It is difficult to meet such a person who has not encountered wood burning in his life. Many people at least once went hiking, which can not do without making a fire. Some have experience in kindling house and sauna stoves. Most people at least once in their life tried to burn wood with a special device or a magnifying glass.
But not many people have wondered at what temperature wood can ignite. Is there a difference between the ignition temperature of different tree species? The reader has a great opportunity to delve into these issues and get a lot of useful information.
How did man master fire?
Fire was known to people who lived in the Stone Age. People have not always been able to make fire on their own. The first acquaintance of a person with the processcombustion, according to scientists, occurred empirically. Fire, extracted from a forest fire or won from a neighboring tribe, was guarded as the most precious thing people had.
Over time, people noticed that some materials have the most burning properties. For example, dry grass or moss can be ignited with just a few sparks.
After many years, again empirically, people learned to extract fire using improvised means. Historians call the first “lighter” of a person tinder and flint, which, when they hit each other, gave sparks. Later, mankind learned to extract fire with the help of a twig placed in a special recess in the wood. The ignition temperature of the tree was achieved by intensive rotation of the end of the twig in the recess. Many Orthodox communities continue to use these methods today.
Much later, in 1805, the French chemist Jean Chancel invented the first matches. The invention has received enormous distribution, and a person could already confidently extract fire if necessary.
The development of the combustion process is considered the main factor that gave impetus to the development of civilization. Moreover, combustion will remain such a factor in the near future.
What is the combustion process?
Combustion is a process at the turn of physics and chemistry, which consists in the transformation of a substance into a residual product. At the same time, thermal energy is released in large quantities. The combustion process is usuallyaccompanied by the emission of light, which is called a flame. Also, during combustion, carbon dioxide is released - CO2, an excess of which in an unventilated room can lead to headaches, suffocation and even death.
For the normal course of the process, a number of mandatory conditions must be met.
Firstly, combustion is possible only in the presence of air. In a vacuum, ignition is impossible.
Secondly, if the area in which combustion occurs is not heated to the ignition temperature of the material, then the combustion process will stop. For example, the flame will go out if a large log is immediately thrown into a newly fired oven, without letting it warm up on small wood.
Third, if the subjects of combustion are wet and emit liquid vapors, and the burning rate is still low, the process will also stop.
At what temperature does wood ignite?
Pyrolysis - the process of decomposition of wood at high temperature into CO2 and combustion residues - occurs in three phases.
Initial runs at 160-260 degrees. Irreversible changes begin to occur in the tree, ending in fire. The ignition temperature of wood fluctuates around 200-250 degrees.
The second phase of pyrolysis is 270-430 degrees. The decomposition of wood under the influence of high temperature begins.
The third phase is typical for a diluted fire, a melted stove. The ignition temperature of wood in Celsius in the third phase is 440-610 degrees. Under these conditions, it will light upthe wood is in almost any condition and will leave behind charcoal.
Different types of wood have different ignition temperatures. The ignition temperature of pine - a tree that is not the most combustible - is 250 degrees. Oak will catch fire at 235 degrees.
Which wood burns better and which burns worse?
Dry wood burns best. Wood saturated with moisture also burns, but it takes a high temperature and some time to remove and evaporate moisture. This process is usually accompanied by a characteristic hiss. Not many people know that when raw wood burns, acetic acid is released. This fact has an extremely negative effect on furnace equipment and on the overall combustion efficiency. It is highly recommended to use dry firewood, as well as to buy firewood in the spring so that it has time to dry out before the onset of cold weather.
What determines combustion efficiency?
Combustion efficiency is an indicator that is determined by thermal energy, which does not “fly away into the chimney”, but is transferred to the furnace, heats it up. This indicator is influenced by several factors.
First of all, this is the integrity of the furnace design. Cracks, cracks, excess ash, a dirty chimney and other problems make combustion inefficient.
The second important factor is the density of the tree. Oak, ash, pear, larch and birch have the highest density. The smallest - spruce, aspen, pine, linden. The higher the density, the longer the piece of wood will burn, and therefore the longer it will release heat.
Recommendations for kindling wood
Large pieces of wood do not immediatelywill light up. It is necessary to kindle a fire, starting with small branches. They will give coals that will provide the necessary temperature to ignite the wood loaded into the furnace in larger portions.
Ignition products, especially in the barbecue, are not recommended, as they emit substances harmful to humans when burned. Too much lighter in a closed firebox can cause an explosion.
Can a fire happen in a bath at a high air temperature?
It is theoretically possible, but practically impossible. In order for the spontaneous combustion of wood in the bath to begin, the air temperature must be about 200 degrees. Not a single bath is capable of this, and even more so, not a single person.
The record for staying in a sauna belongs to a Swede, who at a temperature of 110 degrees was able to hold out for 17 minutes. For most people, a temperature of 90 degrees is the maximum temperature. With such heating of the air, the load on the heart increases sharply and there is a chance to faint.
It is still recommended not to leave a bathhouse or sauna heated above 100 degrees for a long time for reasons of fire safety. Although the ignition temperature of wood starts at 200 degrees, it never hurts to be careful.
Fire safety requirements for handling fire
It should not be forgotten that when dealing with fire, the key to successful action is compliance with fire safety rules. Fulfill a few conditions andprotect yourself and others from fire.
1. The ban on making fires in the forest during the summer period was introduced for a reason. In summer, the chances of the forest floor igniting and quickly spreading fire are much higher than at other times of the year.
2. When making a fire in nature, be sure to dig a small fire, removing the top layer of turf with a shovel. In the future, it is desirable to return the sod to its place.
3. In order to contain the fire, it is recommended to surround the fire with a fence made of stones or bricks.
4. There should always be a fire extinguishing agent within walking distance: a fire extinguisher, sand or a container of water.
5. When extinguishing a fire, make sure that all the coals are extinguished so that the fire does not flare up again. To do this, it is recommended to fill the hearth with plenty of water, sprinkle it with earth on top or lay it with turf.
6. Never leave children alone with a fire source. This can lead to disastrous consequences.
7. When using a stove or fireplace, do not store flammable objects, ignition aids in the immediate vicinity of the firebox. It is advisable to make a floor covering next to the firebox made of non-combustible material (steel sheet).
8. It is necessary to maintain the furnace in good condition: close all the gaps in a timely manner, periodically remove the ashes.
9. The foundation for the furnace must be made of brick. It is not recommended to use wooden scaffolds for this purpose. This is fraught with the collapse of the entire structure.
10. The chimney in the attic must be insulatednon-combustible material, do not store flammable materials in the attic.
11. It is impossible to completely close the furnace damper without making sure that the combustion process in the furnace has stopped. Otherwise, you may suffocate from excess carbon dioxide.
