IPC Definitions - January 01, 2012
F23G - Definition
This subclass covers:
Methods or apparatus specially adapted for combustion of the following substances:
Relationship between large subject matter areas
Relationship with general function-oriented places in class F23
This subclass is to be seen as an application place in relation to the function-oriented aspects covered by F23B (Combustion apparatus using only solid fuel) and F23C (Combustion apparatus using fluent fuel).
Classification is made in F23B or F23C if the method or apparatus is
If methods or apparatus covered by this subclass are also of general interest for combustion of "normal" commercial fuels classification should also be made in other subclasses of F23. The decision on whether an apparatus is specially adapted or not is sometimes not easy to decide. In doubtful situations classification should therefore always be made in both this subclass and other subclasses of F23.
Relationship between this subclass and detail subclasses of class F23
Subclasses F23D and F23H-F23Q are to be seen as general detail places in relation to this subclass. Classification of details of apparatus in this subclass should be restricted to inventions that are clearly specially adapted for methods or apparatus that are covered by the subclass. If a detail of an apparatus is specifically covered in a group of F23D or F23H-F23Q, classification should be made in that group and not in this subclass.
Relationship between this subclass and other application places
Combustion is often used for purpose of heating or performing different operations. This subclass is therefore related to many places providing for uses of heat. In many of these fields the combustion apparatus can be considered a detail of a bigger entity. A non-exhaustive list of examples of such classes or subclasses will be found under the heading "Informative references".
Relationship between this subclass and places for gasification or destructive distillation
Classification is made in these places if the combustible substances produced, e.g. gas or coke, are burned in an apparatus separate from the gasification or distillation apparatus.
Classification is made in this subclass if complete combustion takes place in the same apparatus as the gasification, for example in different parts of the same combustion chamber or in an afterburner immediately connected to a primary combustion chamber.
Relationship between this subclass and class B09
These subclasses only cover matter that is not completely covered by this subclass. Examples of such matter are processes that include a combustion step in combination with other steps that together form a process for disposal of waste or reclamation of contaminated soil.
References relevant to classification in this subclass
This subclass does not cover:
Incinerating radioactive waste | G21F 9/00 |
Disposal of solid waste | B09B |
Reclamation of contaminated soil | B09C |
Gas turbine plants | F02C |
Generating steam | F22B |
Generating combustion products of high temperature or high pressure | F23R |
Domestic stoves or ranges for local heating or cooking | F24B, F24C |
Apparatus for heat treatment of materials or articles | F27B |
Attention is drawn to the following places, which may be of interest for search:
Grates, cleaning or raking of grates | F23H |
Removal or treatment of combustion products (e.g. flue gases) or combustion residues (e.g. ash) | F23J |
Feeding fuel | F23K |
Supplying air or other non-combustible liquids or gases (e.g. water or steam) | F23L |
Constructional details of combustion chambers, not otherwise provided for | F23M |
Regulating or controlling combustion | F23N |
Ignition | F23Q |
Chemical means for combating harmful chemical agents or for making them harmless | A62D 3/00 |
Chemical or biological purification of waste gases | B01D 53/34 |
Chemical or physical processes or apparatus in general | B01J |
Gathering of domestic or like refuse | B65F |
Treatment of water, waste water, sewage or sludge | C02F |
Destructive distillation of carbonaceous material for production of gas, coke, tar or similar matter | C10B |
Production of combustible gases containing carbon monoxide from solid carbonaceous fuels | C10J |
C10L | |
Regeneration of pulp liquors by combustion | D21C 11/12 |
Combustion of "normal" commercial fuels | F23B, F23C |
In this subclass, the following terms or expressions are used with the meaning indicated:
air | a mixture of gases containing free oxygen and able to promote or support combustion |
primary air | air supplied to the burning fuel in order to liberate combustible gases |
secondary air | air supplied to the combustible gases liberated by the primary air in order to complete their combustion. The expression "secondary air" covers "tertiary air" etc. |
burner | a device by which fluent or pulverised fuel is passed to a combustion space where it burns to produce a self-supporting flame. A burner includes means for feeding air that are arranged in immediate connection with a fuel feeding conduit, for example concentric with it. |
combustion | the direct combination of oxygen gas, e.g. in air, and a burnable substance |
combustion chamber | a chamber in which fuel is burned to establish a self-supporting fire or flame and which surrounds that fire or flame |
combustion zone | the part of a combustion apparatus where the reaction takes place between air and fuel |
fuel | any combustible material that can be burned, regardless of whether the main purpose of burning it is for releasing energy therefrom or for disposing of it or rendering it less harmful |
waste | an undesired material that can be consumed by combustion for the primary purpose of disposing of it or rendering it less harmful, and not solely for releasing energy therefrom |
In patent documents the expression "boiler" is often used instead of "combustion apparatus", even when heating of water or other liquids is of no interest.
In patent documents the expression "burner" is often used instead of "combustion apparatus" and not in the restricted meaning defined in the glossary above.
In patent documents the following abbreviations are often used:
CFB | Circulating fluidised bed |
EHC | Electrically heated catalyst |
FBN | Fuel-bound nitrogen |
HC | Hydrocarbons |
NOx | Nitrous oxides |
PFBC | Pressurised fluidised bed combustion |
SOx | Sulfur oxides |
UHC | Unburned hydrocarbons |