DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE

Description

F27D covers structural components, functional elements, and auxiliary devices that are applicable across multiple types of furnaces, kilns, ovens, and retorts. This includes features such as refractory linings, insulation systems, hearths, grates, burners, air supply mechanisms, temperature control devices, and structural supports that are not specific to a single furnace type. Details specific to particular furnace categories (e.g., blast furnace components used only in blast furnaces) are classified in the relevant specialized subclasses instead. This subclass serves as a repository for multi-purpose furnace accessories and shared technical solutions that enhance efficiency, durability, or operational capability across diverse high-temperature processing equipment.

Filing statistics

CPC subclass F27D recorded 44,314 patent applications worldwide between 2013 and 2023. Annual filings grew from 2,923 in 2013 to 4,954 in 2023 (+69%), peaking at 4,996 applications in 2020. The most active applicants in class F27 are POSCO (POHANG IRON AND STEEL COMPANY) (930 applications), JFE STEEL (771 applications) and PAUL WURTH (518 applications).

Source: EPO PATSTAT, worldwide filings

15 direct subcodes

Child Classifications

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F27D 1/00 Casings; Linings; Walls; Roofs
F27D 11/00 Arrangement of elements for electric heating in or on furnaces
F27D 13/00 Apparatus for preheating charges; Arrangements for preheating charges
F27D 15/00 Handling or treating discharged material; Supports or receiving chambers therefor
F27D 17/00 Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
F27D 19/00 Arrangements of controlling devices
F27D 21/00 Arrangement of monitoring devices; Arrangement of safety devices
F27D 2201/00 Manipulation of furnace parts
F27D 25/00 Devices for removing incrustations
F27D 27/00 Stirring devices for molten material (charging or discharging liquid or molten material F27D3/14)
F27D 3/00 Charging; Discharging; Manipulation of charge
F27D 5/00 Supports, screens or the like for the charge within the furnace
F27D 7/00 Forming, maintaining or circulating atmospheres in heating chambers
F27D 9/00 Cooling of furnaces or of charges therein (casings, linings, walls or roofs incorporating cooling arrangements F27D1/12)
F27D 99/00 Subject matter not provided for in other groups of this subclass

Top Applicants

Top 10 applicants by patent filingsfor class F27, 2013–2023, worldwide · Source: EPO PATSTAT

POSCO (POHANG IRON AND STEEL COMPANY) KR 930
JFE STEEL JP 771
PAUL WURTH LU 518
OUTOTEC (FINLAND) FI 436
THYSSEN KRUPP DE 422
REFRACTORY INTELLECTUAL PROPERTY & COMPANY AT 370
THYSSENKRUPP INDUSTRIAL SOLUTIONS DE 341
JFE STEEL 323
PRIMETALS TECHNOLOGIES AUSTRIA AT 310
ZHONGYE CHANGTIAN INTERNATIONAL ENGINEERING COMPANY 299