Improving bimetal t-stat control

Improving bimetal t-stat control

PostBy: LDPosse On: Wed Feb 06, 2013 5:18 pm

I've been thinking of how to better control the burn in my DS Machine after re-loading with coal, especially at higher temperature settings. The issue I've been having is that the stove would cool a bit after reloading, and the tstat would open too far. The fire would get too hot, too quickly, and then the tstat would completely close and the chain would be dangling loose since the stove temp overshot well past the tstat setting.

When the stove is at a low burn, I have no problems. The problem occurs when I want more heat, and using bituminous only excaberates it. I decided to try a makeshift fix to start : (edit - The edge of the coal hod is keeping the flap from opening more than about 1/4")

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Coal hod limiting underfire air
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So far, this has worked beautifully. I was even able to toss on a pile of high vol coal from Valier's. No more raging infernos!
I am thinking a permanent solution might be to build a manual damper that fits behind the air inlet flap, so the max burn rate could be set there.

I'm curious to hear others thoughts on this arrangement.
Last edited by LDPosse on Wed Feb 06, 2013 8:46 pm, edited 1 time in total.
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola

Re: Improving bimetal t-stat control

PostBy: carlherrnstein On: Wed Feb 06, 2013 5:38 pm

I have also been trying to think of a idiot proof way to regulate the temp spikes that happen when my wife dumps a whole bucket of coal in on a nice happy bed of glowing coke. I have wondered about some kind of air duct that has a thermo coil set up that can react to spikes in pipe temp by closing a air shutter in a duct that leads to the factory air shutter. Kind of like a choke on a engine but would close when it gets too hot.

When I tend the stove I open the ash pan door and ramp up the stove and try to get the top temp to about 500 and add maybe 10lbs of coal to one side, close the ash door and let the stove heat up till the shutter closes down then I fill it up.
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous

Re: Improving bimetal t-stat control

PostBy: LDPosse On: Wed Feb 06, 2013 6:06 pm

carlherrnstein wrote:I have also been trying to think of a idiot proof way to regulate the temp spikes that happen when my wife dumps a whole bucket of coal in on a nice happy bed of glowing coke....


I didn't realize the VC Vigilant had a bi-metal tstat. I pulled the owners manual up online and I see that it's supposed to have a restrictor plate in place for bituminous burning. Do you have that installed on your stove?
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola


Re: Improving bimetal t-stat control

PostBy: lsayre On: Wed Feb 06, 2013 6:10 pm

I'm not seeing it. Just what was the makeshift fix?
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (if I ever get it fixed)

Re: Improving bimetal t-stat control

PostBy: LDPosse On: Wed Feb 06, 2013 6:12 pm

lsayre wrote:I'm not seeing it. Just what was the makeshift fix?


The coal hod is blocking the air intake flap from opening more than about 1/4". Taking another look at the pic, I guess it's not that obvious :oops:
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola

Re: Improving bimetal t-stat control

PostBy: Lightning On: Wed Feb 06, 2013 8:43 pm

LDPosse wrote:The coal hod is blocking the air intake flap from opening more than about 1/4".


Oh ok, I couldn't tell either :lol: ... good work 8-)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Improving bimetal t-stat control

PostBy: michaelanthony On: Wed Feb 06, 2013 9:40 pm

LDPosse wrote:
The coal hod is blocking the air intake flap from opening more than about 1/4".


Hi LDP, would it be helpful to hang the necessary weight on the flap so it opens at the desired slow speed, but would close faster because of the weight!...my 2 c$
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly coat rack
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Improving bimetal t-stat control

PostBy: LDPosse On: Wed Feb 06, 2013 9:44 pm

michaelanthony wrote: Hi LDP, would it be helpful to hang the necessary weight on the flap so it opens at the desired slow speed, but would close faster because of the weight!...my 2 c$


I didn't think about that.... it wouldn't be too hard to attach a small weight to it, to find out!
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola