My 1537G Hotbalst US Stove Burning Nut Coal
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- Member
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- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
Here is a thread dedicated to my burning nut coal in my 1537G Hotblast furnace. I have been burning wood for 2 winters so far and when a buddy started talking about burning coal, I got very intrigued!
Here is my set up:
and the chimney:
The chimney is 25 feet from the "T". There are 2 - 3 foot horizontal sections, the 90 and about 40" to a 45 into the furnace.
I have since added a baro draft regulator, went with a Field controls model B-34TJ. With the draft set for the lowest draft in the furnace I am still seeing .1 or slightly higher, My gauge may be reading off a little as I am on the very low end of the scale. My plan is to get a better manometer for this. I do have an awesome draft as long as the chimney is warm.
Here is how the flue pipe is setup...where I measure both draft and temp:
As you can see I am running just over .1" WC and a little over 400 degrees F in the flue. House is at 72 and outside temp is about 20 with no wind. I am heating about 2400 square feet (counting basement) with minimal insulation. I have put in about 100# of coal so far. Started burning this morning at 9:30 and have only put in 2 or 3 small shovel fulls so far!
Here is my set up:
and the chimney:
The chimney is 25 feet from the "T". There are 2 - 3 foot horizontal sections, the 90 and about 40" to a 45 into the furnace.
I have since added a baro draft regulator, went with a Field controls model B-34TJ. With the draft set for the lowest draft in the furnace I am still seeing .1 or slightly higher, My gauge may be reading off a little as I am on the very low end of the scale. My plan is to get a better manometer for this. I do have an awesome draft as long as the chimney is warm.
Here is how the flue pipe is setup...where I measure both draft and temp:
As you can see I am running just over .1" WC and a little over 400 degrees F in the flue. House is at 72 and outside temp is about 20 with no wind. I am heating about 2400 square feet (counting basement) with minimal insulation. I have put in about 100# of coal so far. Started burning this morning at 9:30 and have only put in 2 or 3 small shovel fulls so far!
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- Member
- Posts: 171
- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
I modified the feed door so I can get the best burn I can. I added a piece of fiberfax to the back side of the damper flap and bolted through the holes...
I have also modified the shaker grates so they lock together better and have less play. I need new ones as the front shaker is broken so I need to use vise-grips! I found the idea here and didn't take any pics.
The ash door damper is open about 6 turns here, will go open 9 turns max.
Here is the baro regulator:
I have also modified the shaker grates so they lock together better and have less play. I need new ones as the front shaker is broken so I need to use vise-grips! I found the idea here and didn't take any pics.
The ash door damper is open about 6 turns here, will go open 9 turns max.
Here is the baro regulator:
That's a pretty hot set up. I really like the draft and the temperature control center you have. The switch for flue and chimney is a cool idea. Although, .01 inches of draft is kind of low. Is it reading correctly? I thought .04 inches of draft should be the minimum. Make sure you have a CO detector.
Anyway, Great Job!!! DOUG
Anyway, Great Job!!! DOUG
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- Posts: 171
- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
The draft is .1 not .01. I am definitely getting great draft and have a CO detector. I need to run a new thermocouple wire up to the top of the chimney so it works again. Had to cut the wire when the chimney blew over once! I have since added a roof support kit to the top section.
- Yanche
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Nice set up and good photos. What kind of temperature probes are you using? Type K thermocouple? Are you switching thermocouple inputs?
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- Member
- Posts: 171
- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
I am using type J tc's and I am not switching inputs at this time.
Here are the burning pics as just taken. These are all taken at the same time.
Here are the burning pics as just taken. These are all taken at the same time.
I like the pictures. Could you give us some more through the different stages of the procedure of recharging, the ashes, the draft, and the temperatures at the different stages. Thanks. Really great job!!! DOUG
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- Joined: Mon. Feb. 09, 2009 5:02 pm
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- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
I don't have any more pics as I loaded it up this morning. I had tended to the fire about 9:45 last night where I shook it down and poked the sides to be sure it wasn't bridging and added 2 shovels full to the top. I made sure the fire was burning good (blue dancing ladies) and then closed the feed door and left the ash door spinner full open (9 turns). At 10 pm I went down and checked the fire and it was glowing nice and red with a few blue dancing ladies. I closed the ash door spinner to 6 turns open. The flue temp was around 500. Went to bed with the house at 71 and outside at 17.
Woke up about 7:45 (felt great to sleep in!) and the house is at 67 and outside is still 17. Not too bad really because after almost 10 hours the wood would have been mostly out and the house at 64 with the oil furnace maintaining 64. No oil furnace! Checked on fire and found the bed had settled about 1-2" and was glowing quite red and hot. Flue temp was 505, but the warm air ducts were just barely warm to the touch and not much warm air blowing out of the registers even though the blowers were on. I shook it down and got about 3/4 pan of ash. I also poked the sides with the poker and the bed settled a little. I then added 3 shovel fulls and let it get burning good. With the feed door open the flue temps drop into the lower 300 range and will climb back up once the feed door is closed.
It is now 8:40 and the house is at 66 and the flue temp is 475. Here are pics of the inside of the furnace. I am wondering if the thin layer of creosote/dust/crap on the inside is keeping it from being a decent heat exchanger.
Looks like I may be losing some air behind the back cast iron piece. I will have to fix that next time I shut it down. I blocked off the front piece to keep air from leaking up through by the door rather than the coal bed.
Woke up about 7:45 (felt great to sleep in!) and the house is at 67 and outside is still 17. Not too bad really because after almost 10 hours the wood would have been mostly out and the house at 64 with the oil furnace maintaining 64. No oil furnace! Checked on fire and found the bed had settled about 1-2" and was glowing quite red and hot. Flue temp was 505, but the warm air ducts were just barely warm to the touch and not much warm air blowing out of the registers even though the blowers were on. I shook it down and got about 3/4 pan of ash. I also poked the sides with the poker and the bed settled a little. I then added 3 shovel fulls and let it get burning good. With the feed door open the flue temps drop into the lower 300 range and will climb back up once the feed door is closed.
It is now 8:40 and the house is at 66 and the flue temp is 475. Here are pics of the inside of the furnace. I am wondering if the thin layer of creosote/dust/crap on the inside is keeping it from being a decent heat exchanger.
Looks like I may be losing some air behind the back cast iron piece. I will have to fix that next time I shut it down. I blocked off the front piece to keep air from leaking up through by the door rather than the coal bed.
Those are great pictures! Thanks. I was thinking. Since the firebox is pretty square, it would be possible to add another row of firebrick all the way around the sides and above the rear cast iron baffle plate, supported with angle iron. This will allow you to make the firebed deeper. Thus allowing even longer burn times or possibly more heat from the extra mass. It will aslo make the different zones of the fire larger for a more complete burning of the coal. Just something to think about. What do you think?
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- Posts: 171
- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
Yeah something like that would probably work pretty good. Problem I am having is that the flue has been reading well over 450 since before I got up this morning and the bed is full and red hot and the house is still only at 68. I am not sure what is going on here. I just can't seem to get heat out of the firebox and into the house. The flue stream after the baro regulator is showing around 280 and around 490 before it. draft is still showing a little better than 0.10" wc.
I either have to make this furnace burn coal well or get ready to order my logs for next winter so I can get it cut, split and stacked before too long. I really want to make the coal work as it will be much less labor intensive. I do have the option of ordering the draft inducer kit and mount it to the ash door. I will need to order new grates either way.
I either have to make this furnace burn coal well or get ready to order my logs for next winter so I can get it cut, split and stacked before too long. I really want to make the coal work as it will be much less labor intensive. I do have the option of ordering the draft inducer kit and mount it to the ash door. I will need to order new grates either way.
I think you could capture more heat from your furnace if you use a larger supply to the duct work. This means getting out the tin snips and making the hole larger, and using a larger plenum instead of the two 8" rounds. While you are at it, see if you can insulate the inside of the furnace jacket, with still leaving around 2" of air space around the firebox. The high temperature foil backed insulation with the foil facing the jacket is what I've been using on some other furnaces I've modified. Yes, it is still papered foil and may smell a little when the unit is way overfired, but it does a great job. Especially, when the air flow isn't restricted. Make the plenum and duct to the main larger. The whole system will work much better. This will allow you to operate the stove at a lower temperature, get longer burn times, while using less fuel.
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- Member
- Posts: 171
- Joined: Mon. Feb. 09, 2009 5:02 pm
- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
These are some great ideas Doug! I think they would make the furnace more efficient whether I am burning wood or coal! I may see about getting a tin knocker to give me an estimate to put in a larger hot air duct like you suggested as well as adding the cold air return duct since I am now pulling out of the basement for my cold air. I already have the cold air return kit with filter housing.
I also sealed off around the 8" hot air ducts and also sealed the air gap between the top furnace jacket and front of the furnace above the feed door.
I also checked the zero on my gauge and it was reading high. Once I re-zeroed it, my draft was able to be adjusted from just above 0 to 0.07 or so. I still need a more accurate gauge. House is 70 now but it is about 30 outside.
I also sealed off around the 8" hot air ducts and also sealed the air gap between the top furnace jacket and front of the furnace above the feed door.
I also checked the zero on my gauge and it was reading high. Once I re-zeroed it, my draft was able to be adjusted from just above 0 to 0.07 or so. I still need a more accurate gauge. House is 70 now but it is about 30 outside.
You'll be amazed how much more efficient your set up will be once you get the air moving. The return from upstairs cut in or to the return duct to the existing furnace and the larger plenum. You may have to install back draft dampers after the modification to get it to work automatically, but they are spring activated so they shouldn't cost too much. Your tin knocker should be able to help you with all of the modifications. He should also be able to get you the foil backed insulation with the stick pins to mount inside the furnace jacket.
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- Location: New Haven, NY
- Hot Air Coal Stoker Furnace: Keystoker Koker 160
- Coal Size/Type: Rice
Got home this morning after working all night to find it completely out. This is ok since I am going back to wood for the time being. I did order new shaker grates and a draft inducer fan kit yesterday afternoon. Once they arrive I will season the grates per the procedure I found here and I will install the draft inducer fan so I can mount it either on the back (stock location for over firing) and also on the ash door so I can control the combustion air. Once this is done I hope to go back to burning the rest of the coal I have (300#) for this year. I will then make my decision on whether to go with wood or coal for next year.
Here is what I saw this morning when I shoveled out the over 1/2 full fire box. There was a few pieces of unburnt coal but most of the chunks were light brown to grey in color and there was a LOT of ash in the bottom. It seems the shakers were not getting much out so I suspect even though the fire was hot there wasn't much air getting through the bed. With the new grates, I should be able to shake the ashes out better. I found it weird that after 10 - 12 hours I was only getting about 1/2 an ash pan of ashes.
Here is what I saw this morning when I shoveled out the over 1/2 full fire box. There was a few pieces of unburnt coal but most of the chunks were light brown to grey in color and there was a LOT of ash in the bottom. It seems the shakers were not getting much out so I suspect even though the fire was hot there wasn't much air getting through the bed. With the new grates, I should be able to shake the ashes out better. I found it weird that after 10 - 12 hours I was only getting about 1/2 an ash pan of ashes.