real coal boiler, you are flogging a dead horse with what you have.

 
Mr.Ark
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Post by Mr.Ark » Wed. Dec. 05, 2018 9:20 am

milw boiler wrote:
Wed. Dec. 05, 2018 12:11 am
Royall went to a straight sided chamber because they couldn't get coal to burn in their V grate either. The OP used a lot of coal & it appeared to be mostly burnt. The heat did not go into the boiler water. All the Royall's that I know of used a horseshoe water tank over the top of the boiler. There is no water any where near the coal. The OP has a wood boiler & one that is 50 percent efficient at that. The ones that have said there are wood boilers & coal boilers are right, in my opinion. The V grate Royall is not a coal boiler...again...the factory had to redesign it. Buy a real coal boiler, you are flogging a dead horse with what you have.
I’m starting to think that I just exhausted the coal supply and I would of needed to add more to keep it lit. It definitely put some heat into the water form what I can tell.
While it’s true that the water jacket doesn’t surround the firebrick it’s everywhere else in the firebox. I’m not sure if too many boilers have water right next to the firebrick. EFM Stokers certainly don’t. My heat load must just be one that needs more coal than I put in for that night. I’m pretty sure my stack temps where pretty low from memory which means that if the coal burned then the unit absorbed the energy.
My main concern was if the coal burned up most of the carbon in it or if it went out before that point. From what other have said it seemed like it was done for.
I’m gonna try again with some bituminous lump and see how that works. I’m not giving up on this boiler yet until I can afford something else. Currently on a hot, full out burn and dump with a huge load of wood it seems to get pretty efficient heat output.
Thanks for the input
Drew


 
Torpex
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Post by Torpex » Wed. Dec. 05, 2018 9:53 am

I am quite new to the coal burning arena, and I actually had a similar problem with my Simplex Multitherm.

The first problem I had to fix was the Loading door frame seal. The door & door frame are cast and the boiler is steel. Someone used a hard refractory morter to seal this door frame to the boiler and it was cracked and leaking terribly. It wasn't obvious because you couldn't see this gasket. I am not talking about the door to door frame gasket but the door frame to boiler gasket. Bottom line was to control the air into the boiler, making all air to enter below the grates as I was directed by the veteran coal burners. (They do know their stuff!)

The second thing was to load the sucker up full. I was guided to a minimum of 8" deep bed. I went with heaping it in and making sure it was filled to the sides tight as possible. Its logical that the sides of the boiler/furnace would pull the heat off the outer coal and the only way to minimize half burned coal on the outer edges is is to have a large enough fire in the center to radiate the heat outwards towards the sides, and that requires enough coal in the bed.

I would also monitor your draft and make sure you have what it needs. Once I established I had good draft up the stack, got the leaks fixed, I needed to use a damper to slow the draft on the boiler. Your situation should be checked and adjusted as necessary, if necessary.

When I was heating my house and garage with outside temps around 4dF, I had to shake and load every 6-7 hours with the Simplex105,000 BTU Boiler. The area I am heating is 2080 sqft with 1344sqft having 10' ceilings. The garage has 8' Block with R-30 on the ceiling. 2 Big doors(insulated) and one big 5'x5' window single pane glass. The house has R25 in the cieling, R19 walls and R 25 floors. Not the most energy efficient house but I'm working slowly within budget to improve the doors and windows.

Frank

 
Mr.Ark
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Post by Mr.Ark » Wed. Dec. 05, 2018 11:27 am

Torpex wrote:
Wed. Dec. 05, 2018 9:53 am


The second thing was to load the sucker up full. I was guided to a minimum of 8" deep bed. I went with heaping it in and making sure it was filled to the sides tight as possible. Its logical that the sides of the boiler/furnace would pull the heat off the outer coal and the only way to minimize half burned coal on the outer edges is is to have a large enough fire in the center to radiate the heat outwards towards the sides, and that requires enough coal in the bed.

I would also monitor your draft and make sure you have what it needs. Once I established I had good draft up the stack, got the leaks fixed, I needed to use a damper to slow the draft on the boiler. Your situation should be checked and adjusted as necessary, if necessary.

When I was heating my house and garage with outside temps around 4dF, I had to shake and load every 6-7 hours with the Simplex105,000 BTU Boiler. The area I am heating is 2080 sqft with 1344sqft having 10' ceilings. The garage has 8' Block with R-30 on the ceiling. 2 Big doors(insulated) and one big 5'x5' window single pane glass. The house has R25 in the cieling, R19 walls and R 25 floors. Not the most energy efficient house but I'm working slowly within budget to improve the doors and windows.

Frank
How much coal where you going thru on a day like that and do you think your unit was operating with an acceptable level of efficiency?
I’m assuming your unit was also a wood boiler that could do coal too.

 
Mr.Ark
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Post by Mr.Ark » Wed. Dec. 05, 2018 11:31 am

It should be noted that my unit has a 75 com draft blower that shut down tight when it’s up to temp. I was wondering if it was TOO much air and burned through the coal too fast. Does that seem like a lot of air and should I perhaps try to choke the air supply down a little to extend the burn?


 
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Lightning
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Post by Lightning » Wed. Dec. 05, 2018 12:51 pm

Yes absolutely, experiment with the volume of combustion air. Perfect case scenario is to use as little combustion air as possible to get the amount of heat required. The key is to use as much of the available oxygen from the combustion air as possible. If it's blowing too hard, a bigger percentage of that oxygen will pass thru the fuel bed without reacting with the coal. Along with that higher percentage of oxygen not being used, there is 4 or more times that amount of nitrogen that doesn't react with the coal at all, of course. Said nitrogen is just there to rob BTUs from the fuel bed by cooling it, and then also carrying those BTUs up the chimney with it.

 
Mr.Ark
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Post by Mr.Ark » Wed. Dec. 05, 2018 3:01 pm

Lightning wrote:
Wed. Dec. 05, 2018 12:51 pm
Yes absolutely, experiment with the volume of combustion air. Perfect case scenario is to use as little combustion air as possible to get the amount of heat required. The key is to use as much of the available oxygen from the combustion air as possible. If it's blowing too hard, a bigger percentage of that oxygen will pass thru the fuel bed without reacting with the coal. Along with that higher percentage of oxygen not being used, there is 4 or more times that amount of nitrogen that doesn't react with the coal at all, of course. Said nitrogen is just there to rob BTUs from the fuel bed by cooling it, and then also carrying those BTUs up the chimney with it.
YES! I think that was part of the problem with the burned out coal pile. The whole time that I was watching it I felt that the air supply was just a little too fast (or a lot). As the coal was wearing down my guess is that the extra air supply was actually cooling it off to the extent that it didn’t burn all the way down.
I will try to choke the draft blower back a little and see if it burn longer and more complete.
I don’t think the firebox shape is the biggest player here in the incomplete burn. I say that because the part of the pile that got the most air right above the blower was the first to go out but still left some unburnt coal behind.

 
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Post by titleist1 » Wed. Dec. 05, 2018 3:38 pm

Not sure how your combustion fan is set up but a refrigerator flat magnet has been used more than once to choke down the air intake on a combustion fan.

What size, height and type chimney are you venting into? Do you have a manometer to check the draft in the firebox and flue pipe? Watching the draft, stove temp and flue temp seems to be helpful to dial in an optimal burn.

 
Torpex
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Post by Torpex » Sat. Dec. 08, 2018 10:20 am

Mr.Ark wrote:
Wed. Dec. 05, 2018 11:27 am
How much coal where you going thru on a day like that and do you think your unit was operating with an acceptable level of efficiency?
I’m assuming your unit was also a wood boiler that could do coal too.
Hi, Yes it is listed as a wood burner too. The previous owner said he had to tend it every 3-4 hours because the firebox isn't that big ( 16" x 16") I would speculate, since I have no literature or manual that its primarily a coal burner.
As far as efficiency I am only able to give a very rough estimate right now. I cant be more accurate because I really need to have it burning and heating the house for at least a week straight to gauge use. Right now anywhere from 80-110 lbs a day is my guestimate. I can say that in comparison to oil its at least 150% more capable dollar per dollar. I may not be saying it exactly right, please forgive.
Efficiency right now, for not using it but 2 days a week, is OK. I can say the better and more understanding I am of the air & draft, the more efficient it has become.

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