Thursday, September 22, 2016

What causes back puffing in my catalytic wood burning stove?


When the combustor has an exhaust temperature over 1400° F. (760° C.) it can act like a glow plug (spontaneous combustion igniter).
Usually the wood gas-to air mixture is either too lean or rich to form a highly flammable mixture. There are times when this mixture is just right within the firebox during the normal burning process.

If the combustor is running at or above the ignition temperature of the mixture, spontaneous combustion will result, causing the stove to vent puffs of smoke.

Monday, September 19, 2016

Check you stove's componet parts now.

Is it time for a new replacement catalytic combustor in your wood burning appliance?

Now is the time to check the component parts of your wood burning stove and have it ready for the cold days ahead.


See my homepage for complete details on how to purchase any size for any model stove. 
The friendly service people at Applied Ceramics will be more then happy to help.

Thursday, September 15, 2016

Softwoods used for firewood

If softwoods are your only choice, your best options are:

Yellow Pine, Douglas Fir, and any of the Cedars.


Yellow Poplar is a poor wood for fire fuel. Though it burns and splits easily, it emits some heavy smoke and many sparks.

Southern Yellow Pine easily burns at varying heat levels and is easy to split. It emits some smoke and sparks but makes a relatively good firewood.

Douglas Fir is easy to burn and burns at a high heat level. It is easy to split and doesn't throw many sparks, but because of its smokiness Douglas Fir is just rated as a good source of fire fuel.

Cypress and Redwood are fair softwood sources of fuel. They are both somewhat easy to burn and burn at medium heat levels with some smoke and no sparks.

White Cedar or Western and Eastern Red Cedar all burn at low heat but are very easy to burn. They are easy to split, however they emit some heavy smoke and lots of sparks.

White Pine, Sugar Pine and Ponderosa Pine all easy to burn and burn at low heat levels. They are easy to burn and easy to split though they smoke some and spark a small amount.

Tamarack or Larch both burn at medium heat levels, are easy to burn and split but they both smoke and spark. They are fair sources of fire fuel, but not the best of the softwoods.

Spruce is a poor source of fire fuel because it burns at low heat, it smokes somewhat heavily and sparks considerably. Spruce wood is easy to burn and split but is not the best choice for firewood.
 



 









 

Monday, September 12, 2016

Best firewood for burning.

 
Any dry hardwood will work well, but for keeping your chimney clean, stay away from pine or other pine type trees that have a heavy pitch/sap content.
 
Make sure all firewood is season dried.



Oak is a favorite because it is a very dense hot burning firewood, that cuts and splits easily.

Birch also burns well, but because it is a less dense wood will burn faster (a good fire starter). Where efficiency is concerned any hard wood that is dry and you can get it cheap or free, that's what you might want to go for.

Elm and Box Elder are good, but they are hard to cut and split. However, they burn fine once you get them dry.
Local saw mills will sell their trimmings (slab wood) quite cheap and it only needs to be cut to length.
So you have to factor in what your expenses are (truck, trailer, chain saw, log splitter), cost of the wood, delivery, the system your using to burn it and of course your time and availability.

Catalytic wood burning stoves will deliver a longer more efficient burn, while cutting back on fuel consumption.  (More heat output for less money)

Wednesday, September 7, 2016

Wood vs Oil and Gas as a fuel to burn


The news is full of reports about the need to reduce the production of the so-called greenhouse gases.
Fuel burning is the main cause of the increased levels of atmospheric carbon dioxide.
When the atmospheric concentration increases, these gases, mainly carbon dioxide, cause the average global temperature to rise with potentially disastrous results.

Wood, however, differs from the fossil fuels such as oil and gas because it is a renewable fuel. 


As a tree grows, it absorbs carbon dioxide from the air and stores it in the wood as carbon. This carbon makes up about half of the weight of wood.


When wood is burned, carbon dioxide is released again to the atmosphere. The same amount of carbon dioxide would be released if the tree died and were left to rot on the forest floor. Our forests can be a perpetual source of fuel, provided they are cared for and managed properly.


Burning seasoned dried wood in an EPA approved catalytic appliance, provides us with clean air to breathe. 

Friday, September 2, 2016

Maintaining catalytic burning conditions.


 
When initially starting up a cold stove, a medium to high firing rate must be maintained for approximately 20 to 30 minutes.  This will allow the stove, the catalytic combustor and the fuel to stabilize at a proper operating temperature. Even though temperature can reach 600o f. within a few minutes after the fire has started, if the fire is turned down to soon to a low burning condition, it will result in the fire and/or the catalytic combustor going out.

At the end of a burn cycle, it’s possible that the amount of burning charcoal remaining might not provide sufficient temperature or fuel for the catalyst to stay lit.


During the refueling of a hot stove that has an internal temperature below 500o f., it is best to fire the stove up for 1o to 15 minutes to ensure sufficient temperature and proper amounts of volatile gases for the catalyst to operate well and efficiently. 


However, when refueling a hot stove that has an internal temperature above 500o f., no re-firing is necessary.

Tuesday, August 30, 2016

How can you tell if the combustor is working?


Note: Some stoves are equipped with a combustor view port, it should be noted that the combustor usually glows during the first 20 to 35% of the burn cycle when the catalyst is receiving the most smoke and burning at a high temperature.  The combustor temperature can reach 1000o f. and produce a glow.  However, the combustor does not have to glow to be working.  As less smoke is present to burn, the combustor temperature drops and the glow will cease.  Therefore, we suggest this not be a method of determining whether or not the combustor is working.
 

-The best method is the use of thermo couplings and following the manufacturer’s instructions.
This method will read the inlet and exhaust temperatures of the combustor.
 
-A more simple method is to visually observe the exhaust coming out of the chimney.  When the by-pass is in the closed position and the catalytic combustor is in good operating condition, there should be no dark smoke coming out of the chimney.

-If the catalytic combustor is not working properly, the stove’s operator will notice an increase in fuel usage.

-The stove’s operator will also notice an increase build-up of creosote in the system.

Wednesday, August 24, 2016

What are some of the necessary requirements for building a catalytic wood burning stove?


 

  a. Preheated secondary air supply.

        Since most of the intake oxygen is used up in the firebox burning, preheated secondary air must be supplied to the catalytic combustor.  This air is mixed with the wood gases from the firebox and distributed across the intake face of the combustor.  Air to fuel ratio is important.  Too much air will cool the combustor and not allow it to work properly. To little air will starve the combustor of necessary oxygen needed for its operation.
 

  b. By-pass system. (By-pass damper)

      The by-pass system is used in an open position when starting the initial fire in the stove.

      This allows the smoke to by-pass the combustor while the combustor is heating up and temperatures throughout the stove are stabilizing.  This requires anywhere from 20 to 30 minutes of burning with the by-pass in an open position.  After this period of time the combustor will light-off and the by-pass should be closed.
 
  c. Flame shield.

      The flame shield is designed to protect the combustor from direct flame impingement.  It is located at the top of the firebox.  Most flame shields are removable so that the combustor can be serviced or replaced if necessary.  It is usually held in place with four brass nuts.
 

  d. A Properly sized catalytic combustor.

      This is determined by the manufacturer and the size stove being built. The flow rate going through the stove will have a lot to do in determining the correct combustor size and cell density to be use.  Also the amount of room available where the combustor is to be positioned will help determine what combustor size to use.

      Cell density determines the amount of open frontal area needed to control the flow rate and also the amount of surface area required to burn the gases received by the combustor.

      Height of the combustor (distance through the cells) also plays a role in the residence time the gases have to burn within the combustor.  3” height combustors will create more residence time for the gases to burn, providing the stove has the available area for mounting the combustor.

      Applied Ceramics carries a wide range of combustor in various shapes, sizes and cell densities to select from. 
 

  e. Stove must be airtight.

      In the United States all catalytic stoves are required by law to be airtight.  This allows the consumer control over the flames in the stove’s firebox. 
 

  f. Firebox must have primary adjustable air intakes.

     The firebox air controls are used to control the amount air intake to the firebox.  These controls can be adjusted by the stove’s operator to reduce or increase the amount of oxygen being supplied to the fire.  Reducing the air intakes will lower the flames and create a longer burn rate. Reducing will also keep flames from wrapping the flame shield and burning directly into the combustor when the by-pass is in the closed position.  

Friday, August 19, 2016

Catalytic combustor design.

What makes up a catalytic combustor design?

Catalytic combustors are manufactured to a stove manufacturer's specifications. 
Each combustor requires a certain cell density to allow the stove a proper flow rate of the gases.
They are designed to allow proper residence time for the smoke and gases to burn before exiting the stove.
They are also sized based on the firebox volume.
All catalytic combustors must be EPA approved to assure the consumer they not only work, but will meet EPA emission regulations.

Tuesday, August 16, 2016

How a catalytic combustor works.

Normally, smoke will burn, at a temperature of 1000 F. or higher. Burning a stove this hot would require continuous intense fire and would require a higher wood consumption.
The answer to eliminate this is the catalytic combustor.

Wood smoke gases coming in contact with the catalyst, causes chemical changes to take place. This will then allow the smoke to ignite at temperatures around 500 F. or (260 C.)
 


This temperature is easily achieved in the firebox of a wood burning stove.

As the wood gases ignite and burn within the catalytic combustor, clean by-products of water vapor (H2O) and carbon dioxide (CO2) are emitted.   
 

Friday, August 12, 2016

Advantages of using a catalytic wood burning appliance.


What are some advantages of using a catalytic wood burning appliance?

 


  1. Reduces air pollution by up to 90%

  2. Generates up to 50% more useful heat from each log.

  3. Longer burns.

  4. Saves up to 1/3 on fuel cost.

  5. Reduces Creosote build up. (Up to 90% reduction)

  6. 72% or better heating efficiency.

Tuesday, August 9, 2016

Check the combustor in your catalytic appliance now.

While the weather is still warm and your stove is not in use, it may be a good idea to do your maintenance before the burning season begins.  
Remember the combustor is your heat source, not the firebox temperature.
If it is necessary to replace the combustor, I strongly recommend calling the friendly sales people at Applied Ceramics Inc. 
They will give you expert advice and the best prices you can find anywhere.

The right catalytic combustor is very important to the wood burning appliance's efficiency.




Wednesday, August 3, 2016

Methods for cleaning the combustor.


Now is a good time to check your wood burning appliance.  Don't wait until the last minute.

Depending on the combustor's condition, follow one of these methods:























 
A vacuum cleaner may be used, but never use high pressured air to blow the cells free of any build-up. This can damage the cell walls.
Any cell blockage can be removed with the use of a pipe cleaner or a cotton swab.


























Should the combustor’s cells become masked with fly-ash,...use a paintbrush or soft-bristled brush and dust the combustor gently.


Never use anything abrasive to clean the combustor.


























Normally the catalytic combustor requires little or no maintenance because it generates such high temperatures, it is basically self-cleaning.

However, should the combustor become masked with soot or creosote, it is possible to burn the accumulation off by opening the bypass and building a hot fire.
Once the hot fire is created, close the bypass halfway and burn for 30 to 60 minutes with the bypass left in this position.

Never use cleaning solvents to clean it.
It would be wise to check and clean the combustor, if necessary, before each burning season and inspect the flue system for any signs of creosote build up.

A clean flue helps prevent chimney flue fires.