It is difficult to meet a person who has not encountered in life burning wood. Many people at least once went on hikes that cannot do without making a fire. Some have experience in kindling brownies and bath stoves. Most of them at least once in their life tried to burn wood with a special device or a magnifying glass.
But not many people wondered at what temperature the ignition of a tree becomes possible. 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 make fire?
The fire was also known to people who lived in the Stone Age. People far from always knew how to make fire on their own. The first acquaintance of a person with the combustion process, according to scientists, happened empirically. The fire, obtained from a forest fire or conquered from a neighboring tribe, was guarded as the most expensive thing that people had.
Over time, a person noticed that some materials have the most favorable burning properties. For example, dry grass or moss can ignite with just a few sparks.
After many years, again empirically, people learned how to extract fire using improvised means. The first "lighter" of a man, historians call tinder and flint, which when struck against each other gave sparks. Later, mankind learned to extract fire with the help of a twig placed in a special depression in the wood. The ignition temperature of the tree was achieved due to the intensive rotation of the end of the rod in the recess. Many orthodox communities continue to use these methods today.
Much later, in 1805, the French chemist Jean Chansel invented the first matches. The invention gained enormous distribution, and a person could confidently extract fire if necessary.
Mastering the combustion process is considered the main factor that gave impetus to the development of civilization. Moreover, in the near future, combustion will remain such a factor.
What is the combustion process?
Combustion is a process at the boundary of physics and chemistry, consisting in the conversion of a substance into a residual product. In this case, large amounts of thermal energy are released. The combustion process, as a rule, is accompanied by the emission of light, which is called a flame. Also in the combustion process, carbon dioxide is released - CO 2 , the excess of which in an unventilated room can lead to headache, suffocation and even death.
For the normal course of the process, it is necessary to fulfill a number of mandatory conditions.
First, burning is only possible with air. In a vacuum, the ignition process is not possible.
Secondly, if the region in which combustion occurs is not heated to the ignition temperature of the material, the combustion process will stop. For example, the flame will go out if you immediately throw a large log into the freshly melted stove, preventing it from warming up on small firewood.
Thirdly, if the subjects of combustion are raw and emit liquid vapor, 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 CO 2 and combustion residues - occurs in three phases.
The initial course occurs at 160-260 degrees. Irreversible changes begin to occur in the tree, resulting in a fire. The ignition temperature of wood varies in the region of 200-250 degrees.
The second phase of pyrolysis is 270-430 degrees. Decomposition of wood begins under the influence of high temperature.
The third phase is characteristic of a lighted fire, a melted furnace. The ignition temperature of a tree in Celsius in the third phase is 440-610 degrees. Under such conditions, the tree will light up in almost any condition and leave charcoal after itself.
Different wood species have different ignition temperatures. The ignition temperature of pine - not a combustible tree - is 250 degrees. The oak will light up at a temperature of 235 degrees.
Which firewood burns better and which worse?
Dry fire burns best. Moisture-saturated wood also burns, but it takes a lot of temperature and some time to remove and evaporate moisture. This process is usually accompanied by characteristic hissing. Not many people know that when burning "raw" wood, acetic acid is released. This fact has an extremely negative effect on the furnace equipment and on the overall combustion efficiency. It is highly recommended to use dry firewood, as well as buy firewood in the spring, so that they have time to dry before the onset of cold weather.
What determines the combustion efficiency?
Combustion efficiency - an indicator that is determined by thermal energy, which does not "fly off into the pipe", but is transferred to the furnace, heats it. This indicator is influenced by several factors.
First of all, it is the integrity of the furnace structure. Cracks, cracks, excess ash, dirty chimney and other malfunctions 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 produce heat.
Recommendations for firing wood
Large pieces of wood will not catch fire right away. It is necessary to light a fire, starting with small branches. They will give coals, which will provide the necessary temperature for igniting the tree, loaded into the furnace already in larger portions.
Means for ignition, especially in the brazier, are not recommended, since they emit substances harmful to humans during combustion. Excessive firing agent in a closed fire chamber may cause an explosion.
Can a fire occur in a bathhouse at high air temperature?
This is theoretically possible, but practically impossible. In order for the spontaneous ignition of the tree to start in the bath, the air temperature should be about 200 degrees. Not a single bath is capable of this, and moreover not a single person.
The record for staying in the sauna belongs to the Swede, who at a temperature of 110 degrees could last 17 minutes. For most people, a temperature of 90 degrees is the maximum allowable. With this heating of the air, the load on the heart increases sharply and there is a chance to faint.
A bath or a sauna is nevertheless recommended not to be left heated for over 100 degrees for a long time for reasons of fire safety. Although the ignition temperature of a tree starts at 200 degrees, caution never hurts.
Fire Prevention Requirements
It should not be forgotten that when handling fire, the key to successful action is compliance with fire safety rules. Complete several conditions and protect yourself and others from fire.
1. The ban on making bonfires in the forest in the summer is not just introduced. In summer, the chances of burning forest litter and the rapid spread of fire are much higher than at other times of the year.
2. When making a bonfire in nature, it is imperative to dig out a small bonfire by removing the top layer of turf with a shovel. In the future, it is advisable to return the sod to its place.
3. In order to localize the fire, it is recommended to enclose the fire with a fence made of stones or bricks.
4. There should always be a fire extinguishing agent in the walking distance: a fire extinguisher, sand or a container of water.
5. When extinguishing a fire, it is imperative to make sure that all the coals are extinguished and the fire does not reignite. To do this, it is recommended to flood the hearth abundantly with water, sprinkle earth on top or lay turf.
6. In no case should children be left alone with a source of fire. This can lead to disastrous consequences.
7. When using the stove or fireplace, do not store flammable objects, means for ignition in the immediate vicinity of the furnace. It is advisable to carry out a floor covering next to a furnace made of non-combustible material (steel sheet).
8. It is necessary to maintain the furnace in good condition: promptly close up all the cracks that have formed, periodically rake out the ash.
9. The foundation for the furnace must be made of brick. It is not recommended to use wooden scaffolding for this purpose. This is fraught with the collapse of the entire structure.
10. The chimney in the attic must be insulated with non-combustible material, do not store flammable materials in the attic.
11. Do not completely close the damper of the furnace without making sure that the combustion process in the furnace has stopped. Otherwise, suffocation from excess carbon dioxide is possible.