FURNACES; KILNS; OVENS; RETORTS

Description

F27 encompasses equipment designed for high-temperature processing of materials through controlled heating in enclosed chambers, including furnaces, kilns, ovens, and retorts used across metallurgical, ceramic, chemical, and thermal processing industries. The classification covers structural designs, heating mechanisms, temperature control systems, and operational configurations for batch and continuous heating operations. It addresses both the physical construction of heating vessels and the engineering of heat distribution, insulation, and material handling within such apparatus. Related thermal processing equipment using different technological approaches or serving specialized purposes may be classified in adjacent sections of mechanical engineering or chemical engineering.

Filing statistics

CPC F27 recorded 80,361 patent applications worldwide between 2013 and 2023, summed across its 3 subclasses. Annual filings grew from 5,252 in 2013 to 8,818 in 2023 (+68%), peaking at 9,211 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