Skip over navigation
Printable version [PDF]
DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)
Definition statement
This subclass covers:

Particular elements of heat exchangers; details of heat transfer devices; means for modifying heat transfer; control arrangements for heat exchangers.

Tubular elements; Assemblies of tubular elements (specially adapted for movement F28F 5/00)
Definition statement
This group covers:

Tubular elements; assemblies of tubular elements,e.g. particular shape, construction, geometry of individual tubular element, e.g. multiple wall conduits, tubes with variable shape.

Tubular elements of cross-section which is non circular, e.g. flat tubes, flat multichannel tubes.

Tubular elements of cross-section which is polygonal, e.g. square, rectangular.

Tubular elements which are crimped or corrugated in cross-section.

Tubular elements which are crimped or corrugated in longitudinal section.

Means for increasing heat transfer area, e.g. fins, ribs.

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

Elements specially adapted for movement

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

Tube-rolling by rollers arranged outside the work

Making tubes by extrusion

Making finned tubes by extrusion

Making tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes

Making tubes with welded or soldered seams

Making tubes of special shape , e.g. multi-wall tubes, tubes with non-circular cross-section; tubes with multiple passages

Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies

Making finned or ribbed tubes by fixing strip or like material to tubes

Making annularly-ribbed tubes

Making helically-ribbed tubes

Application of procedures in order to alter the diameter of tube ends

B21C41/00

Making heat exchangers

Moulds for making ribbed tubes

Special rules of classification within this group

The fins are either outside the tubular elements: F28F/12 or inside the tubular elements: F28F 1/40. The subgroup F28F 1/42 covers fins being both inside and outside the elements.

Outside fins can either extend longitudinally: F28F 1/14, or laterally: F28F 1/24 or obliquely: F28F/34, relative to the axis of the tubular elements..

Longitudinal fins can be integral with the elements, e.g. extruded as unitary element,: F28F 1/16 or can be attachable to the element (removable): F28F 1/20, or can have portions which are common to several tubular elements: F28F 1/22.

Transversal fins can be integral with the elements,: F28F 1/26 or can be attachable to the element (removable): F28F 1/30, or can have portions which are common to several tubular elements: F28F 1/32.

Oblique fins can be in the form of helically wound fins or wire spirals: F28F 1/36.

Corrugated fins are classified in F28F 1/12.

Tubular elements which made from finned sections are classified in F28F 1/18 or F28F 1/28.

Staggered fins to form tortuous passages are in F28F 1/38.

Plate-like or laminated elements; Assemblies of plate-like or laminated elements (specially adapted for movement F28F 5/00)
Definition statement
This group covers:

Plate-like or laminated elements; assemblies of plate-like or laminated elements,e.g. particular shape, construction, geometry of individual plate-like or laminated element, e.g. arrangements for preventing direct contact between different heat-exchange media.

Relationship between large subject matter areas

Heat exchangers formed by stacked plates permanently fixed together (not capable of being taken apart) are normally classified only in F28F 9/00 and not in F28F 3/08.

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

Fins to facilitate cooling of reflectors for light sources

Elements specially adapted for movement

Fins for nuclear reactor fuel elements

Heat sinks for resistors

Cooling fins for transformers

Heat sinks for cooling semiconductor

Cooling facilitated by shape of device, e.g. foil, wire, pin

Heat dissipation bodies for electric apparatus

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

Shaping by applying fluid pressure

Making heat exchanger of sheet metal

Special rules of classification within this group

The subgroup F28F 3/02 covers elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, wires, pins, corrugated plates.

The subgroup F28F 3/04 covers means which are integral with the plate-like or laminated element, e.g. in the form of local deformations of the elements, e.g. dimples, corrugations, or in the form of ribs.

The subgroup F28F 3/06 covers means which are attachable to the elements

(removable).

The subgroup F28F 3/08 covers elements constructed for building-up into stacks, e.g. capable of being taken apart, stacked plates with openings forming tubular heat-exchange passages.

The subgroup F28F 3/10 covers sealing means, e.g. gaskets at plate margins.

The subgroup F28F 3/12 covers elements constructed in the shape of a hollow panel, e.g. with channels, e.g. cold plate. Panels manufactured by inflation (roll-bonding, hydro-forming) are classified in F28F 3/14.

Elements specially adapted for movement (arrangements for moving the elements, see the appropriate subclass for the apparatus concerned)
Definition statement
This group covers:

Particular type of moving elements, e.g. rotary drums or rollers (F28F 5/02), hollow impellers (F28F 5/04), hollow screw conveyers (F28F 5/06).

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

Cooling or heating rolls for rolling of metal

Cooled casting wheels

Rollers for mixing or kneading devices for preparation of plastic material

Rolls calenders or drums for shaping plastic material

Rollers for thermal treatment of textiles

Drying cylinders for paper-making

Heating or cooling calender rolls for paper-making

Heated or cooled rollers or drums or cylinders for drying fabrics, fibres, yarns, or other material

Movable elements inside conduits, e.g. stirring means

Movable cleaning elements

Elements not covered by group F28F 1/00, F28F 3/00 or F28F 5/00
Definition statement
This group covers:

Elements not covered by group F28F 1/00, F28F 3/00 or F28F 5/00, e.g. particular heat-exchange elements not in the form of tubular or plate-like elements.

Blocks traversed by passages for heat-exchange media {(F28D 7/0008 takes precedence)}
Informative references
Attention is drawn to the following places, which may be of interest for search:

Manufacture of articles from metallic powder, e.g. by sintering characterised by the special shape of the product of articles with cavities or holes

Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
Definition statement
This group covers:

Particular construction of casings or shells; particular frame elements, e.g. side plates for radiator cores; auxiliary members within casings, e.g. filling means, sealing means.

Auxiliary supports for elements

Supports for tubes or tube-assemblies, e.g. formed by plates, by slats, by tie-rods, by strips, by wires.

Header boxes (manifold, tank), end plates, e.g. header boxes with inner space divided by partitions or baffles; arrangements for fastening header box or end plate with casing; arrangements for fastening header (cover) with end plate; double end plates or hollow end plates; expansion chambers; header boxes with second heat exchanger disposed inside; floating elements; arrangements for connecting header boxes with flow lines; static flow control, e.g. heat exchange media distributing means.

Arrangements for connecting elements to header boxes or end plates, either by dismountable joints (F28F 9/06), or by permanent joints (F28F 9/16).

Dismountable joints can be: wedge-type connections, e.g. taper ferrule (F28F 9/08), or screw-type connection, e.g. gland, stuffing box (F28F 9/10), or flange-type connection, or made by force-joining, e.g. the elements are forced into the end plate, generally with a gasket (F28F 9/14).

Permanent joints means: using a working procedure for permanently deforming the elements or using bonding materials, e.g. adhesive, brazing or welding material for permanently joining the elements with the end plate or header box: the subgroup F28F 9/18 covers permanent joint by welding.

Arrangement of heat reflectors, e.g. protective walls inside casings.

Arrangement of guide plates inside casing, e.g. longitudinal, transversal or oblique baffles for guiding the heat exchange medium flowing inside the casing

Arrangements for promoting turbulent flow inside casing

Arrangements for connection different heat-exchange sections, e.g. elbows, connecting sleeves, nipples.

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

Arrangements or mounting of radiators on vehicles

Mounting of radiators on vehicles front or rear portions

Arrangements or mountings of liquid-to-air heat exchangers for cooling engines

Arrangement of fans or blowers for cooling engines

Filling caps, deaeration devices for motor car radiators

Guiding or ducting cooling air to or from liquid-to-air heat exchangers

Mounting of ventilators

Arrangement of mountings or supports for central heating radiators

Supporting arrangements for steam generators

Drums, headers for steam generators

Casings, cover lids or ornamental panels for domestic radiators.

Casings for air-conditioning units; arrangements for mounting of heat exchangers

Casings, cover lids or ornamental panels for fluid heaters having heat generating means

Arrangement of supports for fluid heaters

Connecting heaters to circulation pipes

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

Adhesives

Brazing, welding

Application of procedures in order to connect tubes with tubes

Procedures for connecting tubes in openings, e.g. rolling-in

Making heat exchangers of both metal tubes and sheet metal

Connections of tubes mutually, including resilient connections

Connections of rods or tubular parts to flat surfaces at an angle

Supports for pipes

Quick acting couplings

Branching pipes to walls

Joining pipes to walls

Arrangements for sealing leaky tubes and conduits (stopping flow from or in pipes in general F16L 55/10)
Definition statement
This group covers:

Devices or processes for repairing damaged heat exchange conduits

F28F 11/02: using obturating elements, e.g. washers, plugs

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

Stopping flow from or in pipes in general

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

Extracting tube bundles

Plugs

Caps

Devices for covering leaks in pipes

Investigating fluid-tightness of structures

Arrangements for modifying heat-transfer, e.g. increasing, decreasing (F28F 1/00 to F28F 11/00 take precedence)
Definition statement
This group covers:

Means for optimizing heat transfer (increasing heat transfer), other than fins; Heat insulating means (decreasing heat transfer); e.g. thermal joints, use of particular conductive materials, thermal barriers, use of permeable mass, perforated or porous materials.

Relationship between large subject matter areas

Increasing heat transfer by using means for increasing heat transfer area, e.g. fins: F28F 1/10, F28F 3/02

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

Particular heat transfer materials

Pulse tube cooler

Cooling semiconductors with porous structures

Cooling semiconductors by jet impingement

H01L23/4373

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

Making porous articles

Coating compositions

C09

Coating processes

C23

Electroplating

Influencing flow of fluids

Influencing fluid boundary layer of a fluid

Compound tubes

Photomechanical, e.g. lithographic production of textured or patterned surfaces

Special rules of classification within this group

The following classification applies depending on the means for modifying heat transfer

F28F 13/02: by influencing fluid boundary

F28F 13/04: by preventing the formation of continuous films of condensate on heat-exchange surface, e.g. by promoting droplet formation (enhancing dropwise condensation)

F28F 13/06: by affecting the pattern of flow of the heat-exchange media, e.g. with inserts, deflectors, vortex generators.

F28F 13/08: by varying the cross-section of the flow channels

F28F 13/10: by imparting a pulsating motion to the flow, e.g. by sonic vibration

F28F 13/12: by creating turbulance, e.g. by stirring, by increasing the force of circulation

F28F 13/14: by endowing the walls of conduits with zones of different degrees of conduction of heat, e.g. heat conductive elements having heat insulating portions.

F28F 13/16: by applying an electrostatic field to the body of heat-exchange medium, e.g. enhancing heat transfer by electro hydrodynamic effects

F28F 13/18: by applying coatings, e.g. radiation-absorbing, radiation-reflecting, hydrophilic coatings, hydrophobic coatings, conductive coatings; porous coatings; by surface treatment, e.g. polishing, obtaining rough surfaces; heat exchange surfaces having microstructures, e.g. nucleation sites for enhancing nucleate boiling.

Removing ice or water from heat-exchange apparatus
Definition statement
This group covers:

Means for draining water from heat exchangers, e.g. means for draining condensates from evaporators

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

Removing condensates in steam condensers

Preventing the formation of deposits or corrosion, e.g. by using filters {or scrapers}
Definition statement
This group covers:

Means for preventing corrosion, abrasion, erosion, damages in heat exchangers, e.g. by using inserts or attachments, by using protective electric currents; preventing deposits of ice, means for preventing freezing of heat exchange media; by using scrapers

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

Preventing or removing incrustations in thermal cracking apparatus

Preventing clogging by frost in cooling towers

Coatings for modifying heat transfer

Removing ice from heat exchangers

Cleaning heat exchangers

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

Filters in general

Shaped ceramic products

Coating compositions

Antifouling paints

Coating processes

Inhibiting corrosion of metallic material

Inhibiting corrosion of metals by anodic or cathodic protection

Devices preventing bursting of pipes by freezing

Preventing icing in gas-turbine plants

Protection of pipes against corrosion

Use of special steel alloy in steam boilers

Protection of water tubes in steam boilers

Devices for preventing or removing corrosion, slime or scale in heating systems

Dispositions against corrosion of combustion products

Removing ice by scraping

Preventing corrosion in refrigeration machines

Defrosting refrigerators

Linings for furnaces

Measuring thickness

Special rules of classification within this group

Depending on the preventing means, the following classification applies:

F28F 19/01 by using means for separating solid materials from heat-exchange fluid, e.g. filters

F28F 19/02 by using coatings

F28F 19/04 plastic coatings

F28F 19/06 metallic coatings

Constructions of heat-exchange apparatus characterised by the selection of particular materials {(coatings for modifying heat-transfer F28F 13/18; coatings for preventing the formation of deposits or corrosion F28F 19/02)}
Definition statement
This group covers:

Heat exchanging elements made by particular materials, e.g. glass.

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

Particular coatings for modifying heat transfer

Particular coatings for preventing corrosion

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

Manufacture of metal sheets, metal tubes

Manufacture of metal sheets, metal tubes by drawing

Extruding metal

Manufacture of tubes of special shape

Working or processing of sheet metal or metal tubes without removing material

Bending sheet metal

Bending tubes

Stamping, deep-drawing

Procedures in order to connect objects

Making heat exchangers

Casting; Powder metallurgy

B22

Pressure die casting or injection die casting

Manufacture of articles from metallic powders

Manufacture of articles from metallic powder characterised by the manner of compacting or sintering

Making articles with cavities or holes

Brazing, welding

Production of ceramic shaped elements

Shaping or joining of plastics

Shaping by casting

Compression moulding

Injection moulding

Extrusion moulding

Blow moulding

Shaping by thermoforming

Shaping by bending, folding, twisting, straightening or flattening

Surface shaping, e.g. embossing

Joining of preformed parts

Producing particular articles from plastics

Joining glass to other material

Shaped ceramic products

Porous mortars, concrete, artificial stone or ceramic ware

Polymers

C08

Alloys

Ferrous alloys, e.g. steel alloys

Manufacturing plastic heat exchangers

Special rules of classification within this group

Depending on the material, the following classification applies:

F28F 21/02: carbon, e.g. graphite

F28F 21/04: ceramic e.g. alumina, beryllia, zirconia carbide, boride, nitride, silicide; concrete; natural stone.

F28F 21/06: plastics, e.g. resins, polymeric materials, reinforced plastics.

F28F 21/08: metal, e.g. steel or ferrous alloys, stainless steel, aluminium or aluminium alloys, copper or copper alloys, titanium, nickel

Features relating to the use of intermediate heat-exchange materials, e.g. selection of compositions (heat-transfer, heat-exchange or heat-storage materials C09K 5/00)
Definition statement
This group covers:

Particular intermediate heat exchange materials

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

Chemical compositions of heat transfer materials

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

Heat exchangers using intermediate heat exchange materials

Component parts of trickle coolers (arrangements for increasing heat transfer F28F 13/00; controlling arrangements F28F 27/00)
Definition statement
This group covers:

Arrangements for distributing, circulation or accumulating liquid

Distributing or accumulator troughs

Spray nozzles

Splashing boards or grids, e.g. for converting liquid sprays into liquid films; Elements or beds for increasing the area of the contact surface, e.g. in the form of spaced elongated bars, laths, horizontal grids, vertical or inclined sheets

Gas or vapour feeding

Ducts; Guide vanes

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

Packing elements for chemical reactors

Packings; Fillings; Grids in apparatus for biological treatment of water

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

Spraying or atomising in general

Water treatment

Control arrangements or safety devices specially adapted for heat-exchange or heat-transfer apparatus (control arrangements in general G05)
Definition statement
This group covers:

Controlling, monitoring heat exchangers, e.g. temperature control, pressure control, flow control, heat transfer control; Safety means.

The feature "controlling" means influencing a variable in any way e.g. changing its value, maintaining it constant, limiting its range of variation; "regulating" means maintaining a variable automatically at a desired value or within a desired range of values. The desired value may be fixed, manually varied or may vary with time according to a predetermined "programme". Regulation is a form of control.

Controlling the distribution of heat exchange media between different channels, e.g. flow control means in heat exchangers, e.g. valves

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

Static flow control means for distributing a heat exchange medium into conduits

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

Thermostatic control in engine cooling systems

Valves

Control or safety means in heating systems

Control or safety systems or apparatus for air conditioning

Control or safety means in fluid heaters

Arrangements or mounting of control or safety devices in refrigeration systems

Measuring the volume flow or mass flow

Measuring quantity of heat; testing heat pipes

Measuring quantity of heat conveyed by flowing media

Investigating thermal conductivity

Thermal testing

G01M19/00

Control of flow

Ratio control

Control of fluid pressure

Control of temperature

Control of temperature by using electric means

Simultaneous control of variables

Digital computing or data processing equipment or methods

Computer-aided design, simulations

This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013