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BURNERS (generating combustion products of high pressure or high velocity F23R)
Definition statement
This subclass covers:

Burners, i.e. devices 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, for example burners in which:

  • pulverulent solid fuel is entrained into the combustion space by air
  • liquid fuel is transported by capillary action to the combustion space where it evaporates, e.g. wick burners
  • liquid fuel evaporates from an open fuel surface, e.g. pot burners
  • liquid fuel is sprayed into the combustion space by fluid pressure
  • liquid fuel is entrained into the combustion space by a stream of gaseous medium, for example air or steam
  • liquid fuel is vaporised within a conduit and released in gaseous form into the combustion space
  • liquid fuel is dispersed into the combustion space by mechanical means, e.g. ultrasonic vibrations or centrifugal action
  • gaseous fuel mixed with air is released into the combustion space
  • gaseous fuel is released into the combustion space where it is mixed with air
  • pulverulent, liquid or gaseous fuels are used simultaneously or alternately
Relationship between large subject matter areas

This subclass is the main function-oriented place for burners. Classification is always made in this subclass if the subject matter is of general interest for burners.

Burners are used in many fields where heat is generated or used. Burners per se are only classified in these application fields if they are specially adapted for a specific application, for example coating by flame spraying. Examples of application fields can be found in the section "References relevant to classification in this subclass" below. In case of doubt, classification should be made both in this subclass and the application field.

Classification is made in F23C if the subject matter to be classified, in addition to a burner, includes further features of a combustion apparatus, such as a particular form of combustion chamber or a particular arrangement of burners in a combustion chamber.

Feeding air

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. Means for feeding air otherwise than in immediate connection with the fuel-feeding conduit of a burner, for example arrangements for feeding secondary air at points distant from a burner, are classified in F23C 7/00 or F23L.

Control of combustion, methods of combustion

With the exception of devices or methods that are specially adapted to particular types of burners, for example the matter of the following groups:

  • Wick-adjusting devices, F23D 3/28
  • Maintaining a predetermined amount of fuel in evaporators, F23D 5/14
  • Provision for varying the rate at which liquid fuel is sprayed, F23D 11/26
  • Devices on vaporisers for controlling the feeding of fuel, F23D 11/46
  • Devices for simultaneous control of gas and combustion air, F23D 14/60

this subclass does not cover control of combustion, which is covered by F23N, or methods of combustion, which are covered by F23C.

Catalytic combustion

With the exception of radiant gas burners using catalysis for flameless combustion, which is covered by F23D 14/18, this subclass does not cover the combustion of fluid fuels in the presence of catalytic material, which is covered by F23C 10/01, F23C 13/00 and F23G 7/07.

References relevant to classification in this subclass
This subclass does not cover:

Candles

Combustion in a fluidised bed of fuel or other particles

Apparatus in which combustion takes place in pulses influenced by acoustic resonance in a gas mass

Igniting of burners

Generating combustion products of high pressure or high velocity

Examples of places where the subject matter of this subclass is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Flame throwers for destroying noxious animals or plants

Bakers' ovens

Cooking devices, e.g. travelling cookers or barbecues

Soldering

Gas flame welding or cutting

Cutting, scarfing, or desurfacing by applying flames

Using burners in chemical vapour deposition

Heating boreholes or wells with burners

Using burners for regenerating exhaust gas filters

Gas-turbine plants

Jet-propulsion plants

Using burners for ignition of internal combustion engines

Incandescent mantles

Non-electric portable lighting devices

Non-electric non-portable lighting devices

Arrangements of mantles or other incandescent bodies on lighting burners

Details of lighting devices employing combustion as light source

Steam boilers

Arrangement of burners in combustion apparatus

Methods or apparatus specially adapted for combustion of waste or low-grade fuels. e.g. waste oil, waste liquors or waste gases

Lighters containing fuel

Ignition using burners

Generating combustion products of high pressure or high velocity, e.g. gas turbine burners

Stoves or ranges for liquid or gaseous fuels

Fluid heaters having heat-generating means, e.g. heating boilers

Arrangement of burners in fluid heaters

Arrangement of burners in furnaces or ovens for heat treatment

Using burners for cleaning heat exchangers

Flame-throwers for attack or defence

Informative references
Attention is drawn to the following places, which may be of interest for search:

Spraying or atomising apparatus in general; Nozzles in general

Fuels

Mixing a gas with another gas or vapour and flow mixers in general

Pressure vessels for gases

Methods or apparatus for combustion using fluid fuel in general

Air supply specially adapted for combustion of fluid fuels

Arrangement of devices for supplying chemicals to fire

Feeding liquid or gaseous fuel to combustion apparatus

Supply of air or non-combustible liquids or gases to combustion apparatus in general

Details of combustion chambers, e.g. linings, doors or baffles

Regulating or controlling combustion in general

Special rules of classification within this subclass

In this subclass methods are classified in the groups which cover the apparatus used.

Multiple classification is mandatory when:

the subject matter to be classified deals with air supply means which are part of a burner, but no relevant subgroup is available in F23D, e.g. arrangements of swirling vanes in a premix gas burner have to be classified in F23C 7/004 and F23D 14/02;

the subject matter to be classified, in addition to a burner, includes further features of the air supply means that are of interest, for example a particular form of a swirling vane, even if a relevant subgroup is available in F23D, e.g. an arrangement of adjustable swirling vanes in a non-premix gas burner having separate air and gas feed conduits have to be classified in F23C 7/006 and F23D 14/24.

When classifying in this subclass, add codes F23D 2200/00-F23D 2214/00;

F23D 2900/00-R23D900/67

F23D 2700/001-F23D 2700/033 are not used for classification purpose.

Glossary of terms
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 fluid fuel or solid fuel suspended in air 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

Pilot flame

a small flame that is lit or kept alight in order to provide ignition to a more powerful burner

Retention flame

a small flame that is kept alight in order to maintain the uninterrupted operation of a more powerful burner

Torch

a burner fired with fuel gas and oxygen and specially adapted to apply heat to a workpiece, for example for use in welding, cutting or brazing

Burners for combustion of pulverulent fuel (disposition of burners F23C)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Disposition of burners

Special rules of classification within this group

When classifying in this group add codes F23D 2201/00-F23D 2201/30 if appropriate.

{burning a mixture of pulverulent fuel delivered as a slurry, i.e. comprising a carrying liquid (preparing slurries F23K 1/02)}
Definition statement
This subgroup covers:

Burners specially adapted for combusting a fine mixture of solid fuel paricles and a liquid, e.g. a slurry of pulverized coal in water.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Mixing solid fuel with a liquid, e.g. preparing slurries

Burner using capillary action
Informative references
Attention is drawn to the following places, which may be of interest for search:

Blue-flame wick burners with flame spreaders

Candles per se

Burners in which liquid fuel evaporates in the combustion space, with or without chemical conversion of evaporated fuel
References relevant to classification in this group
This group does not cover:

Combinations of spraying or vaporising means covered by groups F23D 5/00 and F23D 21/00

Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space (spraying in general B05B, B05D)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Spraying or nozzles in general

Fuel nozzle per se

Refractory bricks or blocks specially shaped for burner openings

Flame tubes located in the fire-box which do not form part of the burner

Vaporizing devices which do not form part of the burner

Igniting devices per se

Starting devices (igniting F23Q)
Definition statement
This subgroup covers:

Liquid fuel burners characterised by the means for starting the combustion, e.g. fixing, locating or assembling the ignition device to the burner

References relevant to classification in this group
This subgroup does not cover:

Starting or igniting devices associated to gas fuel burners

Igniting

Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone (F23D 14/30 to F23D 14/44 take precedence)
References relevant to classification in this group
This subgroup does not cover:

Inverted burner, e.g. for illumination

Burners using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air

Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air

Torches, e.g. for cutting, brazing, welding or heating

with provision for a retention flame (pilot flame igniters F23Q 9/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Pilot flame igniters

using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air (F23D 14/38 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Torches, e.g. for cutting, brazing, welding or heating

Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air (F23D 14/38 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Torches, e.g. for cutting, brazing, welding or heating

Torches, e.g. for cutting, brazing, welding or heating {(nozzles for torches F23D 14/52)}
Informative references
Attention is drawn to the following places, which may be of interest for search:

Nozzles for torches

for welding (F23D 14/44 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Torches specially adapted for use under water

for cutting (F23D 14/44 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Torches specially adapted for use under water

{for torches (F23D 14/52 takes precedence)}
References relevant to classification in this group
This subgroup does not cover:

Nozzles for torches

for spreading the flame over an area, e.g. for desurfacing of solid material, for surface hardening, for heating workpieces, (scarfing by applying flames B23K 7/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Cutting, scarfing or desurfacing by applying flames

Devices for simultaneous control of gas and combustion air (regulation of combustion in general F23N)
Definition statement
This subgroup covers:

Devices operating on both combustion air and fuel gas for controlling air to fuel ratio

Informative references
Attention is drawn to the following places, which may be of interest for search:

Regulation and control of combustion in general

Mixing devices; Mixing tubes
Informative references
Attention is drawn to the following places, which may be of interest for search:

Flow mixers in general

Treating the combustion air or gas, e.g. by filtering, by moistening (in general B01)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Filtering

Moistening combustion air in general

Baffles or like flow-disturbing devices
References relevant to classification in this group
This subgroup does not cover:

Preventing flame lift-off

Preventing flashback or blowback

Safety devices, e.g. operative in case of failure of gas supply (protection or supervision of pipe-line systems F17D 5/00)
Informative references
Attention is drawn to the following places, which may be of interest for search:

Protection or supervision of pipe-line systems

Preventing flame lift-off (F23D 14/70 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Baffles or similar flow-disturbing devices

Preventing flashback or blowback (F23D 14/70 takes precedence; {by use of a retention flame F23D 14/26}; in gas feed lines A62C 4/02)
References relevant to classification in this group
This subgroup does not cover:

Baffles or similar flow-disturbing devices

Preventing flashback or blowback by use of a retention flame

Informative references
Attention is drawn to the following places, which may be of interest for search:

Preventing flashback or blowback in gas feed lines

Flame spreading or otherwise shaping (F23D 14/70 takes precedence)
References relevant to classification in this group
This subgroup does not cover:

Baffles or similar flow-disturbing devices

Burners not otherwise provided for
References relevant to classification in this group
This group does not cover:

Combinations of spraying or vaporising means covered by subgroups F23D 5/00 and F23D 21/00

Informative references
Attention is drawn to the following places, which may be of interest for search:

Using burners for spectroscopy

Assemblies of two or more burners (gas burners with provision for a retention flame F23D 14/26; disposition of burners F23C; for industrial furnaces F27)
References relevant to classification in this group
This group does not cover:

Gas burner with provisions for a retention flame

Informative references
Attention is drawn to the following places, which may be of interest for search:

Disposition of burners

Assembly of burners in industrial furnaces

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Last Modified: 10/11/2013