observations concerning base heater fire pot linings

observations concerning base heater fire pot linings

PostBy: KingCoal On: Fri Jul 18, 2014 8:29 pm

Hi guys,

i'm in the middle of a project stove and have to make a decision about how i am going to handle the fire box lining.

i'm converting a typical square steel hand fired unit to a base heater by the addition of a few specific features. this will optimize the current radiant surface area of the stove and add just enough to put the total slightly over the magic 27 / 1 ratio of surface area to grate area found in the top antique units.

it seems that most all of the early units had or have had the refractory linings replaced and that they are for the most part pretty thick, in the 2" average. this seems to be alot of insulation but, since the heat is being directed between the outside of the fire pot and the inside of the outer skin or body of the stove there is little need for direct radiation thru the walls of the fire pot.

would you agree ?

the donor stove originally had 1.25" hard type standard fire brick, good choice considering the design relied on high heat transfer thru the fire box walls.

my question is might i use the softer more insulating type brick to maintain higher internal firebox temps. and maximize combustion efficiency now that i won't need the heat to transfer laterally out of the fire box toward the stove body ?

another question is what about longevity of the softer bricks in direct contact with the coal bed. 50% of the hard red bricks in the original stove cracked in half horizontally the first season and the stove was rarely above 450 body temp.

thanks,
steve
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: McGiever On: Fri Jul 18, 2014 8:48 pm

I am not familiar with these red fire bricks????
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hot Air Coal Stoker Stove: HARMAN MAGNUM
Hand Fed Coal Stove: RADIANT HOME AIR BLAST
Baseburners & Antiques: OUR GLENWOOD 111 BASEBURNER "1908"
Coal Size/Type: PEA / ANTHRACITE, NUT-STOVE / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Fri Jul 18, 2014 8:58 pm

i may have mis-spoken.

the original bricks look alot like the common kind of stuff from sources like Rutland. kind of oatmeal looking with a slight rose or pinkish tint.

very hard surface, grainy on the inside.

thanks,
steve
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

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Re: observations concerning base heater fire pot linings

PostBy: McGiever On: Fri Jul 18, 2014 9:01 pm

Ahh, okay, gotcha. ;)
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Hot Air Coal Stoker Stove: HARMAN MAGNUM
Hand Fed Coal Stove: RADIANT HOME AIR BLAST
Baseburners & Antiques: OUR GLENWOOD 111 BASEBURNER "1908"
Coal Size/Type: PEA / ANTHRACITE, NUT-STOVE / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: observations concerning base heater fire pot linings

PostBy: franco b On: Fri Jul 18, 2014 9:03 pm

Insulating fire brick is great but can't stand the abuse it will get from coal. It will just abrade away. If in your design the exhaust gas circulates around the brick then insulating brick is little to no advantage over hard brick.

The Oak style base heaters do not circulate gas around the fire box.The brick only retards heat loss in the fire pot which is less effective than the design you contemplate.

Your design sounds similar to the Vermont Castings 2310 which works pretty well but still lacks the superior air distribution of a round fire pot.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Fri Jul 18, 2014 9:23 pm

franco b wrote:Insulating fire brick is great but can't stand the abuse it will get from coal. It will just abrade away. If in your design the exhaust gas circulates around the brick then insulating brick is little to no advantage over hard brick.

in the new design the gas will travel between outside of the steel firebox and the inside of the stove body, so i guess no advantage from the soft brick.

The Oak style base heaters do not circulate gas around the fire box.The brick only retards heat loss in the fire pot which is less effective than the design you contemplate.

yes, this new design is as close as i can get to a full suspended fire pot as is possible inside the original stove.

Your design sounds similar to the Vermont Castings 2310 which works pretty well but still lacks the superior air distribution of a round fire pot.


i tried long and hard to come up with a way to provide for a round fire pot, but it would have taken serious remodeling of the stove including the grates. the way i'm going now is simply an opening and redirecting of the gas path and the addition of a base chamber. very simple but, i believe will be quite effective.

thanks,
steve
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Fri Jul 18, 2014 9:25 pm

well i guess i need practice at replying inside a quote, if you look closely there is more than what printed beneath.
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: Sunny Boy On: Sat Jul 19, 2014 2:49 am

KC,

If your modifying it to be more like a suspended firepot design, do you need to use a fire brick liner ?

You mention 2 inch thick liners and older stoves ? How old ? The early ones I have use only one inch thick bricks. Does casting bricks only one inch thick, help ?

Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Sat Jul 19, 2014 6:25 am

Paul,

looking at many rebuild threads it seemed to me that many stoves got castable liners and were pretty thick. many of the pics of premium BB's have what seems to be quite thick original brick or original cast liners. it could be perspective though and i'm mistaken.

i will have to have bricks, the fire box is a simple square of light steel that was/ is only intended to hold the bricks in place, they are the real containment. using bricks that are .25" thinner won't create any advantage.

i have devised a way to slant the bricks on the front and back walls of the fire box "in" at the bottom to bring the coal down right to the edge of the grate though. there is / was a large ledge there before that just built up a pile of ash, obscured the air flow and dropped the amount of coal actually on the grates.

thanks,
steve
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: Lightning On: Sat Jul 19, 2014 7:36 am

Steve, you got some pics? :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Sat Jul 19, 2014 8:25 am

Hey Lightning,

i do but i'm waiting to post any until i get enough done to make it obvious what "was" and what is new.

i'll have a set of pics that show the process, in order.
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: Sunny Boy On: Sat Jul 19, 2014 9:28 am

KingCoal wrote:Paul,

looking at many rebuild threads it seemed to me that many stoves got castable liners and were pretty thick. many of the pics of premium BB's have what seems to be quite thick original brick or original cast liners. it could be perspective though and i'm mistaken.

I think as you say, it's likely that it's perspective. The top edges are usually sloped so that coal doesn't sit up on them. And it's possible that some restored ones have thicker lining installed.

i will have to have bricks, the fire box is a simple square of light steel that was/ is only intended to hold the bricks in place, they are the real containment. using bricks that are .25" thinner won't create any advantage.

i have devised a way to slant the bricks on the front and back walls of the fire box "in" at the bottom to bring the coal down right to the edge of the grate though. there is / was a large ledge there before that just built up a pile of ash, obscured the air flow and dropped the amount of coal actually on the grates.

Then the bricks will be thicker toward the bottom ? How about tapering the bricks thinner toward the top to gain coal volume ?

thanks,
steve



Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Re: observations concerning base heater fire pot linings

PostBy: Sunny Boy On: Sat Jul 19, 2014 9:45 am

KC,

Here's pictures of one of the original fire bricks out of my #6. As you can see, it's rather thin - only one inch thick. And the top edge (on the left in the second picture) is curved so it doesn't form a ledge for coal to sit on.

But being that the firepot is round, and slopes inward toward the bottom, they all fit snuggly and keep each other in place, so no need for any clips like the two long bricks in my range have overlapping the top center joint to keep them from falling in.

With your firebox not being round, how are you going to keep the bricks in place ? Do the sides slope, or Is there a frame, or you going to just let the coal hold the bricks ?

Paul
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Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Re: observations concerning base heater fire pot linings

PostBy: KingCoal On: Sat Jul 19, 2014 10:14 am

there is a full length "L" bracket as the top brick retainer. this is taller than the brick and you slide the brick up into it and over the lower retainers. when the brick is seated there is a slight gap between the top of the brick and the underside of the covering "L".

the way it works is you put in the side bricks first, then the front and back bricks. once they are in they can't move any direction unless you lift one of the front or back bricks out again.

the side bricks are straight up and down, no room or way to slant them. the front and back i have arranged to slant in to the edge of the grates.

yes,the front and back bricks will be thicker at the bottom.

i don't think there will be a need for added volume. with the hopper full this stove has about 90#'s of nut in it and burns unattended for a looong time.

it has better than average burn efficiency, though i feel this conversion will improve that too along with creating a much better radiant heater than the original design.
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: observations concerning base heater fire pot linings

PostBy: Sunny Boy On: Sat Jul 19, 2014 10:53 am

KC<

Will this re-design aid in preheating the primary air intake too ?

Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Visit Hitzer Stoves