Soot in the chimney! What is dangerous and how to deal with it?

How does soot appear?

When fuel burns in a stove or in a fireplace, along with the release of heat, the process of volatile matter is released, deposited inside the chimney - on its walls.

Soot and resinous deposits take a fancy to horizontal sections, various protrusions and irregularities, corners.

Gradually, the layer thickness increases, and the chimney channel narrows.

If, instead of transparent or white, dark smoke appears from the chimney, and the fire in the firebox acquires a dark orange hue, this is a signal that it is time to clean the chimney.

How and how to clean the chimney from soot

Heating in a private house is a vital system, on which not only comfortable living depends, but often the property and life of residents. A special role is played in this case by the system for removing fuel combustion products from the room - the chimney. Its inner surface is gradually contaminated with condensate and soot, while the cross-section of the chimney channel decreases, the draft decreases, and the full-fledged extraction of smoke from the room is disrupted.

Over time, the chimney becomes clogged with soot, and its ability to remove combustion products decreases

What is the risk of plaque accumulation:

the thrust and efficiency of the stove (fireplace) decreases;
the inner walls of the chimney collapse;
a malfunction in the chimney can cause fire and carbon monoxide poisoning.

The last circumstance is extremely important. Due to the high combustion temperature of soot, the chimney may collapse, any spark from the same fireplace can ignite deposits on the walls of the chimney and cause a fire.

Soot can be of different fractions, oily, loose or resinous - the last variety is the most dangerous in terms of fire.

The temperature when burning soot reaches 1200 degrees, and although the fire does not burn for long, this phenomenon often has the most sad consequences.

In addition, when heated, the chimney can destroy the adjoining elements of the roof.

Plaque will form in any case, but its amount can be minimized by following simple rules.

Dangers of a clogged chimney

Perhaps the greatest danger of a clogged chimney is the flow of combustion products, in particular the most dangerous carbon monoxide CO, into living quarters. Its danger is that it has no smell or color, and only specialized devices can recognize its presence. When the concentration is exceeded, a person is paralyzed, followed by loss of consciousness. Further stay in the room (up to half an hour) with carbon monoxide is fatal.

The next danger of a clogged chimney is in the ignition of soot inside the chimney.... Such a fire can occur in any part of the chimney, sparks from a local fire can get on easily flammable floors - for example, wooden beams. The danger of such a soot fire is that its hearth can be located in hard-to-reach places, and you will not even be aware of an impending disaster.

We take measures:

first of all, the chimney must be built in compliance with all norms and rules, including height requirements;
the fireplace structure must be properly arranged;
the chimney must have good thermal insulation properties;
when burning, it is better not to use resinous pine, spruce logs, wet firewood, freshly cut, with bark, and also not to burn various garbage in the oven;
the device of the revision window is mandatory - for cleaning;
it is desirable to arrange constructive bends as little as possible;
it is necessary to regularly clean the firebox and ash pan;
it is necessary to periodically inspect and check the condition of the chimney, as well as clean the channel - at least once a year.

It is worth noting that not only combustion products can cause blockage in the pipe - birds' nests and cobwebs often complicate the functioning of the heating system.

For preventive purposes and in case of congestion, large accumulations of soot on the walls of the chimney, it is necessary to clean it.

Causes of a fire in a chimney when heated with wood.

For the combustion process to occur, three conditions must be met: the presence of combustible material, the presence of oxygen that supports the combustion process and the ignition temperature.

What combustible materials enter the chimney?

In open furnaces there is no possibility of preliminary mixing of fuel and air, therefore the combustion process is not controlled, but occurs naturally. Such combustion is called incomplete. Incomplete combustion of wood produces carbon dioxide (CO2), water (H2O), carbon monoxide (carbon monoxide, CO), and a number of other substances in the solid and gaseous state. When they cool down, soot is formed, i.e. unburned wood coals and tar.

Soot ignites at 550 degrees, does not burn brightly, but quickly. Tar ignites at 485 degrees, in the initial stage of combustion, a large amount of smoke is released, after heating, it flares up with a bright flame, with flying sparks and crackling.

Factors Affecting Soot Formation

Insufficiently high flame temperature... A lower combustion temperature results in the formation of more combustion by-products and a higher humidity of the flue gases. There are several factors that reduce the temperature of the flame:

The furnace has not been properly insulated,
Too cold combustion air enters the furnace (no preheating),
Damp wood, which reduces the combustion temperature due to evaporation,
The presence of water heat exchangers - contact of the flame with the cooling surface.

Insufficient air flow. If there is no constant excess air in the furnace for complete combustion. This can happen deliberately, when the heating is reduced, or not deliberately, when there is insufficient air circulation in the room due to tightly closed windows, or fresh air access is limited due to the small cross-section of wall air dampers, air ducts.

The formation of tar or tar

As mentioned above, during the combustion process, water vapor is formed, which mixes with other combustion products. When cooled, they condense in the chimney, and as a result of a chemical reaction, a liquid is formed, which has a mild acidity and dissolves soot particles. This condensate with flue gas is sucked into the pores of the chimney and dries up to form a thick layer that adheres to the surface.

The soot that adheres to the chimney walls narrows the duct and reduces chimney draft. Due to the lack of draft, flue gases remain in the chimney for a longer time, accelerating the process of condensation formation. If the chimney is not sufficiently well insulated and air enters through cracks in the pipe or through a loosely closed damper, then the outgoing smoke cools more and the amount of condensate increases.

Significantly increases the amount of condensate. Most often, we are faced with a combination of several risk factors for the chimney:

Incorrectly set dimensions of the firebox
Low combustion air
Narrow chimney cross-section
Increased moisture content in wood

The accumulation of deposits of soot and tar in stoves and air-heating fireplaces begins at the point of narrowing of the chimneys and spreads towards the firebox.At the same time, in furnaces that use water heat exchangers, condensate easily appears on the supercooled surface of the heat exchangers. Plaque reduces the cross-section more and more, thereby exacerbating the situation.

A chimney fire can be deliberate during a chimney inspection or spontaneous, resulting in a fire.

Burning plaque in chimneys, in chimneys periodically carried out by order of a specialized chimney service.

With a spontaneous combustion in pipes, the temperature can reach 1000 degrees, which poses a danger to individual external elements of the chimney structures.

To prevent fire in chimneys it is important to correctly design a system for the removal of combustion products (flue gas flow in pipes), i.e. to calculate the intake of combustion air together with the exhaust of flue gases, precise manufacturing, correct operation (dry wood, sufficient air supply) and regular prophylaxis... In the interest of safety, periodic cleaning of the stove or fireplace, fittings and chimneys must not be neglected.

Imre Henselman

Mechanical cleaning

The most effective method, as practice shows, is mechanical cleaning.

You can tidy up the chimney yourself or with the assistance of a specialist in this area - a chimney sweep.

To remove contamination you will need:

hard brush made of flexible rods. Its length can be increased using separate parts - type-setting meter sticks;
for round sections of the pipe, a ruff is suitable, for square and rectangular - a brush;
at the first stage of cleaning, a scraper is used to remove dense plaque;
a ball-shaped heavy metal core is used to eliminate congestion. It is forbidden to use eccentric dumbbells instead: a stuck object with a displaced center of gravity can lead to a blockage, which is extremely difficult to get rid of, and sometimes even dismantling of the chimney is required.

Sequence of work:

chimney flues are cleaned from below, using a special brush, stove chimneys - from the roof;
do not forget about precautions: the roof can be slippery in winter. Of course, you should not carry out work at a height in strong winds;
cleaning holes, the firebox must be closed to prevent soot from entering the interior;
we inspect the channel: a layer of soot with a thickness of more than 2 mm requires mechanical cleaning;
we check the sixth for the presence of blockages - if there are any, push them with the help of a heavy core fixed on the cable;
remove dense plaque with a scraper, after which we continue cleaning with a brush, the diameter of which is larger than the section of the pipe;
the final step is to open the cleaning holes in order to remove dirt, debris and combustion products from them. The firebox and blower are the last to be cleaned.

Use of chemicals

This method is great for independent use, it allows you to clean hard-to-reach bends with ease and minimal effort.

The industry produces liquid, solid and bulk chemical chimney cleaners - for every taste.

The principle of operation of such funds is as follows. During combustion, substances are released that destroy soot or lead to a catalytic reaction - and the deposits are burned at low temperatures.

One of the most common chemical cleaners is a chimney-log sweep: it is placed in the firebox with or without firewood.

The use of chemicals is excellent as a preventive measure, preventing the formation of plaque.

However, after using them, an unpleasant specific smell remains, and the premises must be well ventilated.

In some cases, mixtures may contain chlorine, which is harmful to human health.

Most of the tools are not universal - before purchasing, you need to read the instructions, which indicate for which heater they are intended.

It is undesirable to use such chemical methods for removing contaminants when there are furnace elbows - so that the fallen off soot does not completely fill up the channel.

The use of folk methods

There are several traditional tools that are analogous to special chemical "chimney sweeps".

Rock salt

During the heating, ordinary salt is poured onto the wood. This method will not help in the event of severe congestion, but as periodic prophylaxis it will do.

Potatoes

Chopped potatoes or peels are scattered over the burning logs. How much cleaning is required depends on the size of the oven - usually no less than half a bucket.

The steam saturated with starch softens the deposits in the chimney, and some of the soot simply comes out of the chimney.

This method is used as an independent method, as well as with the subsequent mechanical removal of contaminants. After this procedure, cleaning the canal with a brush is much easier and faster.

Aspen firewood

The use of aspen logs is considered to be quite effective. However, you should be very careful when heating the stove.

The flame reaches a great height, tongues of fire can appear even above the chimney.

Dry strong heat burns out soot, however, this increases the likelihood of a fire many times over: especially if there are cracks in the walls of the chimney, a spark can get into both the interior and the roofing.

Therefore, before using this method, you should make sure that the chimney, especially a modern one, will withstand and will not crack, otherwise a fire will not be avoided.

Chimney cleaning

Today, with the growing popularity of fireplaces in private homes, the profession of a chimney sweep is becoming more and more in demand. Of course, the price for their work is often very high, so many decide to self-clean the chimney.

Below you will find detailed instructions and describe several methods, the choice of which depends on personal capabilities and the degree of pollution of the chimney. For example, folk methods or chemical methods of cleaning are most often possible only at the very beginning of the buildup of carbon deposits, but if a lot of soot has accumulated, then you will have to resort to mechanical cleaning, and this is the most difficult and time-consuming method, but first things first.

Folk ways

Most of the popular methods are based on burning off soot in the chimney, and therefore, it is necessary to increase the combustion temperature to such an extent that the soot flares up and does not start a fire in the ceilings. That is why, before using one of the listed methods, you need to make sure the quality of the pipe laying.

Rock salt. One of the most popular ways in which soot is burned out of a chimney. Salt is poured onto the burning wood and the firebox is closed. The temperature in the vent will rise and the soot will flare up, while part of it will burn out without a trace, and some will fall down.

Potato peelings... At first glance, the method may seem strange, but in fact, everything is simple - the starch in the potato softens solid soot and ignites it. The main difficulty of this method is that it is very difficult to calculate the required number of cleanings, but on average they take one full bucket for one ignition, after which they check the condition of the chimney and, if necessary, repeat the procedure.
Aspen logs... The fact is that this tree has the highest combustion temperature, so if you fill the firebox with aspen logs, soot will burn out from the chimneys, but this must be done very carefully,since the temperature in the solid fuel stove and chimney will be very high.

Turpentine... Another method, very popular in the past, is that the firewood is abundantly watered and set on fire, thus generating a strong heat, due to which the soot is removed from the chimneys.
PHC. Domestic product, produced in powder form, packaged in packages of 50 grams. The contents of one package must be poured onto the wood and kindled. The active substances in the composition of the product will react with carbon deposits and decompose it into its constituent components, which will burn out without residue.

Important! Burning out soot in chimneys is a very dangerous method, therefore, it can be carried out only on a slightly smoked chimney and as a preventive measure or preparation for basic cleaning.

Chemical method

Today, there is a huge range of products for chemical removal of soot in the chimney, so it is no wonder you get confused when choosing the one that actually works. We will present an overview of several popular remedies that have proven themselves well over the years.

Log chimney sweep... This is a solid composite material, the convenience of which lies in the fact that it is simply added to the firebox to ordinary firewood and burns along with them. Stove specialists advise using it as an aid before removing soot from the chimney. It is necessary to add a chimney sweep to the furnace twice a year for prevention, and this significantly extends the life of the chimney and prevents the formation of carbon deposits.

Kominicek, a means for removing soot in a chimney made in Poland. The main component of this product is copper oxide, which dissolves the accumulated soot.

Important! Chemical cleaning methods, as well as folk methods, cannot be used with a large accumulation of carbon deposits, as this is fraught with consequences. Most often they are used only as a prophylaxis or as an aid before mechanical cleaning.

SOUGH IN THE CHIMNEY! WHAT IS DANGEROUS AND HOW TO FIGHT WITH IT?