How to "Bank" my Viking Boiler

How to "Bank" my Viking Boiler

PostBy: caper1175 On: Wed Oct 22, 2008 12:32 pm

Hi all:
I'm getting more and more comfortable with burning coal and am getting ready to enter the winter months and would like some input on how to bank my furnace. I'll give you some info about my setup and hopefully somebody can provide some suggestions.

I have a Viking boiler with a pressure guage and temperature guage on top of the unit. There is an aquastat that controls my circulator and it is located around 18" up the pipe that comes off my furnace. I also have magnetic stove pipe thermometer located about 16" up the pipe. I have 3 zones, upstairs, downstairs and garage. There is a manual draft control located at the back of my ash box and a draft reduce on the side of my stove pipe. I can also open the shaker access cover to provide draft but never have.

Each day I've been starting from scratch, empty all the ashes and start a new fire. I open the draft slightly, toss in some paper, cardboard, kindling towards the back and light. After 5 minutes I toss a shovel of coal (local bituminous) onto the fire, gradually building up the fire until it's burning nicely and covers the grates. Once it's burning well then I'm tossing on bagged coal and each bag has about 2 normal size shovels of coal. Each bag lasts 1.5 to 2 hours. My boiler temperature is around 180 but I've seen it go to 210+ at times and then I start to panic and close the draft. I have my aquastat turned down quite low so that it circulates most of the time.

So now I'm curious as to how I can "Bank", or "Load" the fire so that I don't need to be starting a fresh fire every day. If somebody could give me some hints it would be great. My biggest concern is the termperature getting too high. Once is starts to go above 180 then I start to get worried.
caper1175
 
Stove/Furnace Make: Viking Jr.

Re: How to "Bank" my Viking Boiler

PostBy: LsFarm On: Wed Oct 22, 2008 12:48 pm

Hello caper, so you don't have any automatic control of the air to the fire?? It is only manual?? If this is so, then it is going to be difficult to control your fire and the resulting water temperature.

Coal goes through several distinct stages.. With bituminous they are more noticable than with anthracite. First there is the fire from fresh coal,, it has volitiles burning off, with Bituminous, this is the gray/yellow smoke and heavy yellow flames and sooty fire.. then the fire burns down to a hot red mass of coals.. With bituminous, sometimes, depending on the coal, this stage of burning has the coal swelling and sticking together, making a big sheet of coal with the fire underneath. You have to break up this 'bridge' of coal to let air through so the upper layer of coal can burn... Then as the coal burns down, the mature stage of the coal is characterised by less heat output, the fire settling and the ash blocking some of the air flow through the grate..

All through the above stages the amount of air needed to maintain the fire varies. and the heat output varies.. so unless you have a way to adjust the air to the fire, it will be difficult to get an even water temperature..

What you may want to do is to just load your fire up very deep, add as much coal as you can,, and once the fire is established, cut back the air to a minimum, and see if using just the air inlet you can keep the fire burning at a low heat.. then just keep adding coal,, shake the ashes down, then add more coal.. many coal burners start just one fire for the year,, and keep it burning all winter long..

Hope this helps..

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: How to "Bank" my Viking Boiler

PostBy: caper1175 On: Wed Oct 22, 2008 2:11 pm

Thanks Greg for the great info.

I only have manual controls. You can see it in the 1st pic below with the chain coming off it. Also, in the 2nd pic, do you know when and if should I ever open this? What exactly is it for?
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Don't know what this is for. It's manual and I always leave it closed.
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Front View
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caper1175
 
Stove/Furnace Make: Viking Jr.

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Re: How to "Bank" my Viking Boiler

PostBy: Tamecrow On: Wed Oct 22, 2008 2:58 pm

Picture #1 is the air inlet. Opening it will allow more air to enter from under the fire. Picture #2 is a manual stove pipe damper. This controls the amount of draft from your chimney. If you have an excessive chimney draft you can open this to reduce the draft. The newer Viking's don't have this. They use an automatic baro damper. I have an excellent article on burning bituminous coal that was sent to me by another member. I think it's from an old Popular Mechanic's magazine. PM me your email and I'll send it to you or anyone else that's interested.

Terry
Tamecrow
 
Stove/Furnace Make: Warden King Ltd.
Stove/Furnace Model: Viking Jr. Boiler/Will-Burt 30

Re: How to "Bank" my Viking Boiler

PostBy: Tamecrow On: Wed Oct 22, 2008 3:42 pm

I should add, as Greg indicates, the various stages of burning bit coal require different amounts of air. These furnaces are far more efficient and will hold a fire much longer when switched to an automatic air inlet control. All you require to switch it to automatic is an aquastat and a damper motor as well as an auto baro damper. You will be able to keep the fire alive for at least 12 hours when you can automaticly control the air feeding the furnace. The boiler temp rises too much, the damper will restrict the air entering the boiler, the boiler cools too much, and the damper will open to allow more air to feed the fire.

Terry
Tamecrow
 
Stove/Furnace Make: Warden King Ltd.
Stove/Furnace Model: Viking Jr. Boiler/Will-Burt 30

Re: How to "Bank" my Viking Boiler

PostBy: caper1175 On: Thu Oct 23, 2008 8:37 am

Thanks Terry for the information. I've PM'ed you my email address.

I like the idea of an automatic damper, but would I be able to use my existing aquastat or would it require a second to connect an automatic damper motor? I'm definitely going to check into the auto baro damper and inlet control. I just have several other projects that are comsuming my money at the moment. Also, is it OK if the water temperature occassionally rises above 180? What would be a normal or safe operating temperature?

Cheers,
Jason.
caper1175
 
Stove/Furnace Make: Viking Jr.

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