F23L SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ( firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS ; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
Introduced: September 1968
Description
F23L encompasses equipment and systems for managing air supply and draught in combustion apparatus, including specialized valves, dampers, and draught-inducing devices. It covers delivery mechanisms for air and non-combustible fluids to furnaces, boilers, and similar combustion systems, as well as physical components like chimney tops and flue terminals that regulate gas flow and prevent downdrafts. This classification excludes fuel supply systems (covered elsewhere in F23) and focuses specifically on the oxidant/air side of combustion control and ventilation management.
Title
Titles differ between systems:
IPC: SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
CPC: SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ( firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS ; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
Full Title
Full titles differ between systems:
SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ( firebridges with means for feeding air or steam F23M3/04; baffles or shields with air supply passages F23M9/04); VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS ; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
Additional Content IPC
Glossary
Air a mixture of gases containing free oxygen and able to promote or support combustion Primary air air supplied to the burning fuel (e.g. together with the 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 Burners a device by which fluid fuel or pulverised solid fuel suspended in air is passed to a combustion space where it burns to produce a self-supporting flame. A burner includes the means for feeding air that are arranged in immediate connection with a fuel feeding conduit, for example concentric with it. 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 combustion chambers a chamber in which fuel is burned to establish a self-supporting fire or flame and which surrounds that fire or flame Firebridge Firebridges 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 flue gas any gaseous products of combustion Grate Grates a perforated surface (e.g. a grid) which supports or delimits a bed of burning solid fuel and serves to supply primary air
Limiting references
Returning flue gases to the combustion chamber of combustion apparatus for solid 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 Firebridges for delivery of air or steam to combustion apparatus Cooling of casings, lining or walls of combustion chambers Doors specially adapted for combustion chambers Baffles or deflectors in air inlets of combustion chambers Baffles or deflectors for air or combustion products with air-supply passages
Application references
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 combustionair Regulating or controlling air supply or draught Systems for regulating or controlling combustion 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
Of 12 combined children, 10 exist in both systems.
2 codes are CPC-only extensions.
Note: 2 CPC extensions are marked as secondary classification only.
2 shared codes have differing titles between IPC and CPC.
Child Classifications
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- F23L 1/00 Passages or apertures for delivering primary air for combustion (baffles or deflectors in air inlets F23M9/02) IPC+CPC Available in IPC and CPC
- F23L 13/00 Construction of valves or dampers for controlling air supply or draught IPC+CPC Available in IPC and CPC
- F23L 17/00 Inducing draught; Tops for chimneys or ventilating shafts; Terminals for flues +1 CPC IPC+CPC Available in IPC and CPC
- F23L 2700/00 Installations for increasing draught in chimneys; Specific draught control devices for locomotives 2nd only +2 CPC CPC only CPC only
- F23L 2900/00 Special arrangements for supplying or treating air or oxidant for combustion; Injecting inert gas, water or steam into the combustion chamber 2nd only +17 CPC CPC only CPC only
- F23L 7/00 Supplying non-combustible liquids or gases, other than air, to the fire, e.g. oxygen, steam +2 CPC IPC+CPC Available in IPC and CPC
- F23L 9/00 Passages or apertures for delivering secondary air for completing combustion of fuel (baffles or deflectors in air inlets F23M9/02) IPC+CPC Available in IPC and CPC
- F23L 99/00 Subject matter not provided for in other groups of this subclass since 2006 IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class F23,2013–2023, worldwide · Source: EPO PATSTAT
- GE (GENERAL ELECTRIC COMPANY) US 2,124
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 1,369
- NINGBO FOTILE KITCHENWARE COMPANY 1,363
- SIEMENS DE 997
- UNITED TECHNOLOGIES CORPORATION (UTC) US 937
- GE (GENERAL ELECTRIC COMPANY) 898
- VATTI 815
- CHINESE ACADEMY OF SCIENCES 719
- RINNAI COMPANY 708
- MITSUBISHI HITACHI POWER SYSTEMS 670
Top Applicants (CPC)
Class F23,2013–2023, worldwide · Source: EPO PATSTAT
- GE (GENERAL ELECTRIC COMPANY) US 2,581
- UNITED TECHNOLOGIES CORPORATION (UTC) US 1,180
- SIEMENS DE 1,157
- GE (GENERAL ELECTRIC COMPANY) 994
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 769
- MITSUBISHI HEAVY INDUSTRIES JP 701
- MITSUBISHI HITACHI POWER SYSTEMS JP 695
- RAYTHEON TECHNOLOGIES CORPORATION US 587
- NINGBO FOTILE KITCHENWARE COMPANY 543
- GENERAL ELECTRIC TECHNOLOGY CH 490