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CENTRIFUGES (high-speed drum mills B02C 19/11; domestic spin driers D06F; analysing, measuring or monitoring physical or chemical properties of samples during centrifuging, see the relevant subclasses for these procedures, e.g. G01N)
Definition statement
This subclass/group covers:

Centrifuges that are intended for separating, drying, extracting, purifying or other ways of treating mixtures composed of matter in the following physical states:

  • liquid/liquid, liquid/gas or gas/gas mixtures;
  • solid/liquid or solid/gas mixtures.

Such centrifuges may comprise centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles; centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneously sifted or filtered; or other centrifuges including radial chamber apparatus such as butyrometers or counter-current apparatus.

Elements or accessories of centrifuges such as casings, lids, rotary bowls, drives, gearing, suspending or balancing of rotary bowls, feeding, charging or discharging of bowls, control arrangements, heating, cooling or suppressing the formation of foam.

Relationship between large subject matter areas

Separation of isotopes of the same chemical element is covered by B01D 59/00, whatever process or apparatus is employed. Processes for separation of different isotopes of the same chemical element by centrifuging are covered by B01D 59/20.

Processes in general that use centrifugal force for separating, extracting or purifying components of mixtures are covered in subclasses B01D and B07B, and not in subclass B04B with the apparatus for accomplishing these processes. Examples of such processes can be found in the "Informative References" section below.

References relevant to classification in this group
This subclass/group does not cover:

High-speed drum mills

Cyclone separators

Domestic spin dryers

Centrifugal casting machines

Examples of places where the subject matter of this subclass is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Centrifuges for producing filtered coffee

Dental appliances for receiving spittle, characterised by provisions for processing the collected matter, e.g. for separating solids or air

Treatment of water, waste water or sewage by centrifugal separation

Exhaust or silencing apparatus for machines or engines having means for removing solid constituents of exhaust, using inertial or centrifugal separators

Drying solid material by using centrifuges

Informative references
Attention is drawn to the following places, which may be of interest for search:

Processes for separation of non-miscible liquids by centrifugal force

Processes for degasification of liquids in rotating vessels, vessels containing movable parts or in which centrifugal movement is caused

Processes for using centrifuges for separating sediment

Processes for separating dispersed particles from gases or vapours by centrifugal forces,the centrifugal forces generated by rotating vanes, discs, drums or brushes

Processes for separation of gases or vapours or for recovering vapours of volatile solvents from gases by centrifugal force

Magnetic or electrostatic separators

Processes using centrifugal force for selective separation of solid materials carried by, or dispersed in, gas currents

Lubrication of machines or engines in general, details of lubricant purifying means

Shock absorbers, vibration dampers

Analysing materials by determining their physical or chemical properties e.g. during centrifuging

Special rules of classification within this group

If a document concerns embodiments which are covered by several subgroups the specific technical information is classified at inventive level in all subgroups.

Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
Definition statement
This subclass/group covers:

Centrifuges with rotary bowls with or without separating walls

with inserted separating walls
Definition statement
This subclass/group covers:

Documents with claims related to the separating walls and/or the construction of the discharging outlets of the lighter fluid(s)

References relevant to classification in this group
This subclass/group does not cover:

Documents with claims related to the discharging outlets for the solids or solids/heavier fluid mixture and the mechanism

Informative references
Attention is drawn to the following places, which may be of interest for search:

Centrifuges with rotating separating walls without a rotary bowl

discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
Definition statement
This subclass/group covers:

Liquid and solids outlets for screw centrifuges

Documents with claims related to disc stacks in a screw centrifuge

Distributers for feeding the material into the bowl of a screw centrifuges

Synonyms and Keywords

In patent documents the expressions "screw centrifuge" "decanter" or decanting centrifuge" are often used as synonyms.

The expressions "scroll, worm, auger, helical, spiral" are often used instead of "screw".

The expression "beach" is often used with the meaning "dewatering portion", which is the area of the bowl where the solids settle before they are discharged.

Centrifuges with rotary bowls in which solid particles or bodies become separated by centrifugal force and simultaneous sifting or filtering
Definition statement
This subclass/group covers:

Any type of centrifuge having a screen, sieve or mesh associated with the bowl for the separation of solids from the liquid, having different types of mechanism for discharging the solid particles.

References relevant to classification in this group
This subclass/group does not cover:

Drying solid material by using centrifuges

Informative references
Attention is drawn to the following places, which may be of interest for search:

Filters with rotary cylindrical filtering surfaces arranged for outward flow filtration

Separating crystals from mother liquor by centrifugal force

discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
References relevant to classification in this group
This subclass/group does not cover:

Aspects relating to details not relating to

The sifting or filtering part of the bowl

L04B1/20B - B04B 2001/2091

Other centrifuges
Definition statement
This subclass/group covers:

Centrifugal separators for fluid circulation systems. Planetary centrifuges. Centrifuges having radially arranged separation chambers with or without separate fluid receptacles, like centrifuges comprising test tubes, flexible receptacles, flat or spatial spiral chambers etc..

References relevant to classification in this group
This subclass/group does not cover:

Centrifugal cuvette type rotors

Informative references
Attention is drawn to the following places, which may be of interest for search:

Suction or pumping devices for medical purposes, other treatment of blood in a by-pass of the natural circulatory system using separation based on different densities of components, e.g. centrifuging

Combination of filters with centrifugal separation devices

Test tubesspecially adapted for centrifugation purposes

Crankcase ventilating or breathing having means for purifying air before leaving crankcase, e.g. removing oil

Arrangements for conditioning of lubricants in the lubricating system by filtration

F01N39/06

Investigating sedimentation of particle suspensions by centrifuging and investigating centrifugates

Centrifugal type cuvettes

Field flow fractionation

Column chromatography using counter-current

Investigating or analysing blood by separating the blood components

{with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation}
Definition statement
This subclass/group covers:

Centrifuges for blood separation and blood washing including the 2-omega type (see e.g. US4221322) and rotary sealing type (see e.g. WO8000227) centrifuges.

Aspects of elutriation, tubings, interface detection, rotary sealings in connection with these centrifuges.

Centrifuges for separating predominantly gaseous mixtures
Definition statement
This subclass/group covers:

Centrifuges for separating different gases from each other, as well as separating solid or liquid particles from gases are classified in this group, see also B01D 45/12 and B01D 45/14.

Informative references
Attention is drawn to the following places, which may be of interest for search:

Processes for separating dispersed particles from gases or vapours by centrifugal forces,the centrifugal forces generated by rotating vanes, discs, drums or brushes

Separation of gases or vapours by centrifugal force

Elements of centrifuges (drives B04B 9/00; feeding, charging, or discharging appurtenances or devices B04B 11/00)
Definition statement
This subclass/group covers:

The group covers:

E.g. details relating to chucks (see e.g. US3785549), gripping arms (see e.g. US3837633), sealings.

References relevant to classification in this group
This subclass/group does not cover:

Rotary seals enclosing an aperture in a bowl body through which a feeding/discharging member is inserted (see e.g. WO8000227)and rotating seals carried on the processing chamber between ports in the chamber and the non-rotating portions of the system (see e.g. US4636193)

Seals in conjunction with bearings

Safety devices; {Regulating}
Definition statement
This subclass/group covers:

E.g. door and lid locking devices, breaking point arrangements, leak detection systems

Safety measures in case of rotor fracturing

Informative references
Attention is drawn to the following places, which may be of interest for search:

Domestic spin-dryers or similar; doors or covers; safety arrangements

Safety devices acting in conjunction with the control or operation of a machine; in connection with the locking of doors, covers, guards, or like members giving access to moving machine parts

Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
Definition statement
This subclass/group covers:

All kind of centrifuge drives, transmission gearings, control of the drives and the suspension and balancing of the rotary bowls.

Control of the drive; Speed regulating {(for solid bowl screw centrifuges B04B 1/2016)}
Definition statement
This subclass/group covers:

E.g. speed limiting arrangements

Suspending rotary bowls; {Bearings; Packings for bearings}
Definition statement
This subclass/group covers:

E.g. sealing, damping, lubricating, cooling of bearings

Feeding, charging, or discharging bowls (B04B 1/00, B04B 3/00, B04B 7/04 take precedence)
Definition statement
This subclass/group covers:

All aspects of feeding, distributing and discharging arrangements in centrifuge bowls.

Periodical feeding or discharging; Control arrangements therefor
Definition statement
This subclass/group covers:

The handling e.g. loading/unloading of sample carriers like tubes or tube racks in close relation with the centrifuge .

Informative references
Attention is drawn to the following places, which may be of interest for search:

Automatic analysis and the handling of sample containers and devices for transferring samples in general

Control arrangements specially designed for centrifuges; Programme control of centrifuges (control arrangements for feed, charge, or discharge B04B 11/00)
Definition statement
This subclass/group covers:

Control arrangements specially adapted for centrifuges.

References relevant to classification in this group
This subclass/group does not cover:

Control arrangements for safety devices like door and lid locking devices

Control arrangements for feed, charge or discharge

Other accessories for centrifuges
Definition statement
This subclass/group covers:

Auxiliary equipment for centrifuges like cooling means, cleaning means, venting means and the like

for cooling, heating, or heat insulating
References relevant to classification in this group
This subclass/group does not cover:

Cooling of bearings:

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Last Modified: 10/11/2013