F28D HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
Introduced: September 1968
Description
This subclass covers heat exchangers where hot and cold fluids are separated by a solid barrier (indirect contact), including plate, shell-and-tube, and compact designs not classified elsewhere in F28. It also encompasses heat storage plants and apparatus of all types, such as thermal energy storage systems using sensible heat, latent heat, or thermochemical storage. The classification applies to stationary and portable heat-exchange equipment and storage devices across industrial, residential, and specialized applications. Adjacent classes F28B and F28C address direct-contact heat exchange and regenerative heat-exchange apparatus respectively.
Title
Titles differ between systems:
IPC: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT; HEAT STORAGE PLANTS OR APPARATUS IN GENERAL
CPC: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
Full Title
Full titles differ between systems:
HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT; HEAT STORAGE PLANTS OR APPARATUS IN GENERAL
HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
IPC and CPC are identically structured here. All 12 subcodes exist in both systems.
4 shared codes have differing titles between IPC and CPC.
Child Classifications
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- F28D 1/00 Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators (F28D5/00 takes precedence) IPC+CPC Available in IPC and CPC
- F28D 15/00 Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls IPC+CPC Available in IPC and CPC
- F28D 17/00 Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles +1 CPC IPC+CPC Available in IPC and CPC
- F28D 19/00 Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium IPC+CPC Available in IPC and CPC
- F28D 20/00 Heat storage plants or apparatus in general; Regenerative heat-exchange apparatus not covered by groups F28D17/00 or F28D19/00 since 1985 +7 CPC IPC+CPC Available in IPC and CPC
- F28D 21/00 Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00 +4 CPC IPC+CPC Available in IPC and CPC
- F28D 3/00 Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium flows in a continuous film, or trickles freely, over the conduits (F28D5/00 takes precedence) IPC+CPC Available in IPC and CPC
- F28D 5/00 Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation IPC+CPC Available in IPC and CPC
- F28D 7/00 Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall +5 CPC IPC+CPC Available in IPC and CPC
- F28D 9/00 Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall +8 CPC IPC+CPC Available in IPC and CPC
Top Applicants
Top Applicants (IPC)
Class F28,2013–2023, worldwide · Source: EPO PATSTAT
- VALEO SYSTEMES THERMIQUES FR 1,902
- MITSUBISHI ELECTRIC CORPORATION JP 1,327
- GREE ELECTRIC APPLIANCES 1,152
- MAHLE INTERNATIONAL DE 999
- ALFA LAVAL SE 960
- HANON SYSTEMS KR 917
- DENSO CORPORATION 905
- DENSO CORPORATION JP 802
- CHINESE ACADEMY OF SCIENCES 787
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 762
Top Applicants (CPC)
Class F28,2013–2023, worldwide · Source: EPO PATSTAT
- VALEO SYSTEMES THERMIQUES FR 1,945
- MITSUBISHI ELECTRIC CORPORATION JP 1,518
- MAHLE INTERNATIONAL DE 1,120
- ALFA LAVAL SE 1,085
- HANON SYSTEMS KR 939
- DENSO CORPORATION JP 900
- LG ELECTRONICS KR 861
- HAMILTON SUNDSTRAND US 795
- DAIKIN INDUSTRIES JP 608
- DENSO CORPORATION 537