US2842650A - Ovens for dielectric heating - Google Patents

Ovens for dielectric heating Download PDF

Info

Publication number
US2842650A
US2842650A US528912A US52891255A US2842650A US 2842650 A US2842650 A US 2842650A US 528912 A US528912 A US 528912A US 52891255 A US52891255 A US 52891255A US 2842650 A US2842650 A US 2842650A
Authority
US
United States
Prior art keywords
oven
electrodes
hood
ovens
conveyor band
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US528912A
Other languages
English (en)
Inventor
Naylor Joseph Francis
Northmore Raymond
Christopher E M Tibbs
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
T&T Vicars Ltd
Radio Heaters Ltd
Original Assignee
T&T Vicars Ltd
Radio Heaters Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by T&T Vicars Ltd, Radio Heaters Ltd filed Critical T&T Vicars Ltd
Application granted granted Critical
Publication of US2842650A publication Critical patent/US2842650A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/46—Dielectric heating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/78—Arrangements for continuous movement of material

Definitions

  • This invention relates to ovens for high-frequency dielectric heating wherein the articles or pieces to be heated are continuously passed through the oven on a conveyor band.
  • Such ovens are used for baking confectionery, biscuits, cakes, rolls and loaves but may also be employed for baking various other articles such as foundry cores, ceramic articles of all kinds and also for drying materials such as cheeses of rayon, cotton or wool, textile fabrics, paper, cardboard, powdered chemical substances and so forth.
  • Such ovens are commonly constructed almost entirely of steel and often have continuous moving-band conveyors, of sheet steel or of a woven steel wire mesh, which are conducted over skid plates arranged to carry the steel band or mesh web in perfect alignment or flat condition. Frequently the conveyor is arranged so that the whole of its track within the oven shell can be raised and lowered. In addition, these ovens are sometimes provided with internal steel ducts for hot air and feeding arrangements for the hot air. For ovens of this kind, a diflicult problem arises when it is attempted to design the apparatus with a low loss return path for the radio frequency space current flowing between the electrodes and the side walls and top of the oven. It will be appreciated that radio frequency currents flowing through steelwork generate a good deal of heat which represents a very serious loss of power. In actual fact, when relatively large electrodes are employed, the space currents in the ovens may be extremely heavy and the Whole output of the radio frequency generator provided may easily be taken up in heating up the steel framework of the unit itself.
  • the object of the present invention is to reduce the loss of energy in the form of waste heat to the lowest possible minimum and according to the invention, this is achieved by mounting the pair of balanced electrodes within a metal screening hood so that radio frequency space currents other than those flowing through the conveyor band tend to flow to the screening hood.
  • Figure 1 is a perspective view showing the arrangement In Figuresl and 2v a conveyorband 3 passes through,
  • the electrodes 8 and 9 are connected to a radio frequency generator 17 by means of strip conductors 18 and 19.
  • the screening hood is cut away at 20 to ensure that the conductors 18 and 19 do not foul the screening hood when the latter is moved to its lower position.
  • the spindles 12 are mounted on the screening hood 11 by means of panels 21 of silicon glass, and the screening hood is in this way insulated from the rest of the oven.
  • the electrodes may be mounted on insulators in a fixed hood and the conveyor band beneath the hood may itself be moved up and down.
  • the hood is made of material having good electrical conducting properties such as sheet aluminum, copper or brass and may be formed of a single sheet of metal or built up from a number of sheets brazed or soldered together.
  • the invention enables currents flowing through the framework of the oven to be largely avoided. If the hood is insulated electrically from the rest of the oven, it also serves as an internal screen and greatly reduces the chances of serious interference radiation from the equipment. Furthermore the provision of balanced electrodes removes the need to cause return current to flow back from the conveyor band through an earthed plate to the radio frequency generator.
  • An oven for the radio frequency di-electric heating of articles comprising an oven casing, a conveyor band passing through said oven casing for carrying the articles to be heated, a pair of balanced electrodes mounted above said conveyor band within said casing and adapted for connection to a radio frequency generator to efllect dielectric heating of articles passing below the electrodes on said conveyor band, and a screening hood of a material having good electrical conducting properties enclosing said electrodes at the top and sides of the latter itatented July-8, 1958v so that radio frequency space currents other than those flowing the conveyor band tend to flow to said screening hood, thereby to avoid the dissipation of the space currents in said oven casing.
  • said means operative to effect relative displacement of said hood and electrodes and of said conveyor band includes spindles extending from said hood and having racks formed therei on, pinions meshing with said racks to effect displacement of the latter in response to rotation of the pinions, and means actuable from outside of said oven casing for effecting rotation of said pinions.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Tunnel Furnaces (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Drying Of Solid Materials (AREA)
US528912A 1954-09-06 1955-08-17 Ovens for dielectric heating Expired - Lifetime US2842650A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB25816/54A GB768725A (en) 1954-09-06 1954-09-06 Improvements in ovens for dielectric heating

Publications (1)

Publication Number Publication Date
US2842650A true US2842650A (en) 1958-07-08

Family

ID=10233785

Family Applications (1)

Application Number Title Priority Date Filing Date
US528912A Expired - Lifetime US2842650A (en) 1954-09-06 1955-08-17 Ovens for dielectric heating

Country Status (7)

Country Link
US (1) US2842650A (fr)
BE (1) BE540885A (fr)
CH (1) CH331033A (fr)
DE (1) DE1084852B (fr)
FR (1) FR1130422A (fr)
GB (1) GB768725A (fr)
NL (2) NL199840A (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2995642A (en) * 1959-06-04 1961-08-08 Stoner Invest Inc Induction heating apparatus
US3107284A (en) * 1959-07-23 1963-10-15 Baker Perkins Inc Heat treatment or baking ovens
US3461263A (en) * 1967-07-31 1969-08-12 Radio Frequency Co Inc Radio frequency heating apparatus
US4364390A (en) * 1975-03-14 1982-12-21 Shaw Robert F Surgical instrument having self-regulating dielectric heating of its cutting edge and method of using the same
US6417499B2 (en) * 2000-07-06 2002-07-09 Heatwave Drying Systems Ltd. Dielectric heating using inductive coupling

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB964180A (en) * 1960-09-12 1964-07-15 Svenska Sockerfabriks Ab Improvements in or relating to dielectrically heated drying apparatuses through which the articles to be dried are continuously advanced

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485609A (en) * 1945-04-19 1949-10-25 American Viscose Corp Drying apparatus
US2560763A (en) * 1950-01-31 1951-07-17 Allis Chalmers Mfg Co Dielectric drier having an adjustable exhaust system

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2233175A (en) * 1940-03-28 1941-02-25 Carborundum Co Manufacture of abrasive coated articles
US2288268A (en) * 1941-05-01 1942-06-30 Compo Shoe Machinery Corp Electrostatic heating system
GB686288A (en) * 1948-10-08 1953-01-21 Willys Overland Motors Inc A method of bonding non-metallic elements together
US2593959A (en) * 1949-03-01 1952-04-22 Westinghouse Electric Corp Dielectric heating unit
DE1674380U (de) * 1953-10-14 1954-04-01 Philips Patentverwaltung Abgeschirmte behandlungskammer fuer kapazitive hochfrequenzerhitzung von werkstuecken.

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2485609A (en) * 1945-04-19 1949-10-25 American Viscose Corp Drying apparatus
US2560763A (en) * 1950-01-31 1951-07-17 Allis Chalmers Mfg Co Dielectric drier having an adjustable exhaust system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2995642A (en) * 1959-06-04 1961-08-08 Stoner Invest Inc Induction heating apparatus
US3107284A (en) * 1959-07-23 1963-10-15 Baker Perkins Inc Heat treatment or baking ovens
US3461263A (en) * 1967-07-31 1969-08-12 Radio Frequency Co Inc Radio frequency heating apparatus
US4364390A (en) * 1975-03-14 1982-12-21 Shaw Robert F Surgical instrument having self-regulating dielectric heating of its cutting edge and method of using the same
US6417499B2 (en) * 2000-07-06 2002-07-09 Heatwave Drying Systems Ltd. Dielectric heating using inductive coupling

Also Published As

Publication number Publication date
FR1130422A (fr) 1957-02-05
NL94210C (fr)
BE540885A (fr)
NL199840A (fr)
CH331033A (fr) 1958-06-30
GB768725A (en) 1957-02-20
DE1084852B (de) 1960-07-07

Similar Documents

Publication Publication Date Title
US2846557A (en) Vapor treating means
US2842650A (en) Ovens for dielectric heating
US1479819A (en) Heater
US3151230A (en) High-frequency oven
US2868939A (en) Suppression of radiation from dielectric heating applicators
US2908234A (en) Bakers' and the like ovens
GB2024578A (en) Microwaya oven
US2560763A (en) Dielectric drier having an adjustable exhaust system
US3321604A (en) Electronic oven
CN103249191B (zh) 感应加热装置
US3107284A (en) Heat treatment or baking ovens
US2807699A (en) Conveyor assembly for dielectric heater
US2483933A (en) Ultra high frequency dielectric heater
US3161480A (en) Dielectrically heated drying apparatus through which the articles to be dried are continuously advanced
CN103940202B (zh) 对流风力纸管烘箱
US1555321A (en) Doughproofing oven
CN207472046U (zh) 一种可自动进料和出料的箱式电阻炉
CN110062489A (zh) 微波炉各器件抗干扰散热风道系统
KR20180083215A (ko) 고주파 해동기
GB2123537A (en) Convective drying
US2476142A (en) Nonmetallic cover for bread toasters
GB1123824A (en) Improvements in or relating to packaging machines
US1973451A (en) Blast furnace charging hopper
US725663A (en) Electrical resistance device or heater.
CN203949449U (zh) 对流风力纸管烘箱