CPC Definition - Subclass F23L
This place covers:
Supply of air or non-combustible gases or liquids to combustion apparatus in general, for example:
- Blast-producing apparatus before the fire, for example fans or induction apparatus;
- Passages or nozzles for delivering air to combustion chambers;
- Methods or devices for supplying steam or oxygen to the fire;
- Methods or devices for heating of combustion air before supply to the combustion chamber, for example by heat exchange with flue gases;
- Special adaptations of valves or dampers for controlling combustion air supply or flue gas draught in combustion apparatus in general;
- Methods or devices for inducing draught in combustion apparatus, for example exhaust fans or exhaust induction apparatus;
- Tops for chimneys or ventilation shafts;
- Terminals for flues.
Combustion apparatus
This subclass is the general place for methods and apparatus for supply of air to combustion apparatus.
The incorporation of air supply means as an integrated part of an entire combustion apparatus, for example the disposition of primary and secondary air ports in relation to other components, is classified in the place for the combustion apparatus as a whole, in F23B, F23C or F23G.
Air supply means that are arranged in immediate connection with the fuel-feeding conduit of a burner (for example concentric with it) are considered to be part of the burner, and are thus classified in F23D. Other means for feeding air that are specially adapted for combustion of liquid fuel, gaseous fuel or pulverised fuel suspended in air are classified in F23C 7/00 or F23C 10/20.
Blast-producing, draught-inducing
This subclass is an application-oriented place for the arrangement of fans, inductors or other pumps in combustion apparatus for the purpose of inducing blast or draught. The integration of such devices in systems for control of combustion, for example together with sensors and actuators, is covered by F23N.
Fans and other pumps per se are classified in class F04, for examples see the section "Informative references" below.
Valves and dampers
This subclass is an application-oriented place for valves and dampers that are specially adapted for controlling air supply or draught of combustion apparatus. The integration of such devices in systems for control of combustion, for example together with sensors and actuators, is covered by F23N.
Valves or dampers that are specially adapted for controlling air supply or draught of domestic stoves are classified in F24B or F24C, for examples see the section "References relevant to classification in this subclass" below.
Valves and dampers in general are classified in F16K.
Heating of combustion air
This subclass is an application-oriented place for the heat exchange apparatus that is specially adapted for use in combustion apparatus for the purpose of heating combustion air. Heat exchangers in general are classified in class F28, for examples see the section "Informative references" below.
This place does not cover:
Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:
Steam generators | |
Air supply specially adapted for combustion apparatus for liquid, gaseous or pulverised fuel | |
Supply of fluidisation air for fluidised bed combustion apparatus | |
Burners | |
Burners where spraying of liquid fuel is induced by a gaseous medium | |
Gas burners specially adapted for use with means for pressurising the combustion air | |
Systems for regulating or controlling combustion | |
Regulating or controlling air supply or draft | |
Air inlet arrangements for combustion chambers for generating combustion products of high pressure or high velocity, e.g. for gas turbine combustion chambers | |
Draught control dampers for solid fuel stoves with open fires | |
Air supply in solid fuel stoves with open fires | |
Hoods for solid fuel stoves with open fires | |
Combustion-air or flue gas circulation in or around solid fuel stoves | |
Stoves for combustion of gaseous or liquid fuels, or for two or more different fuels | |
Fluid heaters, e.g. water or air heaters for central heating |
Attention is drawn to the following places, which may be of interest for search:
Positive displacement air pumps in general | |
Fans in general | |
Jet pumps in general | |
Valves in general | |
Methods or apparatus for combustion using solid fuel | |
Returning flue gases to the combustion chamber of combustion apparatus for solid fuel | |
Methods or apparatus for combustion using fluid fuel | |
Returning flue gases to the combustion chamber of combustion apparatus for liquid or gaseous fuel or pulverised solid fuel suspended in air | |
Grates for combustion apparatus | |
Supplying chemicals to fires | |
Cooling of casings, lining or walls of combustion chambers | |
Doors specially adapted for combustion chambers | |
Baffles or deflectors in air inlets of combustion chambers | |
Domestic stoves or ranges for solid fuels | |
Air humidification | |
Air flow control members for ventilation or air conditioning | |
Heat exchangers in general |
In this subclass, the first place priority rule is applied, i.e. at each hierarchical level, classification is made in the first appropriate place.
When classifying in this subclass, add also codes F23L 2900/00001-F23L 2900/15044 .
Codes F23L 2700/001-F23L 2700/002 are not used.
In this place, 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 term "secondary air" covers "tertiary air" etc. |
Ash | means any solid combustion residues, for example remaining in the fuel bed or suspended in the flue gases |
Burner | a device by which fluid fuel or solid fuel suspended in air is passed to a combustion space where it burns to produce a self-supporting flame |
Combustion | a heat-producing sequence of chemical reactions between a burnable substance and molecular oxygen, e.g. in air, in most cases generating light in the form of flames or a glow |
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 the apparatus where the reaction takes place between air and fuel |
Firebridge | a low wall separating the fuel bed from adjacent flue gas passages in apparatus for combustion of solid fuel, for example in reverberatory furnaces or fire-tube boilers |
Flue gases | any gaseous products of combustion |
Grate | a perforated surface, e.g. a grid, which supports or delimits a bed of burning fuel and serves to supply primary air |
This place covers:
Passages or apertures for delivering primary air for combustion.
This place does not cover:
Baffles or deflectors in air inlets |
This place covers:
Arrangements of valves or dampers before the fire.
This place covers:
Supplying non-combustible liquids or gases, other than air, to the fire, e.g. oxygen, steam.
This place covers:
Passages or apertures for delivering secondary air for completing combustion of fuel.
This place does not cover:
Baffles or deflectors in air inlets |
This place covers:
Arrangements of valves or dampers after the fire.
This place covers:
Construction of valves or dampers for controlling air supply or draught.
Attention is drawn to the following places, which may be of interest for search:
Valves in general |
This place does not cover:
Valves formed as linked slats each pivoted about an axis |
This place covers:
Heating of air supplied for combustion.
This place covers:
Inducing draught.
This place covers:
Subject matter not provided for in other groups of this subclass.