This class provides for processes involving steps resulting in separation of a gas from a fluid mixture comprising (i) a gas and solid or liquid particles entrained therein, (ii) a liquid and gas entrained therein, or (iii) a plurality of gases. As a general rule for this class, there must be a relationship of process steps embracing: (a) inflow of the fluid mixture to be treated, (b) a step or steps effective to cause the separation into constituent parts, and (c) an outflow of at least one constituent which is separate and distinct from the outflow of another constituent, including outflow of a constituent by removing the separating medium itself. The gas separation for this class is effected by processes other than chemical reaction.
The basic subject matter of this class is of a subcombinational nature and may include only such ancillary
process steps (e.g., fluid handling, etc.) as are necessary to perfect the gas separating function. Significant inclusion in a claim of features beyond merely perfecting the gas separating function indicates classification in a more comprehensive class. Thus, the combination of a gas separation process of this class and any cleaning or regenerating of the separation media is properly in this class, because the cleaning or regenerating is perfecting the gas separating function. Generally, however, the mere naming of an art process in a claim to gas separation does not affect classification. Thus, a claim to filtration of a gas from a named source with no details of that source is proper for this class.
(1) Note. The gas separation processes for this class generally involve the use of physical chemistry, chromatography, solid sorption, gas and liquid contact, gas contact, electrical fields, magnetic fields, wave energy, selective diffusion, filtration, deflection, or other mechanical means. (Also see Lines with Other Classes, below.)
(2) Note. This class also provides for processes in which the fluid mixture is treated to change its make-up, but no real separation occurs, provided no other suitable classification exists. Accordingly, in this class are found processes of using "spark arresters," which merely change the size of particles entrained in a gas. These devices are usually deflectors or screens. The processes of using them are included in this class because of their similarity to processes which actually separate the fluid mixture into constituent parts. Similarly, agglomeration, which by itself may not separate particles entrained in a gas, but cause small particles entrained therein to join together or coalesce to form larger particles, is in this class unless basis for other classification exists.
LINES WITH OTHER CLASSES
The gas separation processes for this class generally involve the use of physical chemistry, chromatography, solid sorption, gas and liquid contact, gas contact, electrical fields, magnetic fields, wave energy, selective diffusion, filtration, deflection, or other mechanical means. See the class search note in section III for Class 423, Chemistry of Inorganic Compounds, for the line concerning the processes in which the gas separation is caused by a chemical reaction. Also, see the class search note in section III for Class 588, Hazardous or Toxic Waste Destruction or Containment, for the line concerning the processes in which the gas separation is caused by destruction or permanent containment of the hazardous or toxic waste.
Degassing or purging processes for the removal of a gas from a solid will be placed in the class where the solid is either manufactured or treated. The removal of a gas from a solid sorbent (i.e., regeneration), per se, will be found in Class
502, Catalyst, Solid Sorbent, or Support Therefor: Product or Process of Making. However, the use of a solid sorbent to separate a gas from a fluid mixture and the removal of the gas from the solid sorbent (i.e., regeneration) will be found in this class. For the removal of a gas from a solid, where the solid is not identified, see Class 134, Cleaning and Liquid Contact With Solids. The Search Notes below also contain lines with other classes.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS
29, Metal Working, appropriate subclasses indented under
592, particularly subclass 896.62 for processes of mechanical manufacture for making a filter.
34, Drying and Gas or Vapor Contact With Solids, appropriate subclasses for generic processes for separating liquids from solids (i.e., drying) and the contacting of solids with either gases or vapors. Class 95 takes the separation of a gas from a fluid mixture in combination with the regeneration of the separating media by drying or by gas or vapor contact.
47, Plant Husbandry, appropriate subclasses for processes of separation of a gas from a fluid mixture by use of a plant of higher order.
48, Gas: Heating and Illuminating, appropriate subclasses for processes for the manufacture of heating and illuminating gases.
60, Power Plants,
273+, for processes of treating or handling the materials discharging from the combustion chamber of an internal combustion engine.
62, Refrigeration, appropriate subclasses for processes peculiar to removing heat from a substance, usually by a change of phase of a coolant or refrigerant and for processes involving subject matter for Class 95 combined with a significant refrigeration step. Examples of significant refrigeration are: (i) expansion of a gas through an orifice whereby cooling is effected to condense any of the constituents of the gas by such temperature reduction; (ii) a significant physical relationship or arrangement between elements of a refrigeration circuit (e.g., two related refrigeration coils, detailed description of the circuit, etc.); (iii) change of phase of a coolant or refrigerant (i.e., evaporation, melting, or sublimation) whereby cooling is effected to condense any of the constituents of the gas by such temperature reduction. Some examples of what may be
found in Class 62 are: (a) separation of a constituent from a plurality of gases by a significantly claimed refrigeration step or apparatus; (b) condensation of moisture from the atmosphere as a result of a refrigeration operation; (c) gas drying by sorption followed by contacting the dried gas with a liquid to produce cooling by evaporation; (d) a refrigerated enclosure combined with sorption means; (e) refrigeration producing processes and apparatus combined with steps or means for drying the refrigerant; and (f) extracting a constituent from a plurality of gases by liquefaction and separation (e.g., fractionation or distillation, etc.). Class 95 takes gas separation of general application, including cooling of the sorbent or cooling of gas, but not including evaporative cooling after sorption of the type noted in (c) above. Class 95 takes the cold wall-hot wall thermal diffusion or repulsion type of separation, regardless of any refrigeration claimed. Class 95 also takes expansion through an orifice of a liquid and gas entrained therein where the gas is removed from the liquid through the lowering of the pressure and the cooling effect which inherently results from such pressure reduction is not transferred through a wall to another material; if such heat transfer occurs, classification in Class 62 is proper. 73, Measuring and Testing,
23.2+, for gas analysis, per se, and also the combination of gas separation and significant gas analysis. The combination of gas separation and a nominal step of "analyzing" or "detecting" without further detail of the analysis or detection is insufficient to cause a patent to be placed in Class 73; that patent will be placed in Class 95. Also, if there is feedback from the analytical apparatus to control or effect a change in the gas separating operation, then classification is in Class 95.
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, appropriate subclasses for processes for the treatment of liquid or vaporous metal. See
405, for removal of gas from liquid metal by use of a gas permeable membrane and subclasses 407+ for filtering vaporous metal.
96, Gas Separation: Apparatus, for the corresponding apparatus to the processes of Class 95. When a patent has a claim or claims to a Class 95 process and a claim or claims to a Class 96 apparatus, the patent will be placed as an original in Class 95, even though there may be an apparatus claim that is more comprehensive than a process claim.
128, Surgery,
200.24+, for methods of supplying a breathable gas to, or exhausting such gas from, a living body. Subclass 200.24 and the subclasses mentioned below require that the method be
adapted for use on or in the living body and also include diagnostic or therapeutic methods when the only disclosed utility is for diagnosis or treatment of a living body. See especially subclass 200.25 for an artificial gill or means for separating entrained air from a liquid stream; subclass 201.25 for a respiratory device including body or head supported means covering user's scalp and means for removing a substance from respiratory gas; subclass 204.16 for removal of a substance from respiratory gas by cooling; subclass 205.12 for means for supplying respiratory gas under positive pressure including means for removing a substance from the respiratory gas; and subclass 205.27 for a respiratory device including means for removing a substance from respiratory gas.
137, Fluid Handling, appropriate subclasses for combinations of fluid handling and gas separation involving more than mere flow control to or from the separating means. (a) For classification in either Class 137 or Class 95, where both the fluid handling and gas separation are included in the combination, classification will be based upon the ultimate purpose of the subject matter and not upon the ancillary or subordinate feature of the combination consistent with the objects and aims therefor (e.g., it is not intended that the inclusion of filtering, no matter how specifically defined, will be sufficient to carry a "gas field storage and distribution process" to Class 95 whether the filtering protects the apparatus used in the process or is the last step in the process). The fluid handling for Class 95 should be no more than that necessary to convey or conduct the fluid mixture to, at, or away from the point of separation. (b) Class 137 also takes separation of gases from gases, liquids, or solids by gravity only (i.e., where no specific means is claimed for effecting the separation).
140, Wireworking,
3+, for wire fabric making.
141, Fluent Material Handling, With Receiver or Receiver Coacting Means, 4+, for processes of transferring fluent material through a flow confining system, the source and receiver parts of which are normally separable, including varying gaseous conditions (e.g., causing a vacuum, etc.) in the receiver.
156, Adhesive Bonding and Miscellaneous Chemical Manufacture, appropriate subclasses for processes there classified for adhesively bonding and otherwise manufacturing filters.
165, Heat Exchange, appropriate subclasses for processes where only indirect heat exchange is involved and especially
201+, and 58+ for heating and cooling including addition or removal of water vapor from air. Cold wall-hot wall thermal diffusion processes will be found in Class 95, subclass 289.
166, Wells, for processes involving shafts or deep borings in the earth for the extraction of fluids from the earth. See especially
265+, for processes involving separating material leaving the well. A gas separation process including a nominal recitation of a well process is proper for Class 95. For classification in Class 166, some details specific to a well process should be recited for the combination of a gas separation process and a well process. However, in the situation in which one of the constituents separated is inserted into an input well, a mere broad recitation of such well process is sufficient for classification in Class 166.
203, Distillation: Processes, Separatory,
39+, for processes for separating a liquid mixture (distilland) by vaporizing and condensing at least a portion thereof to isolate in the condensed liquid (distillate) or in the unvaporized portion (residue) a comparatively pure compound combined with subjecting the vapor to a disparate physical treatment to remove a substance. For Class 203, the liquid mixture (distilland) must have a boiling point above 0 deg.C under normal atmospheric pressure (760 mm Hg).
204, Chemistry: Electrical and Wave Energy, appropriate subclasses for processes in which a chemical change is brought about by the application of an electric current or wave energy to material being treated wherein more than the mere thermal effect of the current or energy is involved and
554+, for processes for the separation or purification of liquids by the physical or physical-chemical action of an electrical stress. See particularly subclass 157.3 for processes in which an initial normally gaseous mixture is treated by wave energy so as to remove therefrom by a chemical reaction or change to a different chemical form at least one of the components therein.
208, Mineral Oils: Processes and Products, for processes for the recovery or treatment of naturally occurring mineral oil which result in the production of a purified or modified mineral oil. See particularly 310, for the separation of mineral oils into hydrocarbon fractions, at least one of which is a mineral oil, wherein a mineral oil containing fluid mixture is contacted with a solid material which selectively adsorbs a mineral oil fraction from the fluid mixture. See also subclass 340 for the recovery of liquid mineral oils from natural gases or from uncondensed gas-vapor mixtures obtained from a mineral oil conversion operation including separation of mineral oils into hydrocarbon fractions, at least one of which is a mineral oil. Processes which involve a gas separation procedure classifiable in Class 95 followed by the recovery of a mineral oil by name only (e.g., reciting only
rectification, vacuum pressure or flash distillation, etc.) are classified in Class 95. Processes wherein the mineral oil recovery step includes any details thereof or includes some subsequent treatment of the separated mineral oil are classified in Class 208.
209, Classifying, Separating, and Assorting Solids, subclasses indented under
21, and 133 that include "deposition" in their titles for processes for the separating and segregating into grades components of solid mixtures employing a gaseous suspending medium which is separated from the solids.
210, Liquid Purification or Separation, appropriate subclasses for the separation of a constituent from a flowable liquid mixture; except for the separation of a gas initially present in a liquid mixture. Class 210 is superior to Class 95 and takes separating processes, per se, generically disclosed or claimed as fluid separation or if the disclosure or a claim is restricted to liquid separation. Class 210 also takes processes which remove or vent gas formed incidentally to the handling of the fluid mixture or as a result of a Class 210 treatment (see particularly
603, 640, 664, 718, and 750). However, Class 95 takes processes operating to remove gas initially present in an inflowing liquid mixture, with or without liquid separation. The removal of a volatile organic compound (e.g., ethanol (C2H5OH), gasoline, etc.) from a liquid is not taken to be degasification of a liquid for Class 95 when the volatile organic compound is initially present as a liquid mixed with another liquid. The removal of a volatile organic compound from a liquid may be found in Class 210 for liquid purification or separation or Class 203 for separatory distillation processes. Class 95 will also take a process including a liquid separation step in a Class 95 operation (e.g., regenerating a scrubbing liquid in a gas scrubbing operation).
241, Solid Material Comminution or Disintegration,
18+, for processes for combinations of comminution and separation of solids from a gas. Class 241 is superior to the material separation classes and, therefore, provides for processes in which comminution is combined with steps to separate the material into classes according to the physical characteristics of its components before, during, or after the comminuting operation. Class 95 takes processes, such as deflection or the like, that may act to comminute material as a secondary or incidental function of what is basically a holding back or separating procedure (e.g., disintegration or attrition of ignited particles in spark arresters). Such processes are classified on the basis of their essential function in Class 95.
250, Radiant Energy,
282+, for methods for the ionic separation of materials utilizing the charge-to-mass ratios of particles. These methods may be for subjecting the ionized particles to the effects of an electric or magnetic field, which causes the particles to travel through a curved trajectory, the particles of a certain charge-to-mass ratio having a trajectory different from those particles having other charge-to-mass ratios.
252, Compositions, 189+, for substances (e.g., liquid sorbent compositions, etc.) for use in absorbing or binding carbon monoxide (CO), sulfur (S), negative elements, or acids; subclass 193 for substances (e.g., liquid sorbent compositions, etc.) for use in absorbing or binding ammonia, alkalis, or other bases; and subclass 194 for substances (e.g., liquid sorbent compositions, etc.) for use in absorbing or binding water.
261, Gas and Liquid Contact Apparatus, appropriate subclasses for apparatus for degasifying liquid (e.g., deaerating feed water heater, etc.) wherein the liquid is merely contacted with a gas in a chamber or space for deaeration thereof; for apparatus wherein a gaseous fluid mixture is contacted with a liquid spray, sheet, stream, or bath to precipitate dust or to sorb a constituent from the gaseous fluid mixture; for apparatus comprising a nonabsorbent element on which a gaseous fluid mixture is contacted with a liquid if the element is continuously supplied with a liquid or is continuously moved into and out of a liquid bath or supply; and for apparatus comprising an absorbent porous sheet or mass on which a gaseous fluid mixture is contacted with a liquid if the sheet or mass is: (a) continuously supplied with liquid, (b) cyclically or periodically moved through a liquid reservoir, (c) maintained wet by liquid applying means, or (d) moistened by maintaining some part of a continuous wick type member immersed in liquid, by following the law of the machine, or during normal operation of a gas contacting function. Note that under the provisions of (a) and (b) there must be no affirmative means to dry the sheet or mass, nor means to assure a dry condition of the sheet or mass before gas flow is resumed or the sheet or mass is returned to the gas contacting position. If apparatus for degasifying liquid by contact with a gas has other means to cause gas separation of the liquid with gas entrained therein, of the separated gas, or of the separated liquid, then the apparatus is classified in Class 96. If apparatus in which a gaseous fluid mixture is contacted with a liquid to precipitate dust or to sorb a constituent from the gaseous fluid mixture has other means to cause gas separation or has means to treat the contact liquid, then the apparatus is classified in Class 96.
(1) Note. Apparatus for separating ammonia (NH3) or acid anhydrides
(CO2, SO2, etc.) from a gas by mere contact with a liquid is classified in Class 261.
(2) Note. Processes for gas separation by contacting a gaseous fluid mixture with a liquid and processes of degasifying a liquid are classified in Class 95.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, for processes for induced nuclear reactions combined with steps for reaction product treatment. See particularly
146+, 189, 195, 198, and 201. See subclasses 308+ for processes including fission reactor material treatment.
406, Conveyors: Fluid Current,
154+, for processes to convey solid material in a fluid current with separation of the solids from the fluid at the conveyor outlet.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving or Sterilizing,
4, for processes of acting on a gas for maintaining a protective environment or counteracting a destructive environment by disinfecting, deodorizing, preserving, or sterilizing. The deodorizing for Class 422 generally involves adding a substance to a gas to mask an odor. Class 95 takes deodorizing a gas that involves gas separation of the type that meets the requirements for gas separation in the definition for Class 95. Class 422 is the residual place for deodorizing a gas that does not meet the requirements of the definitions for Class 95 or Class 423.
423, Chemistry of Inorganic Compounds, 210+, for gas separation methods relying upon a chemical reaction (including combustion). However, for a Class 95 process including a chemical reaction not involved in the separation, per se, see the Class 95 Glossary for TREATMENT. A particular chemical must be claimed and the chemical reaction must be inherent or disclosed for patents to be placed in Class 423. Broadly reciting the separating material as a "chemical" or as "gas purifying material" does not exclude the patent from Class 95. Absorption and adsorption are not considered chemical reactions in this respect. Processes for separating a gaseous fluid mixture having therein ammonia (NH3) or acid anhydrides (e.g., CO2, SO2, etc.) by contacting the gaseous fluid mixture with water and thus dissolving these gases out of the gaseous fluid mixture are in Class 95, notwithstanding the fact that a chemical reaction occurs in the solution and that ammonium hydroxide or the acids are formed. Corresponding gas and liquid contact apparatus, per se, is
classified in Class 261. See the search class note for Class 261 in this section for the line. See subclass 658.2 for hydriding an alloy of two or more metals and recovering hydrogen from the hydride.
435, Chemistry: Molecular Biology and Microbiology, for processes of using a micro-organism or enzyme to synthesize a chemical product and for processes of treating a material with a micro-organism or enzyme to separate, liberate, or purify a preexisting substance. See particularly
266, for processes of treating a gas, emulsion, or foam with an enzyme or immobilized enzyme or micro-organism or plant or animal cells to isolate or recover a preexisting substance which is chemically unchanged by the process.
494, Imperforate Bowl: Centrifugal Separators, for processes for the breaking up or subdividing of material, which material comprises a mixture of fluids or fluent substances, into two or more components by utilizing a rotatable, receptaclelike member having a generally solid wall, and commonly termed a bowl, for subjecting the material to centrifugal force. Thus, gas separation processes that use an imperforate bowl, centrifugal separator are proper for Class 494.
502, Catalyst, Solid Sorbent, or Support Therefor: Product or Process of Making,
20+, for regenerating or rehabilitating solid sorbent compositions, per se, subclasses 60+ for zeolite compositions and for processes of making zeolite compositions, and subclasses 400+ for other solid sorbent compositions and for processes of making solid sorbent compositions. Class 95 will take the combination of gas separation using a solid sorbent composition and regenerating or rehabilitating the solid sorbent composition.
516, Colloid Systems and Wetting Agents; Subcombinations Thereof; Processes of Making, Stabilizing, Breaking, or Inhibiting, appropriate subclasses for colloid systems or agents for such systems or making or stabilizing such systems or agents, appropriate subclasses for processes of or compositions for or subcombination compositions for the breaking of or inhibiting of colloid systems (
115+, for defoaming); in each instance, when generically claimed or when there is no hierarchically superior provision in the USPC for the specifically claimed art.
585, Chemistry of Hydrocarbon Compounds,
800+, for processes in which a mixture of a hydrocarbon compound with another substance is treated to recover that same compound in a more usable condition, that is, a purer or more desirable condition, by a treatment which comprises separating the hydrocarbon from the other substance or making
the other substance less noxious. 588, Hazardous or Toxic Waste Destruction or Containment, for hazardous or toxic waste destruction by any means to include heating, chemical action, or the interaction with any form of radiation and hazardous or toxic waste conversion by any means (e.g., chemical, physical, etc.) to an environmentally safe substance. Class 588 includes such destruction or conversion in combination with gas separation.
GLOSSARY:
DETECT
The term "detect," which is used in many of the control subclasses, is used in both a quantitative and a qualitative sense. This means that a definite measurement of a process variable is made (e.g., temperature, pressure, concentration, etc.) or that the presence of a particular event is determined (e.g., presence of sparking, change in liquid level determined by position of float, etc.).
FILTER
An article or mass of material made of closely spaced or intimately arranged intermeshed or unconnected fibers, elements, strands, or particles that collectively act as a barrier to physically retain at least one constituent of a fluid mixture on its surfaces or in the spaces between the fibers, elements, strands, or particles while permitting passage of the remaining constituents.
A filter has no "chemical" affinity for a constituent of a fluid mixture. The retention of the constituent by the filter depends upon a mechanical entrapment of solid or liquid particles because of their relatively large size compared with the interstices or spaces between individual fibers, elements, strands, or particles. The retained particles can be removed by brushing, wiping, shaking, or similar mechanical action.
FLUID MIXTURE
The phrase "fluid mixture" is used throughout the definitions to mean (a) a gas and solid or liquid particles entrained therein, (b) a liquid and gas entrained therein, or (c) a plurality of gases.
GAS
Matter of very low density and viscosity, relatively great expansion and contraction with changes in pressure and temperature, that is readily diffusive, with a tendency to expand indefinitely, with molecules in free movement. The term "gas" includes "vapor" (q.v.).
GASEOUS FLUID MIXTURE
The phrase "gaseous fluid mixture" is used throughout the definitions to mean (a) a gas and solid or liquid particles entrained therein or (b) a plurality of gases.
LIQUID SORBENT
A liquid capable of retaining part of a fluid mixture with which it is contacted. The action in most cases is that of selective retention (i.e., the sorbent removes only that part of the fluid mixture for which it has the greatest affinity).
REGENERATION
Restoration of the separatory material to the condition it was in before the separatory process.
SEPARATING APPARATUS
The entire gas separating means, which consists of all of the apparatus parts related to gas separation and includes apparatus parts that are in addition to the separator.
SEPARATING MEDIUM (MEDIA)
Liquid sorbent or means that effects the separation into constituent parts (e.g., deflector, filter, molecular sieve, sorber, etc.). (Media has been used in the singular and in the plural.)
SEPARATOR
The portion of the apparatus that consists of a separating medium and the structure supporting, retaining, or substantially confining the separating medium. SOLID SORBENT
A solid sorbent is a solid material which separates a constituent (e.g., a gas, vapor, etc.) from a fluid mixture containing such constituents in a "quasi-chemical" manner. The action in most instances is that of selective retention (i.e., the sorbent removes only the part of the fluid mixture for which it has the greatest affinity). The retained constituent cannot be removed by shaking, brushing, or similar mechanical action, but generally can be removed by heating, pressure reduction, or use of a stripping or denuding fluid.
TREATMENT
(a) With respect to the class subject matter, the term is restricted to reversible and nonchemical changes in physical characteristics of the fluid mixture or a separated constituent (e.g., heating, cooling, humidity control, agitating, pressure regulation, etc.). (b) With respect to
the media used to perform the gas separation or to a material used to condition the fluid mixture for separation, the term may include chemical preparation, reconditioning, or reaction.
VAPOR
The gaseous state of matter that is liquid or solid under a temperature of 0 deg.C and 760 mm Hg pressure.