Chimney fire

A chimney or a chimney fire occurs when ignited in the chimney of deposited soot is caused by incomplete combustion.

General

Produced by incomplete combustion

  • Schmierruß, shining soot or hard carbon for solid fuels
  • Flockenruß for liquid and gaseous fuels.

These carbon blacks include significantly more flammable materials to conventional carbon black.

An incomplete combustion occurs,

  • When ( eg fats ) burned wet wood or other unsuitable fuels and / or
  • When fuels burn from lack of oxygen.

Also contributes to large-sized boilers for solid fuels this danger: If heat is not removed through the boiler in the partial load range; by a restricted air supply, the combustion was incomplete: soot is formed.

The deposition of soot in the chimney is favored by a much too large or too small chimney cross -section:

  • Too small a cross-section of the exhaust brakes; they need more time on their way to the exit opening; soot particles contained in the exhaust gas are more likely to deposit on the inner walls of the chimney.
  • Too large a cross- section of the chimney will cause the chimney interior walls after the start of the heating remain relatively long cool. Cool the rising exhaust gas; contained in the exhaust gas moisture and soot particles tend to condense on the inside walls of the chimney or deposit themselves.

To prevent this condensation, send conventional oil and gas heating systems (ie heaters, which have no condensing technology ), the exhaust relatively hot in the chimney. Also, wood-burning stoves do this: on her neck, the exhaust gas at nominal temperatures of about 300 degrees.

Modern chimneys are insulated: contacting the exhaust pipe ( for example, from ceramic or stainless steel) is enclosed by an insulating layer of mineral wool. Prior to 1970, they also built ceramic tubes, which were surrounded by Granulatsteinchen. These chimneys warm up quickly; on their inner walls condenses much less than for non- insulated (for example, brick ) chimney interior walls.

Trigger the fire

Several factors or their interaction can cause an unwanted chimney fire:

  • Flames can hammer home in connectors ( stovepipes ) or trains of the fireplace and ignite located there soot
  • Glut is carried into by strong chimney draft in connector or chimney and ignite the soot there
  • Langflammiges burning material (eg conifers, especially their branches ), or burning material that makes the combustion chamber extremely hot

To save the cost of the boiler inspector, fire repeatedly homeowners their fireplace intentionally to. When controlled Ausbrennenlassen soot deposits can be burned clean. Since the risk of an unwanted fire in the building is great, the deliberate lighting for lay people is illegal in many areas. Often the homeowner is obliged to regularly clean the fireplace through a chimney sweep. This prevents accidental fires in a chimney on the one hand, on the other hand it makes the lighting unnecessary.

Fire-fighting

A chimney fire may not be extinguished with water. Since 1 liter of water would be converted abruptly to 1700 liters of water vapor, the chimney can be severely damaged by the sudden increase in pressure and possibly explode.

Opportunities for fire fighting are:

  • The chimney can be controlled burn, that is under constant observation. One should minimize the air "from below", so keep closed the door of the oven. If several furnaces are connected to the burning chimney, which applies to all furnaces.
  • Reconstitute with chimney sweep tool the burning soot from the walls. This can burn out at the foot of the stove or remove the chimney and pour out of the chimney (for example, in the boiler room ).
  • Since the carbon black may swell by the high combustion temperatures, the clogging of the chimney with a suitable device must be prevented.
  • Powder extinguishers are very efficient in use. Due to the high pollution of the environment is, however, to expect any adverse side effects.
  • The chimney can be flooded with carbon dioxide.
  • You should consult with the fire department and a chimney sweep.
  • Even after the fire was extinguished, should the chimney and monitor the environment for several hours, as it still radiates a lot of heat and could put, for example, to the chimney adjoining roo materials or wooden beams of the roof on fire.
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