CPC Definition - Subclass F27B

Last Updated Version: 2025.01
FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
References
Application-oriented references

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:

Bakers' ovens; Machines or equipment for baking

A21B

Furnaces specially adapted for glass manufacture

C03B 5/00

Retorts

C10B 1/00

Coke ovens with vertical chambers

C10B 3/00

Coke ovens with horizontal chambers

C10B 5/00

Coke ovens with mechanical conveying means for the raw material inside the oven

C10B 7/00

Beehive ovens

C10B 9/00

Coke ovens with inclined chambers

C10B 11/00

Coke ovens with means for bringing and keeping the charge under mechanical pressure

C10B 13/00

Other coke ovens

C10B 15/00

Furnaces, kilns, ovens or retorts specially adapted for cracking hydrocarbons

C10G

Furnaces, kilns, ovens or retorts for production of gases containing carbon monoxide and hydrogen from solid carbonaceous materials by partial oxidation processes involving oxygen or steam

C10J

Blast furnaces

C21B 7/00

Stoves for heating the blast in blast furnaces

C21B 9/00

Manufacture of steel in converters

C21C 5/28

General devices for heat treatment of ferrous or non-ferrous metals or alloys

C21D

Furnaces for electroslag or arc remelting of metals

C22B 9/00

Apparatus or furnaces for melting or fritting enamels

C23D 1/00

Ovens specially adapted for firing enamels

C23D 9/00

Informative references

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

Combustion apparatus

F23

Heat-exchangers

F28D

Electric heating

H05B

Shaft or like vertical or substantially vertical furnaces
References
Application-oriented references

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:

Preheating, burning, calcining or cooling lime, magnesia or dolomite in shaft or vertical furnaces

C04B 2/12

Making pig-iron in blast furnaces

C21B 5/00

Blast furnaces

C21B 7/00

Shaft furnaces for making pig-iron

C21B 11/02

Arrangements of linings
References
Informative references

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

Linings for furnaces, kilns, ovens or retorts in general

F27D 1/00

Arrangements of tuyeres
References
Application-oriented references

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:

Tuyères for blast furnaces

C21B 7/16

Arrangements of devices for charging
References
Application-oriented references

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:

Bell-and-hopper arrangements for blast furnaces

C21B 7/18

Informative references

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

Devices for charging furnaces

F27D 3/00

Arrangements of devices for discharging
References
Application-oriented references

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:

Devices for discharging from blast furnaces

C21B 7/14

Informative references

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

Devices for discharging from furnaces

F27D 3/00

Arrangements of heat-exchange apparatus
References
Informative references

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

Heat-exchangers in general

F28C; F28D

Cooling arrangements
References
Application-oriented references

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:

Cooling devices for blast furnaces

C21B 7/10

Informative references

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

Cooling of furnaces or of charges therein

F27D 9/00

Arrangements of controlling devices
References
Informative references

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

Controlling devices for furnaces in details

F27D 19/00

Arrangements of monitoring devices, of indicators, of alarm devices
References
Informative references

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

Monitoring devices for furnaces in details

F27D 21/00

Hearth-type furnaces, e.g. of reverberatory type (F27B 9/00, F27B 11/00, F27B 13/00, F27B 14/00, F27B 15/00, F27B 21/00 take precedence); Electric arc furnaces {; Tank furnaces}
References
Limiting references

This place does not cover:

Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity

F27B 9/00

Bell-type furnaces

F27B 11/00

Furnaces with both stationary charge and progression of heating

F27B 13/00

Crucible or pot furnaces

F27B 14/00

Fluidised-bed furnaces; Other furnaces using or treating finely-divided materials in dispersion

F27B 15/00

Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction

F27B 21/00

Application-oriented references

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:

Converters used in making steel

C21C 5/28

Manufacturing of steel in electric furnaces

C21C 5/52

Furnaces for general processes of refining metals

C22B 9/00

of multiple-hearth type; of multiple-chamber type; Combinations of hearth-type furnaces
References
Application-oriented references

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:

Manufacture of steel in electrically heated multi-chamber furnace, a combination of electric furnaces or an electric furnace arranged for associated working with a non-electric furnace

C21C 5/5252

Informative references

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

Linings in general

F27D 1/00

heated electrically, with or without any other source of heat
References
Informative references

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

Heated by electric discharge in details

F27D 11/08

Electric heating elements or systems for furnaces in details

F27D 99/0006

Arrangements of linings
References
Informative references

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

Linings in general

F27D 1/00

Walls; Roofs
References
Informative references

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

Linings and walls in details

F27D 1/00

Roofs and crowns in details

F27D 1/02

Arrangements of devices for charging
References
Application-oriented references

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:

Charging of electric furnaces used in the manufacture of steel

C21C 5/527

Informative references

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

Devices for charging furnaces

F27D 3/00

Arrangements of devices for discharging
References
Informative references

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

Devices for discharging in details

F27D 3/00

Arrangements of heating devices
References
Application-oriented references

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:

Burners in electric arc furnaces used in the manufacture of steel

C21C 5/5217

Informative references

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

Burners

F27B 3/205

Heating elements or systems for furnaces, kilns, ovens or retorts

F27D 99/0001

Electric heating

H05B

Arrangements of air or gas supply devices
References
Application-oriented references

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:

Lances or injectors for converters used in the manufacture of steel

C21C 5/4606

Injectors for electric arc furnaces used in the manufacture of steel

C21C 5/5217

Informative references

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

Oxygen blowing

F27B 3/225

Introducing a fluid jet or current into the charge in details

F27D 3/16

Cooling arrangements
References
Informative references

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

Cooling of furnaces or charges therein in details

F27D 9/00

Arrangements of heat-exchange apparatus
References
Informative references

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

Heat-exchange apparatus

F28D 17/00

Arrangement of controlling, monitoring, alarm or the like devices
References
Informative references

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

Monitoring devices for furnaces in details

F21D21/00

Controlling devices for furnaces in details

F27D 19/00

Muffle furnaces; Retort furnaces; Other furnaces in which the charge is held completely isolated (furnaces through which the charge is moved mechanically or in which the charge moves by gravity F27B 9/00)
References
Limiting references

This place does not cover:

Furnaces through which the charge is moved mechanically or in which the charge moves by gravity

F27B 9/00

Application-oriented references

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:

Muffle or retort furnaces for heat treatment of particular metallic articles, e.g. annealing, hardening, quenching or tempering

C21D 9/0043

adapted for treating the charge in vacuum or special atmosphere
References
Application-oriented references

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:

Furnaces for heat treatment of ferrous or non-ferrous metals or alloys

C21D 9/00

Informative references

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

Methods of heat treatment of ferrous or non-ferrous metals or alloys in inert gas, controlled atmosphere, vacuum or pulverulent material

C21D 1/74

Forming, maintaining or circulating atmosphere in heating chambers in details

F27D 7/00

Arrangements of linings
References
Informative references

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

Linings in general

F27D 1/00

Arrangement of devices for charging
References
Application-oriented references

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:

Charging particular metallic articles in heat-treatment furnaces

C21D 9/0018

Informative references

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

Devices for charging furnaces

F27D 3/00

Arrangement of devices for discharging
References
Application-oriented references

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:

Discharging particular metallic articles from heat-treatment furnaces

C21D 9/0018

Informative references

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

Devices for discharging from furnaces

F27D 3/00

Arrangements of heating devices
References
Informative references

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

Methods of heating during heat treatment of ferrous or non-ferrous metals or alloys

C21D 1/34

Arrangement of elements for electric heating in or on furnaces

F27D 11/00

Heating elements or systems for furnaces, kilns, ovens or retorts

F27D 99/0001

Arrangements of air or gas supply devices
References
Informative references

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

Methods of heat treatment of ferrous or non-ferrous metals or alloys in inert gas, controlled atmosphere, vacuum or pulverulent material

C21D 1/74

Supplying steam, vapour, gases or liquids in heating chambers

F27D 7/02

Arrangement of controlling, monitoring, alarm or like devices
References
Informative references

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

Process control or regulation for heat treatments of ferrous or non-ferrous metals or alloys

C21D 11/00

Arrangement of controlling devices for furnaces

F27D 19/00

Arrangement of monitoring devices for furnaces

F27D 21/00

Rotary-drum furnaces, i.e. horizontal or slightly inclined
References
Application-oriented references

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:

Rotary retorts

C10B 1/10

Destructive distillation of solid carbonaceous material with indirect heating in rotary ovens or retorts

C10B 47/30

Making pig-iron in rotary kilns

C21B 11/06

Making spongy iron or liquid steel, by direct processes in rotary furnaces

C21B 13/08

Rotary furnaces with horizontal or slightly inclined axis for heat treatment of ferrous or non-ferrous metals or alloys

C21D 9/0031

Informative references

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

Burning or melting of hydraulic cements

C04B 7/44

Incineration of waste in rotating drums

F23G 5/20

adapted for treating the charge in vacuum or special atmosphere
References
Informative references

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

Methods of heat treatment of ferrous or non-ferrous metals or alloys in inert gas, controlled atmosphere, vacuum or pulverulent material

C21D 1/74

Forming or maintaining special atmospheres or vacuum within heating chambers

F27D 7/06

Details, accessories or equipment specially adapted for rotary-drum furnaces
References
Informative references

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

Burning or melting of hydraulic cements

C04B 7/44, C04B 7/43

Seals between rotary and stationary parts
References
Informative references

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

Seals for furnaces in details

F27D 99/0073

Arrangements of linings
References
Informative references

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

Linings for furnaces in details

F27D 1/0003

Arrangements of partitions
References
Informative references

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

Partitions for furnaces in details

F27D 99/007

Arrangement of devices for charging
References
Informative references

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

Devices for charging for furnaces in details

F27D 3/00

Arrangement of devices for discharging
References
Informative references

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

Devices for charging of furnaces in details

F27D 3/00

Arrangements of cooling devices
Definition statement

This place covers:

Arrangements of cooling devices

References
Informative references

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

Cooling of furnaces or charges therein in details

F27D 9/00

Planetary coolers
Definition statement

This place covers:

Planetary coolers

References
Informative references

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

Cooling of furnaces or charges therein in details

F27D 9/00

Arrangement of controlling, monitoring, alarm or like devices
References
Informative references

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

Monitoring devices for furnaces in details

F21D21/00

Controlling devices for furnaces in details

F27D 19/00

Furnaces through which the charge is moved mechanically, e.g. of tunnel type (rotary-drum furnaces with means for agitating or moving the charge F27B 7/14); Similar furnaces in which the charge moves by gravity
References
Limiting references

This place does not cover:

Rotary-drum furnaces with means for agitating or moving the charge

F27B 7/14

Application-oriented references

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:

Furnaces for heat treatment of ferrous or non-ferrous metals or alloys

C21D 9/00

adapted for treating the charge in vacuum or special atmosphere
References
Application-oriented references

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:

Continuous furnaces for heat treating metal strip or wire with a controlled atmosphere or vacuum

C21D 9/561

Informative references

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

Method of heat treatment of ferrous or non-ferrous metals or alloys in inert gas, controlled atmosphere, vacuum or pulverulent material

C21D 1/74

Forming or maintaining special atmospheres or vacuum within heating chambers

F27D 7/06

heated without contact between combustion gases and charge; electrically heated
References
Informative references

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

Method of heating during heat treatment of ferrous or non-ferrous metals or alloys

C21D 1/34

Arrangement of elements for electric heating in or on furnaces

F27D 11/00

Heating elements or systems for furnaces, kilns, ovens or retorts

F27D 99/0001

characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment (for treating continuous lengths of work F27B 9/28)
References
Limiting references

This place does not cover:

Furnaces for treating continuous lengths of work

F27B 9/28

Application-oriented references

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:

Furnaces in which the charge is moving up or down

C21D 9/005

Furnaces for heat treatment through which the charge is moved in a horizontal straight path

C21D 9/0056

Informative references

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

Travelling or movable supports or containers for the charge

F27D 3/12

Furnace cars

F27D 3/123

the charge moving in a substantially straight path
Definition statement

This place covers:

Furnaces through which the charge is moved mechanically, e.g. tunnel furnaces.

being carried by a conveyor
References
Application-oriented references

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:

Rolls in heat-treating furnaces

C21D 9/0012

Rolls in continuous heat-treating furnaces

C21D 9/563

Informative references

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

Transport by conveyors in general

B65G

on or in trucks, sleds, or containers
References
Informative references

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

Travelling or movable supports or containers for the charge; Furnace cars

F27D 3/12; F27D 3/123

Arrangements of linings
References
Informative references

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

Linings for furnaces in details

F27D 1/0003

Arrangements of heating devices
References
Application-oriented references

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:

Continuous furnaces for heat treating metal strip or wire

C21D 9/56

Informative references

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

Heating elements or system for furnaces, kilns, ovens or retorts

F27D 99/0001

Arrangements of devices for charging
References
Application-oriented references

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:

Charging particular metallic articles in heat-treatment furnaces

C21D 9/0018

Informative references

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

Devices for charging of furnaces

F27D 3/00

Arrangements of devices for discharging
References
Application-oriented references

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:

Discharging particular metallic articles from heat-treatment furnaces

C21D 9/0018

Informative references

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

Devices for discharging of furnaces

F27D 3/00

Arrangements of controlling or monitoring devices
Definition statement

This place covers:

Arrangement of controlling or monitoring devices

References
Informative references

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

Process control or regulation for heat treatments of ferrous or non-ferrous metals or alloys

C21D 11/00

Arrangement of controlling devices for furnaces

F27D 19/00

Arrangement of monitoring devices for furnaces

F27D 21/00

Bell-type furnaces
References
Application-oriented references

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:

Bell-type furnaces for treating metal strips or wire

C21D 9/663

Arrangements of linings
References
Informative references

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

Linings for furnaces in details

F27D 1/0003

Arrangements of heating devices
References
Informative references

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

Heating elements or systems in details; especially burners

F27D 99/0001; F27D 99/0033

Arrangement of controlling, monitoring, alarm or like devices
References
Informative references

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

Monitoring devices for furnaces in details

F21D21/00

Controlling devices for furnaces in details

F27D 19/00

Crucible or pot furnaces
References
Informative references

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

Single crystal growth

C30B

adapted for treating the charge in vacuum or special atmosphere
References
Informative references

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

Forming, maintaining or circulating atmosphere in heating chambers in details

F27D 7/00; F27D 7/02; F27D 7/06

heated electrically, e.g. induction crucible furnaces with or without any other source of heat (F27B 14/04 takes precedence)
References
Informative references

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

Electric heating elements or systems

F27D 99/0033

Electric heating elements in general

H05B

Crucibles
References
Informative references

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

Crucibles for single crystal growth

C30B 13/14

Covers therefor
References
Informative references

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

Covers for furnaces in details

F27D 1/18; F27D 1/1808

Arrangements of heating devices
References
Informative references

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

Heating elements or systems for furnaces in details

F27D 99/0001; F27D 99/0033; F27D 99/0035

Arrangement of controlling, monitoring, alarm or like devices
References
Informative references

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

Monitoring devices for furnaces in details

F21D21/00

Controlling devices for furnaces in details

F27D 19/00

Fluidised-bed furnaces; Other furnaces using or treating finely-divided materials in dispersion
References
Application-oriented references

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:

Making spongy iron or liquid steel, by direct processes in fluidised bed furnaces or apparatus containing a dispersion of the material

C21B 13/0033

Heating metallic strips in fluidised beds

C21D 9/567

Informative references

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

General apparatuses for carrying out chemical or physical processes in a fluidised-bed reactor

B01J 8/24

Combustion apparatus in which combustion takes place in a fluidised bed of fuel or other particles

F23C 10/00

Heat-exchange apparatus using fluidised bed

F28D 13/00

Arrangements of linings
References
Informative references

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

Linings for furnaces in details

F27D 1/0003

Arrangements of devices for charging
References
Informative references

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

Devices for charging of furnaces in details

F27D 3/00

Arrangements of devices for discharging
References
Informative references

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

Devices for discharging of furnaces in details

F27D 3/00

Arrangements of controlling devices
References
Informative references

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

Controlling devices for furnaces in details

F27D 19/00

Arrangements of monitoring devices, of indicators, of alarm devices
References
Informative references

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

Monitoring devices for furnaces in details

F27D 21/00

Furnaces of a kind not covered by any of groups F27B 1/00 - F27B 15/00 (structural combinations of furnaces F27B 19/02)
Definition statement

This place covers:

Types of furnaces not covered by any preceding group:

  • open field furnaces for burning bricks;
  • chamber type furnaces, e.g. specially adapted for treating semiconductor wafers or specially adapted for burning bricks or pottery;
  • chamber type furnaces, where the floor consists of a support carrying the charge, e.g. car type furnaces;
  • furnaces specially designed for laboratory use.
References
Limiting references

This place does not cover:

Structural combinations of furnaces

F27B 19/02

Application-oriented references

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:

Furnace coilers; Hot coilers

C21D 9/68

Furnace for ingots

C21D 9/70

Informative references

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

Furnaces through which the charge is moved mechanically

F27B 9/02

Apparatuses for treating semiconductors or wafers

H01L 21/67

specially designed for laboratory use
Definition statement

This place covers:

Furnaces especially designed for laboratory use.

Furnaces for dental work-pieces

References
Informative references

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

Devices for soldering, casting, moulding or melting dental prostheses

A61C 13/20