CPC Definition - Subclass F25J
This place covers:
Processes or systems for liquefying or solidifying gases or gaseous mixtures and for separating the constituents of gaseous or liquid mixtures involving the use of liquefaction or solidification by rectification or partial condensation, the processes or systems use internal and/or external refrigeration to reach very low temperatures, i.e. so-called cryogenic temperatures, in general well below -50°C;
Arrangements of cold exchangers or cold accumulators in cryogenic separation or liquefaction plants.
If the principal aspect of the application concerns the liquefaction or solidification of a gaseous feed stream but comprises also purification aspects of the feed or product stream in general then the main group concerned is F25J 1/00.
Similarly, if the principal aspect of the application concerns the separation of a feed stream but comprises also the withdrawal of a liquid or solid product stream then the main group concerned is F25J 3/00.
Attention is drawn to the following places, which may be of interest for search:
This place covers:
Processes or systems wherein a gaseous feed or feed mixture is liquefied or solidified using internal and/or external refrigeration and withdrawn as liquefied or solidified product or product mixture. The gases or gaseous mixtures comprises so-called "permanent gases", e.g. noble gases, hydrogen and primary air constituents, and gases or main components of gaseous mixtures having boiling points equal to or lower than -78°C, i.e. the boiling point of carbon dioxide, e.g. natural gas, carbon monoxide.
- Processes or apparatus characterised by the gas or gas mixture to be liquefied or solidified.
- Processes or apparatus characterised by the kind of cold generation for compensating heat leaks and liquid production.
- Processes or apparatus characterised by the refrigerant fluid used.
- Processes or apparatus characterised by details and kind of the refrigeration system used, e.g. by using a single or multi-component vapour compression cycle or a refrigeration cascade; coupling or integration with other units or processes; controlling aspects.
This place does not cover:
Recovering volatile solvents by condensation | |
Vapour recovery systems combined with filling nozzles | |
Solidification of carbonic acid | |
Production of ammonia | |
Cryogenic pumps | |
Pipe-line systems |
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:
Separation of a feed stream and withdrawal of a liquid product |
Attention is drawn to the following places, which may be of interest for search:
Floating working-up processes | |
Refrigerant materials per se | |
Buildings forming part of cooling plants | |
Adaptations of expansion engines for refrigeration plants or for driving | |
Steam engine plants in combination with an industrial process | |
Gas turbine plants in combination with other processes | |
Control of compressors in general |
In this place, the following terms or expressions are used with the meaning indicated:
Refrigeration cascade | The feed stream is cooled by two or more subsequent refrigeration means |
Natural gas | Substitute natural gas, gas obtained from a crude oil well, i.e. associated or petroleum gas, or from a gas well, i.e. non-associated gas, gas recovered from a tertiary oil recovery process, mine or coal-bed-seam gas, landfill gas |
BOG | Boil-off gases i.e. evaporated gases from cryogenic liquid storage vessels |
MCR | Multi-component refrigerant |
SCR | Single-component refrigerant |
In patent documents, the following abbreviations are often used:
LNG | Liquefied natural gas |
C3MR | Propane pre-cooled mixed refrigerant LNG process (APC) |
DMR | Mixed refrigerant pre-cooled mixed refrigerant LNG process (Shell, APC, Liquefin) |
MFC® | Three level cascade mixed refrigerant LNG process (Linde) |
OCLP | Optimised cascade LNG process (Concoco-Phillips) |
This place covers:
Processes or apparatus for separating the constituents of a feed stream at cryogenic temperatures involving the use of liquefaction or solidification by rectification or partial condensation. The feed stream can be a gas, a gaseous mixture, a cryogenic liquid or a cryogenic liquid mixture.
- Cryogenic separation of gaseous or liquid mixtures, e.g. gaseous or liquefied natural gas, refinery off-gases, gaseous mixtures comprising hydrogen and/or carbon monoxide, carbon dioxide or nitrogen, by rectification in a column or dephlegmator, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream.
- Cryogenic separation of atmospheric air into its primary components, i.e. nitrogen, oxygen, argon, krypton, xenon, neon and/or helium.
- Cryogenic separation of gaseous or liquid mixtures, e.g. gaseous or liquefied natural gas, refinery off-gases, gaseous mixtures comprising hydrogen and/or carbon monoxide, carbon dioxide or nitrogen, by partial condensation, i.e. by condensation or anti-sublimation of the high-boiling components and subsequent simple phase separation of the liquefied or solidified components from the remaining low-boiling gaseous components. The high-boiling liquid components can be withdrawn in gaseous or liquid phase.
- Cryogenic separation of gaseous impurities from an almost pure feed stream (i.e. the concentration of the impurities is in generally less than 5 vol%) wherein the main component of the feed stream and the impurities do have similar volatilities and wherein the product stream has a high or ultra high purity, i.e. with only some ppm or ppb of remaining impurities.
This place does not cover:
Distillation or related processes other than cryogenic processing | |
Recovering volatile solvents by condensation | |
Production of hydrogen containing gas not using cryogenic processing | |
Preparation of oxygen not using cryogenic processing | |
Production or purification of nitrogen not using cryogenic processing | |
Purification or separation of noble gases not using cryogenic processing | |
Production of carbon monoxide containing gas not using cryogenic processing | |
Production of carbon dioxide | |
Purification of hydrocarbons | |
Distillation of hydrocarbon oils | |
Working-up liquefied petroleum gas | |
Treating radioactively contaminated gases |
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:
Purification of a gas stream during its liquefaction |
Attention is drawn to the following places, which may be of interest for search:
Separation of gases or vapours by condensation | |
Separation of gases or vapours by absorption | |
Separation of isotopes | |
Packing elements | |
Preparation or purification of gas mixtures for synthesis | |
Separation of hydrogen at low temperatures | |
Purge gas treatment from ammonia synthesis | |
Recovery of liquid hydrocarbon mixtures from gases by cooling | |
Working-up undefined normally gaseous hydrocarbon mixtures | |
Working-up natural gas | |
Buildings forming part of cooling plants | |
Adaptations of expansion engines for refrigeration plants or for driving | |
Steam engine plants in combination with an industrial process | |
Steam engine plants in combination with a gasification process and an oxygen producing plant | |
Gas turbine plants supplying working fluid to a user | |
Control of compressors in general |
In this place, the following terms or expressions are used with the meaning indicated:
Cold box | Housing comprising all the cold equipments of the separation/liquefaction process, i.e. working normally under cryogenic temperatures conditions |
Natural gas liquids | C2+ hydrocarbons |
Liquefied petroleum gas | C3+ hydrocarbons |
In patent documents, the following abbreviations are often used:
ASU | Air separation unit |
BAC | Booster air compressor |
MAC | Main air compressor |
LNG | Liquefied natural gas |
NGL | Natural gas liquids |
LPG | Liquefied petroleum gas |
HYCO | Synthesis gases comprising hydrogen and carbon monoxide as main constituents |
This place covers:
Particular configuration and constructional design of cold exchangers and cold accumulators for use in cryogenic separation or liquefaction plants (in contrast to the description of the general functioning of said exchangers and accumulators as found in the flowsheet of the cryogenic process which are to be classified in the corresponding main groups F25J 1/00 and F25J 3/00)
- Cold regenerators, i.e. cold exchange means cools the feed stream and removes higher boiling impurities by liquefaction/solidification, e.g. H2O, CO2 from the feed gas by alternating purification and regeneration phase, either as reversing heat exchangers or as cold accumulators.
- Recuperative heat exchangers for continuously recuperating cold from separated components in separation plants or from refrigerant streams in cryogenic liquefaction plants.
- Reboiler and/or Condensers in a cryogenic separation or liquefaction apparatus.
- Reflux heat exchangers or dephlegmators, i.e. cold exchangers with continuous interchange of heat and material between a vapour stream and a liquid stream.
Attention is drawn to the following places, which may be of interest for search:
In this place, the following terms or expressions are used with the meaning indicated:
Reversing heat exchanger | Recuperative ("counter-current") heat exchanger with continuous heat exchange during the purification phase followed by a regeneration phase; there is no cold accumulation; can be arranged in a single, compact heat exchanger |
Cold accumulator | Heat exchange means containing a cold regenerative material for storing and exchanging the cold in a discontinuous manner, i.e. alternating purification and regenerating phase; always at least two heat exchange vessels are necessary |
Bath type reboiler | Thermo-siphon reboiler, with natural or forced liquid circulation, or core-in-kettle reboiler with pool boiling |
Down-flowing type reboiler | Thin falling liquid film flowing down the heat exchange surface, plate or tube, and is subsequently vaporised |
In patent documents, the following abbreviations are often used:
BA-PFHE | Brazed aluminium - plate fine heat exchanger |
MCHE | Main cryogenic heat exchanger |
MHE | Main heat exchanger |
REVEX | Reversing heat exchanger |
SWHE / CWHE | Spiral-/coil wound heat exchanger |
In patent documents, the following words/expressions are often used as synonyms:
- "kettle", "bath" and "pool-boiling"