homemade Sub-Bit flatbed stoker Utube link

homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Tue Jun 17, 2014 4:53 am

This is the Sub-Bit flatbed stoker i made to heat my house http://youtu.be/qS-Kpjj7TQ0

it works ok but needs a faster feed motor....the max throw is 1.125" and the bed depth is 1.5" and its not feeding fast enough for my liking.....if i increase the bed depth it soots the glass up

it is completely homemade apart from the electrical stuff like fans and motors etc

it has a fire controller based off the coal pilot designed by that guy that got himself banned in spectacular fashion from this forum (GeoriePorgie...???) that works really well...power to solenoid gives full fire, no power to solenoid gives idle fire
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: Lightning On: Tue Jun 17, 2014 5:29 am

Wow.. Awesome piece of work there!! Is this the one I read about with sand and piping to absorb heat? How's the heat output? How many square feet you heating? How many tons did you use last winter? what was your winter weather like?

Nice job!! :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Tue Jun 17, 2014 5:31 am

some pic from when i was making it
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fitting the side and bottom of the grate
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more making sure it fits right
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the grate pieces layed out on the bench
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the support for the grate bottom...the lengthways flat bars are angled down to allow airflow to the outer edges of the grate bottom
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the underside of all the plates showing the chamfered air holes and the reinforcing ribs of the original BBQ plate...the larger holes in the side plates are threaded to allow it to be bolted to the sides of the box section that is the main body of the burner
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Snazzy hole pattern in the bottom grate
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unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1


Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Tue Jun 17, 2014 5:44 am

No sand and pipe in this stove....you must be thinking of someone elses design

lol heat output is ok but not as much as i would like....i'm heating about 1000 sqft...our winters are milder than alot of places in the US...most nights in winter are around or just below freezing most days only raise the temperature about 10 to 12 deg above freezing....if we get 3 inches of snow you would think the world has ended by the way the media goes on about it.

i have only just finished this stove a week or so back so i have no benchmark to judge against coal use wise but last winter i used 5 tons of lump coal in the open fire that this stove now is exhausting into....and that was just to heat the living room, the rest of the house was cold all the time.....this stove allows me to leave the doors open to the other rooms in the house and heats all of them without breaking a sweat so far....altho this weekend will be the real test.....snow to sea level forcast from thursday to sunday

Cheers
Callum
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: Lightning On: Tue Jun 17, 2014 6:05 am

Oh ok.. yeah I read about someone using sand and piping for a heat transfer medium but I don't think it got followed up... if memory servers me right, he didn't complete it... anyways, nice job on the boiler! How much cost do you have in it? How much is the sub bit per ton?
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Tue Jun 17, 2014 6:56 am

this one is a stove not a boiler.....the boiler plan is still at the collecting all the needed piping pumps valves etc stage

i have probably $500NZ in this stove plus another faster feed motor on it way to me so say $600NZ all up.....you can't buy a coal stoker stove here so there is nothing available "off the shelf" to compare it to pricewise....you can get pellet stoves here but pellets are out of this world expensive...like $660NZD per ton....and $1 NZ is worth about 85c US at the moment.

the Sub-Bit coal i get is $85NZ a ton pick up at the mine

Cheers
Callum
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: rockwood On: Tue Jun 17, 2014 9:56 pm

Good Job, I like it!

Because you're using sub bit coal, which will have a lower ignition temperature compared to higher grades of coal, you will want to make absolutely sure that the hopper is airtight to prevent the chance of burn-back into the hopper.

Do you have more photos? I would like to see photos of the burner (fully assembled with no fire) and of the inside of the hopper empty...or any other photos.

I'm surprised stove manufacturers haven't developed a stove with this type of burner for soft coal...I've always thought it could be done, and your stove is proof that it can be done!!!

Be sure to have at least one CO detector, just to be safe ;)
rockwood
 
Hot Air Coal Stoker Furnace: Stokermatic coal furnace
Hand Fed Coal Stove: Rockwood Stoveworks Circulator
Baseburners & Antiques: Malleable/Monarch Range
Coal Size/Type: Soft coal: Lump and stoker (slack coal)

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Wed Jun 18, 2014 2:25 am

The top of the hopper is gasketed but more for dust than anything else, however where the hopper slides into the stove isn't sealed (it is a serious wriggle in fit tho) and neither is the rear cover that the slide moves under....i was a bit concerned about the possibility of a burn back but i tested it extensively at the workshop to try to get it to burn back and could not get it to even start burning back towards the hopper....the coal has to move about 5 inches from the throat plate that adjusts the bed hight before it hits the first line of air holes.

even when i negative pressured the stove with a blower the same as the combustion blower (set up venturi style into the exhaust) it showed no tendancy to start burning back up the bed of coal....all that happened when i turned off the feed and combustion air was that the fire went out

i don't have any pics of the finished burner before i testfired it...i have a video of the burner running on the bench but lets just say that my best work isn't done with a camera.

The US manufacturers really haven't done anything new in coal burner design in many years......adoption of the coaltrol type controls was really the last 'big thing' that happened as far as i can see from a position many miles away....altho there is probably things going on that never make it to the internet

Polish manufacturers however seem to have been flat out coming up with several new designs including a flatbed stoker that has everything i built into my one, plus a few more things that i would build into it if i was to do it again. http://youtu.be/vkzm_BuOkAI

i'm seriously thinking about just buying an underfeed burner from there when i get to building my boiler.....

Cheers
Callum
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Tue Jun 24, 2014 8:04 am

Having had the stove running for a couple of weeks now, i'm getting a bit more of a feel for how to drive it....the damper on the combustion fan is set about 1/3 open and the feeder is pushing an inch a minute into a firebed that is about 1.5 inches deep....due to the pushblock being 3/4 of an inch high, when the coal pushes out into the fire it only moves about half an inch per minute.

i had to shut the stove down find why the coal had stopped feeding evenly down the grate....found that the first set of airholes that are set 3/4" ahead of the start of the main pattern of air holes were causing the coal to form a layer of charcoal like buildup that was about 1/4" deep on the surface of the grate between these first line of holes and the start of the main pattern of holes....i chipped the deposit off and blocked the first line of holes with stove cement and haven't had a problem since....

The house is the warmest it has ever been in winter and its dried out the interior really well....first world war era house on the wrong side of a hill is a recipe for a damp house....this stove has fixed that problem.

now i'm just waiting for my faster motor to turn up

cheers
Callum
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: rockwood On: Sun Aug 17, 2014 4:56 pm

Any updates with this?
rockwood
 
Hot Air Coal Stoker Furnace: Stokermatic coal furnace
Hand Fed Coal Stove: Rockwood Stoveworks Circulator
Baseburners & Antiques: Malleable/Monarch Range
Coal Size/Type: Soft coal: Lump and stoker (slack coal)

Re: homemade Sub-Bit flatbed stoker Utube link

PostBy: unhippy On: Fri Sep 19, 2014 9:22 pm

Well the stove has been running all winter.....have had it running on idle for the last week due to warmer spring weather.....i haven't had any more problems with it apart from having a build up of the hard charcoal type stuff on the grate a couple of times.....too little or too much air seems to be the cause.....i have the air set right now, and haven't had any build up for a month so i think thats sorted.

I fitted the 2 RPM motor and it worked well, i had about an inch and a bit of ash at the end of the grate....however it ate coal at a disgusting rate for what seemed to be not alot more heat output.....that actually has me a little puzzled, my exhaust temps only lifted by about 25 deg c.....but the heat output of the stove wasn't much higher than with the 1 RPM motor fitted....certainly not enough to justify doubling the coal consumption.... so i have pretty much run the whole winter on the 1 RPM motor that runs about 4 inches of ash on the end of the grate :?

I'm building a boiler burner at the moment....screw feed, vee bed side feed....blatantly plagiarized off this one http://www.kotly-witkowski.pl/en/palniki ....the boiler that i'm building to go on top of it is a simple vertical tube water jacket type with turbulator that also acts a cleaner/scraper for the heat exchange surface.....not as efficiant as a multipass type but it allows the exhaust gas to retain some heat, which is sort of important when the coal your running is 1.5-2% sulfur....any flue gas that condenses causes corrosion damage real quick.....an insulated chimney should help avoid that problem as well.

Cheers
Callum
unhippy
 
Stove/Furnace Make: Homemade
Stove/Furnace Model: MK1