Charring

Charring

Charring is a chemical process of incomplete combustion of certain solids when subjected to high heat. The resulting residue matter is called Char. By the action of heat, charring removes hydrogen and oxygen from the solid, so that the remaining char is composed primarily of carbon. Polymers like thermoset or most solid organic compounds like wood or biological tissue, exhibit charring behaviour.

Charring is the result of naturally occurring processes like fire but also a deliberate and controlled reaction used in the manufacturing of certain products.

The mechanism of charring is part of the normal burning of certain solid fuels like wood. During normal combustion the volatile compounds created by charring and pyrolysis are consumed at the flames within the fire, while combustion of char can be seen as glowing red coals or embers which burn without the presence of flames.

Production of Char

Coke and charcoal are both produced by charring, whether on an industrial scale or through normal combustion of coal or wood. Normal combustion consumes the char as well as the gases produced in its creation, while industrial processes seek to recover the purified char with minimal loss to combustion. This is accomplished by either burning the parent fuel (wood or coal) in a low-oxygen environment or by heating it to a high temperature without allowing combustion to occur. In industrial production of coke and charcoal the volatile compounds driven off during charring are often captured for use in other chemical processes.

A "coal burning" blacksmith's forge actually produces the heat necessary for high-temperature metalworking by the continuous production and consumption of coke within a carefully managed fire. An inner ring of burning coke provides heat which converts the encircling coal into coke, which is then itself fed into the center of the fire to provide the required heat and to create more coke; coal itself is incapable of producing the heat required for some blacksmithing operations.

Charring and fire protection

Charring is an important process in the combustion ignition of solid fuels and in smouldering. In construction of heavy-timbered wood buildings the predictable formation of char is used to determine the fire rating of supporting timbers and is an important consideration in fire protection engineering. If a wood column is of large enough diameter, during a structure fire its exposed surface will be converted to char until the thickness of char provides sufficient insulation to prevent additional charring. This layer then serves to protect the remaining structurally sound core of wood, which can continue to carry the building loads if appropriately designed.

Legal definitions

Charring had a special meaning under the common law of England. Under that system, the crime of arson required charring of a dwelling—actual damage to the fiber of the material from which the structure was built—and not mere "scorching" or damage to the surface, or to surface coverings such as carpets and wallpaper.



Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Charring — Char Char (ch[aum]r), v. t. [imp. & p. p. {Charred} (ch[aum]rd); p. pr. & vb. n. {Charring}.] [Prob. the same word as char to perform (see {Char}, n.), the modern use coming from charcoal, prop. coal turned, turned to coal.] 1. To reduce to coal… …   The Collaborative International Dictionary of English

  • Charring Cross, Ooty — Charring cross   junction   Night time view of Charring Cross, Ooty …   Wikipedia

  • charring — noun The incomplete combustion of organic material …   Wiktionary

  • charring — tʃɑː n. cleaning woman v. scorch, singe, burn; be scorched; do cleaning work …   English contemporary dictionary

  • charring — present part of char or of chare …   Useful english dictionary

  • Biochar — is a charcoal produced from biomass that can store carbon. It is of increasing interest because of concerns about global warming caused by emissions of CO2 and other greenhouse gases. In some cases, the term is used specifically to mean biomass… …   Wikipedia

  • Carbon black — is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of amorphous carbon that has a high surface area to… …   Wikipedia

  • Pittsburgh rare — A Pittsburgh rare steak is one that has been heated to a very high temperature very quickly, so it is charred on the outside but still rare or raw on the inside. This has the effect of intensifying the meat s flavor by cooking, without destroying …   Wikipedia

  • Cut of Ice (Hawaiian Eye) — Infobox Television episode Title = Cut of Ice Series = Hawaiian Eye Caption = Season = 1 Episode = 20 Airdate = February 17, 1960 Production = Writer = Ed Jurist Steven Ritch, from original story by Steven Ritch Director =Charles Haas Guests =… …   Wikipedia

  • charcoal — Carbon obtained by heating or burning wood with restricted access of air. SYN: carbo. activated c. the residue from the destructive distillation of various organic materials, treated to increase its adsorptive power; used in diarrhea, as an… …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”